Pulsed-Field Ablation on Mitral Isthmus in Persistent Atrial Fibrillation: Preliminary Data on Efficacy and Safety.

ABSTRACT

BACKGROUND: Pulsed-field ablation (PFA) is a new and promising modality of ablation that has been shown to specifically ablate cardiac tissue while sparing other anatomic structures, thus avoiding thermal ablation-related complications. Recent studies have certified safety and efficacy of PFA for pulmonary vein isolation (PVI) in the setting of paroxysmal atrial fibrillation (AF). However, there are very limited data assessing the feasibility and safety of PFA ablation of different substrates within the left atrium in the setting of persistent AF. OBJECTIVES: The purpose of this study was to evaluate the feasibility and safety of mitral isthmus (MI) ablation in addition to PVI and posterior wall (PW) ablation with PFA in patients with persistent AF. METHODS: We prospectively included all consecutive patients with persistent AF who underwent a first ablation procedure with PFA. We performed in all these patients a substrate ablation strategy comprising PVI, PW, and MI ablation with the use of PFA only. The primary feasibility endpoint was obtaining a persistent MI block at the end of the procedure. The safety endpoint was a composite of major safety events. RESULTS: From November 2021 to September 2022, we included 45 patients. Complete MI block was achieved in all 45 (100%). Three patients presented with complications, among them 2 cases (4.4%) of reversible and nonfatal coronary spasm. During a mean follow-up time of 107.8 ± 59.5 days, a 20% recurrence rate was observed. CONCLUSIONS: PFA is a feasible and safe ablation approach for mitral isthmus ablation in addition to PVI in patients with persistent AF.