One-year outcomes of focal pulsed-field ablation for redo procedures in atrial fibrillation and atypical flutter.

Background: Redo ablation procedures are frequently required in patients with recurrent atrial fibrillation (AF) and atypical atrial flutter following initial pulmonary vein isolation (PVI). While focal pulsed-field ablation (PFA) has emerged as a promising nonthermal alternative, data on its long-term efficacy and safety in redo procedures remain limited. This study evaluates the 1-year outcomes of focal PFA in redo ablations for AF and atypical flutter, focusing on arrhythmia recurrence, procedural success, and safety.

Methods: A retrospective analysis was conducted on 54 patients undergoing redo ablation with focal PFA at a single center. Procedural endpoints included acute and chronic procedural success, additional ablation line integrity, and complication rates. Arrhythmia recurrence was assessed via ECG and 24-h Holter monitoring at 6 and 12 months.

Results: Complete PVI and bidirectional block of all additional ablation lines were confirmed in all cases at the end of the procedure. During the 1-year follow-up, 29.63% of patients experienced arrhythmia recurrence. Among patients undergoing a further redo ablation, reconnections were most frequently observed in the anterior mitral line, suggesting challenges in lesion durability in this region. The overall complication rate was low (1.85%), with one case of coronary vasospasm during cavotricuspid isthmus ablation.

Conclusion: Focal PFA appears to be a feasible and safe option for redo ablations in AF and atypical flutter, with high acute success rates and acceptable arrhythmia control at 1 year. However, lesion durability, especially for complex lines, remains a limitation, underscoring the need for optimization and further prospective evaluation against thermal ablation.