Impact of Left Atrial Posterior Wall Isolation using Pulsed-field Ablation in Patients Undergoing Repeat Catheter Ablation for Atrial Fibrillation.

Background Durable pulmonary vein isolation (PVI) is the primary objective of catheter ablation of atrial fibrillation (AF). In repeat procedures, posterior wall isolation (PWI) is the primary adjunctive target, particularly with pulsed-field ablation (PFA), although evidence supporting its clinical benefit remains limited.Objective To compare procedural characteristics, safety, and efficacy of two ablation strategies in repeat AF ablation: redo-PVI alone (PVI group) versus redo-PVI with adjunctive PWI (PVI+ group).Methods Consecutive patients undergoing redo-PVI at two centers, with 1-2 reconnected PVs identified on pre-ablation mapping, were enrolled. PFA or radiofrequency ablation (RFA) was used in the PVI group, while only PFA was used in the PVI+ group. Propensity score matching (1:1 ratio) was performed.Results A total of 122 patients were included in each group (median age 67 years; 30% female). Median left atrial diameter was 41 [37-46] mm, and 46% had persistent AF. Procedure duration, left atrial dwell time, and fluoroscopy time were significantly shorter in the PVI group (all p<0.001). Procedural success was 100% in both groups. One major complication occurred in each group (0.8%). At a median follow-up of 370 days, arrhythmia-free survival was 69% in the PVI group and 72% in the PVI+ group (p=0.517).Conclusion Redo-PVI with or without adjunctive PWI is safe and effective, with comparable arrhythmia-free survival. Adjunctive PWI prolongs procedural duration without improving outcomes. Randomized trials are required to clarify its role.