Interim analysis of a prospective randomized comparison of pulsed field ablation vs. radiofrequency ablation for longstanding persistent atrial fibrillation

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Benefits of pulsed field ablation (PFA) compared to radiofrequency ablation (RFA) are not known in patients with longstanding persistent atrial fibrillation (LSPAF). PURPOSE: To present interim procedural and short-term clinical results of an ongoing prospective randomized comparison of PFA vs. RFA in patients with LSPAF. METHODS: In 9/2021-10/2022, 125 patients underwent catheter ablation for LSPAF using PFA (n=64, 69±8 years, 11 F, continuous AF 32±20 months) vs. RFA (n=61, 68±8 years, 17 F, continuous AF 29±23 months). PFA included pulmonary vein isolation (PVI) and extra-PV left atrial (LA) ablation. RFA included stepwise PVI, electrogram-guided LA ablation, CS isolation, and electrogram-guided right atrial ablation. Intermediate endpoints were PVI, mitral isthmus, LA roof and CTI blocks); sinus rhythm (SR) restoration by ablation was the desired procedural endpoint. Follow-up included 7-day ECG monitoring every 3 months during the first year, and every 6 months afterwards. RESULTS: In groups PFA vs. RFA, procedure and fluoroscopy times were 116±32 vs. 204±44 minutes, and 17±5 vs. 8±2 minutes, respectively (both p<0.001). AF termination (into intermediate AT or directly into SR) and SR restoration by ablation were achieved in 30 (47%) vs. 42 (69%) patients (p=0,19), and in 23 (36%) vs. 35 (57%) patients (p=0,15). Of those 48 vs. 50 patients with follow-up ≥3 months (≥6 months in 37 vs. 39 patients), freedom from any AF/AT (>30 s) was achieved in 38 (79%) vs. 23 (46%) patients. CONCLUSION: Interim results of ongoing comparison suggest procedure time reduction and improved AF/AT free survival after PFA as compared to RFA in patients with LSPAF.