Ablation of atrial fibrillation in patients 75 years: long-term clinical outcome and safety

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1 Europace (216) 18, doi:1.193/europace/euv229 CLINICAL RESEARCH Ablation for atrial fibrillation Ablation of atrial fibrillation in patients 75 years: long-term clinical outcome and safety Ilka Metzner*, Erik Wissner, Roland R. Tilz, Andreas Rillig, Shibu Mathew, Boris Schmidt, Julian Chun, Peter Wohlmuth, Sebastian Deiss, Christine Lemes, Tilman Maurer, Thomas Fink, Christian Heeger, Feifan Ouyang, Karl-Heinz Kuck, and Andreas Metzner Department of Cardiology, Asklepios-Klinik St. Georg, Lohmühlenstr. 5, Hamburg 299, Germany Received 19 March 215; accepted after revision 4 June 215; online publish-ahead-of-print 29 January 216 Aims The prevalence of atrial fibrillation (AF) increases with age. Catheter ablation is an established treatment option for patients with symptomatic AF. We sought to determine the safety and long-term clinical efficacy of AF ablation in patients 75 years.... Methods Patients 75 years with symptomatic, drug-refractory AF were included in the study. Circumferential pulmonary vein and results isolation (PVI) was performed in all patients, extended to ablation of complex fractionated atrial electrograms, and/or linear lesions in PVI non-responders. Retrospective follow-up (FU) was based on routine outpatient clinic visits and regular telephone interviews. A total of 94 patients (54 male, age years, and left atrium diameter mm) with drug-refractory AF [55/94 (59%) paroxysmal AF (PAF), 29/94 (31%) persistent AF, and 1/94 (11%) long-standing persistent AF] underwent ablation. Follow-up was obtained in 93/94 (99%) patients. Following a single procedure, 35/93 (38%) patients were in stable sinus rhythm (SR; 46% PAF, 31% persistent AF, and 1% longstanding persistent AF) after a mean FU of months. After a mean of procedures, 55/93 (59%) patients were ultimately in stable SR (76% PAF, 41% persistent AF, and 2% long-standing persistent AF). In a total of 137 procedures, 8 major (5.8%) and 26 minor (19%) complications occurred.... Conclusions Catheter ablation in patients 75 years is associated with a favourable clinical long-term outcome in patients with PAF, while results are less promising in persistent or long-standing persistent patients. The safety profile of AF ablation in patients 75 years is comparable with patients of younger age Keywords Atrial fibrillation Ablation Elderly Outcome Long-term results Complications Introduction Atrial fibrillation (AF) is the most frequent arrhythmia encountered in daily practice and its incidence increases with age. 1 4 Based on the predicted life expectancy, the incidence of AF is expected to double in the next 5 years. 5 Ablation of AF in younger patients has become an established treatment option as implemented in the current guidelines for the treatment of AF. 3 Recent studies on catheter ablation using radiofrequency (RF) energy reported a mid- and long-term multi-procedure clinical success rate of up to 81% for paroxysmal AF (PAF), 89% for persistent, and 65% for longstanding persistent AF, respectively With regard to peri- and post-procedural major complications, a world-wide survey reported an incidence of 4.5% in patients between 15 and 9 years of age. 12 To date, safety and efficacy data for older patients undergoing catheter ablation of AF are sparse. 13 The present retrospective analysis sought to evaluate the clinical long-term outcome and rate of complications of AF ablation in patients 75 years. * Corresponding author. Tel: ; fax: address: i.metzner@asklepios.com These authors contributed equally. Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 216. For permissions please journals.permissions@oup.com.

