Multielectrode catheter-based pulsed field ablation for persistent atrial fibrillation: safety, 1-year efficacy and impact on left atrial function of ablation protocols beyond pulmonary vein isolation

Abstract Background Pulsed Field Ablation (PFA) is emerging as a promising new technology in atrial fibrillation (AF) catheter ablation. 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 stiff left atrium (LA) syndrome. Purpose The aim of this study is to evaluate the impact of an ablation strategy beyond PVs using PFA, on arrhythmia freedom and LA function in PersAF. Methods This study included patients with PersAF undergoing first-time PFA. Ablation using a multielectrode catheter targeted the PVs and other extra-targets. Outcomes included freedom from any documented atrial arrhythmia lasting >30seconds, at one-year follow-up, after a 2-month blanking period, and the use of antiarrhythmic drugs (AAD) during follow-up. Secondary outcome was the impact on LA function evaluated through transthoracic echocardiography. Results Ninety-three patients (mean age 65 ± 10 years; 34.4% female; 31% with Early-PersAF; 69% with PersAF>3-months; 73% on AAD at baseline; 44% with heart failure) were included with a mean follow-up of 12 months. PVs isolation were performed in all patients. Extra-PVs 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. Among these patients, 77.9% were weaned off AAD. 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, LA emptying fraction and left ventricular ejection fraction significantly improved from baseline in PersAF >3-months. Conclusion One-year atrial arrhythmia freedom in PersAF patients after extensive PFA by means of a multielectrode catheter was high. Extra-PV was safe, did not alter LA compliance but promoted a positive reverse remodeling with improved LA compliance and left ventricular systolic function.Kaplan-Meier Table