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1 is committed to open peer review. As part of this commitment we make the peer review history of every article we publish publicly available. When an article is published we post the peer reviewers comments and the authors responses online. We also post the versions of the paper that were used during peer review. These are the versions that the peer review comments apply to. The versions of the paper that follow are the versions that were submitted during the peer review process. They are not the versions of record or the final published versions. They should not be cited or distributed as the published version of this manuscript. is an open access journal and the full, final, typeset and author-corrected version of record of the manuscript is available on our site with no access controls, subscription charges or pay-per-view fees ( If you have any questions on s open peer review process please info.bmjopen@bmj.com : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

2 Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network metaanalysis incorporating complementary external evidence Journal: Manuscript ID bmjopen-0-0 Article Type: Research Date Submitted by the Author: -Apr-0 Complete List of Authors: Mir, Hassan; McMaster University, Medicine; Siemieniuk, Reed; Mcmaster University, Clinical Epidemiology and Biostatistics; University of Toronto, Department of Medicine Ge, Long; The First Clinical Medical College of Lanzhou University, Foroutan, Farid; University Health Network, Medicine/Cardiology Fralick, Michael; University of Toronto, Eliot Phillison Clinician Scientist Training Program, Department of Medicine Syed, Talha; McMaster University Department of Medicine, Medicine Lopes, Luciane; Universidade de Sorocaba Kuijpers, Ton; Nederlands Huisartsen Genootschap, Guideline development and research Mas, Jean-Louis; Sainte-Anne Hospital, Neurology Vandvik, Per; Norwegian Knowledge Centre for the Health Services, Agoritsas, Thomas; University Hospitals of Geneva, Division of General Internal Medicine & Division of Clinical Epidemiology; McMaster University Faculty of Health Sciences, Department of Health Research Methods, Evidence, and Impact Guyatt, Gordon; Mcmaster University, Clinical Epidemiology and Biostatistics Keywords: Cryptogenic stroke, Patent foramen ovale, Anticoagulation < HAEMATOLOGY, Antiplatelet, PFO Closure : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright. -

3 Page of Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network meta-analysis incorporating complementary external evidence Hassan Mir, internal medicine and cardiology physician, Reed A.C. Siemieniuk,, PhD student and internal medicine physician, Long Ge, PhD student, Farid Foroutan,, PHD student, Michael Fralick, research fellow and internal medicine physician, Talha Syed, internal medicine and cardiology physician, Luciane Cruz Lopes, clinical pharmacologist, Ton Kuijpers, clinical epidemiologist, Jean- Louis Mas, professor, Per O. Vandvik 0,, associate professor, Thomas Agoritsas,, assistant professor, Gordon H. Guyatt, distinguished professor. Department of Health Research Methods, Evidence, and Impact, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou 0000, China. Department of Clinical Epidemiology and Biostatistics, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Heart Failure/Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. Eliot Phillipson Clinician Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Canada, MG C. University of Sorocaba, UNISO, Sorocaba, Sao Paulo, Brazil. Department of guideline development and research, Dutch College of General Practitioners, Utrecht, The Netherlands. Sainte-Anne Hospital, Department of Neurology, rue Cabanis, 0 Paris. 0. Norwegian Institute of Public Health, Oslo, Norway. Department of Medicine, Innlandet Hospital Trust - division Gjøvik, Norway. Division General Internal Medicine & Division of Clinical Epidemiology, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil, CH-, Geneva, Switzerland - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

4 Page of Abstract Objective: To examine the relative impact of three management options in patients less than 0 years old with cryptogenic stroke and a patent foramen ovale (PFO): PFO closure plus antiplatelet therapy, antiplatelet therapy alone, and anticoagulation alone. Design: Systematic review and network meta-analysis (NMA) supported by complementary external evidence Data sources: Medline, EMBASE, and Cochrane CENTRAL. Study selection: Randomised controlled trials (RCTs) addressing PFO closure and/or medical therapies in patients with PFO and cryptogenic stroke. Review methods: We conducted an NMA complemented with external evidence and rated certainty of evidence using the GRADE system. Results: Ten RCTs in eight studies proved eligible (n=). Seven RCTs (n = ) addressed PFO closure versus medical therapy. Of these, (n=) addressed PFO closure versus antiplatelet therapy, (n=0) addressed PFO closure versus mixed antiplatelet and anticoagulation therapies, and (n= ) addressed PFO closure versus anticoagulation. The remaining three RCTs (n= 0) addressed anticoagulant versus antiplatelet therapy. PFO closure versus antiplatelet therapy probably results in substantial reduction in ischaemic stroke recurrence (risk difference per 000 patients over years [RD]: -, % credible interval [CrI] -00 to -; moderate certainty). Compared with anticoagulation, PFO closure may confer little or no difference in ischaemic stroke recurrence (low certainty) but probably has a lower risk of major bleeding (RD -0, % Crl - to -, moderate certainty). Relative to either medical therapy, PFO closure probably increases the risk of persistent atrial fibrillation (RD, CI + to +, moderate certainty) and device-related adverse events (RD +, % CI + to +0, high certainty). Anticoagulation, compared to antiplatelet therapy, may reduce the risk of ischaemic stroke recurrence (RD -, % CrI -00 to +, low certainty), but probably increases the risk of major bleeding (RD +, CrI - to +, moderate certainty). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

5 Page of Conclusions: In patients less than 0 years old, PFO closure probably confers an important reduction in ischaemic stroke recurrence compared to antiplatelet therapy alone but may make no difference compared to anticoagulation. PFO closure incurs a risk of persistent atrial fibrillation and device-related adverse events. Compared to alternatives, anticoagulation probably increases major bleeding. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

6 Page of INTRODUCTION: Stroke is one of the leading causes of death worldwide and, for those who survive, often results in substantial disability. Central to the management of patients with stroke is preventing additional ischaemic events; the optimal management depends on the underlying aetiology. In up to 0% of patients with an acute ischaemic stroke, investigations fail to identify a clear cause the Trial of Org 0 in Acute Stroke Treatment (TOAST) criteria classify these strokes as of undetermined aetiology or cryptogenic (). Patients who have had a cryptogenic stroke are less likely to have classical risk factors for stroke (e.g., hypertension, hyperlipidaemia, diabetes mellitus) and are more likely to have a patent foramen ovale (PFO) compared to patients with a stroke from a known aetiology (, ). A PFO can allow a systemic venous thrombus to travel directly into the systemic arterial circulation instead of the pulmonary venous circulation a phenomenon known as a paradoxical embolism (, ). The importance of this phenomenon as a cause of stroke is, however, controversial. Other potential mechanisms of PFO-associated stroke include intracardiac thrombus formed in the tunnel of the PFO, on the surface of the atrial septal aneurysm, or left atrial appendage (). Until recently, randomised controlled trials (RCTs) had failed to definitively establish that closing a PFO reduces the risk of subsequent stroke (-). Meta-analyses including earlier trials offered conflicting conclusions (-). Current clinical practice guidelines recommend against PFO closure for most patients who have had a cryptogenic stroke (). In September 0, two new trials (, ) and the long-term follow-up of a previously reported trial () addressed the utility of PFO closure for patients less than 0 years old with cryptogenic stroke. Evidence from recent meta-analyses that incorporate data from these RCTs suggests that PFO closure may prevent stroke. However, despite evidence that anticoagulation is more effective than antiplatelet therapy at preventing stasis-related venous or intracardiac thrombi, these meta-analyses make the assumption that antiplatelet and anticoagulation therapies are similarly effective (). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

7 Page of This systematic review is part of the BMJ Rapid Recommendations project, a collaborative effort from the MAGIC research and innovation programme ( and the BMJ (). The aim of the project is to respond to new potentially practice changing evidence and provide trustworthy practice guidelines in a timely manner. In light of the new evidence for PFO closure and because other reviews do not report clinically relevant comparisons (e.g., PFO closure vs. antiplatelet therapy), we performed a systematic review to inform the parallel guideline published in a multi-layered electronic format on bmj.com and MAGICapp ( As requested by the Rapid Recommendations panel, in the absence of sufficient direct evidence to fully inform recommendations, we conducted complementary analyses using indirect evidence. METHODS Protocol The study protocol was registered with PROSPERO: CRD00 (0). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

8 Page of Guideline panel, patient involvement, and choice of outcomes According to the BMJ Rapid Recommendations process (), a multi-professional guideline panel provided critical oversight to the systematic review and identified populations, subgroups, and outcomes of interest. The BMJ Rapid Recommendation panel, and in particular three people who had experienced a cryptogenic stroke (two of whom had undergone PFO closure), assessed the relative importance of the outcomes (). The guideline panel submitted a list of possible outcomes and then rated the importance of each outcome on a scale from (least important) to (most important). For items with scores of, the panel considered further and made a final decision by consensus, with special consideration of the views of the patient panellists. The patients stressed the importance of several outcomes that other panel members had identified and uniquely highlighted the importance of detailed information about the device or procedure related adverse events. Search strategy A search from a previous systematic review that we judged as comprehensive included research articles indexed before May, 0 (). We updated that review with a search of Medline, Medline in-process, EMBASE, and Cochrane CENTRAL from January 0 to October 0 using a combination of keywords and MeSH terms for patent foramen ovale AND stroke, using the sensitive search filters for therapeutic interventions developed by the Health Information Research Unit at McMaster University (Appendix ). (, ) We also searched all references from included studies and all of the studies citing the included studies on Google Scholar. Study selection We included RCTs addressing the relative impact of PFO closure versus antiplatelet therapy versus anticoagulation in patients, and anticoagulation versus antiplatelet therapy with PFO and cryptogenic stroke. We also included prior rigorous systematic reviews addressing antiplatelet versus anticoagulant therapy in patients with deep venous thrombosis (DVT), atrial fibrillation, and heart - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

9 Page of failure. Reviewers screened titles and abstracts in duplicate and subsequently assessed eligibility from the full text for all possible eligible articles. In comparing PFO closure to antiplatelet therapy for the outcome of stroke, we used only RCTs in which at least 0% of medical therapy patients received antiplatelet rather than anticoagulation. Data collection Two reviewers independently abstracted data from the included RCTs and resolved conflicts by discussion. We searched the clinical trial registration page on clinicaltrials.gov for additional outcome data and ed the corresponding authors of the included RCTs requesting outcome data when it was missing or could not, as presented in the public domain, be included in meta-analytic estimates. The patient-important outcomes we considered included ischaemic stroke, death, major bleeding, persistent atrial fibrillation or flutter, transient or paroxysmal atrial fibrillation, device or procedure related adverse events, pulmonary embolism, transient ischaemic attacks (TIAs), and systemic embolism. For serious device or procedure-related complications, two independent clinician reviewers categorized the specific serious adverse events in the primary studies as probably related or unrelated to the device or implantation procedure; reviewers resolved disagreement with, if necessary, input from a third reviewer. We used the definitions in the original studies for all outcomes except for persistent atrial fibrillation; our classification included the definition used in the original study but also included patients who underwent a cardioversion. We also abstracted key outcomes from the external evidence systematic reviews. Risk of bias and certainty of evidence We assessed risk of bias in duplicate using a modified Cochrane tool in which we used response options of definitely or probably yes (assigned a low risk of bias) and definitely or probably no (assigned a high risk of bias), an approach that has proved valid (, ). Specifically, we assessed - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

10 Page of random sequence generation; concealment of treatment allocation; and blinding of participants, caregivers, and outcome assessors. Reviewers resolved conflicts through discussion. We followed the GRADE approach to rate the quality of evidence derived from pair-wise and network meta-analyses (NMA) as well as from external evidence (, ). Direct evidence from RCTs starts at high quality and may be rated down based on risk of bias, indirectness, imprecision, inconsistency, and publication bias. For network estimates, we rated the quality of evidence in each of the direct, indirect, and network estimates (). The rating of indirect estimates starts at the lowest rating of the two pairwise estimates that contribute to the indirect estimate and can be rated down further for intransitivity. If direct and indirect estimates contributed similar power to the network estimate, then we used the higher rating. The network estimates were further rated down for incoherence between direct and indirect evidence. For analyses that incorporated external evidence, we rated down the quality of evidence for indirectness (down one level for major bleeding and two levels for ischaemic stroke) (). Review authors and the linked Rapid Recommendation panel members came to consensus regarding certainty of evidence ratings. Statistical Analysis We analysed patients in groups to which they were randomised. For both pairwise and NMA, we report pooled odds ratios (ORs); for estimates from NMA we report % credible intervals (CrI) from the Bayesian analysis and for direct estimates % confidence intervals (CI). We present pooled risk differences (RD) and their certainty/confidence intervals for all comparisons, applying relative risks to baseline risk estimates when there were adequate numbers of events, and direct calculation of risk differences when events were very infrequent. In reporting absolute events, we standardized absolute estimates to a rate per,000 patients followed for years assuming proportional event occurrence (in other words, for a reported follow-up of years we would multiply by /). Atrial fibrillation and device or procedure-related adverse events were, however, very likely to have occurred soon after the procedure and we therefore report events per,000 patients as reported in the studies. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

11 Page of The PFO closure arm was used for the baseline risk to allow consistency across comparisons involving PFO closure versus antiplatelet agents and anticoagulants. Baseline risk estimates represent the median risk of the outcome in the six RCTs of PFO closure. For comparisons of antiplatelet agents and anticoagulants, the antiplatelet arm provided the baseline risk to estimate the absolute effect estimate in the anticoagulation arm. The baseline risk for the antiplatelet arm calculated in Table considering the baseline risk in the PFO closure arm (0%) proved similar to the median of three studies that included an antiplatelet arm (%) and maintained consistency with the PFO closure comparisons. Network meta-analysis To compare effects of alternative medical therapies, for ischaemic stroke, recurrent TIA, death, major bleeding, and systemic embolism, we conducted a NMA of RCTs within a Bayesian hierarchical fixed effect framework with non-informative priors and adjusted for correlation between effects in the multiarm trial. We generated posterior samples using Markov Chain Monte-Carlo (MCMC) simulation technique running the analysis in three parallel chains. We used 00,000 burn-in simulations to allow convergence and then a further 00,000 simulations to produce the outputs. We assessed model convergence using the Gelman and Rubin test, accepting a threshold of <.0 and used the nodesplitting approach for the assessment of loop inconsistency (, ). We calculated direct estimates of absolute effects using the modified Dias model, incorporating lines into the Dias model (0). We performed the network meta-analyses with R version.. (R Core Team. 0. Vienna, Austria: R Foundation for Statistical Computing) using the gemtc library (). Pairwise meta-analysis As there is no reason, for the outcomes of atrial fibrillation and device or procedure-related adverse events, to expect any difference whether PFO closure is compared to anticoagulation or antiplatelet therapy, for these outcomes we conducted a pairwise meta-analysis of PFO closure versus either medical therapy. We used the random-effects Mantel-Haenszel (M-H) method to estimate relative risk - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

12 Page 0 of (RRs) and % confidence intervals (CIs), using the M-H risk difference approach for studies that did not have any events in either arm. For outcomes with event rates less than %, we used the Peto fixed effects method to estimate OR and % CI. For all outcomes, we examined statistical heterogeneity among studies using the I statistic and visual inspection of the forest plots (). Meta-regression analysis We hypothesised that anticoagulation may be more effective than antiplatelet therapy for preventing stroke. Thus, we expected that the effect of PFO closure vs. medical therapy would be largest in the RCTs that had proportionally more patients in the medical therapy group that were treated with antiplatelet therapy rather than anticoagulation. To explore this, we performed a random-effects metaregression of PFO closure vs. medical therapy, with the proportion of patients in the medical therapy arm who received anticoagulation as the independent variable. We used random-effects metaregression with the studies were weighed by the inverse of their variance. Modelling with external data from other indications Because few patients were randomised to PFO closure versus anticoagulation (N=) or anticoagulation versus antiplatelet agents (N=0) and events were infrequent, the estimates of effect of PFO closure versus anticoagulation were extremely imprecise. For instance, for ischaemic stroke the credible interval (Crl) around the relative effect included a relative reduction in events of 0% to a more than quadrupling of events (NMA OR 0., CrI 0.0 to.). We considered this information essentially uninformative, as did the Rapid Recommendations panel. We nevertheless considered the option of anticoagulation crucial to the decision, and therefore sought strategies for more informative estimates of effect. For ischaemic stroke, the most likely mechanism of cryptogenic stroke associated with PFO is stasisrelated thrombi, most notably paradoxical venous thromboembolism (VTE). The panel and systematic review team therefore deduced that the relative effects of anticoagulation versus antiplatelet therapy - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

13 Page of in the secondary prevention of VTE could provide credible estimates of effect for patients with cryptogenic stroke and PFO. For major bleeding, we deduced that the relative effects of VKAanticoagulation and low-dose ASA are similar to those seen in other common indications including VTE, heart failure, and atrial fibrillation and could therefore provide credible estimates of relative bleeding risk of antiplatelet agents (with or without PFO) and anticoagulants. Thus, the panel and systematic review team ultimately decided to use this evidence to provide indirect evidence of estimates of effect for three key outcomes (ischaemic stroke, major bleeding and pulmonary embolism). We therefore performed a secondary analysis that also included RCT evidence from other conditions (VTE, heart failure, and atrial fibrillation). For ischaemic stroke, we digitised Kaplan-Meier curves and extracted patient-level time-to-event data (). For illustrative purposes we present the individual patient data by treatment arm (PFO closure plus antiplatelet therapy, antiplatelet therapy alone, anticoagulation, and medical therapy left to the discretion of the treating physician). Each enrolled patient contributed equally to the survival curves. Subgroup analysis We planned subgroup analyses based on the echocardiography-determined shunt size and the presence of an atrial septal aneurysm. We hypothesised that patients with a larger shunt size will have a larger benefit with PFO closure than patients with a small shunt size and that patients with an atrial septal aneurysm will have a larger benefit with PFO closure than patients without an atrial septal aneurysm (). RESULTS Our systematic literature search yielded potentially relevant publications; ten trials presented in eight reports ultimately proved eligible (Figure ) (,, -, -). Seven eligible multicenter RCTs published in 0 or later comparing PFO closure plus antiplatelet therapy versus medical - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

14 Page of therapy enrolled patients (range per RCT: 0 to 0 patients) (Table ). The CLOSE trial included three separate randomized trials (). In the first trial, patients eligible for all options were randomised to PFO closure (N = ), antiplatelet therapy (N=), or anticoagulation with a vitamin K antagonist or direct oral anticoagulant (N=0; % of which were a VKA). In the second trial, patient s ineligible for anticoagulation were randomised to PFO closure (N=) or antiplatelet therapy (N=). In the third trial, patients with contraindications to PFO closure were randomised to antiplatelet therapy (n=) or anticoagulation (n=). Of the remaining eligible RCTs, one specified that all patients in the group who were not randomised to PFO closure were treated with antiplatelet therapy (N=) (). Four RCTs allowed the treating physician to choose between antiplatelet and/or anticoagulation therapy for the patients randomised to medical therapy: a minority of these patients (range 0% to %) were prescribed anticoagulation at the time of discharge from initial hospital admission (,,, ). The last three studies compared antiplatelet therapy to anticoagulation (N=0) (,, ). One study reported a composite endpoint for ischaemic stroke and TIA; we therefore could not use the data in our meta-analyses of stroke (N=) (). However, we were able to use data from this RCT in analyses of death and major bleeding. Another RCT reported only a composite outcome of stroke and death (N=) (), with non-significant results suggesting a possible reduction with anticoagulation compared to antiplatelet therapy (HR 0., CI 0. to., p-value 0.). We contacted the authors of three RCTs for additional outcome data (,, ); the lead author of the CLOSE study (JLM) provided additional unpublished data (). The authors of the two remaining studies did not respond. We identified a recent rigorous systematic review of trials and participants for secondary prevention of VTE () and a recent rigorous systematic review of trials and participants across indications that provided a trustworthy estimate for an increase in major bleeds (); both reviews compared anticoagulant to antiplatelet therapy. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

15 Page of Table presents the characteristics of the eligible studies. In most, the mean age was approximately years, approximately 0 to 0% were male, and approximately 0%, or more, had moderate or larger shunt. The median follow-up was. years with a range of. to. years. PFO closure plus antiplatelet therapy versus antiplatelet therapy alone Table provides estimates of effect and certainty of evidence for all patient-important outcomes, including, as presented subsequently, complications of PFO-closure. PFO closure plus antiplatelet therapy reduced the risk of ischaemic stroke compared to antiplatelet therapy alone (NMA OR 0., 0.0 to 0.; risk difference per 000 patient-years followed for years [RD]: -, % confidence interval [CI] -00 to -; moderate certainty) (Appendix, Figure ). Along with the three RCTs in which all medical patients received only antiplatelet therapy (,, ), we included a meta-regression model data from an additional RCTs that enrolled patients in which more than 0% of medically treated patients received anticoagulation (Figure ) (,,, ). The reduction in stroke with PFO closure decreased as the proportion of patients receiving anticoagulation in the medical therapy arm increased (p = 0.0). Figure presents a Kaplan-Meier curve of individual patient time-to-event data for each of the randomised interventions, including PFO closure plus antiplatelet versus antiplatelet therapy alone and is again consistent with large relative reductions in hazard with PFO closure versus antiplatelet therapy and smaller benefits of PFO closure when compared to mixed populations of patients receiving anticoagulants and antiplatelet agents. PFO closure did not appear to reduce the risk of TIA compared to antiplatelet therapy alone: NMA OR 0., CrI 0.,.; RD -, - to +; moderate certainty (Table ; Appendix ). Systemic emboli were rare: there were events in one study (), and none in another (); we therefore calculated the risk difference directly. There was no important difference between PFO - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