2 544 I. Metzner et al. What s new? New data on long-term clinical success of AF ablation in patients 75 years. Multiple procedure success rate for paroxysmal AF is comparable with younger patient cohorts; however, it is less favourable for persistent and long-standing persistent AF. The safety profile is comparable with younger patient cohorts. Methods and materials Inclusion and exclusion criteria Consecutive patients with symptomatic, drug-refractory PAF, persistent, or long-standing persistent AF (definitions according to ESC guidelines for the management of AF) and 75 years of age were admitted and consented for RF-based catheter ablation. 3 Exclusion criteria were a prior left atrium (LA) ablation, LA diameter.6 mm, severe valvular heart disease, contraindications to post-interventional oral anticoagulation, or a life expectancy,1 year. Transoesophageal echocardiography was performed prior to ablation in all patients to assess the LA diameter and to rule out intracardiac thrombi. No additional pre-procedural imaging was performed. All data were assessed retrospectively. All patients gave written informed consent. The study was approved by our institutional review committee. Intraprocedural management Catheter ablation was performed under deep sedation without the need for general anaesthesia using midazolam, fentanyl, and propofol. Two diagnostic catheters were introduced via a femoral vein and/or the left subclavian vein and positioned within the coronary sinus (CS) and along the His-bundle. Double or triple transseptal puncture was performed via the right femoral vein under fluoroscopic guidance, using a modified Brockenbrough technique and 8.5-French transseptal sheaths (SL1, St. Jude Medical, Inc., St. Paul, MN, USA). After transseptal puncture, heparin was administered at 3 min intervals targeting an activated clotting time of 25 3 s. Selective pulmonary vein (PV) angiographies were performed to identify the PV ostia. Ablation procedure After completion of an electroanatomical 3D LA map (Carto, Biosense Webster, Diamond Bar, CA, USA), the individual PV ostia were tagged based on data derived from PV angiographies and electrical information. A spiral mapping catheter (Lasso, Biosense Webster) was placed inside the ipsilateral superior PV and wide circumferential ablation around the ipsilateral PVs was performed using a 3.5 mm irrigated-tip catheter (NaviStar Thermo Cool, Biosense Webster). Radiofrequency energy was delivered at a target temperature of 438C using a power limit of 3 W and an infusion rate of 17 ml/min along the superior, posterior, and inferior portions of the PVs, and a power limit of 4 W and an infusion rate of 25 ml/min along the anterior part. Ablation was continued until complete electrical PVI was achieved. Patients in continuous AF underwent biphasic electrical cardioversion (ECV) in order to verify PVI in SR, and PVI was reassessed in all patients after a 3-min waiting period. In case of unsuccessful ECV or re-initiation of AF after ECV (PVI non-responders), ablation targeted complex fractionated atrial electrograms (CFAEs) within the LA as well as in the CS and/or the RA, if necessary. If AF converted to an atrial tachycardia (AT), activation and entrainment mapping was performed and linear lesion sets were placed according to the underlying tachycardia mechanism. Electrophysiological evidence for bidirectional block was obtained in SR. During ablation of CFAEs or linear lesions, the spiral mapping catheter was positioned in the left atrial appendage (LAA) to monitor LAA activity. In patients with documented typical atrial flutter, bidirectional block of the cavotricuspid isthmus (CTI) was performed thereafter. Repeat procedures due to recurrence of atrial arrhythmia In patients with recurrent atrial arrhythmias during follow-up (FU), a repeat procedure was recommended. During the repeat procedure, previously isolated PVs were assessed for re-conduction. If PV reconduction was present, repeat PVI was performed as described above. In case of failure to restore SR after PVI by ECV, or if the PVs were still isolated, CFAE ablation was performed and/or linear lesion sets were placed as described above. In patients presenting with an AT, activation and entrainment mapping and focal ablation or ablation of linear lesion sets was performed followed by repeat PVI, if necessary. Definition of complications Major complications were defined as transient ischaemic attack (TIA), stroke, pericardial tamponade, pneumo- or haematothorax, high-degree ( 5%) PV stenosis requiring intervention (based on TEE-measurements during FU, and on selective PV-angiography in patients with repeat procedures), or other severe bleeding from the access sites or internal bleeding leading to haemorrhagic shock and requiring catecholamines. Haematoma at access sites, pericardial effusion and PV-stenosis (,5%) were considered minor complications. 12 Post-procedural care Following ablation, all patients underwent transthoracic echocardiography and fluoroscopy to rule out a pericardial effusion or pneumothorax, respectively. All patients were treated with proton-pump inhibitors twice daily for 6 weeks. Low-molecularweight heparin was administered in patients on vitamin K antagonists and an INR,2. until a therapeutic INR of 2 3 was achieved. Previously ineffective antiarrhythmic drugs were continued for 3 months. A 24-h Holter electrocardiogram (ECG) and a 12-lead surface ECG were performed prior to discharge. Follow-up Patients completed routine outpatient clinic visits at 3, 6, and 12 months followed by 12-month intervals. Each visit included a 24-h Holter ECG. In addition, regular telephone interviews were

