Safety and impact of pulsed field ablation on pulmonary vein stenosis after prior thermal ablation

Background Pulsed field ablation (PFA) selectively targets myocardial tissue while minimizing injury to surrounding structures. Although its safety and efficacy for pulmonary vein (PV) isolation have been previously reported, the feasibility of performing PFA in PVs with pre-existing stenosis after prior thermal ablation remains uncertain. Purpose This study aimed to evaluate the safety and morphological impact of PFA in patients with recurrent atrial fibrillation (AF) who had PV stenosis following previous radiofrequency or cryoballoon ablation. Methods Six patients with recurrent AF underwent PFA after prior thermal ablation. Contrast-enhanced computed tomography was performed, and PV cross-sectional areas were quantified at 5-mm intervals from the ostium. The PV area reduction rate was calculated before and after the prior ablation, and before and three months after PFA. Changes in PV area reduction rates were compared to determine the impact of PFA on PV narrowing. Results The mean PV area reduction rate after prior thermal ablation was 31.1 ± 27.8%. At three months after PFA, the rate remained stable (30.9 ± 29.5%, P = 0.35). Five PVs showed >50% stenosis before PFA, yet none demonstrated further worsening following the procedure. (Figure) No patient developed symptomatic PV stenosis or major complications during follow-up. Conclusion PFA can be safely and effectively performed in patients with pre-existing PV stenosis after prior thermal ablation, without evidence of further narrowing. These findings support PFA as a safe and practical re-ablation strategy for recurrent AF.