16 Page of closure and antiplatelet therapy: NMA OR 0., CrI 0.,.; RD -, - to + per,000 patients; high certainty (Table ; Appendix, Figure ). Death occurred infrequently: in the PFO closure group a median of per 000 patients died over a period of years. The relative effect estimate for mortality was very imprecise, and the absolute estimates included a small increase or decrease in deaths: NMA OR., CrI 0. to.; RD +, CI - to +; moderate certainty (Table ; Appendix, Figure ). The risk of major bleeding did not differ significantly between the PFO closure plus antiplatelet therapy and antiplatelet therapy alone groups: NMA OR 0., CI 0.0 to.; RD -, CI - to +, moderate certainty (Table ; Appendix, Figure ). Pulmonary embolism was rare and no more frequent in the PFO closure group (/, 0.%) than the antiplatelet therapy alone group (/, 0.%). No additional NMA evidence was available for pulmonary embolism because none of the RCTs that included an anticoagulation arm reported pulmonary emboli; thus, we present a pair-wise estimate for PFO closure vs. antiplatelet therapy alone: Peto OR.0, CI 0.0,.; RD +0, CI - to +, high certainty (Table ; Appendix, Figure ). PFO closure plus antiplatelet therapy versus anticoagulation Table provides estimates of effect and quality of evidence for all patient-important outcomes including, as presented below, complications of PFO-closure. One RCT randomised patients to PFO closure plus antiplatelet therapy (n=) or anticoagulation (n=0) (). In the NMA, compared with anticoagulation, PFO closure did not significantly reduce the risk of ischaemic stroke, but the CrI around the relative effect was very wide (NMA OR 0., CrI 0.0 to.; RD: -, % CI - to +0; low certainty). Figure presents a Kaplan-Meier curve of individual patient time-to-event data for each of the randomised interventions, including PFO closure plus antiplatelet versus anticoagulation alone. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

17 Page of Results from the meta-regression analysis described previously suggest that PFO closure was less effective relative to medical therapy as the proportion of patients receiving anticoagulation increased (Figure ). To complement the above analyses, we added the effect estimate from a systematic review of RCTs comparing low-dose ASA to anticoagulation with a VKA for the secondary prevention of VTE to the network meta-analysis (). Similar to the primary analysis, the analysis with the external evidence failed to show a difference between PFO closure and anticoagulation for ischaemic stroke, with a point estimate substantially closer to.0: NMA OR 0., CI 0. to.; RD: -, -0 to +; low certainty (Table ; Appendix, Figure ). For this complementary analysis, we rated down our certainty in the evidence to low because of very serious indirectness because this analysis relies on the assumption that the relative effect of anticoagulation versus antiplatelet therapy is the same for secondary prevention VTE as it is for secondary prevention of cryptogenic stroke in patients with a PFO. There was no important difference in TIA: NMA OR., CrI 0.0 to.; RD +, CI - to +; moderate certainty (Table ; Appendix, Figure ). No patient experienced a systemic embolism in either arm of the RCT that included an anticoagulation arm (Appendix, Figure ). Few patients randomised to PFO closure plus antiplatelet therapy experienced a pulmonary embolism (median risk per 000 patients over years). The RCT that randomised patients to PFO closure versus anticoagulation did not measure pulmonary emboli (). Using external evidence from a systematic review of RCTs that compared ASA to anticoagulation with a VKA for secondary prevention of VTE in the NMA, PFO closure plus antiplatelet therapy probably has a higher risk of pulmonary embolism than anticoagulation: RD +, CI + to +; moderate certainty (Table ; Appendix, Figure ). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

18 Page of Patients randomised to PFO closure plus antiplatelet therapy had a lower risk of major bleeding than those randomised to anticoagulation: NMA OR 0., CI 0.0 to 0.; RD -0, CI - to -, moderate certainty (Table ; Appendix, Figure ). Adding the effect estimate for major bleeding of low-dose ASA compared to anticoagulation with a VKA from a systematic review of RCTs enrolling patients with atrial fibrillation, VTE, or heart failure () to the NMA, resulted in an almost identical point estimate, but a narrower confidence interval: OR 0., CrI 0. to 0.; RD -, CI - to -; moderate certainty (Table ). There was no difference in death between PFO closure and anticoagulation (RD -, - to +, moderate certainty) (Table ). Complications of PFO closure PFO closure, when compared to medical therapy, probably substantially increases the risk of atrial fibrillation (including transient, persistent, and paroxysmal): six RCTs with 0 patients; RR.0, % confidence interval (CI). to.0; risk difference per 000 patients (RD) +, CI + to +; moderate certainty (Table ; Appendix, Figure ). All six studies assessed persistent atrial fibrillation at a follow-up of.0 to. years. PFO closure probably increases the risk of persistent atrial fibrillation: RR., CI. to.; RD +, CI + to +; moderate certainty (Table ; Appendix, Figure ). PFO closure also probably increases the risk of transient atrial fibrillation: RR., CI. to.0; RD +, CI + to +; moderate certainty (Table ; Appendix, Figure ). The studies were limited by risk of bias because they did not report sufficient detail to know how persistent atrial fibrillation was detected (Tables and ). Serious device or procedure-related adverse events occurred in approximately per 000 patients, CI to 0, high certainty (Table ; Appendix, Figure ). The most common device or procedurerelated complications were vascular complications (%), conduction abnormalities (%), device dislocation (0.%), and device thrombosis (0.%). Although serious, air embolism (0.%), cardiac - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

19 Page of tamponade (0.%), and cardiac perforation (0.%) were rare (Tables and ). No deaths were attributed to the procedure or the device placement (Tables and ). Anticoagulation versus antiplatelet therapy Table provides estimates of effect and certainty of evidence for all patient-important outcomes comparing the two medical therapies. There may be fewer ischaemic strokes in patients randomised to anticoagulation than to antiplatelet therapy, but the CI included no effect: NMA OR 0., CrI 0.0 to.; RD: -, CI -00 to +; low certainty (Table ; Appendix, Figure ). Figure presents a Kaplan Meier curve of individual patient time-to-event data for each of the randomized interventions, including anticoagulation versus antiplatelet therapy suggesting a lower rate of stroke in patients receiving anticoagulant than antiplatelet therapy. The complementary model including external evidence from a systematic of RCTs comparing lowdose ASA to anticoagulation with a VKA for secondary prevention of VTE yielded a somewhat larger reduction in strokes with anticoagulants and substantially narrowed the CI: OR 0., CrI 0.0 to 0.; RD -, CI - to -; low certainty (Table ) (). There may be little or no difference in risk of TIA between anticoagulation and antiplatelet therapy (NMA OR 0., CrI 0. to.; RD -, CI - to +; low certainty (Table, Appendix, Figure ). There were no reported systemic emboli, although it is not clear what the monitoring and ascertainment processes were. Our analysis suggested more major bleeding events among patients randomised to anticoagulation than to antiplatelet therapy, but the CI included no effect: NMA OR.0, CI 0. to.; RD +, - to +; moderate certainty (Table ; Appendix, Figure ). Including external evidence from a systematic review of RCTs comparing low-dose ASA to anticoagulation with a VKA in patients with atrial fibrillation, VTE, and heart failure yielded a very similar point estimate and substantially narrowed the CI: OR., CI. to.; RD +, CI + to +; moderate certainty (Table ) (). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

20 Page of The RCT that included an anticoagulation arm did not report pulmonary emboli; the risk of pulmonary embolism was low in other RCTs that included an antiplatelet arm (median per 000 patient-years over years). External evidence from a systematic review of secondary prevention of VTE suggests that the risk of pulmonary embolism is probably lower with anticoagulation than antiplatelet therapy: RD -, CI - to -; moderate certainty (). Deaths were extremely rare and there was no appreciable difference between the anticoagulation and antiplatelet therapy: RD +0, CI - to +, low certainty (Table, Appendix, Figure ). Subgroup Analyses Data proved insufficient to perform the prespecified subgroup analyses when anticoagulation and antiplatelets were assumed to have different effects, as we had prespecified. We performed one posthoc meta-regression analysis to explore the effect of PFO shunt size on the relative effectiveness of PFO closure compared to medical therapy. Five RCTs reported ischaemic stroke and the proportion of patients with a moderate or large shunt vs. small shunt, all with slightly different definitions. PFO closure was more effective in the RCTs that enrolled a higher proportion of patients with a moderate or large shunt (interaction p=0.0) (Appendix, Figure ). However, this is confounded by the fact that the RCTs that enrolled a higher proportion of patients with moderate or large PFO shunts also had a larger proportion of patients with antiplatelet agents rather than anticoagulation (Appendix Figure ). When both possible effect modifiers were included in the model neither was statistically significant: p=0. for proportion with moderate or large shunt and p=0. for proportion receiving anticoagulation; however, this model is severely underpowered with two effect modifiers and only five studies. DISCUSSION We found moderate certainty evidence that in patients less than 0 years old with a PFO and cryptogenic stroke, PFO closure plus antiplatelet therapy results in a substantial reduction in the risk - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

21 Page of of recurrent ischaemic stroke compared to antiplatelet therapy alone by approximately.% over years, but increases the risk of persistent atrial fibrillation (approximately.%) and device-related adverse events (approximately.%) in the first year after procedure (Table ). Although the evidence regarding anticoagulation versus alternatives is of low quality and comes in large part from indirect evidence, it is possible that anticoagulation and PFO closure may achieve a similar reduction in the risk of recurrent ischaemic stroke and thus appreciably fewer strokes than antiplatelet agents alone. Anticoagulation, compared to either PFO closure plus antiplatelet therapy or antiplatelet therapy alone probably increases the risk of major bleeding by approximately % over years and probably reduces the risk of pulmonary embolism by approximately 0.%. There does not appear to be an important difference in the risk of death or in the risk of systemic emboli between any of the interventions. Our results provide further strong support for the hypothesis that stasis-related paradoxical venous thromboemboli and/or intra-cardiac thrombi cause a large proportion of cryptogenic strokes in younger patients with PFO. Given that is the case, it is plausible, though uncertain, that anticoagulation has a similar relative benefit versus antiplatelet agents in preventing cryptogenic strokes in patients with PFO as it does in preventing recurrent VTE. Our results, including the metaregression examining comparisons of PFO closure versus studies in which varying proportion of patients received anticoagulants (Figure ) support this inference. Only one of the RCTs included an arm in which all patients were offered anticoagulation or PFO closure; as a result, the direct evidence includes relatively few patients and very few events. Moreover, the evidence from studies of VTE is very indirect. Thus, we categorised the evidence regarding anticoagulation versus PFO closure, and versus antiplatelet therapy, in preventing stroke as low certainty (Tables and ). Resolving the uncertainty that currently bedevils decision-making will require larger RCTs that compare anticoagulation to PFO closure. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

22 Page 0 of A recent systematic review suggested that PFO closure may be more effective in patients with larger shunt (). We show that this subgroup analysis has low credibility because it is confounded by the anticoagulation in the patients randomised to medical therapy in RCTs with a higher proportion of patients with smaller shunts. PFO closure may be less effective relative to medical therapy when patients receive anticoagulation and/or have smaller shunts. The results of the NMA, in addition to indirect evidence from patients with a VTE, suggest that the subgroup effect by type of medical therapy may be the most credible explanation. PFO closure comes with infrequent but important risks: an approximately % to % chance of serious device or procedure-related complications and an approximately % increased incidence of atrial fibrillation, of which approximately half is persistent. Anticoagulation with VKAs carries a % to % increase in major bleeding over years in this patient population. The risk of major bleeding may be marginally lower with some direct acting oral anticoagulants than with VKAs (). Patients must also consider the important practical implications of taking anticoagulants, including limitations to diet and activities with an appreciable risk of trauma, possible drug interactions and, with VKAs, the need for repeat laboratory testing. Strengths and limitations: Our study has several strengths. In contrast with recent systematic reviews summarising the recent RCTs on PFO closure (-); we separately addressed the three management alternatives of PFO closure plus antiplatelet therapy, anticoagulation alone, and antiplatelet therapy alone. In doing so, we applied several analytical approaches, including network meta-analysis, meta-regression, and individual patient analyses from survival curves, as well as judicious use of external evidence, to bring to bear all the relevant evidence for decision-making. In addition, we used the GRADE approach to assess the certainty of evidence informing the estimates in the study. Our review also includes one recently published study not included in prior reviews. We thus summarised all of the highest quality - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

23 Page of available evidence, providing optimal insight into the comparative effects of the alternative management strategies for patients with PFO who have experienced a cryptogenic stroke. The results are limited primarily by the available evidence. Of the ten RCTs that we included in this review, three compared PFO closure to a medical therapy arm that was not predefined the key choice between antiplatelet and anticoagulation was left to the discretion of the physician and patient. As corroborated in our evidence synthesis, there are probably important differences between anticoagulation and antiplatelet therapy. As a result, these three RCTs cannot directly inform the clinical decisions in which antiplatelet therapy and anticoagulation are two distinct choices, and we could not include them in many of the analyses bearing on the choice between PFO closure and antiplatelet therapy. Our meta-regression analysis that included these studies suggested an inverse relationship between stroke reduction and proportion of patients in the medical therapy arms prescribed anticoagulation, thus providing support for the benefit of anticoagulants versus antiplatelet therapy (Figure ). The NMA also has limitations: the network is sparsely populated, it includes patients with no contraindications to any of three management strategies, those with patients with contraindications to anticoagulants, and those with contraindications to PFO. Nevertheless, we found no suggestion of incoherence between direct and indirect estimates in the NMA and suggest that it provides the best estimates available. The applicability of these findings to older patient populations, particularly those over 0 years of age, and those with traditional cerebrovascular risk factors such as exposure to diabetes, hypertension, and hyperlipidaemia, is uncertain. The proportion of patients with a cryptogenic stroke caused by paradoxical emboli rather than large vessel atheroembolism or intracardiac thrombus almost certainly decreases with age. Thus, we expect that the benefits of PFO closure would be smaller in older patients and the harms (e.g. atrial fibrillation) greater. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

24 Page of CONCLUSIONS In patients less than 0 years old with cryptogenic stroke and a PFO, PFO closure plus antiplatelet therapy probably confers a substantial reduction in the risk of ischaemic stroke recurrence compared to antiplatelet therapy alone, with a modest risk of persistent atrial fibrillation or flutter and serious device or procedure-related complications. Based on low certainty evidence, anticoagulation may confer a similar reduction in the risk of ischaemic stroke compared to PFO closure, but likely confers a modest increased risk of major bleeding. Future RCTs comparing anticoagulation to PFO closure would substantially reduce uncertainty for several critical outcomes. Acknowledgement: We thank members of the BMJ Rapid Recommendations panel for critical feedback on outcome selection, subgroup selection, GRADE judgments, and manuscript feedback. We thank Rachel Couban for helping develop the search strategy. Contributors: GHG and RAS conceived the study idea. HM performed the literature search and data analysis. HM, RAS, TA, GHG, POV interpreted the data analysis. HM, RAS, and GHG wrote the first draft of the manuscript. TS, LL, and MF acquired data and judged risk of bias in the studies. FF extracted patient level survival data from Kaplan-Meier curves. LG provided statistical advice. RAS, GHG, TA, POV, TK, JLM, MF critically reviewed the manuscript. HM had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. HM is guarantor. Funding: None Competing interests: All authors have completed the BMJ Rapid Recommendations disclosure form, which asks about any possible financial, intellectual, and professional conflicts of interest. JLM has received consulting honoraria from Bayer, Bristol Meyer Squibb, Boehringer-Ingelheim, Daichii- Sankyo, GECKO, and Servier. HM, RAS, TK, and GHG are also panel members of the linked Rapid Recommendation guideline panel. Ethical approval: Not required - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

25 Page of Data sharing: No additional data available Transparency declaration: The lead author (HM) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

26 Page of Legend: Table : Characteristics of patients in eligible studies Table Summary of findings of PFO closure plus antiplatelet therapy vs antiplatelet therapy Table : Summary of findings of PFO closure plus antiplatelet therapy vs anticoagulation therapy Table : Summary of findings of anticoagulation vs antiplatelet therapy Figure. PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke Figure. Meta-regression curve based on the proportion of anticoagulant in the medical therapy arm for ischaemic stroke Figure. Combined Kaplan-Meier curves with individualized patient data based on the type of intervention for ischaemic stroke - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

27 Page of Table : Characteristics of patients in eligible studies Author n randomised Mean Age % Male Inclusion criteria PFO closure plus antiplatelet vs antiplatelet therapy Furlan (CLOSURE, 0.0. Cryptogenic 0) stroke, PFO, > yo and < 0yo Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > yo and < 0yo Meier (PC Trial, 0) Saver (RESPECT, 0) Sondergaard (REDUCE, 0) Lee (DEFENCE PFO, 0) Moderate or higher shunt (%) ().. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, > yo and < 0yo. 0. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, no age limit PFO closure plus antiplatelet vs anticoagulation Mas (CLOSE, 0) NA NA Cryptogenic stroke, PFO, > yo and < 0yo Anticoagulation vs antiplatelet therapy Homma (PICSS, 00) 0 ( with cryptogenic stroke).. PFO with or without cryptogenic stroke >0yo and < yo Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > yo and < 0yo Shariat (0).. Cryptogenic stroke, PFO, > yo Atrial septal aneurysm > 0mm (%) () Most common device used for closure. (). STARFlex 00%. (). Amplatzer %. (). () Amplatzer 00%. (). () Amplatzer 00%.0 () NR for AP group Cardioform % NA 0. Amplatzer 00% NA NA NA.% ().% NA NA NA NA NA NA NA. Shunt size was measured based on the number of microbubbles in the left atrium within cycles of being seen in the right atrium on transthoracic or transoesophageal echocardiography. Greater than or equal to Microbubbles. Greater than or equal to 0 Microbubbles. Greater than or equal to 0 Microbubbles. Size of shunt not clearly defined - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

28 Page of At least microbubble. Atrial septal aneurysm was assessed on transoesophageal echo and was defined as septal mobility or protrusion. Atrial septal aneurysm greater than mm. Atrial septal aneurysm not clearly defined % Intrasept PFO occluder, % STARFlex septal closure System, % Premere, % Amplatzer cribriform occluder, % Figulla flex II PFO occluder, % Atriasept II occluder, % Gore helex septal occluder, % Amplatzer AS occluder, % Figulla flex II UNI occluder, % Figulla flex II ASD occluder % Gore helex septal occluder NA Not available - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

29 Page of Table : GRADE summary of findings of PFO closure plus antiplatelet therapy vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome (Timeframe) Ischaemic stroke (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Persistent x atrial fibrillation or Flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse events (Standardized to year) Pulmonary embolism (Standardized to years) Transient ischaemic attack (Standardized to years) Systemic embolism (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patient-years Antiplatelet therapy 00 per 000 PFO closure plus antiplatelet therapy per 000 Difference: fewer (CI % 00 fewer* - fewer) Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years per 000 per 000 Difference: more (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Difference: 0 fewer (CI % fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) Certainty in effect estimates (Quality of evidence) Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious risk of bias Moderate Due to serious risk of bias High High Moderate Due to serious imprecision - High Plain text summary PFO closure plus antiplatelet therapy probably results in a large decrease in ischemic stroke There is probably little or no difference in death There is probably little or no difference in major bleeding PFO closure plus antiplatelet therapy probably increases persistent atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increase device or procedure related adverse events PFO plus antiplatelet therapy has no effect on pulmonary embolism There is probably little or no difference in transient ischaemic attack There is little or no difference in systemic embolism : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

30 Page of Note: The baseline risk for PFO closure was used to estimate the absolute effect in the antiplatelet arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and thus allowing ease in comparison.. Risk of bias: No serious. Despite inadequate/lack of blinding of participants and personnel, resulting in potential for performance bias, we decided not to downgrade since we rated ischaemic stroke as an objective outcome (borderline decision). Inconsistency: No serious. Borderline decision I %, not rated down. Imprecision: Serious. Low number of events.. Imprecision: Serious. Wide confidence intervals, included appreciable harm. Low number of events.. Imprecision: Serious. Low number of events.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Inconsistency: No serious. Inconsistency: study as high 0/00 and as low as 0/000., Point estimates vary widely. Not rated down.. Imprecision: Serious. Wide confidence intervals, included both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

