Redo ablation after primary radiofrequency or pulsed field ablation for paroxysmal or persistent atrial fibrillation: results from a pre-specified substudy of the BEAT-AF trial

Background Pulmonary vein isolation (PVI) remains the cornerstone of interventional therapy for atrial fibrillation (AF). The introduction of pulsed field ablation (PFA) has further advance PVI techniques. This novel energy modality has demonstrated comparable efficacy and improved safety profile compared with radiofrequency ablation (RFA). However, data on atrial tachyarrhythmia (ATA) recurrence mechanisms and redo ablation strategies following PFA remain limited, particularly in comparison with RFA. Purpose To characterize ATA recurrence mechanisms and ablation strategies during repeat procedures in a pre-specified substudy of the BEAT-AF trial, a European multicenter open-label randomized controlled trial comparing PFA and RFA for the treatment of paroxysmal and persistent AF. Methods Patients who consented to participate in the substudy were included if they underwent a repeat ablation procedure (263/292 [90%] in the PAROX-AF arm and 71/83 [84%] in the PERS-AF arm of the BEAT-AF trial). Clinical characteristics, index ablation data, and ATA recurrence information were prospectively collected. Additionally, pre-procedural imaging and electroanatomical mapping (EAM) data obtained during redo procedures were systematically analyzed. Results A total of 36 patients underwent a redo procedure (PAROX-AF: 24/263 [9%]; PERS-AF: 12/71 [17%]). The mean age was 65 ± 11 years, 39% were female, and the median CHA2DS2-VA score was 2 [1–2]. At index ablation, 53% had received PFA and 47% RFA. Redo procedures were performed for recurrent AF (28/36, 78%; 86% paroxysmal and 14% persistent), atypical atrial flutter (9/36, 25%), and/or typical atrial flutter (9/36, 25%). Recurrent arrhythmia characteristics did not significantly differ between patients treated with index PFA versus RFA. Pulmonary vein (PV) reconnection rates were comparable between groups. However, reconnection patterns differed: index PFA was associated with more distal PV isolation or broader regions of reconnection, whereas index RFA more frequently resulted in discrete conduction gaps. All redo procedures were performed using radiofrequency energy. Re-ablation after index RFA was predominantly limited to PV ablation, whereas redo procedures following index PFA more often required additional left atrial linear ablation. Post-redo ATA burden was similar between groups, and no procedural adverse events were observed. Conclusion In this pre-specified substudy of the BEAT-AF trial, recurrent arrhythmia phenotype and pulmonary vein reconnection rates after PFA and RFA were comparable. However, reconnection patterns differed, with broader and more distal reconnections observed after PFA. Redo procedures following PFA more frequently featured additional left atrial ablation beyond PV re-isolation. Despite these differences, post-redo arrhythmia burden and procedural safety were similar between groups.