Initial experience with a new balloon-in-basket pulsed field ablation system for pulmonary vein isolation

Background: Success rates of pulse field ablation (PFA) pulmonary vein isolation (PVI) have been reported to match those achieved with thermal-based ablation technologies. Several factors such as the energy utilized, catheter design and tissue contact seem to be crucial to achieve irreversible electroporation and transmural lesions. A novel, fully 3D-integrated balloon-in-basket PFA ablation system has been designed to offer better tissue contact and thus result in transmural and permanent lesions with few applications.

Objective: To evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system.

Methods: A subcohort of patients enrolled in the VOLT CE Mark (NCT06106594) study at one tertiary center in Germany were used for this analysis. The VOLT CE Mark Study is a pre-market prospective, multi-center, single-arm study evaluating the safety and effectiveness of the VOLT™ PFA system, a balloon-in-basket PFA system, for the treatment of symptomatic, drug-refractory paroxysmal or persistent AF. All patients underwent de-novo AF ablation using the balloon-in-basket PFA system. No additional ablations beyond PVI were allowed. Study endpoints include the rate of primary serious adverse events within 7 days and acute procedural effectiveness.

Results: A total of 30 patients (average age 65 years; 60% male, 50% paroxysmal AF) underwent PVI with the new balloon-in-basket PFA system. The procedure included pre- and post-procedure phrenic nerve assessment, pre- and post-procedure voltage mapping, and a 20-min wait period. All procedures were undertaken under conscious sedation using Midazolam, Propofol and Fentanyl. Procedure and fluoroscopy times were 78.2 ± 10.6 min and 10.0 ± 4.5 min. The ablation catheter left atrial dwell time was 27.1 ± 8.5 min. An average of 16.5 ± 2.0 PFA applications were delivered per subject, with 4.2 ± 0.7, 4.4 ± 0.6, 3.8 ± 1.1, and 4.1 ± 0.9 applications per left superior PV, left inferior PV, right superior PV, and right inferior PV, respectively. Acute effectiveness was achieved in 100% (116/116) of treated pulmonary veins, including four left common PVs. One subject experienced a primary safety endpoint event; pneumonia with respiratory compromise 6 days after procedure. Of note, there were no deaths, clinical strokes, phrenic nerve injury, clinical coronary artery spasm or renal failure.

Conclusion: The VOLT balloon-in-basket PFA system is safe and effective for PVI and is well tolerated under conscious sedation. Through its unique design it offers several potential advantages over the currently available PFA systems.