31 Page of Table : Summary of GRADE evidence profile of PFO closure plus antiplatelet therapy vs anticoagulation in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Major bleeding - modelling data from VTE literature (Standardized to years) Persistent x atrial fibrillation or flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse event (Standardized to year) Transient ischaemic attack (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patientyears Anticoagulation per 000 PFO closure plus antiplatelet therapy per 000 Odds Ratio: 0. (CI % 0. -.) Relative risk: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Difference: fewer (CI % fewer* - 0 more) per 000 per 000 Difference: fewer (CI % 0 fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: 0 fewer (CI % fewer* - fewer) per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to serious imprecision and serious indirectness Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious indirectness Moderate Due to serious risk of bias Moderate Due to serious risk of bias High Moderate Due to serious imprecision Difference: more per 000 (CI % fewer* - more) - Plain text summary There may be little or no difference in ischaemic stroke There may be little or no difference in ischaemic stroke There is probably little or no difference in death PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably increases nontransient atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increases device or procedure related adverse events There is probably little or no difference in transient ischaemic attack : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

32 Page 0 of Pulmonary embolism - modelling data from VTE literature (Standardized to years) Systemic embolism (Standardized to years) Odds Ratio:.0 (CI %. -.0) Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years per 000 per 000 Difference: more per 000 (CI % more - more) 0 per per 000 Difference: 0 fewer per 000 (CI % fewer - more) Moderate Due to serious indirectness Moderate Due to serious imprecision 0 There is probably little or no difference in pulmonary embolism There is probably little or no difference in systemic embolism Note: The baseline risk for PFO closure was used to estimate the absolute effect in the anticoagulation arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and and the anticoagulation arms in table and allowing for ease in comparison.. Imprecision: Very Serious. Wide confidence interval. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm.. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence interval, included a not important benefit. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Imprecision: Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years VTE, venous thromboembolism; AF, atrial fibrillation; CHF, congestive heart failure - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

33 Page of Table : Summary of GRADE evidence profile of anticoagulation vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major Bleeding (Standardized to years) Major bleeding - modelling data from VTE literature (Standardized to years) Transient ischaemic attack (Standardized to years) Pulmonary embolism - modelling data from VTE literature (Standardized to years) Systemic embolism (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patient-years Antiplatelet 00 y per 000 Anticoagulation per 000 Odds Ratio: 0. (CI % ) Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI %. -.) Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Not estimable Direct evidence in NMA from patients in studies Follow up. years Difference: fewer (CI % 00 fewer* - more) 00 per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: 0 more (CI % fewer* - more) per 000 per 000 Difference: more (CI % fewer - more) per 000 per 000 Difference: more (CI % more - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer - fewer) 0 per per 000 Difference: 0 fewer (CI % fewer - more) Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to very serious indirectness Low Due to very serious imprecision Moderate Due to serious imprecision Moderate Due to serious indirectness Low Due to very serious imprecision Moderate Due to serious indirectness Moderate Due to serious imprecision Plain text summary Anticoagulation may decrease ischaemic stroke Anticoagulation may decrease ischaemic stroke There may be little or no difference in death Anticoagulation probably increases major bleeding Anticoagulation probably increases major bleeding There may be little or no difference in transient ischaemic attack There is probably little or no difference in pulmonary embolism. There is probably little or no difference in systemic embolism Note: The baseline risk for antiplatelet was obtained using calculated absolute effect estimate. This was done to maintain consistency across the tables. The calculated baseline risk (0%) was similar to the baseline risk calculated using the median of studies included (%). Imprecision: Very Serious. Wide confidence interval, includes appreciable harm. Low number of events. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

34 Page of Indirectness: Very Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence intervals, Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. We did not rate down with two levels because we felt the outcome is less indirect compared to VTE literature than Ischaemic stroke.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable harm and benefit. Low number of events. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event rate. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

35 Page of Included Eligibility Screening Identification Figure. PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke Records identified through database searching (total n = ): MEDLINE (n=), EMBASE (n=0), CENTRAL (n=) Records after duplicates removed (n = ) Records screened (n = ) Full-text articles assessed for eligibility (n = ) Studies included in qualitative synthesis (n = ) Studies included in quantitative synthesis (meta-analysis) (n = ) Records excluded (n = 0) Full-text articles excluded, with reasons (n = ) Study added (published after search completion) (n = ) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

36 Page of Figure. Meta-regression curve of the proportion of patients prescribed an anticoagulant in the medical therapy arm for the outcome ischaemic stroke Figure. Combined Kaplan-Meier curves of individual participant data in the included trials, by type of intervention for the outcome ischaemic stroke Note: ) Y-axis is truncated from 0% to 00% Event-free Survival ) Mixed medical therapy includes studies where the proportion of antiplatelet agents was less than 0% and the proportion of anticoagulant was greater than % ) Proportion of patients: PFO Closure + antiplatelet therapy (N= ; 0%), Mixed medical therapy (N= ; %), Antiplatelet therapy (N= ; %), and Anticoagulation (N= 0; %) ) K-M curves were available for the outcome of ischaemic stroke in the CLOSE study ()(PFO closure, anticoagulation, and antiplatelet), the PC Trial () (PFO closure and mixed medical therapy), the RESPECT trial ()(PFO closure and mixed medical therapy), and the REDUCE trial ()(PFO closure and antiplatelet). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

37 Page of APPENDICES Appendix : Summary of search and strategies Appendix : Tables ) Table : Characteristics of eligible studies ) Table : Direct and indirect estimates of effects for the network meta-analysis Appendix : Figures ) Figure : Risk of bias of included randomised controlled trials ) Figure : Network of included RCTs with available direct comparisons for ischaemic stroke. ) Figure : Meta-regression evaluating the effect of moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy ) Figure : Meta-regression evaluating the proportion of patients on anticoagulation compared to those with moderate or higher shunt size Appendix : PFO closure vs antiplatelet forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic emboli Figure : Death Figure : Major bleeding Figure : Pulmonary embolism Appendix : PFO closure vs anticoagulation forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic emboli Figure : Pulmonary emboli Figure : Major bleeding Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) Figure : All atrial fibrillation Figure : Persistent atrial fibrillation Figure : Transient atrial fibrillation Figure : Serious device or procedure related Appendix : Anticoagulation vs antiplatelet forest plots (Direct evidence only) Figure : Stroke Figure : TIA Figure : Major bleeding Figure : Death - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

38 Page of Appendix : Summary of search and strategies Database: OVID Medline Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R) to Present Search Strategy: cerebrovascular disorders/ or basal ganglia cerebrovascular disease/ or exp brain ischemia/ or carotid artery diseases/ or carotid artery thrombosis/ or intracranial arterial diseases/ or cerebral arterial diseases/ or exp "intracranial embolism and thrombosis"/ or exp stroke/ () (isch?emi$ adj (stroke$ or apoplex$ or cerebral vasc$ or cerebrovasc$ or cva or attack$)).tw. () ((brain or cerebr$ or cerebell$ or vertebrobasil$ or hemispher$ or intracran$ or intracerebral or infratentorial or supratentorial or middle cerebr$ or mca$ or anterior circulation) adj (isch?emi$ or infarct$ or thrombo$ or emboli$ or occlus$ or hypoxi$)).tw. (0) (TIA or TIAs).mp. () Embolism, Paradoxical/ () heart atria/ and (embolism/ or thromboembolism/) () ((paradoxic$ or crossed) adj embolism$).tw. () (cryptogenic adj stroke).tw. () or/- (0) Annotation: population part : stroke or cryptogenic stroke 0 heart septal defects, atrial/ or foramen ovale, patent/ () heart septum/ or atrial septum/ or foramen ovale/ (00) (patent foramen ovale or PFO).tw. () (atrial sept$ adj defect$).tw. (0) ((right to left or R-L or venous to arterial or venous-arterial or V-A) adj shunt).tw. () or/0- (0) Annotation: population part : PFO and () Annotation: population Stroke and PFO limit to yr="0 -Current"(0) Annotation: since last review limit to ("therapy(maximizes sensitivity)" or "therapy(maximizes specificity)" or "therapy(best balance of sensitivity and specificity)") () randomised controlled trial.pt. (0) 0 controlled clinical trial.pt. () randomised.ab. (0) placebo.ab. (00) drug therapy.fs. (00) randomly.ab. () trial.ab. () groups.ab. () or/- (0) exp animals/ not humans.sh. () not () 0 and () - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

39 Page of or 0 () Annotation: Population stroke and PFO limit to since 0 and RCTs "prostheses and implants"/ or septal occluder device/ () Wound Closure Techniques/ () (close or closure or septal occluder).tw. (0) (cardioseal or gore helex or amplatzer or starflex or cardia or intrasept or premere).tw. (0) su.fs. () or/- () Annotation: Septal occluder device as per Liu 0 CDSR exp Anticoagulants/ (0) anticoagulant$.tw. () 0 (acenocoumarol$ or dicoumarol$ or ethyl biscoumacetate$ or phenprocoumon$ or warfarin$ or ancrod$ or citric acid$ or coumarin$ or chromonar$ or coumestro$ or esculi$ or ochratoxin$ or umbelliferone$ or dermatan?sul$ or dextran$ or edetic acid$ or enoxaparin$ or gabexate$ or heparin$ or lmwh$ or nadroparin$ or pentosan sulfuric polyester$ or phenindione$ or protein c or protein s or tedelparin$).tw. (0) (argatroban or tinzaparin or parnaparin or reviparin or danaparoid or lomoparan or org 0 or mesoglycan or polysaccharide sulphate$ or sp or sp- or md0 or md-0 or cy or cy- or cy or cy-).tw. () (Marevan or Fragmin$ or Fraxiparin$ or Klexane).tw. () exp Pipecolic acids/ae, tu () exp Vitamin K/ai () Vitamin K antagonist$.tw. () exp Antithrombins/ae, pd, de, tu () exp Blood coagulation factors/ai, de (00) exp Blood coagulation/de () (anticoagulat$ or antithromb$).tw. (0) 0 or/- () Annotation: anticoagulants as per Berge 00 CDSR Factor Xa Inhibitors/ () Dabigatran/ () Rivaroxaban/ (0) (dabigatran or rivaroxaban or apixaban or edoxaban).mp. (0) anti-factor Xa.mp. () (factor Xa adj (antag* or inhibit*)).mp. () novel oral anticoagulant*.mp. (0) noac.mp. () noacs.mp. () 0 pradax.mp. () pradaxa.mp. () BIBR-.mp. () BIBR-ZW.mp. () xarelto.mp. () BAY -.mp. () BMS-.mp. () eliquis.mp. () lixiana.mp. () DU-.mp. () 0 DU-b.mp. () non-vitamin K.mp. () - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

40 Page of or/- (0) direct oral anticoagulant*.mp. () DOAC.mp. () DOACs.mp. (0) TSOAC.mp. () TSOACs.mp. [mp=title, abstract, original title, name of substance word, subject heading word, keyword heading word, protocol supplementary concept word, rare disease supplementary concept word, unique identifier, synonyms] (0) oral anticoagulant.mp. (0) (new or novel or direct or direct-acting or target-specific or targeted or non-vitamin K).mp. [mp=title, abstract, original title, name of substance word, subject heading word, keyword heading word, protocol supplementary concept word, rare disease supplementary concept word, unique identifier, synonyms] (0) 0 and (0) or or or or 0 () Annotation: NOACs or DOACs from 0 Canadian Cardiac Society GL search RC exp Platelet aggregation inhibitors/ (0) (antiplatelet$ or anti-platelet$ or antiaggreg$ or anti-aggreg$ or (platelet$ adj inhibit$) or (thrombocyt$ adj inhibit$)).tw. (00) (alprostadil$ or aspirin$ or dipyridamol$ or disintegrin$ or epoprostenol$ or iloprost$ or ketanserin$ or ketorolac tromethamine$ or milrinone$ or mopidamol$ or pentoxifyllin$ or procainamide$ or ticlopidine$ or thiophen$ or trapidil$).tw. () (acetyl salicylic acid$ or acetyl?salicylic acid or clopidogrel$ or picotamide$ or ligustrazine$ or levamisol$ or suloctidil$ or ozagrel$ or oky0 or oky-0 or defibrotide$ or cilostazol or satigrel or sarpolgrelate or kbt0 or kbt-0 or isbogrel or cv or cv- or triflusal).tw. () (Dispril or Albyl$ or Ticlid$ or Persantin$ or Plavix).tw. (0) exp Platelet glycoprotein gpiib-iiia complex/ai, de () (((glycoprotein iib$ or gp iib$) adj (antagonist$ or inhibitor$)) or GR0 or GR-0 or abciximab$ or tirofiban$ or eftifibatid$).tw. () (ReoPro or Integrilin$ or Aggrastat).tw. () 0 exp Platelet activation/de () exp Blood platelets/de () or/- (0) Annotation: antiplatelets as per Berge 00 CDSR or 0 or or () Annotation: Intervention block and () remove duplicates from () Central Date Run: /0/ ::. Description: ID Search Hits # MeSH descriptor: [Stroke] explode all trees # MeSH descriptor: [Cerebrovascular Disorders] explode all trees # (isch*emi* near/ (stroke* or apoplex* or cerebral next vasc* or cerebrovasc* or cva or attack*)) : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

41 Page of # ((brain or cerebr* or cerebell* or vertebrobasil* or hemispher* or intracran* or intracerebral or infratentorial or supratentorial or middle next cerebr* or mca* or "anterior circulation") near/ (isch*emi* or infarct* or thrombo* or emboli* or occlus* or hypoxi*)) 0 # (tia or tias) 0 # MeSH descriptor: [Embolism, Paradoxical] explode all trees # ((paradoxic* or crossed) near/ embolism*) # (cryptogenic near/ stroke) # MeSH descriptor: [Heart Atria] explode all trees #0 MeSH descriptor: [Embolism and Thrombosis] explode all trees # # and #0 # atria* near/ (emboli* or thromboemboli*) 0 # # or # or # or # or # or # or # or # or # or # # MeSH descriptor: [Heart Septal Defects, Atrial] explode all trees # "patent foramen ovale" or PFO # atrial sept* near/ defect* 0 # (("right to left" or "R-L" or "venous to arterial" or "venous-arterial" or "V-A") near/ shunt) # # or # or # or # # # and # Publication Year from 0 to : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

42 Page 0 of Appendix : Tables Table : Characteristics of eligible studies PFO closure plus antiplatelet vs antiplatelet therapy Study, year Intervention Medical therapy Withdrawn or loss to follow-up Crossover from med therapy to PFO closure (%) Crossover from PFO closure to med therapy Percent PFO closure performed /patients in PFO cohort Percent technical success/pfo closure attempt Medical PFO (%) therapy (%) STARFlex Device. Clopidogrel for Furlan, 0 months and ASA for years ASA mg daily (%) Mas, 0 Meier, 0 Saver, 0 Sondergaard, 0 Lee, 0 PFO closure (Amplatzer.% X ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Amplatzer occluder. ASA - months. clopidogrel or ticlopidine - months Amplatzer occluder 00%. ASA -mg daily plus clopidogrel mg daily x months then ASA x months PFO Closure (Cardoiform Septal occluder %, Gore helex Septal occluder %) plus antiplatelet (ASA -mg daily, aggrenox, or clopidogrel. Clopidogrel 00mg x then daily x days for everyone PFO Closure (00% Amplatzer PFO occluder). Suggested DAPT for months with ASA 00mg and clopidogrel mg daily. However, up to treating physician. Could even use anticoagulation PFO closure plus antiplatelet vs anticoagulation Aspirin or clopidogrel or aspirin plus ER dipyridamole Antiplatelet (%) or anticoagulation (%) ASA, warfarin, clopidogrel (%), or ASA plus dipyridamole (%) Antiplatelet (ASA -mg daily, ASA plus dipyridamole, or clopidogrel. (00%) Antiplatelet with ASA or ASA and Clopidogrel mg daily, or ASA and Cilostazol 00mg daily. Could anticoagulate with warfarin (INR.0-.0) Study, year Intervention Control Withdrawn or loss to follow-up Crossover from antiplatelet to anticoagulation Crossover from anticoagulation to antiplatelet - Percent technical success/pfo Percent technical success/pfo : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

43 Page of Mas 0 PFO closure (Amplatzer.% ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Anticoagulation vs antiplatelet therapy PFO Closure plus antiplatelet Anticoagulation (%) (%) closure attempts closure attempts Warfarin with target INR - (%) or direct oral anticoagulant (%) NA NA NA NA NA NA Study, year Intervention Control Withdrawn or loss to follow-up Anticoagulation (%) Antiplatelet (%) Crossover from antiplatelet to anticoagulation (%) Crossover from anticoagulation to antiplatelet (%) Aspirin or Mas 0 Warfarin with target INR - (%) or direct oral anticoagulant (%) clopidogrel or aspirin plus ER dipyridamole Shariat, 0 Warfarin.mg po daily (INR -) Aspirin 0mg po tid (00%) Homma (PICSS, 00) Warfarin (INR.-.) F/U months Aspirin mg po od.. NA NA % Intrasept PFO occluder, % STARFlex Septal Closure System, % Premere, % Amplatzer cribriform occluder, % Figulla Flex II PFO occluder, % Atriasept II occluder, % Gore Helex eptal occluder, % Amplatzer AS occluder, % Figulla Flex II UNI occluder, %Figulla Flex II ASD occluder NA = Not available - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

44 Page of Table : Direct and indirect estimates of effects Outcomes Comparisons Direct [OR,%CrI] Ischemic stroke Death Major bleeding Recurrent TIA Systemic embolism PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation Indirect [OR,%CrI]$ NMA [OR,%CrI] 0. (0.0, 0.) Not estimable* 0. (0.0, 0.).e- (.0e-,.e+) 0. (0.0,.) 0. (0.0,.). (0.0,.) Not estimable*. (0.,.).e+ (.,.e+) Not estimable*. (0.,.).e-0 (.e-,.) 0. (0.0,.) 0. (0.0,.) 0. (0.0,.) Not estimable* 0. (0.0,.) 0. (0.,.0) Not estimable* 0. (0.0,.0) 0.0 (0.00,.) 0.0 (0.0,.) 0. (0.0, 0.) 0.0 (0.,.0) Not estimable* 0. (0.,.) 0. (0.,.) Not estimable* 0. (0.,.0). (0.,.) 0. (0.,.). (0.,.). (0.,.) Not estimable*. (0.0,.) 0. (0.,.) Not estimable* 0. (0.,.) 0.0 (.e-0,.0e+0) 0.0 (.e-0,.0e+0) 0.0 (.e-0,.0e+0) Not estimable* $ Indirect results were from back-calculated * Cannot be estimated because the intervention was not connected in a loop in the evidence network (.0e-0, 0.0) 0.0 (.e-0,.0) : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

45 Page of Appendix : Figures Figure : Risk of bias of included randomised controlled trials - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

46 Page of Figure : Network of included RCTs with available direct comparisons for ischaemic stroke. Note: The thickness of the lines (edges) is proportional to the number of RCTs evaluating each treatment and direct comparison. Figure : Meta-regression evaluating the effect of the proportion of participants with a moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy in patients with a PFO and cryptogenic stroke. PFO closure was more effective in RCTs that had a higher proportion of patients with moderate or - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

47 Page of higher PFO shunts, p=0.0. Note, the shunt size was not reported in the DEFENSE-PFO Trial and thus it was not included in the analysis. Figure : Scatter plot of randomised trials of PFO closure in patients with cryptogenic stroke showing an inverse relationship between the proportion of participants with a moderate or higher shunt and proportion of patients prescribed anticoagulation in the medical therapy arm. Note, the shunt size was not reported in the DEFENSE-PFO Trial and thus it was not included in the analysis. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

48 Page of Appendix : PFO closure vs antiplatelet therapy forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

49 Page of Figure : Death Figure : Major bleeding Figure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

50 Page of Appendix : PFO closure vs Anticoagulation forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic embolism Figure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

51 Page of Figure : Major bleeding - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

52 Page 0 of Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) Figure : All atrial fibrillation Figure : Persistent atrial fibrillation Figure : Transient atrial fibrillation - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

53 Page of Figure : Device or procedure related adverse events - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

54 Page of Appendix : Anticoagulation vs antiplatelet therapy forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Major bleeding Figure : Death - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

