PVI and What Else for Persistent AF Lessons Learned from STAR AF 2 CCCEP 2015 October 31, New York

Transcription

1 PVI and What Else for Persistent AF Lessons Learned from STAR AF 2 CCCEP 2015 October 31, New York Atul Verma, MD FRCPC FHRS Director, Arrhythmia Services Southlake Regional Health Centre Faculty of Medicine University of Toronto, McGill University Affiliate Scientist, Li Ka Shing Knowledge Institute

2 Disclosures Moderate Support (honoraria, speaking bureau, research) St Jude Medical International Medtronic Inc. Biosense Webster Bayer Boehringer Ingelheim Advisory Board St Jude Medical International Biosense Webster Bayer Boehringer Ingelheim Pfizer/Bristol Meyers Squibb Acutus Medical Colibri Medical Devices Nicoya Medical Devices

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4 Background Ablation of persistent AF is challenging and typically has less favorable outcomes compared to paroxysmal AF To improve outcomes for persistent AF, guidelines suggest that operators should consider more extensive ablation based on linear lesions or complex fractionated electrograms in addition to PV isolation 1 Whether more extensive ablation improves outcomes is unclear 1 Calkins et al, Consensus Guidelines Catheter Ablation, Heart Rhythm 2012

5 Purpose To compare the efficacy of three different AF ablation strategies in patients with persistent AF*: (1) Pulmonary vein isolation (PVI) alone (2) PVI plus complex fractionated electrograms (PVI+CFE) (3) PVI plus linear ablation (PVI+Lines). * Defined as AF episode lasting > 7 days but less than 3 years

6 Methods - Patients 589 patients were recruited from 48 experienced ablation centers in 12 countries Inclusion: symptomatic persistent AF (a sustained episode > 7 days and < 3 years) refractory to at least one antiarrhythmic drug undergoing first-time ablation Exclusion: paroxysmal AF, sustained AF episode > 3 years, left atrial diameter > 60 mm

7 Methods Trial Design Patients were randomized 1:4:4 to the three strategies: PVI, PVI+CFE, PVI+Lines Patients were blinded to the strategy (single blind) Repeat ablation procedures allowed between 3-6 months using the same randomized strategy as the first ablation

8 Methods Ablation Strategy ** Complete elimination of CFE (not defragmentation) until termination or all CFE regions eliminated. CFE strategy Linear strategy ** Pre-specified pacing manoeuvres to determine linear block

9 Methods Follow-up Patients were followed for 18 months Visit, ECG and 24 hour Holter at 3, 6, 9, 12 and 18 months Weekly TTM transmissions for 18 months TTM transmissions every time symptoms felt Tele-ECG-Card, Vitaphone, Germany

10 Results - Ablation characteristics 79% of patients presented to EP lab in spontaneous AF Successful PV isolation obtained in 97% of all patients (all groups) CFE were eliminated in 80% of patients 11% not ablated because AF non-inducible after PVI 9% all CFE could not be eliminated Both lines with block achieved in 74% of patients Roof line only 93% Mitral line only 75%

11 Results - Procedural Characteristics PVI PVI+CFE PVI+LINES p value Procedure time (min) ± ± ± < Mapping time (min) ± ± ± 7.68 < Fluoroscopy time (min) ± ± ±

12 Results - Primary Outcome Documented AF > 30 seconds after one procedure with or without AAD p= % 48% 44%

13 Results - Secondary Outcomes Freedom from AF/AFL/AT after 1 procedure Freedom from AF after 2 procedures Freedom from AF/AFL/AT after 2 procedures Percentage of patients still on AAD at 18 mo PVI PVI+CFE PVI+LINES p value 49 % 41 % 37 % % 60 % 58 % % 50 % 48 % % 12 % 12 % 0.35 * AAD = antiarrhythmic drug

14 The Future STAR AF II pushes the reset button on best strategy for persistent AF ablation Emphasizes the need for a good, wide antral PV isolation as the cornerstone of persistent AF ablation Can leave certain strategies in the past empiric lines, CFE Does it mean that no adjuvant ablation is required in addition to PVI? Not necessarily... But look forward to an exciting field of novel target identification to see if we can improve outcomes Rotors, repetitive patterns, non-pv foci, scar regions, etc

15 Patients with >1 recovered PV (%) Percentage of Patients with PV Recovery at Repeat Procedure PVI PVI+CFE PVI+Lines Total * 80% of PVI+Lines pts also had gap in one or more lines, 63% of PVI+CFE had more CFE to ablate