3 AF Ablation in the elderly: clinical outcome and safety 545 Table 1 Baseline characteristics Paroxysmal AF Persistent AF Long-standing persistent AF... N Male, n (%) 31 (56) 19 (66) 5 (5) Age, mean + SD (years) AF duration, median (Q1 Q3) (months) 81 (46 12) 72 (36 12) 72 (6 12) LA diameter, mean + SD (mm) CHADS 2 score CHA 2 DS 2 -VASc score Art. hypertension, n (%) 47 (85) 26 (9) 1 (1) Diabetes mellitus, n (%) 2 (4) 2 (7) () Normal LV function, n (%) 52 (95) 26 (9) 9 (9) Structural heart disease, n (%) 14 (25) 12 (41) 7 (7) AF, atrial fibrillation; LA, left atrium; LV, left ventricular; Structural heart disease defined as moderate valvular insufficiency or stenosis and/or ischaemic or dilated cardiomyopathy and/or coronary artery disease and/or status post-valvular replacement. performed. Additional outpatient clinic visits were initiated if patients reported symptoms suggestive of arrhythmia recurrence. Any documented episode of atrial tachyarrhythmia lasting.3 s was considered as recurrence. No blanking period post-ablation was included. Statistical analysis Continuous variables are expressed as mean + SD or median and quartiles (Q1 Q3) when appropriate. Categorical variables are presented as absolute and relative frequencies. Time-to-event curves were generated using the Kaplan Meier technique. An exploratory data analysis was performed. Statistics were calculated using SPSS for Windows (SPSS Inc.). Results Baseline characteristics A total of 94 patients [54 (57%) male, mean age years, mean LA diameter mm] with drug-refractory AF (3 + 1antiarrhythmic drugs) were included in the analysis. A history of hypertension was documented in 83/94 (88%) patients, diabetes mellitus in 4/94 (4%) patients, stable coronary artery disease in 19/94 (2%) patients, and a previous history of TIA or stroke in 1/94 (11%) patients. Eighty-seven of 94 (93%) patients demonstrated a normal left ventricular ejection fraction (LVEF), while in 7/94 (7%) patients the LVEF was moderately impaired (LVEF 45% and 35%). The mean CHADS 2 score was 2 + 1andthe mean CHA 2 DS 2 -VASc score was A total of 55/94 (59%) patients presented with PAF, 29/94 (31%) patients with persistent AF, and 1/94 (11%) patients with long-standing persistent AF. The median duration of AF since first diagnosis was 81 (46 12) months for patients with PAF, 72 (36 12) months for patients with persistent AF, and 72 (6 12) months for patients with longstanding persistent AF (Table 1). First ablation procedure In all 94 patients, successful PVI was performed as described above. In 6/55 (11%) patients with PAF an additional CTI line was placed due to documented typical right atrial flutter. Among patients with persistent AF, 2/29 (7%) patients underwent CFAE ablation, while in 2/29 (7%) patients an anterior line, in 2/29 (7%) patients a roof line, and in 1/29 (3%) patients a mitral isthmus line, were placed. In addition, 2/29 (7%) patients underwent ablation of the CTI. In patients with long-standing persistent AF, CFAE ablation was performed in 2/1 (2%) patients and in 1/1 (1%) patients the vena cava superior was isolated. The mean procedure and fluoroscopy time for patients with PAF, persistent AF and long-standing persistent AF were and min, and min, and and min, respectively. Clinical outcome after the initial ablation procedure Clinical FU was available for 93/94 (99%) patients. One patient was lost to FU. A total of 5/94 (5%) patients died during the FU (1/5 patients due to bronchial cancer, 1/5 patients due to prostate cancer, 2/5 patients due to myocardial infarction, and 1/5 patients died of unknown reason). In the latter patients, clinical FU was obtained until the time of death. After a mean FU of months, 25/54 (46%) patients with PAF, 9/29 (31%) patients with persistent AF, and 1/1 (1%) patients with long-standing persistent AF were in stable SR (Figure 1). Overall, 35/93 (38%) patients were in stable SR after a single procedure. In 29 patients with PAF as the initial diagnosis, the mode of recurrence was PAF in 17/29 (59%) patients, persistent AF in 3/29 (1%) patients, and an AT in 9/29 (31%) patients. In 2 patients with persistent AF as the initial diagnosis, the mode of recurrence was PAF in 7/2 (35%) patients, persistent AF in 6/2 (3%)patients,andanATin7/2(35%)patients.In9patients with long-standing persistent AF as initial diagnosis, recurrence presented as PAF in 2/9 (22%) patients, persistent AF in 6/9 (67%) patients, and an AT in 1/9 (11%) patients.

