Termination of atrial arrhythmia and restoration of sinus rhythm during pulsed field ablation deliveries in patients with persistent atrial fibrillation

Abstract Background Restoring sinus rhythm (SR) by ablation alone is an endpoint often used in radiofrequency ablation for persistent atrial fibrillation (AF). Limited data exist on pulsed-field ablation (PFA). Purpose We aimed to analyze the significance of termination of ongoing atrial arrhythmia and restoration of SR (TASR) and identify factors associated to TASR in persistent AF patients treated with PFA. Methods Consecutive patients undergoing AF ablation with the Farapulse PFA system at 15 centers were enrolled in the ATHENA registry. Protocol-directed PVI was delivered using 2 kV with eight applications per vein. Pulmonary vein (PV) isolation and non-PV triggers were targeted at operator’s discretion. Results A total of 288 patients with a history of persistent AF (193, 67.0%, early persistent AF; 95, 33.0%, long-standing persistent AF) were included in the analysis (56, 19.4%, female; mean age of 64±9 years; mean LVEF of 54±9%). A 3D mapping system was used in 87 (30.2%) of the cases, a non-PV ablation target was applied in 179 (62.2%) of cases. Among the 288 patients analyzed, 54 (18.8%) were cardioverted to SR before the procedure and maintained SR at the procedure’s conclusion. Seven (3.0%) patients were in AF at both the beginning and end of the procedure (in 5 cases electrical cardioversion -CVE- was not attempted, in 2 cases CVE failed to achieve TASR). The remaining 227 (78.8%) patients began the procedure in AF and subsequently achieved TASR. Of these,142 (62.6%) patients achieved TASR through CVE, while 85 (37.4%) attained TASR during PFA deliveries without requiring CVE. Multivariate regression analysis adjusted for baseline confounders indicated that only the inclusion of an additional lesion set beyond PVI was significantly associated with achieving TASR (43.3% with additional lesion set beyond PVI vs 26.6% with PVI only approach, p=0.015, OR = 1.90, 95%CI: 1.03 to 3.49, p=0.039). Among the 144 patients with complete follow-up data, 32 (22.2%) experienced recurrent AF beyond the 3-months blanking period. The proportion of patient who achieved TASR and remained free from AF recurrence was similar to those without TASR (86.7% vs 73.7%, p=0.129). Achieving TASR showed a trend toward a lower risk of AF recurrence, though this was not statistically significant (HR=0.47, 95%CI: 0.19 to 1.14, p=0.09). No major complications were reported. Conclusion In our experience, SR restoration at the end of the procedure, without the need for CVE, is achieved in approximately 40% of patients with persistent AF during PFA delivery. Ablation involving an additional lesion set beyond PVI is more strongly associated with successful restoration of SR without CVE.