55 Page of References. Adams H, Bendixen, BH, Kappelle, LJ, et al. Classification of Subtype of Acute Ischemic Stroke: Definitions for Use in a Multicenter Clinical Trial. Stroke. ;():-.. Lechat P, Mas, JL, Lascault, G, et al. Prevalence of patent foramen ovale in patients with stroke. New England Journal of Medicine. ;():-.. Lamy C, Giannesini, C, Zuber, M, et al. Clinical and Imaging Findings in Cryptogenic Stroke Patients With and Without Patent Foramen Ovale The PFO-ASA Study. Stroke. 00;:0-.. Alsheikh-Ali A, Thaler, DE, Kent, DM. Patent foramen ovale in cryptogenic stroke: incidental or pathogenic? Stroke. 00;0:-.. Ning M, Lo, EH, Ning, PC, et al.. The Brain s Heart Therapeutic Opportunities for Patent Foramen Ovale (PFO) and Neurovascular Disease. Pharmacology & Therapeutics. 0;():-.. Meier B, Kalesan, B, Mattle, HP, et al. Percutaneous closure of patent foramen ovale in cryptogenic embolism. New England Journal of Medicine. 0;:0-.. Carroll J, Saver, JL, Thaler, DE, et al. Closure of patent foramen ovale versus medical therapy after cryptogenic stroke. New England Journal of Medicine. 0;: Furlan A, Reisman, M, Massaro, J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. New England Journal of Medicine. 0;:-.. Khan A, Bin-Abdulhak, AA, Sheikh, MA, et al. Device closure of patent foramen ovale versus medical therapy in cryptogenic stroke: a systematic review and meta-analysis. JACC Cardiovascular Interventions. 0;():-. 0. Kent D, Dahabreh, IJ, Ruthazer, R, et al. Device Closure of Patent Foramen Ovale After Stroke: Pooled Analysis of Completed Randomised Trials. Journal of the American College of Cardiology. 0;():0-.. Li J, Liu, J, Liu, M, et al. Closure versus medical therapy for preventing recurrent stroke in patients with patent foramen ovale and a history of cryptogenic stroke or transient ischaemic attack. Cochrane Database Syst Rev. 0():CD00.. Spencer F, Lopes, LC, Kennedy, SA, et al. Systematic review of percutaneous closure versus medical therapy in patients with cryptogenic stroke and patent foramen ovale.. 0;:e00.. Messé S, Gronseth, G, Kent, DM, et al. Practice advisory: Recurrent stroke with patent foramen ovale (update of practice parameter): Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology. 0;():-.. Mas J-L, Derumeaux, G, Guillon, B, et al. Patent foramen ovale closure or anticoagulation vs. antiplatelets after stroke. New England Journal of Medicine. 0;:0-.. Søndergaard L, Kasner, SE, Rhodes, JF, et al. Patent foramen ovale closure or antiplatelet therapy for cryptogenic stroke. New England Journal of Medicine. 0;:0-.. Saver J, Carroll, JD, Thaler, DE, et al. Long-term outcomes of patent foramen ovale closure or medical therapy after stroke. New England Journal of Medicine. 0;:0-.. Castellucci L, Cameron, C, LeGal, G, et al. Efficacy and safety outcomes of oral anticoagulants and antiplatelet drugs in the secondary prevention of venous thromboembolism: systematic review and network meta-analysis. British Medical Journal. 0;:f.. Siemieniuk R, Agoritsas, T, Macdonald, H, et al. Introduction to BMJ Rapid Recommendations. BMJ. 0;:i.. Kuijpers T, Spencer, FA, Siemieniuk, RA, et al. Patent foramen ovale closure plus antiplatelet therapy versus antiplatelet or anticoagulation therapy alone for cryptogenic stroke: a clinical practice guideline. British Medical Journal Mir H, Siemieniuk, RA, Agoritsas, T, et al. Percutaneous closure versus antiplatelet therapy vs anticoagulation therapy in patients with patent foramen ovale and cryptogenic stroke: a protocol for a systematic review and network meta-analysis 0 [Available from: : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

56 Page of Unit) HHIR. Search Strategies for EMBASE in Ovid Syntax [Website]. [updated February, 0. Available from: Unit) HHIR. Search Filters for MEDLINE in Ovid Syntax and the PubMed translation [Website]. [updated February, 0. Available from: Akl E, Sun, X, Busse, JW, et al. Specific instructions for estimating unclearly reported blinding status in randomised trials were reliable and valid. Journal of Clinical Epidemiology. 0;:-.. Higgins J, Altman, DG, Gotzsche, PC, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. British Medical Journal. 0;:d.. Guyatt G, Oxman, AD, Vist, GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. British Medical Journal. 00;:-.. Brignardello-Petersen R, Bonner, A, Alexander, PE, et al. Advances in the GRADE approach to rate the certainty in estimates from a network meta-analysis. Journal of Clinical Epidemiology. 0;:-.. Guyatt G, Oxman, AD, Kunz, R, et al. Rating the quality of evidence-indirectness. Journal of Clinical Epidemiology. 0;():0-0.. Gelman A, Rubin, DB. Inference from Iterative Simulation Using Multiple Sequences. Statistical Science. ;:-.. vanvalkenhoef G, Dias, S, Ades, AE, et al. Automated generation of node-splitting models for assessment of inconsistency in network meta-analysis. Research Synthesis Methods. 0;: Dias S, Sutton, AJ, Ades, AE, et al. Evidence synthesis for decision making : a generalized linear modeling framework for pairwise and network meta-analysis of randomized controlled trials. Medical Decision Making. 0;():0-.. vanvalkenhoef G, Lu, G, debrock, B et al. Automating network meta-analysis. Research Synthesis Methods. 0;:-.. Guyot P, Ades, AE, Ouwens, MJ, Welton, NJ. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves. BMC Med Res Methodol. 0;().. Mas J, Arquizan, C, Lamy, C, et al. Recurrent Cerebrovascular Events Associated with Patent Foramen Ovale, Atrial Septal Aneurysm, or Both. New England Journal of Medicine. 00;:0-.. Shariat A, Yaghoubi, E, Farazdaghi, M, et al. Comparison of medical treatments in cryptogenic stroke patients with patent foramen ovale: A randomized clinical trial. Journal of Research in Medical Sciences. 0;():-.. Homma S, Sacco, RL, DiTullio, MR, et al. Effect of Medical Treatment in Stroke Patients With Patent Foramen Ovale: Patent Foramen Ovale in Cryptogenic Stroke Study. Circulation. 00;0:-.. Lee P, Song, JK, Kim, JS, et al. Cryptogenic Stroke and High-Risk Patent Foramen Ovale: The DEFENSE- PFO Trial. Journal of the American College of Cardiology. 0;doi: 0.0/j.jacc Vazquez F, Gonzalez, JP, LeGal, G, et al. Risk of major bleeding in patients receiving vitamin K antagonists or low doses of aspirin. A systematic review and meta-analysis. Thrombosis Research. 0;:-.. De Rosa S, Sievert, H, Sabatino, J, et al. Percutaneous closure versus medical treatment in stroke patients with patent foramen ovale. Annals of Internal Medicine. 0:-.. Mojadidi M, Elgendy, AY, Elgendy, IY, et al. Transcatheter Patent Foramen Ovale Closure After Cryptogenic Stroke. JACC Cardiovascular Interventions. 0;0(): Vaduganathan M, Qamar, A, Gupta, A, et al. Patent Foramen Ovale Closure for Secondary Prevention of Cryptogenic Stroke: Updated Meta-Analysis of Randomized Clinical Trials. The American Journal of Medicine. 0;S000-():-.. Shah R, Nayyar, M, Jovin, IS, et al. Device closure versus medical therapy alone for patent foramen ovale in patients with cryptogenic stroke. Annals of Internal Medicine. 0: : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

57 Page of Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network meta-analysis incorporating complementary external evidence Hassan Mir, internal medicine and cardiology physician, Reed A.C. Siemieniuk,, PhD student and internal medicine physician, Long Ge, PhD student, Farid Foroutan,, PHD student, Michael Fralick, research fellow and internal medicine physician, Talha Syed, internal medicine and cardiology physician, Luciane Cruz Lopes, clinical pharmacologist, Ton Kuijpers, clinical epidemiologist, Jean- Louis Mas, professor, Per O. Vandvik 0,, associate professor, Thomas Agoritsas,, assistant professor, Gordon H. Guyatt, distinguished professor. Department of Health Research Methods, Evidence, and Impact, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou 0000, China. Department of Clinical Epidemiology and Biostatistics, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Heart Failure/Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. Eliot Phillipson Clinician Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Canada, MG C. University of Sorocaba, UNISO, Sorocaba, Sao Paulo, Brazil. Department of guideline development and research, Dutch College of General Practitioners, Utrecht, The Netherlands. Sainte-Anne Hospital, Department of Neurology, rue Cabanis, 0 Paris. 0. Norwegian Institute of Public Health, Oslo, Norway. Department of Medicine, Innlandet Hospital Trust - division Gjøvik, Norway. Division General Internal Medicine & Division of Clinical Epidemiology, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil, CH-, Geneva, Switzerland - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

58 Page of Legend: Table : Characteristics of patients in eligible studies Table Summary of findings of PFO closure plus antiplatelet therapy vs antiplatelet therapy Table : Summary of findings of PFO closure plus antiplatelet therapy vs anticoagulation therapy Table : Summary of findings of anticoagulation vs antiplatelet therapy Appendix : Tables ) Table : Characteristics of eligible studies ) Table : Direct and indirect estimates of effects for the network meta-analysis - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

59 Page of Table : Characteristics of patients in eligible studies Author n randomised Mean Age % Male Inclusion criteria PFO closure plus antiplatelet vs antiplatelet therapy Furlan (CLOSURE, 0.0. Cryptogenic 0) stroke, PFO, > yo and < 0yo Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > yo and < 0yo Meier (PC Trial, 0) Saver (RESPECT, 0) Sondergaard (REDUCE, 0) Lee (DEFENCE PFO, 0) Moderate or higher shunt (%) ().. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, > yo and < 0yo. 0. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, no age limit PFO closure plus antiplatelet vs anticoagulation Mas (CLOSE, 0) NA NA Cryptogenic stroke, PFO, > yo and < 0yo Anticoagulation vs antiplatelet therapy Homma (PICSS, 00) 0 ( with cryptogenic stroke).. PFO with or without cryptogenic stroke >0yo and < yo Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > yo and < 0yo Shariat (0).. Cryptogenic stroke, PFO, > yo Atrial septal aneurysm > 0mm (%) () Most common device used for closure. (). STARFlex 00%. (). Amplatzer %. (). () Amplatzer 00%. (). () Amplatzer 00%.0 () NR for AP group Cardioform % NA 0. Amplatzer 00% NA NA NA.% ().% NA NA NA NA NA NA NA. Shunt size was measured based on the number of microbubbles in the left atrium within cycles of being seen in the right atrium on transthoracic or transoesophageal echocardiography. Greater than or equal to Microbubbles. Greater than or equal to 0 Microbubbles. Greater than or equal to 0 Microbubbles. Size of shunt not clearly defined - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

60 Page of At least microbubble. Atrial septal aneurysm was assessed on transoesophageal echo and was defined as septal mobility or protrusion. Atrial septal aneurysm greater than mm. Atrial septal aneurysm not clearly defined % Intrasept PFO occluder, % STARFlex septal closure System, % Premere, % Amplatzer cribriform occluder, % Figulla flex II PFO occluder, % Atriasept II occluder, % Gore helex septal occluder, % Amplatzer AS occluder, % Figulla flex II UNI occluder, % Figulla flex II ASD occluder % Gore helex septal occluder NA Not available - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

61 Page of Table : GRADE summary of findings of PFO closure plus antiplatelet therapy vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome (Timeframe) Ischaemic stroke (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Persistent x atrial fibrillation or Flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse events (Standardized to year) Pulmonary embolism (Standardized to years) Transient ischaemic attack (Standardized to years) Systemic embolism (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patient-years Antiplatelet therapy 00 per 000 PFO closure plus antiplatelet therapy per 000 Difference: fewer (CI % 00 fewer* - fewer) Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years per 000 per 000 Difference: more (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Difference: 0 fewer (CI % fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) Certainty in effect estimates (Quality of evidence) Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious risk of bias Moderate Due to serious risk of bias High High Moderate Due to serious imprecision - High Plain text summary PFO closure plus antiplatelet therapy probably results in a large decrease in ischemic stroke There is probably little or no difference in death There is probably little or no difference in major bleeding PFO closure plus antiplatelet therapy probably increases persistent atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increase device or procedure related adverse events PFO plus antiplatelet therapy has no effect on pulmonary embolism There is probably little or no difference in transient ischaemic attack There is little or no difference in systemic embolism : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

62 Page 0 of Note: The baseline risk for PFO closure was used to estimate the absolute effect in the antiplatelet arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and thus allowing ease in comparison.. Risk of bias: No serious. Despite inadequate/lack of blinding of participants and personnel, resulting in potential for performance bias, we decided not to downgrade since we rated ischaemic stroke as an objective outcome (borderline decision). Inconsistency: No serious. Borderline decision I %, not rated down. Imprecision: Serious. Low number of events.. Imprecision: Serious. Wide confidence intervals, included appreciable harm. Low number of events.. Imprecision: Serious. Low number of events.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Inconsistency: No serious. Inconsistency: study as high 0/00 and as low as 0/000., Point estimates vary widely. Not rated down.. Imprecision: Serious. Wide confidence intervals, included both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

63 Page of Table : Summary of GRADE evidence profile of PFO closure plus antiplatelet therapy vs anticoagulation in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Major bleeding - modelling data from VTE literature (Standardized to years) Persistent x atrial fibrillation or flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse event (Standardized to year) Transient ischaemic attack (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patientyears Anticoagulation per 000 PFO closure plus antiplatelet therapy per 000 Odds Ratio: 0. (CI % 0. -.) Relative risk: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Difference: fewer (CI % fewer* - 0 more) per 000 per 000 Difference: fewer (CI % 0 fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: 0 fewer (CI % fewer* - fewer) per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to serious imprecision and serious indirectness Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious indirectness Moderate Due to serious risk of bias Moderate Due to serious risk of bias High Moderate Due to serious imprecision Difference: more per 000 (CI % fewer* - more) - Plain text summary There may be little or no difference in ischaemic stroke There may be little or no difference in ischaemic stroke There is probably little or no difference in death PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably increases nontransient atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increases device or procedure related adverse events There is probably little or no difference in transient ischaemic attack : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

64 Page of Pulmonary embolism - modelling data from VTE literature (Standardized to years) Systemic embolism (Standardized to years) Odds Ratio:.0 (CI %. -.0) Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years per 000 per 000 Difference: more per 000 (CI % more - more) 0 per per 000 Difference: 0 fewer per 000 (CI % fewer - more) Moderate Due to serious indirectness Moderate Due to serious imprecision 0 There is probably little or no difference in pulmonary embolism There is probably little or no difference in systemic embolism Note: The baseline risk for PFO closure was used to estimate the absolute effect in the anticoagulation arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and and the anticoagulation arms in table and allowing for ease in comparison.. Imprecision: Very Serious. Wide confidence interval. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm.. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence interval, included a not important benefit. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Imprecision: Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years VTE, venous thromboembolism; AF, atrial fibrillation; CHF, congestive heart failure - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

65 Page of Table : Summary of GRADE evidence profile of anticoagulation vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major Bleeding (Standardized to years) Major bleeding - modelling data from VTE literature (Standardized to years) Transient ischaemic attack (Standardized to years) Pulmonary embolism - modelling data from VTE literature (Standardized to years) Systemic embolism (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patient-years Antiplatelet 00 y per 000 Anticoagulation per 000 Odds Ratio: 0. (CI % ) Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI %. -.) Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Not estimable Direct evidence in NMA from patients in studies Follow up. years Difference: fewer (CI % 00 fewer* - more) 00 per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: 0 more (CI % fewer* - more) per 000 per 000 Difference: more (CI % fewer - more) per 000 per 000 Difference: more (CI % more - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer - fewer) 0 per per 000 Difference: 0 fewer (CI % fewer - more) Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to very serious indirectness Low Due to very serious imprecision Moderate Due to serious imprecision Moderate Due to serious indirectness Low Due to very serious imprecision Moderate Due to serious indirectness Moderate Due to serious imprecision Plain text summary Anticoagulation may decrease ischaemic stroke Anticoagulation may decrease ischaemic stroke There may be little or no difference in death Anticoagulation probably increases major bleeding Anticoagulation probably increases major bleeding There may be little or no difference in transient ischaemic attack There is probably little or no difference in pulmonary embolism. There is probably little or no difference in systemic embolism Note: The baseline risk for antiplatelet was obtained using calculated absolute effect estimate. This was done to maintain consistency across the tables. The calculated baseline risk (0%) was similar to the baseline risk calculated using the median of studies included (%). Imprecision: Very Serious. Wide confidence interval, includes appreciable harm. Low number of events. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

66 Page of Indirectness: Very Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence intervals, Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. We did not rate down with two levels because we felt the outcome is less indirect compared to VTE literature than Ischaemic stroke.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable harm and benefit. Low number of events. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event rate. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

67 Page of Appendix : Tables Table : Characteristics of eligible studies PFO closure plus antiplatelet vs antiplatelet therapy Study, year Intervention Medical therapy Withdrawn or loss to follow-up Crossover from med therapy to PFO closure (%) Crossover from PFO closure to med therapy Percent PFO closure performed /patients in PFO cohort Percent technical success/pfo closure attempt Medical PFO (%) therapy (%) STARFlex Device. Clopidogrel for Furlan, 0 months and ASA for years ASA mg daily (%) Mas, 0 Meier, 0 Saver, 0 Sondergaard, 0 Lee, 0 PFO closure (Amplatzer.% X ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Amplatzer occluder. ASA - months. clopidogrel or ticlopidine - months Amplatzer occluder 00%. ASA -mg daily plus clopidogrel mg daily x months then ASA x months PFO Closure (Cardoiform Septal occluder %, Gore helex Septal occluder %) plus antiplatelet (ASA -mg daily, aggrenox, or clopidogrel. Clopidogrel 00mg x then daily x days for everyone PFO Closure (00% Amplatzer PFO occluder). Suggested DAPT for months with ASA 00mg and clopidogrel mg daily. However, up to treating physician. Could even use anticoagulation PFO closure plus antiplatelet vs anticoagulation Aspirin or clopidogrel or aspirin plus ER dipyridamole Antiplatelet (%) or anticoagulation (%) ASA, warfarin, clopidogrel (%), or ASA plus dipyridamole (%) Antiplatelet (ASA -mg daily, ASA plus dipyridamole, or clopidogrel. (00%) Antiplatelet with ASA or ASA and Clopidogrel mg daily, or ASA and Cilostazol 00mg daily. Could anticoagulate with warfarin (INR.0-.0) Study, year Intervention Control Withdrawn or loss to follow-up Crossover from antiplatelet to anticoagulation Crossover from anticoagulation to antiplatelet - Percent technical success/pfo Percent technical success/pfo : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

68 Page of Mas 0 PFO closure (Amplatzer.% ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Anticoagulation vs antiplatelet therapy PFO Closure plus antiplatelet Anticoagulation (%) (%) closure attempts closure attempts Warfarin with target INR - (%) or direct oral anticoagulant (%) NA NA NA NA NA NA Study, year Intervention Control Withdrawn or loss to follow-up Anticoagulation (%) Antiplatelet (%) Crossover from antiplatelet to anticoagulation (%) Crossover from anticoagulation to antiplatelet (%) Aspirin or Mas 0 Warfarin with target INR - (%) or direct oral anticoagulant (%) clopidogrel or aspirin plus ER dipyridamole Shariat, 0 Warfarin.mg po daily (INR -) Aspirin 0mg po tid (00%) Homma (PICSS, 00) Warfarin (INR.-.) F/U months Aspirin mg po od.. NA NA % Intrasept PFO occluder, % STARFlex Septal Closure System, % Premere, % Amplatzer cribriform occluder, % Figulla Flex II PFO occluder, % Atriasept II occluder, % Gore Helex eptal occluder, % Amplatzer AS occluder, % Figulla Flex II UNI occluder, %Figulla Flex II ASD occluder NA = Not available - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

69 Page of Table : Direct and indirect estimates of effects Outcomes Comparisons Direct [OR,%CrI] Ischemic stroke Death Major bleeding Recurrent TIA Systemic embolism PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation PFO+antiplatelet vs. antiplatelet PFO+antiplatelet vs. anticoagulation Antiplatelet vs. anticogualation Indirect [OR,%CrI]$ NMA [OR,%CrI] 0. (0.0, 0.) Not estimable* 0. (0.0, 0.).e- (.0e-,.e+) 0. (0.0,.) 0. (0.0,.). (0.0,.) Not estimable*. (0.,.).e+ (.,.e+) Not estimable*. (0.,.).e-0 (.e-,.) 0. (0.0,.) 0. (0.0,.) 0. (0.0,.) Not estimable* 0. (0.0,.) 0. (0.,.0) Not estimable* 0. (0.0,.0) 0.0 (0.00,.) 0.0 (0.0,.) 0. (0.0, 0.) 0.0 (0.,.0) Not estimable* 0. (0.,.) 0. (0.,.) Not estimable* 0. (0.,.0). (0.,.) 0. (0.,.). (0.,.). (0.,.) Not estimable*. (0.0,.) 0. (0.,.) Not estimable* 0. (0.,.) 0.0 (.e-0,.0e+0) 0.0 (.e-0,.0e+0) 0.0 (.e-0,.0e+0) Not estimable* $ Indirect results were from back-calculated * Cannot be estimated because the intervention was not connected in a loop in the evidence network (.0e-0, 0.0) 0.0 (.e-0,.0) : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