4 546 I. Metzner et al. Survival probability PAF 54 PERM 1 PERS 29 Kaplan-Meier plot with number of subjects at risk + Censored PAF PERM PERS Time (years) Second ablation procedure In a total of 36/58 (62%) patients with recurrent atrial tachyarrhythmia, a second ablation procedure was performed. In 23 patients with PAF as the initial diagnosis, a repeat ablation procedure was undertaken after a median of 134 (41 255) days. Reisolation due to recurrent PV conduction was performed in 22/23 (96%) patients. Additional linear lesion sets were placed in 7/23 (3%) patients (3 mitral isthmus lines, 1 anterior line, 1 roof line, and 2 CTI lines). A focal AT was ablated in three patients and the superior vena cava was isolated in one patient. The mean procedure and fluoroscopy time were and min, respectively. In nine patients presenting with persistent AF during the initial procedure, a second ablation was performed after a median of 152 (49 255) days. Pulmonary vein re-isolation was performed in 5/9 (56%) patients. Additional linear lesion sets were placed in 7/9 (78%) patients (4 mitral isthmus lines, 3 anterior lines, 3 roof lines, 1 posterior line, and 2 CTI lines). In one patient, ablation of CFAE and in another patient ablation of focal ATs was performed. In 2/9 (22%) patients, the LAA was isolated after placement of an anterior line in combination with a mitral isthmus line. In one patient, the His-bundle was ablated followed by permanent pacemaker placement. Procedure and fluoroscopy times were and min, respectively. In four patients with a previous diagnosis of long-standing persistent AF, a second ablation procedure was performed after a median of 651 ( ) days. Re-PVI was done in 3/4 (75%) patients. In one patient, a mitral isthmus line was placed, while one patient underwent His-bundle ablation and subsequent implantation of a permanent pacemaker. Procedure and fluoroscopy times were and min, respectively. Clinical outcome after the second ablation procedure After the second procedure, 8/23 (35%) patients initially diagnosed with PAF, 6/9 (67%) patients initially diagnosed with persistent AF, Figure 1 Kaplan Meier curve demonstrating the relative proportion of patients in stable SR after the initial ablation procedure during a mean FU period of months. and 3/4 (75%) patients initially diagnosed with long-standing persistent AF developed recurrent atrial tachyarrhythmia. Therefore, 4/54 (74%) patients with initially PAF, 12/29 (41%) patients with initially persistent AF, and 2/1 (2%) patients with initially longstanding persistent AF were in stable SR after two ablation attempts. Mode of recurrence in patients with initially PAF and recurrence after the second ablation was PAF in 6/8 (75%) patients and AT in another 2/8 (25%) patients. In patients with initially persistent AF and recurrence after the second procedure 2/6 (33%) patients had PAF, 3/6 (5%) patients persistent AF, and 1/6 (17%) patients AT. And finally in patients with initially long-standing persistent AF and a second procedure 2/3 (67%) patients had persistent AF, and 1/3 (33%) patients persistent AF and AT. Three or more ablation procedures In 4/8 (5%) patients with PAF and recurrence after two ablation attempts, a third ablation was performed after a median of 287 ( ) days after the second procedure. Re-isolation of the septal and lateral PVs was performed in one patient and re-isolation of only the septal PVs in a second patient. In a third patient, all PVs were isolated and a mitral isthmus line, an anterior line and a roof line were placed resulting in LAA isolation. In a fourth patient, a permanent pacemaker was implanted followed by ablation of the His-bundle. After the third procedure, 1/4 (25%) patients remained in stable SR, while 3/4 (75%) patients developed recurrent atrial arrhythmias. In 1/3 patients, a permanent pacemaker was implanted and the Hisbundle ablated. In 2/6 (33%) patients presenting with persistent AF during the initial procedure, a third ablation attempt was undertaken 126 and 742 days after the second procedure. In both patients, the PVs were still isolated. In one patient, CFAEs were ablated, while in the other patient a mitral isthmus line was placed due to perimitral flutter. However, both patients developed recurrences in the form of PAF and ATs and persistent AF, respectively (Figure 2). In 2/3 (67%) patients with long-standing persistent AF prior to the first procedure, a third ablation was performed 46 and 397 days after the second procedure. In one patient, the lateral PVs were reisolated followed by ablation of CFAE, an anterior line, a roof line, and a CTI block. In the second patient CFAE, a mitral isthmus line and an anterior line (not bidirectionally blocked) were performed. However, both patients developed recurrent atrial arrhythmias during FU, both in the form of persistent AF. One patient received a permanent pacemaker after ablation of the His-bundle (Figure 2). Overall clinical outcome After a mean of procedures, 41/54 (76%) patients presenting with PAF during the initial procedure remained in stable SR. Among patients with persistent AF as presenting rhythm during the initial procedure, 12/29 (41%) patients were in stable SR after a mean of ablation procedures. Only 2/1 (2%) patients with long-standing persistent AF prior to the first ablation remained in stable SR at the end of the FU period and a mean of ablation procedures (Table 2). At the end of the FU, a total of 14/55 (25%) patients in stable SR were still under Class Ic or Class III antiarrhythmic medication, another 32/55 (58%) patients were on a beta-blocker.

