Results of pulsed field ablation for longstanding persistent fibrillation in 500 patients

Introduction Radiofrequency ablation (RFA) for long-standing persistent atrial fibrillation (LSPAF) has poor long-term outcome after single procedure. In addition, there is limited data on the potential impact of procedural endpoints such as termination of AF and restoration of sinus rhythm (SR) using pulsed-field ablation (PFA). Purpose To evaluate long-term outcomes of PFA, including the impact of SR restoration with PFA and findings in repeat ablation in patients with LSPAF. Methods Between 10/2021 - 7/2025, 500 consecutive patients (66±9 years, 138 women) underwent PFA for LSPAF with restoration of sinus rhythm (SR) by ablation as the desired procedural endpoint, while avoiding damage to the conduction system and preserving early activation of the left atrial appendage (LAA). Pulmonary vein isolation (PVI), posterior box lesions, and mitral isthmus block were the integral endpoints of the procedure. Intermediate atrial tachycardia (AT) was targeted selectively. Redo ablation was scheduled after ≥6 months. Follow-up included regular 7day ECG monitoring after 3, 6, (9),12, and then every 6 months. Results At the index ablation, complete PVI and posterior box lesion were achieved in all patients, acute efficacy in mitral isthmus block reached 92%. No LAA isolation occurred, delayed LAA activation (interval LAA-QRS <40 ms) was present in 21 (4%) patients; AF termination (into SR or AT) and restoration of SR by ablation were successful in 224 (45%) and 195 (39%) patients, respectively. Out of 459 patients with ≥6 (19±8) month follow-up, 261 (57%) patients remained free from recurrent AF/AT, with improved outcome in patients with restored SR (Log Rank p = 0.0004) (Figures). Redo procedures (n=104) were performed in 99 patients; 111 AT types in 73 cases were identified, of which 53 (48%) originated from localized sources and 58 (52%) were macroreentry ATs, with dominant peri-mitral reentry AT in 48 cases and complete absence of roof-dependent reentry AT. Conclusions Patients with restored SR had better outcome as compared to patients with cardioversion at the end of index PFA for LSAF. Recurrent AT prevailed over AF, with dominant peri-mitral reentry AT due to mitral isthmus block recovery, while durable box lesion was associated with complete absence of roof-dependent reentry AT.2.1. LSPAF all2.2 LSPAF SR