70 Page of Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network meta-analysis incorporating complementary external evidence Hassan Mir, internal medicine and cardiology physician, Reed A.C. Siemieniuk,, PhD student and internal medicine physician, Long Ge, PhD student, Farid Foroutan,, PHD student, Michael Fralick, research fellow and internal medicine physician, Talha Syed, internal medicine and cardiology physician, Luciane Cruz Lopes, clinical pharmacologist, Ton Kuijpers, clinical epidemiologist, Jean- Louis Mas, professor, Per O. Vandvik 0,, associate professor, Thomas Agoritsas,, assistant professor, Gordon H. Guyatt, distinguished professor. Department of Health Research Methods, Evidence, and Impact, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou 0000, China. Department of Clinical Epidemiology and Biostatistics, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Heart Failure/Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. Eliot Phillipson Clinician Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Canada, MG C. University of Sorocaba, UNISO, Sorocaba, Sao Paulo, Brazil. Department of guideline development and research, Dutch College of General Practitioners, Utrecht, The Netherlands. Sainte-Anne Hospital, Department of Neurology, rue Cabanis, 0 Paris. 0. Norwegian Institute of Public Health, Oslo, Norway. Department of Medicine, Innlandet Hospital Trust - division Gjøvik, Norway. Division General Internal Medicine & Division of Clinical Epidemiology, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil, CH-, Geneva, Switzerland - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

71 Page of Legend: Figure. PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke Figure. Meta-regression curve based on the proportion of anticoagulant in the medical therapy arm for ischaemic stroke Figure. Combined Kaplan-Meier curves with individualized patient data based on the type of intervention for ischaemic stroke - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

72 Page 0 of Included Eligibility Screening Identification Figure. PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke Records identified through database searching (total n = ): MEDLINE (n=), EMBASE (n=0), CENTRAL (n=) Records after duplicates removed (n = ) Records screened (n = ) Full-text articles assessed for eligibility (n = ) Studies included in qualitative synthesis (n = ) Studies included in quantitative synthesis (meta-analysis) (n = ) Records excluded (n = 0) Full-text articles excluded, with reasons (n = ) Study added (published after search completion) (n = ) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

73 Page of Figure. Meta-regression curve of the proportion of patients prescribed an anticoagulant in the medical therapy arm for the outcome ischaemic stroke Figure. Combined Kaplan-Meier curves of individual participant data in the included trials, by type of intervention for the outcome ischaemic stroke Note: ) Y-axis is truncated from 0% to 00% Event-free Survival ) Mixed medical therapy includes studies where the proportion of antiplatelet agents was less than 0% and the proportion of anticoagulant was greater than % ) Proportion of patients: PFO Closure + antiplatelet therapy (N= ; 0%), Mixed medical therapy (N= ; %), Antiplatelet therapy (N= ; %), and Anticoagulation (N= 0; %) ) K-M curves were available for the outcome of ischaemic stroke in the CLOSE study ()(PFO closure, anticoagulation, and antiplatelet), the PC Trial ()(PFO closure and mixed medical therapy), the RESPECT trial ()(PFO closure and mixed medical therapy), and the REDUCE trial ()(PFO closure and antiplatelet). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

74 Page of Appendices Appendix : Figures ) Figure : Risk of bias of included randomised controlled trials ) Figure : Network of included RCTs with available direct comparisons for ischaemic stroke. ) Figure : Meta-regression evaluating the effect of moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy ) Figure : Meta-regression evaluating the proportion of patients on anticoagulation compared to those with moderate or higher shunt size Appendix : PFO closure vs antiplatelet forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic emboli Figure : Death Figure : Major bleeding Figure : Pulmonary embolism Appendix : PFO closure vs anticoagulation forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic emboli Figure : Pulmonary emboli Figure : Major bleeding Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) Figure : All atrial fibrillation Figure : Persistent atrial fibrillation Figure : Transient atrial fibrillation Figure : Serious device or procedure related Appendix : Anticoagulation vs antiplatelet forest plots (Direct evidence only) Figure : Stroke Figure : TIA Figure : Major bleeding Figure : Death - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

75 Page of Appendix : Figures Figure : Risk of bias of included randomised controlled trials - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

76 Page of Figure : Network of included RCTs with available direct comparisons for ischaemic stroke. Note: The thickness of the lines (edges) is proportional to the number of RCTs evaluating each treatment and direct comparison. Figure : Meta-regression evaluating the effect of the proportion of participants with a moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy in patients with a PFO and cryptogenic stroke. PFO closure was more effective in RCTs that had a higher proportion of patients with moderate or - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

77 Page of higher PFO shunts, p=0.0. Note, the shunt size was not reported in the DEFENSE-PFO Trial and thus it was not included in the analysis. Figure : Scatter plot of randomised trials of PFO closure in patients with cryptogenic stroke showing an inverse relationship between the proportion of participants with a moderate or higher shunt and proportion of patients prescribed anticoagulation in the medical therapy arm. Note, the shunt size was not reported in the DEFENSE-PFO Trial and thus it was not included in the analysis. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

78 Page of Appendix : PFO closure vs antiplatelet therapy forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

79 Page of Figure : Death Figure : Major bleeding Figure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

80 Page of Appendix : PFO closure vs Anticoagulation forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Systemic embolism Figure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

81 Page of Figure : Major bleeding - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

82 Page 0 of Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) Figure : All atrial fibrillation Figure : Persistent atrial fibrillation Figure : Transient atrial fibrillation - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

83 Page of Figure : Device or procedure related adverse events - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

84 Page of Appendix : Anticoagulation vs antiplatelet therapy forest plots (Direct evidence only) Figure : Ischaemic stroke Figure : TIA Figure : Major bleeding Figure : Death - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

85 Page of PRISMA NMA Checklist of Items to Include When Reporting A Systematic Review Involving a Network Meta-analysis TITLE Section/Topic Item # Checklist Item Title Identify the report as a systematic review incorporating a network meta-analysis (or related form of meta-analysis). ABSTRACT - Structured summary INTRODUCTION Provide a structured summary including, as applicable: Background: main objectives Methods: data sources; study eligibility criteria, participants, and interventions; study appraisal; and synthesis methods, such as network meta-analysis. Results: number of studies and participants identified; summary estimates with corresponding confidence/credible intervals; treatment rankings may also be discussed. Authors may choose to summarize pairwise comparisons against a chosen treatment included in their analyses for brevity. Discussion/Conclusions: limitations; conclusions and implications of findings. Other: primary source of funding; systematic review registration number with registry name. Rationale Describe the rationale for the review in the context of what is already known, including mention of why a network metaanalysis has been conducted. Objectives Provide an explicit statement of questions being addressed, with reference to participants, interventions, comparisons, outcomes, and study design (PICOS). METHODS Protocol and registration Indicate whether a review protocol exists and if and where it can be accessed (e.g., Web address); and, if available, provide registration information, including registration number. Eligibility criteria Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale. Clearly describe eligible treatments included in the treatment network, and note whether any have been clustered or merged into the same node (with justification). Information sources Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched. Search Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated. - Reported on Page # -, - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

86 Page of Study selection State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis). Data collection process 0 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators. Data items List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made. Geometry of the network Risk of bias within individual studies Summary measures Planned methods of analysis Assessment of Inconsistency Risk of bias across studies Additional analyses S Describe methods used to explore the geometry of the treatment network under study and potential biases related to it. This should include how the evidence base has been graphically summarized for presentation, and what characteristics were compiled and used to describe the evidence base to readers. Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis. State the principal summary measures (e.g., risk ratio, difference in means). Also describe the use of additional summary measures assessed, such as treatment rankings and surface under the cumulative ranking curve (SUCRA) values, as well as modified approaches used to present summary findings from meta-analyses. Describe the methods of handling data and combining results of studies for each network meta-analysis. This should include, but not be limited to: Handling of multi-arm trials; Selection of variance structure; Selection of prior distributions in Bayesian analyses; and Assessment of model fit. S Describe the statistical methods used to evaluate the agreement of direct and indirect evidence in the treatment network(s) studied. Describe efforts taken to address its presence when found. Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies). Describe methods of additional analyses if done, indicating which were pre-specified. This may include, but not be limited to, the following: Sensitivity or subgroup analyses; Meta-regression analyses; Alternative formulations of the treatment network; and Use of alternative prior distributions for Bayesian analyses (if applicable) : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

87 Page of RESULTS Study selection Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram. Presentation of S Provide a network graph of the included studies to enable network structure Summary of network geometry Study characteristics Risk of bias within studies Results of individual studies S Synthesis of results Exploration for inconsistency Risk of bias across studies Results of additional analyses DISCUSSION Summary of evidence visualization of the geometry of the treatment network. Provide a brief overview of characteristics of the treatment network. This may include commentary on the abundance of trials and randomized patients for the different interventions and pairwise comparisons in the network, gaps of evidence in the treatment network, and potential biases reflected by the network structure. For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations. Present data on risk of bias of each study and, if available, any outcome level assessment. 0 For all outcomes considered (benefits or harms), present, for each study: ) simple summary data for each intervention group, and ) effect estimates and confidence intervals. Modified approaches may be needed to deal with information from larger networks. Present results of each meta-analysis done, including confidence/credible intervals. In larger networks, authors may focus on comparisons versus a particular comparator (e.g. placebo or standard care), with full findings presented in an appendix. League tables and forest plots may be considered to summarize pairwise comparisons. If additional summary measures were explored (such as treatment rankings), these should also be presented. S Describe results from investigations of inconsistency. This may include such information as measures of model fit to compare consistency and inconsistency models, P values from statistical tests, or summary of inconsistency estimates from different parts of the treatment network. Present results of any assessment of risk of bias across studies for the evidence base being studied. Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression analyses, alternative network geometries studied, alternative choice of prior distributions for Bayesian analyses, and so forth). Summarize the main findings, including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy-makers). Limitations Discuss limitations at study and outcome level (e.g., risk of bias), and at review level (e.g., incomplete retrieval of identified research, reporting bias). Comment on the validity of the assumptions, such as transitivity and consistency. Comment on : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

88 Page of any concerns regarding network geometry (e.g., avoidance of certain comparisons). Conclusions Provide a general interpretation of the results in the context of other evidence, and implications for future research. FUNDING Funding Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review. This should also include information regarding whether funding has been received from manufacturers of treatments in the network and/or whether some of the authors are content experts with professional conflicts of interest that could affect use of treatments in the network. PICOS = population, intervention, comparators, outcomes, study design. * Text in italics indicates wording specific to reporting of network meta-analyses that has been added to guidance from the PRISMA statement. Authors may wish to plan for use of appendices to present all relevant information in full detail for items in this section. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

89 Page of !"# #!"$% ### # % &# ##' ##% # % # # % (#! # ##% According to the BMJ Rapid Recommendations process (), a multi-professional guideline panel provided critical oversight to the systematic review and identified populations, subgroups, and outcomes of interest. The BMJ Rapid Recommendation panel, and in particular three people who had experienced a cryptogenic stroke (two of whom had undergone PFO closure), assessed the relative importance of the outcomes (). The guideline panel submitted a list of possible outcomes and then rated the importance of each outcome suggested on a scale from (least important) to (most important). Items with scores of or more were considered, and a final decision was made by consensus, with special consideration of the views of the patient panellists. The patients stressed the importance of several outcomes that other panel members had identified and uniquely highlighted the importance of detailed information about the device or procedure related adverse events. ) Further explanation would be helpful to make clear why you included prior systematic reviews addressing antiplatelet versus anticoagulant therapy in patients with deep venous thrombosis (DVT), atrial fibrillation, and heart failure earlier in the paper. # ##!" #$%!"&"' (" $!)*" - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

90 Page of ,-%.!(/%)%0%"$!"--%"" "!"" % "&!"&$"$& " "'!'$#"''%"$ """"$ "$' "$ &%'! "",,,""!"! '"''& " "% "!"$ $" "&$"&!'$'% "$$"-(" (! "!'% "! #$ %&' ()")"* + &,-.(/,0 () ' &,-. % $ $ # %$#! )*$( % # # + % ) $# +! # % * ' - - ' - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

91 Page of %# # # # # # # ## ## &,$ # # # % # +# - ##.% # %/ ## ## &,$# # # # # # 0 ## # #### # &,$ # # ## # #%! %0 ## &,$# # # # # % # ## &,$# # %% ' #+# # % / # # # &,$# % ## Although the evidence regarding anticoagulation versus alternatives is of low quality and comes in large part from indirect evidence, it is possible that anticoagulation and PFO closure may achieve a similar reduction in the risk of recurrent ischaemic stroke and thus appreciably fewer strokes than antiplatelet agents alone. Further, in the next section addressing the issue, we have added the qualifier though admittedly uncertain : Our results provide further strong support for the hypothesis that stasis-related paradoxical venous thromboemboli and/or intra-cardiac thrombi cause a large proportion of cryptogenic strokes in younger patients with PFO. Given that is the case, it is plausible, though admittedly uncertain, that anticoagulation has a similar relative benefit versus antiplatelet agents in preventing cryptogenic strokes in patients with PFO as it does in preventing recurrent VTE. Another passage from the discussion avoids, we think, overstatement: Only one of the RCTs, however, included an arm in which all patients were offered anticoagulation or PFO closure and as a result the direct evidence includes relatively few - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

92 Page 0 of patients and very few events. Moreover, the evidence from studies of VTE is very indirect. Thus, we categorised the evidence regarding anticoagulation versus PFO closure, and versus antiplatelet therapy, in preventing stroke as low certainty (Tables and ). : ; % # # # -.% <! #' #&,$ ## # # # # # # # ## # ##")): % # ## #% - #.% = ' #+# #; #% > - 0 #0? %& -< #.!=< #%'## #-%>?. # ##.. #?. # #. < ## #% ## ### # ### -A &$!"# /"%## # - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

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104 Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network metaanalysis incorporating complementary external evidence Journal: Manuscript ID bmjopen-0-0.r Article Type: Research Date Submitted by the Author: -Jun-0 Complete List of Authors: Mir, Hassan; McMaster University, Medicine;. Department of Medicine, University of Toronto, Toronto, Ontario, Canada Siemieniuk, Reed; Mcmaster University, Clinical Epidemiology and Biostatistics; University of Toronto, Department of Medicine Ge, Long; The First Clinical Medical College of Lanzhou University, Foroutan, Farid; University Health Network, Medicine/Cardiology Fralick, Michael; University of Toronto, Eliot Phillison Clinician Scientist Training Program, Department of Medicine Syed, Talha; McMaster University Department of Medicine, Medicine Lopes, Luciane; Universidade de Sorocaba Kuijpers, Ton; Nederlands Huisartsen Genootschap, Guideline development and research Mas, Jean-Louis; Sainte-Anne Hospital, Neurology Vandvik, Per; Norwegian Knowledge Centre for the Health Services, Agoritsas, Thomas; University Hospitals of Geneva, Division of General Internal Medicine & Division of Clinical Epidemiology; McMaster University Faculty of Health Sciences, Department of Health Research Methods, Evidence, and Impact Guyatt, Gordon; Mcmaster University, Clinical Epidemiology and Biostatistics <b>primary Subject Heading</b>: Secondary Subject Heading: Keywords: Cardiovascular medicine Evidence based practice, Medical management, Neurology, Patient-centred medicine, Research methods Cryptogenic stroke, Patent foramen ovale, Anticoagulation < HAEMATOLOGY, Antiplatelet, PFO Closure : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright. -

105 Page of Patent foramen ovale closure, antiplatelet therapy or anticoagulation in patients with patent foramen ovale and cryptogenic stroke: a systematic review and network meta-analysis incorporating complementary external evidence Hassan Mir,, internal medicine and cardiology physician, Reed A.C. Siemieniuk,, PhD student and internal medicine physician, Long Ge, PhD student, Farid Foroutan,, PHD student, Michael Fralick, research fellow and internal medicine physician, Talha Syed, internal medicine and cardiology physician, Luciane Cruz Lopes, clinical pharmacologist, Ton Kuijpers, clinical epidemiologist, Jean- Louis Mas, professor, Per O. Vandvik 0,, associate professor, Thomas Agoritsas,, assistant professor, Gordon H. Guyatt, distinguished professor. Department of Health Research Methods, Evidence, and Impact, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou 0000, China. Department of Clinical Epidemiology and Biostatistics, McMaster University, 0 Main St West, Hamilton, Ontario, Canada LS L. Heart Failure/Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. Eliot Phillipson Clinician Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Canada, MG C. University of Sorocaba, UNISO, Sorocaba, Sao Paulo, Brazil. Department of guideline development and research, Dutch College of General Practitioners, Utrecht, The Netherlands. Sainte-Anne Hospital, Department of Neurology, rue Cabanis, 0 Paris. 0. Norwegian Institute of Public Health, Oslo, Norway. Department of Medicine, Innlandet Hospital Trust - division Gjøvik, Norway. Division General Internal Medicine & Division of Clinical Epidemiology, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil, CH-, Geneva, Switzerland Corresponding author: Dr Hassan Mir 0 Main St West, Hamilton, Ontario, Canada LS L hassan.mir@gmail.com - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

106 Page of Abstract Objective: To examine the relative impact of three management options in patients less than 0 years old with cryptogenic stroke and a patent foramen ovale (PFO): PFO closure plus antiplatelet therapy, antiplatelet therapy alone, and anticoagulation alone. Design: Systematic review and network meta-analysis (NMA) supported by complementary external evidence Data sources: Medline, EMBASE, and Cochrane CENTRAL. Study selection: Randomised controlled trials (RCTs) addressing PFO closure and/or medical therapies in patients with PFO and cryptogenic stroke. Review methods: We conducted an NMA complemented with external evidence and rated certainty of evidence using the GRADE system. Results: Ten RCTs in eight studies proved eligible (n=). Seven RCTs (n = ) addressed PFO closure versus medical therapy. Of these, (n=) addressed PFO closure versus antiplatelet therapy, (n=0) addressed PFO closure versus mixed antiplatelet and anticoagulation therapies, and (n= ) addressed PFO closure versus anticoagulation. The remaining three RCTs (n= 0) addressed anticoagulant versus antiplatelet therapy. PFO closure versus antiplatelet therapy probably results in substantial reduction in ischaemic stroke recurrence (risk difference per 000 patients over years [RD]: -, % credible interval [CrI] -00 to -; moderate certainty). Compared with anticoagulation, PFO closure may confer little or no difference in ischaemic stroke recurrence (low certainty) but probably has a lower risk of major bleeding (RD -0, % Crl - to -, moderate certainty). Relative to either medical therapy, PFO closure probably increases the risk of persistent atrial fibrillation (RD, CI + to +, moderate certainty) and device-related adverse events (RD +, % CI + to +0, high certainty). Anticoagulation, compared to antiplatelet therapy, may reduce the risk of ischaemic stroke recurrence (RD -, % CrI -00 to +, low certainty), but probably increases the risk of major bleeding (RD +, CrI - to +, moderate certainty). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

107 Page of Conclusions: In patients less than 0 years old, PFO closure probably confers an important reduction in ischaemic stroke recurrence compared to antiplatelet therapy alone but may make no difference compared to anticoagulation. PFO closure incurs a risk of persistent atrial fibrillation and device-related adverse events. Compared to alternatives, anticoagulation probably increases major bleeding. Article Summary: Strengths and limitations of this study - Summarized the highest quality available evidence by addressing three management alternatives of PFO closure plus antiplatelet therapy, anticoagulation alone, and antiplatelet therapy alone. - Used network meta-analysis, meta-regression, external evidence, and individual patient analyses from survival curves to assist in decision-making. - Applied GRADE approach to thoroughly assess certainty of evidence. - Results were limited primarily by available evidence. - Within the medical therapy arm, the decision to use antiplatelet or anticoagulation was left to the discretion of the physician and patient. Due to this, three studies could not be used in the primary analysis. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