5 AF Ablation in the elderly: clinical outcome and safety 547 Progression and regression of atrial fibrillation during follow-up Progression from initially PAF to persistent AF was seen in 3/54 (5.6%) patients during the FU. In contrast, in patients with persistent AF as initial presenting rhythm regression to PAF was documented in 6/29 (2.6%) patients and from long-standing persistent AF to PAF in 2/1 (2%) patients. Peri-interventional complications In the present patient cohort, major complications were noted in 7/94 (7%) patients and 8/137 (5.8%) ablation procedures. Importantly, no patient died due to complications. In 2/137 (1.5%) procedures, a pericardial tamponade occurred. In both patients, percutaneous pericardiocentesis was performed without the need for surgical intervention. In 1/137 (.7%) procedures, severe Survival probability PAF PERM PERS Kaplan-Meier plot with number of subjects at risk + Censored PAF PERM PERS Time (years) Figure 2 Kaplan Meier curve demonstrating the relative proportion of patients in stable SR after multiple ablation procedures during a mean FU period of months. Table 2 Ablation summary and clinical outcome mediastinal and splenic bleeding occurred during peri-interventional anticoagulation. The patient required blood-transfusions and catecholamines and stabilized. A pneumothorax and haematothorax due to puncture of the left subclavian vein developed in 1/137 (.7%) and 2/137 (1.5%) procedures, respectively. One patient presenting with haematothorax required surgical debridement of pleural adhesions and parietal pleurectomy. In another 1/137 (.7%) procedures, a cerebellar stroke with dizziness and ataxia occurred. However, complete remission occurred within days. A TIA causing transient paresis of the right arm was documented in 1/137 (.7%) procedures. During the initial ablation procedure, 7/8 (88%) major complications and during the second ablation procedure, 1/8 (12%) major complications occurred. No atrioesophageal fistula, retroperitoneal haematoma, or severe/symptomatic PV stenosis was noted in the patient cohort (Table 3). In 24/94 (26%) patients and in 26/137 (19%) procedures, minor complications occurred: a groin haematoma in 18/137 (13%) procedures requiring blood transfusion in 7/18 (39%) procedures, subclavian access haematoma in 2/137 (1.5%) procedures, pericardial effusion in 5/137 (3.6%) procedures with spontaneous regression, and a 4% PV stenosis in 1/137 (.7%) procedures. A total of 18/26 (69%) minor complications were registered during the initial ablation procedure, while 6/26 (31%) minor complications occurred during the second ablation procedure. Discussion The current study performed in patients 75 years could demonstrate that (i) the clinical success rate after 3-year FU and a single procedure is 46% for PAF, 31% for persistent AF, and 1% for longstanding persistent AF, (ii) the clinical success rate after multiple procedures ( ) increases to 76% for PAF, to 41% for persistent AF, and to 2% for long-standing persistent AF, (iii) the regression rates from persistent and long-standing persistent AF to PAF following catheter ablation are 2.6 and 2%, respectively, whereas the progression rate from PAF to persistent AF is only 5.6%, and (iv) ablation of AF in patients 75 years is associated with a major complication rate of 5.8%. Paroxysmal AF (n 5 55) Persistent AF (n 5 29) Long-standing persistent AF (n 5 1)... PVI only, n (%) 46/55 (84) 19/29 (66) 5/1 (5) SR, n (%) 35/46 (76) 8/19 (42) /5 PVI + linear lesions, n (%) 9/55 (16) 5/29 (17) 1/1 (1) SR, n (%) 6/9 (67) 2/5 (4) 1/1 (1) PVI + CFAE, n (%) 1/29 (3) 2/1 (2) SR, n (%) 1/1 (1) 1/2 (5) PVI + linear lesions + CFAE, n (%) 4/29 (14) 2/1 (2) SR, n (%) 1/4 (25) /2 SR total, n (%) 41/54 (76) 12/29 (41) 2/1 (2) AF, atrial fibrillation; CFAE, complex fractionated atrial electrogram; PVI, pulmonary vein isolation; SR, sinus rhythm.

