Patterns of Reconnection at Redo Ablation after Pulsed-Field Ablation for Atrial Fibrillation (REDO-PFA)

Background Pulsed-field ablation (PFA) is increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation, but lesion durability in patients returning for redo ablation remains incompletely characterized. Objective We sought to characterize pulmonary vein (PV) and non-PV reconnection patterns and procedural outcomes in patients undergoing redo ablation after index PFA. Methods We conducted a retrospective, single-center study of adults undergoing redo left atrial ablation for recurrent atrial arrhythmia after index PFA between July 2024 and February 2026. Lesion durability was assessed using electroanatomic mapping. The primary outcome was durable PVI at the patient level and PV reconnection at the vein level. Results Among 887 patients who underwent index PFA, 25 underwent redo ablation. Durable PVI was observed in 6 patients (24%), whereas 19 (76%) had reconnection of at least 1 PV. Overall, 42 of 96 PVs (43.5%) demonstrated reconnection. Reconnection was most frequent in the left inferior PV (54.6%) and right superior PV (54.2%) and least frequent in the right inferior PV (29.2%). Posterior wall reconnection was observed in 19 of 22 patients (86.4%). Acute re-isolation was achieved in 24 patients (96%) without complications. Conclusion In this redo-selected cohort after index PFA, PV and non-PV reconnection were common, particularly involving posterior wall isolation. Redo ablation was feasible, with high acute success and no procedural complications. Larger prospective studies are needed to define lesion durability across PFA platforms.