108 Page of INTRODUCTION: Stroke is one of the leading causes of death worldwide and, for those who survive, often results in substantial disability. Central to the management of patients with stroke is preventing additional ischaemic events; the optimal management depends on the underlying aetiology. In up to 0% of patients with an acute ischaemic stroke, investigations fail to identify a clear cause the Trial of Org 0 in Acute Stroke Treatment (TOAST) criteria classify these strokes as of undetermined aetiology or cryptogenic (). Patients who have had a cryptogenic stroke are less likely to have classical risk factors for stroke (e.g., hypertension, hyperlipidaemia, diabetes mellitus) and are more likely to have a patent foramen ovale (PFO) compared to patients with a stroke from a known aetiology (, ). A PFO can allow a systemic venous thrombus to travel directly into the systemic arterial circulation instead of the pulmonary venous circulation a phenomenon known as a paradoxical embolism (, ). The importance of this phenomenon as a cause of stroke is, however, controversial. Other potential mechanisms of PFO-associated stroke include intracardiac thrombus formed in the tunnel of the PFO, on the surface of the atrial septal aneurysm, or left atrial appendage (). Until recently, randomised controlled trials (RCTs) had failed to definitively establish that closing a PFO reduces the risk of subsequent stroke (-). Meta-analyses including earlier trials offered conflicting conclusions (-). Current clinical practice guidelines recommend against PFO closure for most patients who have had a cryptogenic stroke (). In September 0, two new trials (, ) and the long-term follow-up of a previously reported trial () addressed the utility of PFO closure for patients less than 0 years old with cryptogenic stroke. Evidence from recent meta-analyses that incorporate data from these RCTs suggests that PFO closure may prevent stroke. However, despite evidence that anticoagulation is more effective than antiplatelet therapy at preventing stasis-related venous or intracardiac thrombi, these meta-analyses make the assumption that antiplatelet and anticoagulation therapies are similarly effective (). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

109 Page of This systematic review is part of the BMJ Rapid Recommendations project, a collaborative effort from the MAGIC research and innovation programme ( and the BMJ (). The aim of the project is to respond to new potentially practice changing evidence and provide trustworthy practice guidelines in a timely manner. In light of the new evidence for PFO closure and because other reviews do not report clinically relevant comparisons (e.g., PFO closure vs. antiplatelet therapy), we performed a systematic review to inform the parallel guideline published in a multi-layered electronic format on bmj.com and MAGICapp ( As requested by the Rapid Recommendations panel, in the absence of sufficient direct evidence to fully inform recommendations, we conducted complementary analyses using indirect evidence. METHODS Protocol The study protocol was registered with PROSPERO: CRD00 (0). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

110 Page of Patient and Public involvement According to the BMJ Rapid Recommendations process (), a multi-professional guideline panel provided critical oversight to the systematic review and identified populations, subgroups, and outcomes of interest. The BMJ Rapid Recommendation panel, and in particular three people who had experienced a cryptogenic stroke (two of whom had undergone PFO closure), assessed the relative importance of the outcomes (). The guideline panel submitted a list of possible outcomes and then rated the importance of each outcome on a scale from (least important) to (most important). For items with scores of, the panel considered further and made a final decision by consensus, with special consideration of the views of the patient panellists. The patients stressed the importance of several outcomes that other panel members had identified and uniquely highlighted the importance of detailed information about the device or procedure related adverse events. Search strategy A search from a previous systematic review that we judged as comprehensive included research articles indexed before May, 0 (). We updated that review with a search of Medline, Medline in-process, EMBASE, and Cochrane CENTRAL from January 0 to October 0 using a combination of keywords and MeSH terms for patent foramen ovale AND stroke, using the sensitive search filters for therapeutic interventions developed by the Health Information Research Unit at McMaster University (Appendix ). (, ) We also searched all references from included studies and all of the studies citing the included studies on Google Scholar. Study selection We included RCTs addressing the relative impact of PFO closure versus antiplatelet therapy versus anticoagulation in patients, and anticoagulation versus antiplatelet therapy with PFO and cryptogenic stroke. We also included prior rigorous systematic reviews addressing antiplatelet versus anticoagulant therapy in patients with deep venous thrombosis (DVT), atrial fibrillation, and heart - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

111 Page of failure. Reviewers screened titles and abstracts in duplicate and subsequently assessed eligibility from the full text for all possible eligible articles. In comparing PFO closure to antiplatelet therapy for the outcome of stroke, we used only RCTs in which at least 0% of medical therapy patients received antiplatelet rather than anticoagulation. Data collection Two reviewers independently abstracted data from the included RCTs and resolved conflicts by discussion. We searched the clinical trial registration page on clinicaltrials.gov for additional outcome data and ed the corresponding authors of the included RCTs requesting outcome data when it was missing or could not, as presented in the public domain, be included in meta-analytic estimates. The patient-important outcomes we considered included ischaemic stroke, death, major bleeding, persistent atrial fibrillation or flutter, transient or paroxysmal atrial fibrillation, device or procedure related adverse events, pulmonary embolism, transient ischaemic attacks (TIAs), and systemic embolism. For serious device or procedure-related complications, two independent clinician reviewers categorized the specific serious adverse events in the primary studies as probably related or unrelated to the device or implantation procedure; reviewers resolved disagreement with, if necessary, input from a third reviewer. We used the definitions in the original studies for all outcomes except for persistent atrial fibrillation; our classification included the definition used in the original study but also included patients who underwent a cardioversion. We also abstracted key outcomes from the external evidence systematic reviews. Risk of bias and certainty of evidence We assessed risk of bias in duplicate using a modified Cochrane tool in which we used response options of definitely or probably yes (assigned a low risk of bias) and definitely or probably no (assigned a high risk of bias), an approach that has proved valid (, ). Specifically, we assessed - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

112 Page of random sequence generation; concealment of treatment allocation; and blinding of participants, caregivers, and outcome assessors. Reviewers resolved conflicts through discussion. We followed the GRADE approach to rate the quality of evidence derived from pair-wise and network meta-analyses (NMA) as well as from external evidence (, ). Direct evidence from RCTs starts at high quality and may be rated down based on risk of bias, indirectness, imprecision, inconsistency, and publication bias. For network estimates, we rated the quality of evidence in each of the direct, indirect, and network estimates (). The rating of indirect estimates starts at the lowest rating of the two pairwise estimates that contribute to the indirect estimate and can be rated down further for intransitivity. If direct and indirect estimates contributed similar power to the network estimate, then we used the higher rating. The network estimates were further rated down for incoherence between direct and indirect evidence. For analyses that incorporated external evidence, we rated down the quality of evidence for indirectness (down one level for major bleeding and two levels for ischaemic stroke) (). Review authors and the linked Rapid Recommendation panel members came to consensus regarding certainty of evidence ratings. Statistical Analysis We analysed patients in groups to which they were randomised. For both pairwise and NMA, we report pooled odds ratios (ORs); for estimates from NMA we report % credible intervals (CrI) from the Bayesian analysis and for direct estimates % confidence intervals (CI). We present pooled risk differences (RD) and their certainty/confidence intervals for all comparisons, applying relative risks to baseline risk estimates when there were adequate numbers of events, and direct calculation of risk differences when events were very infrequent. In reporting absolute events, we standardized absolute estimates to a rate per,000 patients followed for years assuming proportional event occurrence (in other words, for a reported follow-up of years we would multiply by /). Atrial fibrillation and device or procedure-related adverse events were, however, very likely to have occurred soon after the procedure and we therefore report events per,000 patients as reported in the studies. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

113 Page of The PFO closure arm was used for the baseline risk to allow consistency across comparisons involving PFO closure versus antiplatelet agents and anticoagulants. Baseline risk estimates represent the median risk of the outcome in the six RCTs of PFO closure. For comparisons of antiplatelet agents and anticoagulants, the antiplatelet arm provided the baseline risk to estimate the absolute effect estimate in the anticoagulation arm. The baseline risk for the antiplatelet arm (0%) was calculated using the baseline risk in the PFO closure arm. This proved similar to the median of three studies that included an antiplatelet arm (%) and maintained consistency with the PFO closure comparisons. Network meta-analysis To compare effects of alternative medical therapies, for ischaemic stroke, recurrent TIA, death, major bleeding, and systemic embolism, we conducted a NMA of RCTs within a Bayesian hierarchical fixed effect framework with non-informative priors and adjusted for correlation between effects in the multiarm trial. We generated posterior samples using Markov Chain Monte-Carlo (MCMC) simulation technique running the analysis in three parallel chains. We used 00,000 burn-in simulations to allow convergence and then a further 00,000 simulations to produce the outputs. We assessed model convergence using the Gelman and Rubin test, accepting a threshold of <.0 and used the nodesplitting approach for the assessment of loop inconsistency (, ). We calculated direct estimates of absolute effects using the modified Dias model, incorporating lines into the Dias model (0). We performed the network meta-analyses with R version.. (R Core Team. 0. Vienna, Austria: R Foundation for Statistical Computing) using the gemtc library (). Pairwise meta-analysis As there is no reason, for the outcomes of atrial fibrillation and device or procedure-related adverse events, to expect any difference whether PFO closure is compared to anticoagulation or antiplatelet therapy, for these outcomes we conducted a pairwise meta-analysis of PFO closure versus either medical therapy. We used the random-effects Mantel-Haenszel (M-H) method to estimate relative risk - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

114 Page 0 of (RRs) and % confidence intervals (CIs), using the M-H risk difference approach for studies that did not have any events in either arm. For outcomes with event rates less than %, we used the Peto fixed effects method to estimate OR and % CI. For all outcomes, we examined statistical heterogeneity among studies using the I statistic and visual inspection of the forest plots (). Meta-regression analysis We hypothesised that anticoagulation may be more effective than antiplatelet therapy for preventing stroke. Thus, we expected that the effect of PFO closure vs. medical therapy would be largest in the RCTs that had proportionally more patients in the medical therapy group that were treated with antiplatelet therapy rather than anticoagulation. To explore this, we performed a random-effects metaregression of PFO closure vs. medical therapy, with the proportion of patients in the medical therapy arm who received anticoagulation as the independent variable. We used random-effects metaregression with the studies were weighed by the inverse of their variance. Modelling with external data from other indications Because few patients were randomised to PFO closure versus anticoagulation (N=) or anticoagulation versus antiplatelet agents (N=0) and events were infrequent, the estimates of effect of PFO closure versus anticoagulation were extremely imprecise. For instance, for ischaemic stroke the credible interval (Crl) around the relative effect included a relative reduction in events of 0% to a more than quadrupling of events (NMA OR 0., CrI 0.0 to.). We considered this information essentially uninformative, as did the Rapid Recommendations panel. We nevertheless considered the option of anticoagulation crucial to the decision, and therefore sought strategies for more informative estimates of effect. For ischaemic stroke, the most likely mechanism of cryptogenic stroke associated with PFO is stasisrelated thrombi, most notably paradoxical venous thromboembolism (VTE). The panel and systematic review team therefore deduced that the relative effects of anticoagulation versus antiplatelet therapy - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

115 Page of in the secondary prevention of VTE could provide credible estimates of effect for patients with cryptogenic stroke and PFO. For major bleeding, we deduced that the relative effects of VKAanticoagulation and low-dose ASA are similar to those seen in other common indications including VTE, heart failure, and atrial fibrillation and could therefore provide credible estimates of relative bleeding risk of antiplatelet agents (with or without PFO) and anticoagulants. Thus, the panel and systematic review team ultimately decided to use this evidence to provide indirect evidence of estimates of effect for three key outcomes (ischaemic stroke, major bleeding and pulmonary embolism). We therefore performed a secondary analysis that also included RCT evidence from other conditions (VTE, heart failure, and atrial fibrillation). For ischaemic stroke, we digitised Kaplan-Meier curves and extracted patient-level time-to-event data (). For illustrative purposes we present the individual patient data by treatment arm (PFO closure plus antiplatelet therapy, antiplatelet therapy alone, anticoagulation, and medical therapy left to the discretion of the treating physician). Each enrolled patient contributed equally to the survival curves. Subgroup analysis We planned subgroup analyses based on the echocardiography-determined shunt size and the presence of an atrial septal aneurysm. We hypothesised that patients with a larger shunt size will have a larger benefit with PFO closure than patients with a small shunt size and that patients with an atrial septal aneurysm will have a larger benefit with PFO closure than patients without an atrial septal aneurysm (). RESULTS Our systematic literature search yielded potentially relevant publications; ten trials presented in eight reports ultimately proved eligible (Figure, Appendix : etable) (,, -, -). Seven eligible multicenter RCTs published in 0 or later comparing PFO closure plus antiplatelet therapy - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

116 Page of versus medical therapy enrolled patients (range per RCT: 0 to 0 patients) (Table ). The CLOSE trial included three separate randomized trials (). In the first trial, patients eligible for all options were randomised to PFO closure (N = ), antiplatelet therapy (N=), or anticoagulation with a vitamin K antagonist or direct oral anticoagulant (N=0; % of which were a VKA). In the second trial, patient s ineligible for anticoagulation were randomised to PFO closure (N=) or antiplatelet therapy (N=). In the third trial, patients with contraindications to PFO closure were randomised to antiplatelet therapy (n=) or anticoagulation (n=). Of the remaining eligible RCTs, one specified that all patients in the group who were not randomised to PFO closure were treated with antiplatelet therapy (N=) (). Four RCTs allowed the treating physician to choose between antiplatelet and/or anticoagulation therapy for the patients randomised to medical therapy: a minority of these patients (range 0% to %) were prescribed anticoagulation at the time of discharge from initial hospital admission (,,, ). The last three studies compared antiplatelet therapy to anticoagulation (N=0) (,, ). One study reported a composite endpoint for ischaemic stroke and TIA; we therefore could not use the data in our meta-analyses of stroke (N=) (). However, we were able to use data from this RCT in analyses of death and major bleeding. Another RCT reported only a composite outcome of stroke and death (N=) (), with non-significant results suggesting a possible reduction with anticoagulation compared to antiplatelet therapy (HR 0., CI 0. to., p-value 0.). There is risk of bias in most studies due to a lack of blinding of medical personnel or patients regarding the placement of a PFO closure device (Appendix : efigure ). Also, half of the studies had incomplete data; we contacted the authors of three RCTs for additional outcome data (,, ). The lead author of the CLOSE study (JLM) provided additional unpublished data however the authors of the two remaining studies did not respond. We identified a recent rigorous systematic review of trials and participants for secondary prevention of VTE () and a recent rigorous systematic review of trials and participants - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

117 Page of across indications that provided a trustworthy estimate for an increase in major bleeds (); both reviews compared anticoagulant to antiplatelet therapy. Table presents the characteristics of the eligible studies. In most, the mean age was approximately years, approximately 0 to 0% were male, and approximately 0%, or more, had moderate or larger shunt. The median follow-up was. years with a range of. to. years. Table : Characteristics of patients in eligible studies Author n randomised Mean Age % Male Inclusion criteria PFO closure plus antiplatelet vs antiplatelet therapy Furlan (CLOSURE, 0.0. Cryptogenic 0) stroke, PFO, > yo and < 0yo Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > yo and < 0yo Meier (PC Trial, 0) Saver (RESPECT, 0) Sondergaard (REDUCE, 0) Lee (DEFENCE PFO, 0).. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, > yo and < 0yo. 0. Cryptogenic stroke, PFO, > yo and < 0yo 0.. Cryptogenic stroke, PFO, no age limit PFO closure plus antiplatelet vs anticoagulation Mas (CLOSE, 0) NA NA Cryptogenic stroke, PFO, > yo and < 0yo Anticoagulation vs antiplatelet therapy Homma (PICSS, 00) 0 ( with cryptogenic stroke).. PFO with or without cryptogenic stroke >0yo and < yo Moderate or higher shunt (%) () Atrial septal aneurysm > 0mm (%)() Most common device used for closure. (). STARFlex 00%. (). Amplatzer %. (). () Amplatzer 00%. (). () Amplatzer 00%.0 () NR for AP group Cardioform % NA 0. Amplatzer 00% NA NA NA.% ().% NA Mas (CLOSE, 0)..0 Cryptogenic stroke, PFO, > NA NA NA - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

118 Page of yo and < 0yo Shariat (0).. Cryptogenic stroke, PFO, > yo NA NA NA. Shunt size was measured based on the number of microbubbles in the left atrium within cycles of being seen in the right atrium on transthoracic or transoesophageal echocardiography. Greater than or equal to Microbubbles. Greater than or equal to 0 Microbubbles. Greater than or equal to 0 Microbubbles. Size of shunt not clearly defined. At least microbubble. Atrial septal aneurysm was assessed on transoesophageal echo and was defined as septal mobility or protrusion. Atrial septal aneurysm greater than mm. Atrial septal aneurysm not clearly defined % Intrasept PFO occluder, % STARFlex septal closure System, % Premere, % Amplatzer cribriform occluder, % Figulla flex II PFO occluder, % Atriasept II occluder, % Gore helex septal occluder, % Amplatzer AS occluder, % Figulla flex II UNI occluder, % Figulla flex II ASD occluder % Gore helex septal occluder NA Not available PFO closure plus antiplatelet therapy versus antiplatelet therapy alone Table provides estimates of effect and certainty of evidence for all patient-important outcomes, including, as presented subsequently, complications of PFO-closure. PFO closure plus antiplatelet therapy reduced the risk of ischaemic stroke compared to antiplatelet therapy alone (NMA OR 0., 0.0 to 0.; risk difference per 000 patient-years followed for years [RD]: -, % confidence interval [CI] -00 to -; moderate certainty) (Appendix : efigure ). Along with the three RCTs in which all medical patients received only antiplatelet therapy (,, ), we included a meta-regression model data from an additional RCTs that enrolled patients in which more than 0% of medically treated patients received anticoagulation (Figure ) (,,, ). The reduction in stroke with PFO closure decreased as the proportion of patients receiving anticoagulation in the medical therapy arm increased (p = 0.0). Figure presents a Kaplan-Meier curve of individual patient time-to-event data for each of the randomised interventions, including PFO closure plus antiplatelet versus antiplatelet therapy alone - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

119 Page of and is again consistent with large relative reductions in hazard with PFO closure versus antiplatelet therapy and smaller benefits of PFO closure when compared to mixed populations of patients receiving anticoagulants and antiplatelet agents. PFO closure did not appear to reduce the risk of TIA compared to antiplatelet therapy alone: NMA OR 0., CrI 0.,.; RD -, - to +; moderate certainty (Table, Appendix : efigure ). Systemic emboli were rare: there were events in one study (), and none in another (); we therefore calculated the risk difference directly. There was no important difference between PFO closure and antiplatelet therapy: NMA OR 0., CrI 0.,.; RD -, - to + per,000 patients; high certainty (Table, Appendix : efigure ). Death occurred infrequently: in the PFO closure group a median of per 000 patients died over a period of years. The relative effect estimate for mortality was very imprecise, and the absolute estimates included a small increase or decrease in deaths: NMA OR., CrI 0. to.; RD +, CI - to +; moderate certainty (Table, Appendix : efigure ). The risk of major bleeding did not differ significantly between the PFO closure plus antiplatelet therapy and antiplatelet therapy alone groups: NMA OR 0., CI 0.0 to.; RD -, CI - to +, moderate certainty (Table, Appendix : efigure ). Pulmonary embolism was rare and no more frequent in the PFO closure group (/, 0.%) than the antiplatelet therapy alone group (/, 0.%). No additional NMA evidence was available for pulmonary embolism because none of the RCTs that included an anticoagulation arm reported pulmonary emboli; thus, we present a pair-wise estimate for PFO closure vs. antiplatelet therapy alone: Peto OR.0, CI 0.0,.; RD +0, CI - to +, high certainty (Table, Appendix : efigure ). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

120 Page of Table : GRADE summary of findings of PFO closure plus antiplatelet therapy vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome (Timeframe) Ischaemic stroke (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Persistent x atrial fibrillation or Flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse events (Standardized to year) Pulmonary embolism (Standardized to years) Transient ischaemic attack (Standardized to years) Systemic embolism (Standardized to years) Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Absolute effect estimates per 000 patient-years Antiplatelet therapy 00 per 000 PFO closure plus antiplatelet therapy per 000 Difference: fewer (CI % 00 fewer* - fewer) per 000 per 000 Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Difference: more (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Difference: 0 fewer (CI % fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer* - more) Certainty in effect estimates (Quality of evidence) Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious risk of bias Moderate Due to serious risk of bias High High Moderate Due to serious imprecision - High Plain text summary PFO closure plus antiplatelet therapy probably results in a large decrease in ischemic stroke There is probably little or no difference in death There is probably little or no difference in major bleeding PFO closure plus antiplatelet therapy probably increases persistent atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increase device or procedure related adverse events PFO plus antiplatelet therapy has no effect on pulmonary embolism There is probably little or no difference in transient ischaemic attack There is little or no difference in systemic embolism : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

121 Page of Note: The baseline risk for PFO closure was used to estimate the absolute effect in the antiplatelet arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and thus allowing ease in comparison.. Risk of bias: No serious. Despite inadequate/lack of blinding of participants and personnel, resulting in potential for performance bias, we decided not to downgrade since we rated ischaemic stroke as an objective outcome (borderline decision). Inconsistency: No serious. Borderline decision I %, not rated down. Imprecision: Serious. Low number of events.. Imprecision: Serious. Wide confidence intervals, included appreciable harm. Low number of events.. Imprecision: Serious. Low number of events.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Inconsistency: No serious. Inconsistency: study as high 0/00 and as low as 0/000., Point estimates vary widely. Not rated down.. Imprecision: Serious. Wide confidence intervals, included both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years. PFO closure plus antiplatelet therapy versus anticoagulation Table provides estimates of effect and quality of evidence for all patient-important outcomes including, as presented below, complications of PFO-closure. One RCT randomised patients to PFO closure plus antiplatelet therapy (n=) or anticoagulation (n=0) (). In the NMA, compared with anticoagulation, PFO closure did not significantly reduce the risk of ischaemic stroke, but the CrI around the relative effect was very wide (NMA OR 0., CrI 0.0 to.; RD: -, % CI - to +0; low certainty). Figure presents a Kaplan-Meier curve of individual patient time-to-event data for each of the randomised interventions, including PFO closure plus antiplatelet versus anticoagulation alone. Results from the meta-regression analysis described previously suggest that PFO closure was less effective relative to medical therapy as the proportion of patients receiving anticoagulation increased (Figure ). To complement the above analyses, we added the effect estimate from a systematic review of RCTs comparing low-dose ASA to anticoagulation with a VKA for the secondary prevention of VTE to the network meta-analysis (). Similar to the primary analysis, the analysis with the external evidence failed to show a difference between PFO closure and anticoagulation for ischaemic stroke, with a point estimate substantially closer to.0: NMA OR 0., CI 0. to.; RD: -, -0 to +; low - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

122 Page of certainty (Table, Appendix : efigure ). For this complementary analysis, we rated down our certainty in the evidence to low because of very serious indirectness because this analysis relies on the assumption that the relative effect of anticoagulation versus antiplatelet therapy is the same for secondary prevention VTE as it is for secondary prevention of cryptogenic stroke in patients with a PFO. There was no important difference in TIA: NMA OR., CrI 0.0 to.; RD +, CI - to +; moderate certainty (Table, Appendix : efigure ). No patient experienced a systemic embolism in either arm of the RCT that included an anticoagulation arm (Appendix : efigure ). Few patients randomised to PFO closure plus antiplatelet therapy experienced a pulmonary embolism (median risk per 000 patients over years). The RCT that randomised patients to PFO closure versus anticoagulation did not measure pulmonary emboli (). Using external evidence from a systematic review of RCTs that compared ASA to anticoagulation with a VKA for secondary prevention of VTE in the NMA, PFO closure plus antiplatelet therapy probably has a higher risk of pulmonary embolism than anticoagulation: RD +, CI + to +; moderate certainty (Table, Appendix : efigure ). Patients randomised to PFO closure plus antiplatelet therapy had a lower risk of major bleeding than those randomised to anticoagulation: NMA OR 0., CI 0.0 to 0.; RD -0, CI - to -, moderate certainty (Table, Appendix : efigure ). Adding the effect estimate for major bleeding of low-dose ASA compared to anticoagulation with a VKA from a systematic review of RCTs enrolling patients with atrial fibrillation, VTE, or heart failure () to the NMA, resulted in an almost identical point estimate, but a narrower confidence interval: OR 0., CrI 0. to 0.; RD -, CI - to -; moderate certainty (Table ). There was no difference in death between PFO closure and anticoagulation (RD -, - to +, moderate certainty) (Table ). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

123 Page of Table : Summary of GRADE evidence profile of PFO closure plus antiplatelet therapy vs anticoagulation in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major bleeding (Standardized to years) Major bleeding - modelling data from VTE literature (Standardized to years) Persistent x atrial fibrillation or flutter (Standardized to year) Transient or paroxysmal atrial fibrillation or flutter (Standardized to year) Device or procedure related adverse event (Standardized to year) Transient ischaemic attack (Standardized to years) Pulmonary embolism - modelling data from VTE Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % 0. -.) Absolute effect estimates per 000 patientyears Anticoagulation per 000 PFO closure plus antiplatelet therapy per 000 Difference: fewer (CI % fewer* - 0 more) per 000 per 000 Relative risk: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Relative risk:. (CI %. -.) Based on data from 0 patients in studies Follow up. years Risk difference: 0.0 (CI % ) Based on data from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio:.0 (CI %. -.0) Difference: fewer (CI % 0 fewer - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: 0 fewer (CI % fewer* - fewer) per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: more per 000 (CI % more - more) per 000 per 000 Difference: more per 000 (CI % more - more) 0 per 000 per 000 Difference: more per 000 (CI % more - 0 more) per 000 per 000 Difference: more per 000 (CI % fewer* - more) per 000 per 000 Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to serious imprecision and serious indirectness Moderate Due to serious imprecision Moderate Due to serious imprecision Moderate Due to serious indirectness Moderate Due to serious risk of bias Moderate Due to serious risk of bias High Moderate Due to serious imprecision Moderate Due to serious - Plain text summary There may be little or no difference in ischaemic stroke There may be little or no difference in ischaemic stroke There is probably little or no difference in death PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably decreases major bleeding PFO closure plus antiplatelet therapy probably increases nontransient atrial fibrillation PFO closure plus antiplatelet therapy probably increases transient atrial fibrillation PFO closure plus antiplatelet therapy increases device or procedure related adverse events There is probably little or no difference in transient ischaemic attack There is probably little or no difference in : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

124 Page 0 of literature (Standardized to years) Systemic embolism (Standardized to years) Odds Ratio:.0 (CI % ) Direct evidence in NMA from patients in studies Follow up. years Difference: more per 000 (CI % more - more) 0 per per 000 Difference: 0 fewer per 000 (CI % fewer - more) indirectness Moderate Due to serious imprecision 0 pulmonary embolism There is probably little or no difference in systemic embolism Note: The baseline risk for PFO closure was used to estimate the absolute effect in the anticoagulation arm. The baseline risk in the PFO arm was calculated based on the median risk of the outcome in the six RCTs included. This allowed for consistency in the absolute effect estimate in the PFO closure arms in table and and the anticoagulation arms in table and allowing for ease in comparison.. Imprecision: Very Serious. Wide confidence interval. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm.. Imprecision: Serious. Wide confidence intervals, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence interval, included a not important benefit. Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Risk of bias: Serious. Not clearly stated how this was measured or assessed with prolonged ECG monitoring. Also, it is not clear for all events whether it was transient or persistent.. Imprecision: Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events. x Defined as persistent according to the study definition or requiring a cardioversion attempt *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event In the first year after procedure rather than years VTE, venous thromboembolism; AF, atrial fibrillation; CHF, congestive heart failure Complications of PFO closure PFO closure, when compared to medical therapy, probably substantially increases the risk of atrial fibrillation (including transient, persistent, and paroxysmal): six RCTs with 0 patients; RR.0, % confidence interval (CI). to.0; risk difference per 000 patients (RD) +, CI + to +; moderate certainty (Table, Appendix : efigure ). All six studies assessed persistent atrial fibrillation at a follow-up of.0 to. years. PFO closure probably increases the risk of persistent atrial fibrillation: RR., CI. to.; RD +, CI + to +; moderate certainty (Table, Appendix : efigure ). PFO closure also probably increases the risk of transient atrial fibrillation: RR., CI. to.0; RD +, CI + to +; moderate certainty (Table, Appendix : efigure ). The studies were limited by risk of bias because they did not report sufficient detail to know how persistent atrial fibrillation was detected (Tables and ). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

125 Page of Serious device or procedure-related adverse events occurred in approximately per 000 patients, CI to 0, high certainty (Table, Appendix : efigure ). The most common device or procedurerelated complications were vascular complications (%), conduction abnormalities (%), device dislocation (0.%), and device thrombosis (0.%). Although serious, air embolism (0.%), cardiac tamponade (0.%), and cardiac perforation (0.%) were rare (Tables and ). No deaths were attributed to the procedure or the device placement (Tables and ). Anticoagulation versus antiplatelet therapy Table provides estimates of effect and certainty of evidence for all patient-important outcomes comparing the two medical therapies. There may be fewer ischaemic strokes in patients randomised to anticoagulation than to antiplatelet therapy, but the CI included no effect: NMA OR 0., CrI 0.0 to.; RD: -, CI -00 to +; low certainty (Table, Appendix : efigure ). Figure presents a Kaplan Meier curve of individual patient time-to-event data for each of the randomized interventions, including anticoagulation versus antiplatelet therapy suggesting a lower rate of stroke in patients receiving anticoagulant than antiplatelet therapy. The complementary model including external evidence from a systematic of RCTs comparing lowdose ASA to anticoagulation with a VKA for secondary prevention of VTE yielded a somewhat larger reduction in strokes with anticoagulants and substantially narrowed the CI: OR 0., CrI 0.0 to 0.; RD -, CI - to -; low certainty (Table ) (). There may be little or no difference in risk of TIA between anticoagulation and antiplatelet therapy (NMA OR 0., CrI 0. to.; RD -, CI - to +; low certainty (Table, Appendix : efigure ). There were no reported systemic emboli, although it is not clear what the monitoring and ascertainment processes were. Our analysis suggested more major bleeding events among patients randomised to anticoagulation than to antiplatelet therapy, but the CI included no effect: NMA OR.0, CI 0. to.; RD +, : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

126 Page of to +; moderate certainty (Table, Appendix : efigure ). Including external evidence from a systematic review of RCTs comparing low-dose ASA to anticoagulation with a VKA in patients with atrial fibrillation, VTE, and heart failure yielded a very similar point estimate and substantially narrowed the CI: OR., CI. to.; RD +, CI + to +; moderate certainty (Table ) (). The RCT that included an anticoagulation arm did not report pulmonary emboli; the risk of pulmonary embolism was low in other RCTs that included an antiplatelet arm (median per 000 patient-years over years). External evidence from a systematic review of secondary prevention of VTE suggests that the risk of pulmonary embolism is probably lower with anticoagulation than antiplatelet therapy: RD -, CI - to -; moderate certainty (). Deaths were extremely rare and there was no appreciable difference between the anticoagulation and antiplatelet therapy: RD +0, CI - to +, low certainty (Table, Appendix : efigure ). Table : Summary of GRADE evidence profile of anticoagulation vs antiplatelet therapy alone in patients with cryptogenic stroke Outcome Timeframe Ischaemic stroke (Standardized to years) Ischaemic stroke - modelling data from VTE literature (Standardized to years) Death (Standardized to years) Major Bleeding (Standardized to years) Major bleeding - modelling data from VTE literature Study results and measurements Odds Ratio: 0. (CI % ) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI % 0. -.) Direct evidence in NMA from 0 patients in studies Follow up. years Odds Ratio:. (CI %. -.) Absolute effect estimates per 000 patient-years Antiplatelet 00 y per 000 Anticoagulation per 000 Difference: fewer (CI % 00 fewer* - more) 00 per 000 per 000 Difference: fewer (CI % fewer - fewer) per 000 per 000 Difference: 0 more (CI % fewer* - more) per 000 per 000 Difference: more (CI % fewer - more) per 000 per 000 Certainty in effect estimates (Quality of evidence) Low Due to very serious imprecision Low Due to very serious indirectness Low Due to very serious imprecision Moderate Due to serious imprecision Moderate Due to serious - Plain text summary Anticoagulation may decrease ischaemic stroke Anticoagulation may decrease ischaemic stroke There may be little or no difference in death Anticoagulation probably increases major bleeding Anticoagulation probably increases major bleeding : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

127 Page of (Standardized to years) Transient ischaemic attack (Standardized to years) Pulmonary embolism - modelling data from VTE literature (Standardized to years) Systemic embolism (Standardized to years) Odds Ratio: 0. (CI % 0. -.) Direct evidence in NMA from patients in studies Follow up. years Odds Ratio: 0. (CI % ) Difference: more (CI % more - more) per 000 per 000 Difference: fewer (CI % fewer* - more) per 000 per 000 Difference: fewer (CI % fewer - fewer) Not estimable Direct evidence in NMA from patients in studies Follow up. years 0 per per 000 Difference: 0 fewer (CI % fewer - more) indirectness Low Due to very serious imprecision Moderate Due to serious indirectness Moderate Due to serious imprecision There may be little or no difference in transient ischaemic attack There is probably little or no difference in pulmonary embolism. There is probably little or no difference in systemic embolism Note: The baseline risk for antiplatelet was obtained using calculated absolute effect estimate. This was done to maintain consistency across the tables. The calculated baseline risk (0%) was similar to the baseline risk calculated using the median of studies included (%). Imprecision: Very Serious. Wide confidence interval, includes appreciable harm. Low number of events.. Indirectness: Very Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable benefit and harm. Low number of events.. Imprecision: Serious. Wide confidence intervals, Low number of events.. Indirectness: Serious. In addition to the direct evidence from randomised trials in patients with PFO and a cryptogenic ischaemic stroke, we additionally considered external evidence from randomised trials that assessed the impact of anticoagulation vs. antiplatelet therapy for the secondary prevention of venous thromboembolism. We did not rate down with two levels because we felt the outcome is less indirect compared to VTE literature than Ischaemic stroke.. Imprecision: Very Serious. Wide confidence interval, includes both appreciable harm and benefit. Low number of events. *: The calculated confidence interval using risk difference, because of uncertainty in the point estimates, permits reductions greater than the point estimates in the PFO group. To avoid confusion, we have truncated to present the maximum reduction as equal to the PFO event rate. Subgroup Analyses Data proved insufficient to perform the prespecified subgroup analyses when anticoagulation and antiplatelets were assumed to have different effects, as we had prespecified. We performed one posthoc meta-regression analysis to explore the effect of PFO shunt size on the relative effectiveness of PFO closure compared to medical therapy. Five RCTs reported ischaemic stroke and the proportion of patients with a moderate or large shunt vs. small shunt, all with slightly different definitions. PFO closure was more effective in the RCTs that enrolled a higher proportion of patients with a moderate or large shunt (interaction p=0.0) (Appendix : efigure ). However, this is confounded by the fact that the RCTs that enrolled a higher proportion of patients with moderate or large PFO shunts also - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

128 Page of had a larger proportion of patients with antiplatelet agents rather than anticoagulation (Appendix : efigure ). When both possible effect modifiers were included in the model neither was statistically significant: p=0. for proportion with moderate or large shunt and p=0. for proportion receiving anticoagulation; however, this model is severely underpowered with two effect modifiers and only five studies. DISCUSSION We found moderate certainty evidence that in patients less than 0 years old with a PFO and cryptogenic stroke, PFO closure plus antiplatelet therapy results in a substantial reduction in the risk of recurrent ischaemic stroke compared to antiplatelet therapy alone by approximately.% over years, but increases the risk of persistent atrial fibrillation (approximately.%) and device-related adverse events (approximately.%) in the first year after procedure (Table ). Although the evidence regarding anticoagulation versus alternatives is of low quality and comes in large part from indirect evidence, it is possible that anticoagulation and PFO closure may achieve a similar reduction in the risk of recurrent ischaemic stroke and thus appreciably fewer strokes than antiplatelet agents alone. Anticoagulation, compared to either PFO closure plus antiplatelet therapy or antiplatelet therapy alone probably increases the risk of major bleeding by approximately % over years and probably reduces the risk of pulmonary embolism by approximately 0.%. There does not appear to be an important difference in the risk of death or in the risk of systemic emboli between any of the interventions. Our results provide further strong support for the hypothesis that stasis-related paradoxical venous thromboemboli and/or intra-cardiac thrombi cause a large proportion of cryptogenic strokes in younger patients with PFO. Given that is the case, it is plausible, though uncertain, that anticoagulation has a similar relative benefit versus antiplatelet agents in preventing cryptogenic strokes in patients with PFO as it does in preventing recurrent VTE. Our results, including the meta- - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

129 Page of regression examining comparisons of PFO closure versus studies in which varying proportion of patients received anticoagulants (Figure ) support this inference. Only one of the RCTs included an arm in which all patients were offered anticoagulation or PFO closure; as a result, the direct evidence includes relatively few patients and very few events. Moreover, the evidence from studies of VTE is very indirect. Thus, we categorised the evidence regarding anticoagulation versus PFO closure, and versus antiplatelet therapy, in preventing stroke as low certainty (Tables and ). Resolving the uncertainty that currently bedevils decision-making will require larger RCTs that compare anticoagulation to PFO closure. A recent systematic review suggested that PFO closure may be more effective in patients with larger shunt (). We show that this subgroup analysis has low credibility because it is confounded by the anticoagulation in the patients randomised to medical therapy in RCTs with a higher proportion of patients with smaller shunts. PFO closure may be less effective relative to medical therapy when patients receive anticoagulation and/or have smaller shunts. The results of the NMA, in addition to indirect evidence from patients with a VTE, suggest that the subgroup effect by type of medical therapy may be the most credible explanation. PFO closure comes with infrequent but important risks: an approximately % to % chance of serious device or procedure-related complications and an approximately % increased incidence of atrial fibrillation, of which approximately half is persistent. Anticoagulation with VKAs carries a % to % increase in major bleeding over years in this patient population. The risk of major bleeding may be marginally lower with some direct acting oral anticoagulants than with VKAs (). Patients must also consider the important practical implications of taking anticoagulants, including limitations to diet and activities with an appreciable risk of trauma, possible drug interactions and, with VKAs, the need for repeat laboratory testing. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

130 Page of Strengths and limitations: Our study has several strengths. In contrast with recent systematic reviews summarising the recent RCTs on PFO closure (-); we separately addressed the three management alternatives of PFO closure plus antiplatelet therapy, anticoagulation alone, and antiplatelet therapy alone. In doing so, we applied several analytical approaches, including network meta-analysis, meta-regression, and individual patient analyses from survival curves, as well as judicious use of external evidence, to bring to bear all the relevant evidence for decision-making. In addition, we used the GRADE approach to assess the certainty of evidence informing the estimates in the study. Our review also includes one recently published study not included in prior reviews. We thus summarised all of the highest quality available evidence, providing optimal insight into the comparative effects of the alternative management strategies for patients with PFO who have experienced a cryptogenic stroke. The results are limited primarily by the available evidence. Of the ten RCTs that we included in this review, three compared PFO closure to a medical therapy arm that was not predefined the key choice between antiplatelet and anticoagulation was left to the discretion of the physician and patient. As corroborated in our evidence synthesis, there are probably important differences between anticoagulation and antiplatelet therapy. As a result, these three RCTs cannot directly inform the clinical decisions in which antiplatelet therapy and anticoagulation are two distinct choices, and we could not include them in many of the analyses bearing on the choice between PFO closure and antiplatelet therapy. Our meta-regression analysis that included these studies suggested an inverse relationship between stroke reduction and proportion of patients in the medical therapy arms prescribed anticoagulation, thus providing support for the benefit of anticoagulants versus antiplatelet therapy (Figure ). The NMA also has limitations: the network is sparsely populated (Appendix : efigure ), it includes patients with no contraindications to any of three management strategies, those with patients with contraindications to anticoagulants, and those with contraindications to PFO. Nevertheless, we found - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

131 Page of no suggestion of incoherence between direct and indirect estimates in the NMA and suggest that it provides the best estimates available (Appendix, etable ). The applicability of these findings to older patient populations, particularly those over 0 years of age, and those with traditional cerebrovascular risk factors such as exposure to diabetes, hypertension, and hyperlipidaemia, is uncertain. The proportion of patients with a cryptogenic stroke caused by paradoxical emboli rather than large vessel atheroembolism or intracardiac thrombus almost certainly decreases with age. Thus, we expect that the benefits of PFO closure would be smaller in older patients and the harms (e.g. atrial fibrillation) greater. CONCLUSIONS In patients less than 0 years old with cryptogenic stroke and a PFO, PFO closure plus antiplatelet therapy probably confers a substantial reduction in the risk of ischaemic stroke recurrence compared to antiplatelet therapy alone, with a modest risk of persistent atrial fibrillation or flutter and serious device or procedure-related complications. Based on low certainty evidence, anticoagulation may confer a similar reduction in the risk of ischaemic stroke compared to PFO closure, but likely confers a modest increased risk of major bleeding. Future RCTs comparing anticoagulation to PFO closure would substantially reduce uncertainty for several critical outcomes. Acknowledgement: We thank members of the BMJ Rapid Recommendations panel for critical feedback on outcome selection, subgroup selection, GRADE judgments, and manuscript feedback. We thank Rachel Couban for helping develop the search strategy. Contributors: GHG and RAS conceived the study idea. HM performed the literature search and data analysis. HM, RAS, TA, GHG, POV interpreted the data analysis. HM, RAS, and GHG wrote the first draft of the manuscript. TS, LL, and MF acquired data and judged risk of bias in the studies. FF extracted patient level survival data from Kaplan-Meier curves. LG provided statistical advice. RAS, GHG, TA, POV, TK, JLM, MF critically reviewed the manuscript. HM had full access to all of the data - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