6 548 I. Metzner et al. Table 3 Major complications 1. Ablation 2. Ablation 3. Ablation... Pericardial 2/94 (2.1) /36 () /7 () tamponade, n (%) Pneumothorax, n (%) 1/94 (1.1) /36 () /7 () Haematothorax, n (%) 1/94 (1.1) 1/36 (2,8) /7 () Stroke, n (%) 1/94 (1.1) /36 () /7 () TIA, n (%) 1/94 (1.1) /36 () /7 () Splenic bleeding, n (%) 1/94 (1.1) /36 () /7 () To date, there is a scarcity of data on the clinical outcome and complication rate of catheter ablation for AF in patients 75 years of age. 14,15 The present study provides additional evidence that ablation in this patient cohort is associated with a favourable clinical outcome for patients with PAF and less beneficial outcome data for patients with persistent or long-standing persistent AF and a moderate complication rate. The herein described ablation strategy focuses on electrical isolation of the PVs as the initial step, irrespective of whether the patient presents with PAF, persistent, or long-standing persistent AF. Additional CFAE ablation is only performed if the patient fails electrical CV after successful PVI or if all PVs remain isolated during a repeat ablation procedure. Additional linear lesion sets are applied only if AF converts to an AT during CFAE ablation or if an AT is the presenting rhythm. This strategy has proved effective and save as described in previous publications from our laboratory for ablation of PAF and longstanding persistent AF. 7,11 Additional confirmation comes from the STAR-AF II trial, which demonstrated that pure PVI is noninferior to more extensive ablation including linear lesion deployment or targeting CFAE 16 (NCT367757). Furthermore, a more conservative approach may reduce the incidence of periinterventional complications while providing comparable clinical success rates. Long-term clinical success Depending on the ablation strategy and the duration of FU, clinical success rates in younger patient cohorts following multiple procedures using RF energy reach 81% for PAF, 6,7 89% for persistent AF, 8,9 and up to 65% for long-standing persistent AF. 1,11 In a study from Bunch et al., 14 catheter ablation in octogenarians with PAF or persistent AF resulted in an overall clinical success rate of 78% after 1 year. In a different study by Santangeli et al., 15 clinical success of AF ablation in a mixed cohort of patients with PAF and persistent AF and.8 years of age was evaluated. After a single procedure and ameanfuof18+ 6 months, 69% of patients were in stable SR and the success rate increased to 87% after a second procedure. Stepanyan and Gerstenfeld 17 provided data on different singlecentre trials of catheter ablation in the elderly finding similar success rates (64 86%) compared with younger patient cohorts (71 88%). Moreover, Blandino et al. 18 could demonstrate that catheter ablation of persistent AF in patients 7 years is more effective than antiarrhythmic drugs in maintaining SR and improving quality of life. The current study could demonstrate a 76% clinical success rate for PAF after a mean of 1.5 procedures and an average FU duration of months, which is comparable with reported clinical results in younger patient cohorts. 6,7 For patients with persistent AF and long-standing persistent AF, long-term clinical success rates of 41% after 1.4 procedures and 2% after 1.6 procedures are less favourable than reported in other studies However, only a limited number of patients in the current study cohort presented with persistent or long-standing persistent AF. Peri- and post-procedural complications In the world-wide survey on catheter ablation of AF, 4.5% of patients between 15 and 9 years of age suffered major complications. 