Feasibility and safety of pulsed-field ablation for mitral isthmus in persistent atrial fibrillation

Introduction Pulsed-field ablation (PFA) is a novel ablation technology capable of selectively targeting myocardial tissue while sparing adjacent structures, thereby reducing complications associated with thermal ablation methods. Although PFA has demonstrated safety and efficacy for pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF), evidence regarding its use in other left atrial substrates in patients with persistent AF remains limited. Purpose This study aimed to evaluate the feasibility and safety of mitral isthmus (MI) ablation with PFA in combination with PVI and posterior wall (PW) isolation in patients with persistent AF. Methods This prospective, observational, single-center study included 130 patients (mean age: 60 years, 86% male) with persistent AF undergoing their first ablation with PFA between January 2022 and September 2024. The ablation strategy involved PVI, PW ablation, and MI ablation. The primary endpoints were feasibility, assessed by achieving a sustained MI block at the end of the procedure, and safety, based on the occurrence of major complications. Results A durable MI block after a 30-minute waiting period was achieved in all patients (100%). Only two complications were documented: a reversible case of acute kidney injury due to hemolysis and a femoral hematoma requiring surgical repair. No clinically significant coronary spasms were observed. After a mean follow-up of 289 days, a 24% recurrence rate was noted, including six cases of atrial flutter (five perimitral and one associated with the right pulmonary veins). Conclusion PFA appears to be a reliable and safe ablation method for MI ablation when combined with PVI in patients with persistent AF, demonstrating promising outcomes over a medium-term follow-up period.