16 Freedom from AF/AT after 1 procedure based on linear block achieved

17 Freedom from AF/AT after 1 procedure based on all CFE ablated

18 What s next...?

19 The Individualized Ablation Customizing the ablation according to the patient s unique electrical and/or anatomical substrate Avoidance of empirical lesions The new miracle cures Rotor ablation Scar based ablation Non-PV triggers

20 Focal Impulse & Rotor Modulation (FIRM) Ablation Narayan et al, JACC 2012

21 Scar Based Ablation B ox I solation F ibrotic A reas Kottkamp et al, JACC 2015

22 Non-PV triggers DiBiase et al, Circulation [abstract] 2014

23 But remember the past... CFE Dominant frequency Shannon entropy All individualized approaches, but none borne out by robust data

24 Atienza et al, Heart Rhythm 2009 Acute reduction in DF in all chambers associated with higher freedom from AF long-term. Ablation of DFmax sites associated with higher freedom from AF (88% vs 30%) Overall success rate 88% parox and 56% persistent for combined strategy.

25 Verma et al, JCE 2011 Ablation of all DF sites above the mean DF plus PV isolation vs PVI alone for persistent AF Acute termination rate only 14% for DF+PVI DF+PVI vs PVI P=0.18

26 Rotor Ablation PRO CON Biologically plausible Temporally inconsistent Early, small studies suggesting efficacy of approach 1,2 Transient rotors vs stable rotors Requires simultaneous mapping Capable of demonstrating rotors on more than one technology Spatial stability some meandering but confined anatomically Quality & resolution of signals for analysis (incomplete contact or non-contact mapping Limitations of phase analysis/hilbert transformation Phase analysis more forgiving of complex signal analysis How does it deal with very complex signals? Rotational assumptions

27 Scar-based Ablation (BIFA, etc) PRO CON Biologically plausible Small studies suggesting efficacy of approach 1,2 Simplicity does not require simultaneous mapping for activation No widely accepted validation of voltage cut-offs to define scar, abnormal voltage Incidence of significant scar unknown No validation of low voltage regions against a gold standard (e.g. MRI) No consistent method of what to do with these regions Circumferential ablation? Linear ablation through the region? Homogenization? Connection to anatomical barrier?

28 Ablation of non-pv triggers PRO CON Biologically plausible fits well with our current trigger based hypothesis for AF initiation No consistent technique for non-pv trigger identification Isoproterenol Single center studies suggesting efficacy of approach 1,2 Adenosine Both, other? Transience of non-pv trigger Probably needs simultaneous mapping Distinguish important from unimportant triggers leave no PAC behind?

29 Do we need to be agnostic? Remember...atrial fibrillation is complicated... Multiple mechanisms may be at play simultaneously. Based on Repetitive atrial patterns, Hummel et al, AHA 2014

30 Circulation, 2006

31 Column 1: Single counter-clockwise epicardial re-entry with a single phase singularity and a stable heterogenous dominant frequency pattern. Circulation, 2006

32 Column 2: Complex phase analysis With multiple phase singularities. Consistent with multiple wavelet breakthrough. DF still has a stable heterogeneous pattern. Circulation, 2006

33 Column 4: Single clockwise epicardial reentry in a location distinct from initial re-entry pattern. DF now has an unstable, heterogeneous pattern. Circulation, 2006

34 For all of these techniques, what is an appropriate endpoint...? Completion of the task? AF termination? Achieving sinus rhythm during ablation?

35 AF Termination Rates AF termination during procedure (%) PVI PVI+CFE PVI+LINES p value 8 % 45 % 22 % <0.001 * Cardioversion rates were higher in PVI arm Is it really about AF termination? Or is it that when you have sinus rhythm during the procedure, your outcome is better (e.g. you can better assess your procedural endpoint, like PVI)?

36 What are our goals...?

37 Results - Primary Outcome Documented AF > 30 seconds after one procedure with or without AAD p= % 48% 44%

38 AF Burden Reduction Burden calculation based on maximum of burden calculated from all follow-up Holters or # of weeks with at least one TTM of AF or number of days in AF from CRF

39 Conclusions We know where we have been CFE and empiric linear ablation do not seem to be the answers New techniques are being studied, each with their pros and cons Be wary of the miracle cure watch for data Ultimately, we need large-scale clinical trials to evaluate outcomes proof is in the pudding Remember, AF is complicated be agnostic