132 Page of in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. HM is guarantor. Funding: None Competing interests: All authors have completed the BMJ Rapid Recommendations disclosure form, which asks about any possible financial, intellectual, and professional conflicts of interest (available upon request). To summarize, JLM has received consulting honoraria from Bayer, Bristol Meyer Squibb, Boehringer-Ingelheim, Daichii-Sankyo, GECKO, and Servier. HM, RAS, TK, PV, TA, and GHG are also panel members of the linked Rapid Recommendation guideline panel. LG, FF, MF, and TS do not have any competing interests to declare. Ethical approval: Not required Data sharing: Extra data can be accessed via the Dryad data repository at with the doi: 0.0/dryad.ng0rc Transparency declaration: The lead author (HM) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

133 Page of Figure Legend: Figure. PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke Figure. Meta-regression curve based on the proportion of anticoagulant in the medical therapy arm for ischaemic stroke Figure. Combined Kaplan-Meier curves with individualized patient data based on the type of intervention for ischaemic stroke Foot note Figure. ) Y-axis is truncated from 0% to 00% Event-free Survival ) Mixed medical therapy includes studies where the proportion of antiplatelet agents was less than 0% and the proportion of anticoagulant was greater than % ) Proportion of patients: PFO Closure + antiplatelet therapy (N= ; 0%), Mixed medical therapy (N= ; %), Antiplatelet therapy (N= ; %), and Anticoagulation (N= 0; %) ) K-M curves were available for the outcome of ischaemic stroke in the CLOSE study () (PFO closure, anticoagulation, and antiplatelet), the PC Trial () (PFO closure and mixed medical therapy), the RESPECT trial () (PFO closure and mixed medical therapy), and the REDUCE trial () (PFO closure and antiplatelet). - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

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135 Page of Unit) HHIR. Search Strategies for EMBASE in Ovid Syntax [Website]. [updated February, 0. Available from: Unit) HHIR. Search Filters for MEDLINE in Ovid Syntax and the PubMed translation [Website]. [updated February, 0. Available from: Akl E, Sun, X, Busse, JW, et al. Specific instructions for estimating unclearly reported blinding status in randomised trials were reliable and valid. Journal of Clinical Epidemiology. 0;:-.. Higgins J, Altman, DG, Gotzsche, PC, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. British Medical Journal. 0;:d.. Guyatt G, Oxman, AD, Vist, GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. British Medical Journal. 00;:-.. Brignardello-Petersen R, Bonner, A, Alexander, PE, et al. Advances in the GRADE approach to rate the certainty in estimates from a network meta-analysis. Journal of Clinical Epidemiology. 0;:-.. Guyatt G, Oxman, AD, Kunz, R, et al. Rating the quality of evidence-indirectness. Journal of Clinical Epidemiology. 0;():0-0.. Gelman A, Rubin, DB. Inference from Iterative Simulation Using Multiple Sequences. Statistical Science. ;:-.. vanvalkenhoef G, Dias, S, Ades, AE, et al. Automated generation of node-splitting models for assessment of inconsistency in network meta-analysis. Research Synthesis Methods. 0;: Dias S, Sutton, AJ, Ades, AE, et al. Evidence synthesis for decision making : a generalized linear modeling framework for pairwise and network meta-analysis of randomized controlled trials. Medical Decision Making. 0;():0-.. vanvalkenhoef G, Lu, G, debrock, B et al. Automating network meta-analysis. Research Synthesis Methods. 0;:-.. Guyot P, Ades, AE, Ouwens, MJ, Welton, NJ. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves. BMC Med Res Methodol. 0;().. Mas J, Arquizan, C, Lamy, C, et al. Recurrent Cerebrovascular Events Associated with Patent Foramen Ovale, Atrial Septal Aneurysm, or Both. New England Journal of Medicine. 00;:0-.. Shariat A, Yaghoubi, E, Farazdaghi, M, et al. Comparison of medical treatments in cryptogenic stroke patients with patent foramen ovale: A randomized clinical trial. Journal of Research in Medical Sciences. 0;():-.. Homma S, Sacco, RL, DiTullio, MR, et al. Effect of Medical Treatment in Stroke Patients With Patent Foramen Ovale: Patent Foramen Ovale in Cryptogenic Stroke Study. Circulation. 00;0:-.. Lee P, Song, JK, Kim, JS, et al. Cryptogenic Stroke and High-Risk Patent Foramen Ovale: The DEFENSE- PFO Trial. Journal of the American College of Cardiology. 0;doi: 0.0/j.jacc Vazquez F, Gonzalez, JP, LeGal, G, et al. Risk of major bleeding in patients receiving vitamin K antagonists or low doses of aspirin. A systematic review and meta-analysis. Thrombosis Research. 0;:-.. De Rosa S, Sievert, H, Sabatino, J, et al. Percutaneous closure versus medical treatment in stroke patients with patent foramen ovale. Annals of Internal Medicine. 0:-.. Mojadidi M, Elgendy, AY, Elgendy, IY, et al. Transcatheter Patent Foramen Ovale Closure After Cryptogenic Stroke. JACC Cardiovascular Interventions. 0;0(): Vaduganathan M, Qamar, A, Gupta, A, et al. Patent Foramen Ovale Closure for Secondary Prevention of Cryptogenic Stroke: Updated Meta-Analysis of Randomized Clinical Trials. The American Journal of Medicine. 0;S000-():-.. Shah R, Nayyar, M, Jovin, IS, et al. Device closure versus medical therapy alone for patent foramen ovale in patients with cryptogenic stroke. Annals of Internal Medicine. 0: : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

136 Page of PRISMA flow diagram of studies included in review treatment of patients with PFO and cryptogenic stroke xmm (00 x 00 DPI) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

137 Page of Meta-regression curve based on the proportion of anticoagulant in the medical therapy arm for ischaemic stroke 0xmm (00 x 00 DPI) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

138 Page of Combined Kaplan-Meier curves with individualized patient data based on the type of intervention for ischaemic stroke Footnote: ) Y-axis is truncated from 0% to 00% Event-free Survival ) Mixed medical therapy includes studies where the proportion of antiplatelet agents was less than 0% and the proportion of anticoagulant was greater than % ) Proportion of patients: PFO Closure + antiplatelet therapy (N= ; 0%), Mixed medical therapy (N= ; %), Antiplatelet therapy (N= ; %), and Anticoagulation (N= 0; %) ) K-M curves were available for the outcome of ischaemic stroke in the CLOSE study () (PFO closure, anticoagulation, and antiplatelet), the PC Trial () (PFO closure and mixed medical therapy), the RESPECT trial () (PFO closure and mixed medical therapy), and the REDUCE trial () (PFO closure and antiplatelet). xmm (00 x 00 DPI) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

139 Page of Appendices Legend: Appendix : Summary of search and strategies Appendix : Tables etable : Characteristics of eligible studies Appendix : Figures efigure : Risk of bias of included randomised controlled trials Appendix : PFO closure vs antiplatelet forest plots (Direct evidence only) efigure : Ischaemic stroke efigure : TIA efigure : Systemic emboli efigure : Death efigure : Major bleeding efigure : Pulmonary embolism Appendix : PFO closure vs anticoagulation forest plots (Direct evidence only) efigure : Ischaemic stroke efigure : TIA efigure : Systemic emboli efigure : Pulmonary emboli efigure : Major bleeding Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) efigure : All atrial fibrillation efigure : Persistent atrial fibrillation efigure : Transient atrial fibrillation efigure : Serious device or procedure related Appendix : Anticoagulation vs antiplatelet forest plots (Direct evidence only) efigure : Stroke efigure : TIA efigure : Major bleeding efigure : Death Appendix : Meta-regression and NMA Figures efigure : Meta-regression evaluating the effect of moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy efigure : Meta-regression evaluating the proportion of patients on anticoagulation compared to those with moderate or higher shunt size efigure : Network of included RCTs with available direct comparisons for ischaemic stroke. Appendix : NMA Table etable : Direct and indirect estimates of effects for the network meta-analysis - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

140 Page of Appendix : Summary of search and strategies Database: OVID Medline Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R) to Present Search Strategy: cerebrovascular disorders/ or basal ganglia cerebrovascular disease/ or exp brain ischemia/ or carotid artery diseases/ or carotid artery thrombosis/ or intracranial arterial diseases/ or cerebral arterial diseases/ or exp "intracranial embolism and thrombosis"/ or exp stroke/ () (isch?emi$ adj (stroke$ or apoplex$ or cerebral vasc$ or cerebrovasc$ or cva or attack$)).tw. () ((brain or cerebr$ or cerebell$ or vertebrobasil$ or hemispher$ or intracran$ or intracerebral or infratentorial or supratentorial or middle cerebr$ or mca$ or anterior circulation) adj (isch?emi$ or infarct$ or thrombo$ or emboli$ or occlus$ or hypoxi$)).tw. (0) (TIA or TIAs).mp. () Embolism, Paradoxical/ () heart atria/ and (embolism/ or thromboembolism/) () ((paradoxic$ or crossed) adj embolism$).tw. () (cryptogenic adj stroke).tw. () or/- (0) Annotation: population part : stroke or cryptogenic stroke 0 heart septal defects, atrial/ or foramen ovale, patent/ () heart septum/ or atrial septum/ or foramen ovale/ (00) (patent foramen ovale or PFO).tw. () (atrial sept$ adj defect$).tw. (0) ((right to left or R-L or venous to arterial or venous-arterial or V-A) adj shunt).tw. () or/0- (0) Annotation: population part : PFO and () Annotation: population Stroke and PFO limit to yr="0 -Current" (0) Annotation: since last review limit to ("therapy (maximizes sensitivity)" or "therapy (maximizes specificity)" or "therapy (best balance of sensitivity and specificity)") () randomised controlled trial.pt. (0) 0 controlled clinical trial.pt. () randomised.ab. (0) placebo.ab. (00) drug therapy.fs. (00) randomly.ab. () trial.ab. () groups.ab. () or/- (0) exp animals/ not humans.sh. () not () 0 and () or 0 () Annotation: Population stroke and PFO limit to since 0 and RCTs "prostheses and implants"/ or septal occluder device/ () Wound Closure Techniques/ () - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

141 Page of (close or closure or septal occluder).tw. (0) (cardioseal or gore helex or amplatzer or starflex or cardia or intrasept or premere).tw. (0) su.fs. () or/- () Annotation: Septal occluder device as per Liu 0 CDSR exp Anticoagulants/ (0) anticoagulant$.tw. () 0 (acenocoumarol$ or dicoumarol$ or ethyl biscoumacetate$ or phenprocoumon$ or warfarin$ or ancrod$ or citric acid$ or coumarin$ or chromonar$ or coumestro$ or esculi$ or ochratoxin$ or umbelliferone$ or dermatan?sul$ or dextran$ or edetic acid$ or enoxaparin$ or gabexate$ or heparin$ or lmwh$ or nadroparin$ or pentosan sulfuric polyester$ or phenindione$ or protein c or protein s or tedelparin$).tw. (0) (argatroban or tinzaparin or parnaparin or reviparin or danaparoid or lomoparan or org 0 or mesoglycan or polysaccharide sulphate$ or sp or sp- or md0 or md-0 or cy or cy- or cy or cy-).tw. () (Marevan or Fragmin$ or Fraxiparin$ or Klexane).tw. () exp Pipecolic acids/ae, tu () exp Vitamin K/ai () Vitamin K antagonist$.tw. () exp Antithrombins/ae, pd, de, tu () exp Blood coagulation factors/ai, de (00) exp Blood coagulation/de () (anticoagulat$ or antithromb$).tw. (0) 0 or/- () Annotation: anticoagulants as per Berge 00 CDSR Factor Xa Inhibitors/ () Dabigatran/ () Rivaroxaban/ (0) (dabigatran or rivaroxaban or apixaban or edoxaban).mp. (0) anti-factor Xa.mp. () (factor Xa adj (antag* or inhibit*)).mp. () novel oral anticoagulant*.mp. (0) noac.mp. () noacs.mp. () 0 pradax.mp. () pradaxa.mp. () BIBR-.mp. () BIBR-ZW.mp. () xarelto.mp. () BAY -.mp. () BMS-.mp. () eliquis.mp. () lixiana.mp. () DU-.mp. () 0 DU-b.mp. () non-vitamin K.mp. () or/- (0) direct oral anticoagulant*.mp. () DOAC.mp. () DOACs.mp. (0) - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

142 Page of TSOAC.mp. () TSOACs.mp. [mp=title, abstract, original title, name of substance word, subject heading word, keyword heading word, protocol supplementary concept word, rare disease supplementary concept word, unique identifier, synonyms] (0) oral anticoagulant.mp. (0) (new or novel or direct or direct-acting or target-specific or targeted or non-vitamin K).mp. [mp=title, abstract, original title, name of substance word, subject heading word, keyword heading word, protocol supplementary concept word, rare disease supplementary concept word, unique identifier, synonyms] (0) 0 and (0) or or or or 0 () Annotation: NOACs or DOACs from 0 Canadian Cardiac Society GL search RC exp Platelet aggregation inhibitors/ (0) (antiplatelet$ or anti-platelet$ or antiaggreg$ or anti-aggreg$ or (platelet$ adj inhibit$) or (thrombocyt$ adj inhibit$)).tw. (00) (alprostadil$ or aspirin$ or dipyridamol$ or disintegrin$ or epoprostenol$ or iloprost$ or ketanserin$ or ketorolac tromethamine$ or milrinone$ or mopidamol$ or pentoxifyllin$ or procainamide$ or ticlopidine$ or thiophen$ or trapidil$).tw. () (acetyl salicylic acid$ or acetyl?salicylic acid or clopidogrel$ or picotamide$ or ligustrazine$ or levamisol$ or suloctidil$ or ozagrel$ or oky0 or oky-0 or defibrotide$ or cilostazol or satigrel or sarpolgrelate or kbt0 or kbt-0 or isbogrel or cv or cv- or triflusal).tw. () (Dispril or Albyl$ or Ticlid$ or Persantin$ or Plavix).tw. (0) exp Platelet glycoprotein gpiib-iiia complex/ai, de () (((glycoprotein iib$ or gp iib$) adj (antagonist$ or inhibitor$)) or GR0 or GR-0 or abciximab$ or tirofiban$ or eftifibatid$).tw. () (ReoPro or Integrilin$ or Aggrastat).tw. () 0 exp Platelet activation/de () exp Blood platelets/de () or/- (0) Annotation: antiplatelets as per Berge 00 CDSR or 0 or or () Annotation: Intervention block and () remove duplicates from () Central Date Run: /0/ ::. Description: ID Search Hits # MeSH descriptor: [Stroke] explode all trees # MeSH descriptor: [Cerebrovascular Disorders] explode all trees # (isch*emi* near/ (stroke* or apoplex* or cerebral next vasc* or cerebrovasc* or cva or attack*)) 00 # ((brain or cerebr* or cerebell* or vertebrobasil* or hemispher* or intracran* or intracerebral or infratentorial or supratentorial or middle next cerebr* or mca* or "anterior circulation") near/ (isch*emi* or infarct* or thrombo* or emboli* or occlus* or hypoxi*)) 0 # (tia or tias) 0 # MeSH descriptor: [Embolism, Paradoxical] explode all trees - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

143 Page of # ((paradoxic* or crossed) near/ embolism*) # (cryptogenic near/ stroke) # MeSH descriptor: [Heart Atria] explode all trees #0 MeSH descriptor: [Embolism and Thrombosis] explode all trees # # and #0 # atria* near/ (emboli* or thromboemboli*) 0 # # or # or # or # or # or # or # or # or # or # # MeSH descriptor: [Heart Septal Defects, Atrial] explode all trees # "patent foramen ovale" or PFO # atrial sept* near/ defect* 0 # (("right to left" or "R-L" or "venous to arterial" or "venous-arterial" or "V-A") near/ shunt) # # or # or # or # # # and # Publication Year from 0 to : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

144 Page 0 of Appendix : Tables etable : Characteristics of eligible studies PFO closure plus antiplatelet vs antiplatelet therapy Study, year Intervention Medical therapy Withdrawn or loss to follow-up Crossover from med therapy to PFO closure (%) Crossover from PFO closure to med therapy Percent PFO closure performed /patients in PFO cohort Percent technical success/pfo closure attempt Medical PFO (%) therapy (%) STARFlex Device. Clopidogrel for Furlan, 0 months and ASA for years ASA mg daily (%) Mas, 0 Meier, 0 Saver, 0 Sondergaard, 0 Lee, 0 PFO closure (Amplatzer.% X ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Amplatzer occluder. ASA - months. clopidogrel or ticlopidine - months Amplatzer occluder 00%. ASA -mg daily plus clopidogrel mg daily x months then ASA x months PFO Closure (Cardoiform Septal occluder %, Gore helex Septal occluder %) plus antiplatelet (ASA -mg daily, aggrenox, or clopidogrel. Clopidogrel 00mg x then daily x days for everyone PFO Closure (00% Amplatzer PFO occluder). Suggested DAPT for months with ASA 00mg and clopidogrel mg daily. However, up to treating physician. Could even use anticoagulation PFO closure plus antiplatelet vs anticoagulation Aspirin or clopidogrel or aspirin plus ER dipyridamole Antiplatelet (%) or anticoagulation (%) ASA, warfarin, clopidogrel (%), or ASA plus dipyridamole (%) Antiplatelet (ASA -mg daily, ASA plus dipyridamole, or clopidogrel. (00%) Antiplatelet with ASA or ASA and Clopidogrel mg daily, or ASA and Cilostazol 00mg daily. Could anticoagulate with warfarin (INR.0-.0) Study, year Intervention Control Withdrawn or loss to follow-up Crossover from antiplatelet to Crossover from anticoagulation - Percent technical success/pfo Percent technical success/pfo : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

145 Page of Mas 0 PFO closure (Amplatzer.% ) plus ASA mg daily and clopidogrel mg daily x months then aspirin or clopidogrel or aspirin plus ER dipyridamole Anticoagulation vs antiplatelet therapy PFO Closure plus antiplatelet Anticoagulation anticoagulation (%) to antiplatelet (%) closure attempts closure attempts Warfarin with target INR - (%) or direct oral anticoagulant (%) NA NA NA NA NA NA Study, year Intervention Control Withdrawn or loss to follow-up Anticoagulation (%) Antiplatelet (%) Crossover from antiplatelet to anticoagulation (%) Crossover from anticoagulation to antiplatelet (%) Aspirin or Mas 0 Warfarin with target INR - (%) or direct oral anticoagulant (%) clopidogrel or aspirin plus ER dipyridamole Shariat, 0 Warfarin.mg po daily (INR -) Aspirin 0mg po tid (00%) Homma (PICSS, 00) Warfarin (INR.-.) F/U months Aspirin mg po od.. NA NA % Intrasept PFO occluder, % STARFlex Septal Closure System, % Premere, % Amplatzer cribriform occluder, % Figulla Flex II PFO occluder, % Atriasept II occluder, % Gore Helex eptal occluder, % Amplatzer AS occluder, % Figulla Flex II UNI occluder, %Figulla Flex II ASD occluder NA = Not available - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

146 Page of Appendix : Figures efigure : Risk of bias of included randomised controlled trials - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

147 Page of Appendix : PFO closure vs antiplatelet therapy forest plots (Direct evidence only) efigure : Ischaemic stroke efigure : TIA efigure : Systemic embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

148 Page of efigure : Death efigure : Major bleeding efigure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

149 Page of Appendix : PFO closure vs Anticoagulation forest plots (Direct evidence only) efigure : Ischaemic stroke efigure : TIA efigure : Systemic embolism efigure : Pulmonary embolism - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

150 Page of efigure : Major bleeding - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

151 Page of Appendix : Complications of PFO closure vs medical therapy forest plots (Direct evidence only) efigure : All atrial fibrillation efigure : Persistent atrial fibrillation efigure : Transient atrial fibrillation - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

152 Page of efigure : Device or procedure related adverse events - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

153 Page of Appendix : Anticoagulation vs antiplatelet therapy forest plots (Direct evidence only) efigure : Ischaemic stroke efigure : TIA efigure : Major bleeding efigure : Death - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.

154 Page 0 of Appendix : Meta-regression and NMA Figures efigure : Meta-regression evaluating the effect of the proportion of participants with a moderate or higher shunt size on the effectiveness of PFO closure versus medical therapy in patients with a PFO and cryptogenic stroke. PFO closure was more effective in RCTs that had a higher proportion of patients with moderate or higher PFO shunts, p=0.0. Note, the shunt size was not reported in the DEFENSE-PFO Trial and thus it was not included in the analysis. - : first published as 0./bmjopen-0-0 on July 0. Downloaded from on March 0 by guest. Protected by copyright.