Pulsed-field ablation for repeat procedures after failed prior thermal ablation for atrial fibrillation

Background Pulsed-field ablation (PFA) is a novel non-thermal ablation technology. Its potential value for repeat procedures after unsuccessful thermal ablation for atrial fibrillation has not been assessed. Objective We sought to summarize our initial experience of patients undergoing repeat procedures using PFA. Methods Consecutive patients with arrhythmia recurrences after a prior thermal ablation undergoing a repeat procedure using a multipolar PFA catheter from May 2021 until December 2022 were included. After 3D-Electroanatomical mapping, reconnected pulmonary veins (PVs) were re-isolated and veins with only ostial isolation wither-ablated to widen antral PV isolation. Posterior wall ablation was performed if all PVs were durably isolated or in case of low-voltage areas on the posterior wall at the discretion of the operator. Patients were followed-up with 7-day-Holter-ECGs after 3, 6, and 12 months. Results A total of 186 patients undergoing a repeat procedure using PFA were included. The median number of previous ablations was 1 (range 1-6). The prior ablation modality was radiofrequency in 129 (69.4%), cryoballoon in 51 (27.4%), and epicardial ablation in 6 (3.2%) patients. At the beginning of the procedure, 258 of 744 PVs (35%) showed reconnections. Additional antral ablations were applied in 236 of 486 still isolated veins (49%). Posterior wall ablation was added in 125 (67%) patients. Major complications occurred in 1 patient (TIA, 0.5%). Freedom from arrhythmia recurrence in Kaplan-Meier-analysis was 78% after 6 months and 54% after 12 months. Conclusion PFA is a versatile and safe option for repeat procedures after failed prior thermal ablation.