Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA Randomized Clinical Trial

Key Points Question Does adding posterior wall isolation (PWI) to pulmonary vein isolation (PVI) improve success in patients with persistent atrial fibrillation (AF) undergoing first-time catheter ablation? Findings In this randomized clinical trial that included 338 patients with persistent AF, there was no significant difference in 12-month freedom from recurrent atrial arrhythmia after a single procedure and without antiarrhythmic medication among those with PVI and PWI compared with PVI alone (52.4% vs 53.6%, respectively; hazard ratio, 0.99). Meaning Among patients with persistent AF undergoing first-time catheter ablation, the addition of PWI to PVI did not improve freedom from atrial arrhythmias compared with PVI alone. Importance Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison. Objective To compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation. Design, Setting, and Participants Investigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022. Interventions The PVI with PWI group (n=170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n=168) underwent wide antral pulmonary vein isolation alone. Main Outcomes and Measures Primary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications. Results Among 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, -1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P=.98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P=.57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P=.36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P=.47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P<.001) and ablation times (34 [SD, 21] vs 28 [SD, 12] minutes, P<.001) were significantly shorter for PVI alone. There were 6 complications for PVI with PWI and 4 for PVI alone. Conclusions and Relevance In patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF. Trial Registrationanzctr.org.au Identifier: ACTRN12616001436460 This randomized clinical trial compares pulmonary vein isolation (PVI) vs PVI with posterior wall isolation for achieving freedom from atrial arrhythmia in adult patients with persistent atrial fibrillation undergoing first-time catheter ablation in Australia, the UK, and Canada.