12 In another study from Spragg et al., 19 the incidence of severe complications among 517 patients and a mean age of years was 5%. A third study by Shah et al. 2 reported an incidence of 5% of procedural complications among 4156 patients with a mean age of years. In the current patient cohort, the mean age was years and the incidence of major complications was 5.8%, which is comparable with data collected in younger patient cohorts. Furthermore, results are in line with the aforementioned studies by Bunch et al. 14 and Santangeli et al., 15 which did not detect a higher incidence of major complications in patients.8 years undergoing catheter ablation for AF. Also Nademanee et al. 21 could demonstrate in a recently published study that ablation due to AF in patients 75 years can be considered as safe but also effective in maintaining SR. However, Guiot et al. 22 could also demonstrate that age.75 years is an independent predictor of late cerebrovascular events after ablation of AF and Wutzler et al. 23 analysed that the rate of respiratory infections and renal failure after AF ablation is significantly higher in the elderly. Progression and regression of atrial fibrillation Several studies have described the natural progression from PAF to chronic forms of AF over time. 7,11,15,24,25 Progression rates ranging from 5 to 2% per annum have been reported, while risk factors for AF progression are summarized and included in the HATCH score. 24,25 In contrast, a reduction in the rate of progression could be demonstrated after catheter ablation of PAF and when compared with medical treatment only. 26 In the present study, the rate of progression from PAF to persistent AF over a FU period of months was only 5.6%. The rates of regression from persistent AF to PAF and from long-standing persistent AF to PAF were 21 and 2%, respectively. Hence, even in the very elderly, if catheter ablation proves unsuccessful in maintaining SR, the conversion of non-paroxysmal types of AF to PAF may benefit some patients. Limitations The current study reflects a single-centre long-term experience and is a retrospective analysis. Furthermore, only a limited number of patients with persistent and long-standing persistent AF as initial presenting rhythm were analysed. Lastly, no comparison group of patients,75 years of age is provided.

7 AF Ablation in the elderly: clinical outcome and safety 549 Conclusions Catheter ablation of AF in patients 75 years of age is associated with a safety profile that is comparable with younger patient cohorts and associated with the favourable clinical long-term outcome in patients presenting with PAF. Following ablation, the rate of progression from paroxysmal to persistent types of AF is low, while a considerable number of patients demonstrated regression from persistent or long-standing persistent AF to PAF. Conflict of interest: none declared. References 1. Benjamin EJ, Wolf PA, D Agostino RB, Silbershatz H, Kannel WB, Levy D. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation 1998; 98: Lévy S, Breithardt G, Campbell RW, Camm AJ, Daubert JC, Allessie M et al. Atrial fibrillation: current knowledge and recommendations for management. Working Group on Arrhythmias of the European Society of Cardiology. Eur Heart J 1998; 19: Camm AJ, Lip GY, De Caterina R, Savelieva I, Atar D, Hohnloser SH et al. ESC Committee for Practice Guidelines-CPG; Document Reviewers. 212 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 21 ESC Guidelines for the management of atrial fibrillation developed with the special contribution of the European Heart Rhythm Association. Europace 212;14: Go AS, Hylek EM, Phillips KA, Chang Y, Henault LE, Selby JV et al. Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the anticoagulation and risk factors in atrial fibrillation (atria) study. JAMA 21;285: Krijthe BP, Kunst A, Benjamin EJ, Lip GY, Franco OH, Hofman A et al. Projections on the number of individuals with atrial fibrillation in the European Union, from 2 to 26. Eur Heart J 213;34: Takigawa M, Takahashi A, Kuwahara T, Okubo K, Takahashi Y, Watari Y et al. Longterm follow-up after catheter ablation of paroxysmal atrial fibrillation: the incidence of recurrence and progression of atrial fibrillation. Circ Arrhythm Electrophysiol 214; 7: Ouyang F, Tilz R, Chun J, Schmidt B, Wissner E, Zerm T et al. Long-term results of catheter ablation in paroxysmal atrial fibrillation: