Balloon-in-Basket Pulsed Field Ablation for Pulmonary Vein Isolation: 1-Year Outcomes of the VOLT-AF IDE Study

Background: A novel balloon-in-basket catheter integrated into a mapping system may advance pulsed field ablation (PFA) of atrial fibrillation (AF) with demonstrated deeper lesions, less hemolysis, and promising initial clinical experience. Objectives: The goal of this study was to assess the 1-year clinical outcomes of the balloon-in-basket PFA system. Methods: The multicenter VOLT-AF IDE Clinical Study enrolled patients with symptomatic, paroxysmal (PAF), and persistent AF (PeAF) . Pulmonary vein isolation (PVI) was performed with the investigational system. The primary effectiveness endpoint was acute PVI and 12-month freedom from atrial arrhythmia, antiarrhythmic escalation/initiation, cardioversion, or repeat ablation. The primary safety endpoint was device- and/or procedure-related serious adverse events within 7 days of any ablation. Follow-up consisted of 12-lead electrocardiograms at discharge, 3 months, and 12 months; biweekly and symptomatic transtelephonic monitoring; and 24-hour Holter monitoring at 12 months. Results: Of the 392 patients enrolled, 335 were main cohort patients (57 roll-ins), and 320 were treated (165 PAF and 155 PeAF). Their mean age was 65 ± 11 years, and the mean CHA₂DS₂-VASc score was 2.3 ± 1.6. Left atrial catheter dwell time was 44.1 ± 18.1 minutes (including a 20-minute wait). A mean of 4.6 ± 0.9 applications were delivered per vein. Primary effectiveness was 81.1% (95% CI: 74.3%-86.3%) in PAF and 63.3% (95% CI: 55.1%-70.4%) in PeAF. Freedom from documented arrhythmia recurrence was 84.2% in the PAF group and 67.8% in the PeAF group. Primary safety events occurred in 1.9% of patients, with none in the PAF group. During redo ablation in 19 patients, 78.5% of pulmonary veins remained durably isolated. Conclusions: This multicenter trial reports high PVI-based effectiveness of the novel balloon-in-basket PFA device with excellent safety.(VOLT-AF