Pulsed-field ablation beyond pulmonary vein for persistent atrial fibrillation: efficacy and impact on left atrial function

BACKGROUND: Pulsed field ablation (PFA) is a novel, non-thermal energy for atrial fibrillation (AF) catheter ablation that selectively targets cardiomyocytes with minimal to no risk of collateral damage. Among ablation strategies in persistent AF (PersAF), targeting sites other than the pulmonary veins (PVs) remains controversial, with concerns on improved success without increasing the risk of periprocedural complications and stiff left atrium (LA) syndrome. This study evaluates the impact of an ablation strategy beyond PVs using PFA on arrhythmia freedom and LA function in PersAF patients. METHODS: This study included 93 patients with PersAF undergoing first-time PFA targeting PVs and other extra-PV targets. AF-related symptoms, adverse events, electrocardiograms, and transthoracic echocardiograms were assessed at follow-up visits at 1, 6, and 12 months. RESULTS: Extra-PV targets included posterior wall (100%), anterior roof (50.5%), mitral isthmus (22.6%), anterior wall (36.6%), and right atrium applications (8.6%). No serious procedure-related adverse events were reported. At 1-year follow-up, 82.8% of patients were free from atrial arrhythmias. PFA significantly reduced A-wave velocity of mitral inflow and altered the E/A ratio but did not change LA compliance markers (e.g., LA strain reservoir and LA stiffness index (LASI)). LASI and left ventricular ejection fraction significantly improved from baseline in the PersAF > 3-month group. CONCLUSIONS: One-year atrial arrhythmia freedom in PersAF patients after extensive PFA by means of a multielectrode catheter was high. Extra-PV ablation was safe, did not alter LA compliance but promoted a positive reverse remodeling with improved LA compliance and left ventricular systolic function.