lessons from a 5-year follow-up. Circulation 21;122: Scherr D, Khairy P, Miyazaki S, Aurillac-Lavignolle V, Pascale P, Wilton SB et al. Fiveyear outcome of catheter ablation of persistent atrial fibrillation using termination of atrial fibrillation as a procedural endpoint. Circ Arrhythm Electrophysiol 214; pii: CIRCEP [Epub ahead of print] 9. Rostock T, Salukhe TV, Steven D, Drewitz I, Hoffmann BA, Bock K et al. Long-term single- and multiple-procedure outcome and predictors of success after catheter ablation for persistent atrial fibrillation. Heart Rhythm 211;8: Lin D, Frankel DS, Zado ES, Gerstenfeld E, Dixit S, Callans DJ et al. Pulmonary vein antral isolation and nonpulmonary vein trigger ablation without additional substrate modification for treating longstanding persistent atrial fibrillation. J Cardiovasc Electrophysiol 212;23: Tilz RR, Rillig A, Thum AM, Arya A, Wohlmuth P, Metzner A et al. Catheter ablation of long-standing persistent atrial fibrillation: 5-year outcomes of the Hamburg Sequential Ablation Strategy. J Am Coll Cardiol 212;6: Cappato R, Calkins H, Chen SA, Davies W, Iesaka Y, Kalman J et al. Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circ Arrhythm Electrophysiol 21;3: Chen J, Hocini M, Larsen TB, Proclemer A, Sciaraffia E, Blomström-Lundqvist C; Scientific Initiative Committee, European Heart Rhythm Association. Clinical management of arrhythmias in elderly patients: results of the European Heart Rhythm Association survey. Europace 215;17: Bunch TJ, Weiss JP, Crandall BG, May HT, Bair TL, Osborn JS et al. Long-term clinical efficacy and risk of catheter ablation for atrial fibrillation in octogenarians. Pacing Clin Electrophysiol 21;33: Santangeli P, Di Biase L, Mohanty P, Burkhardt JD, Horton R, Bai R et al. Catheter ablation of atrial fibrillation in octogenarians: safety and outcomes. J Cardiovasc Electrophysiol 212;23: Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer I, Mantovan R et al. Approaches to catheter ablation for persistent atrial fibrillation. NEnglJMed215;372: Stepanyan G, Gerstenfeld EP. Atrial fibrillation ablation in octogenarians: where do we stand? Curr Cardiol Rep 213;15: Blandino A, Toso E, Scaglione M, Anselmino M, Ferraris F, Sardi D et al. Long-term efficacy and safety of two different rhythm control strategies in elderly patients with symptomatic persistent atrial fibrillation. J Cardiovasc Electrophysiol 213; 24: Spragg D, Dalal D, Cheema A, Scherr D, Chilukuri K, Cheng A et al. Complications of catheter ablation for atrial fibrillation: incidence and predictors. J Cardiovasc Electrophysiol 28;19: Shah RU, Freeman JV, Shilane D, Wang PJ, Go AS, Hlatky MA. Procedural complications, rehospitalizations, and repeat procedures after catheter ablation for atrial fibrillation. J Am Coll Cardiol 212;59: Nademanee K, Amnueypol M, Lee F, Drew CM, Suwannasri W, Schwab MC et al. Benefits and risks of catheter ablation in elderly patients with atrial fibrillation. Heart Rhythm 215;12: Guiot A, Jongnarangsin K, Chugh A, Suwanagool A, Latchamsetty R, Myles JD et al. Anticoagulant therapy and risk of cerebrovascular events after catheter ablation of atrial fibrillation in the elderly. J Cardiovasc Electrophysiol 212;23: Wutzler A, Loehr L, Huemer M, Parwani AS, Steinhagen-Thiessen E, Boldt LH et al. Deep sedation during catheter ablation for atrial fibrillation in elderly patients. J Interv Card Electrophysiol 213;38: Kerr CR, Humphries KH, Talajic M, Klein GJ, Connolly SJ, Green M et al. Progression to chronic atrial fibrillation after the initial diagnosis of paroxysmal atrial fibrillation: results from the Canadian Registry of Atrial Fibrillation. Am Heart J 25;149: de Vos CB, Pisters R, Nieuwlaat R, Prins MH, Tieleman RG, Coelen RJ et al. Progression from paroxysmal to persistent atrial fibrillation clinical correlates and prognosis. J Am Coll Cardiol 21;55: Pappone C, Radinovic A, Manguso F, Vicedomini G, Ciconte G, Sacchi S et al. Atrial fibrillation progression and management: a 5-year prospective follow-up study. Heart Rhythm 28;5:151 7.