Initial Clinical Experience with the Balloon-in-Basket Pulsed Field Ablation System: Acute Results of the VOLT CE Mark Feasibility Study

Background and Aims Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared to thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first generation PFA systems. Here we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation. Methods The VOLT CE Mark Study is a premarket, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA System for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest CT, and cerebral MRI. Study endpoints were the rate of primary serious adverse event within 7-days and acute procedural effectiveness. Results A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 minutes respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or esophageal lesions causally related to the PFA system, and 3 subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events. Conclusions The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF.