Durability of Pulmonary Vein Isolation With the Heliostar Radiofrequency Balloon-The Prospective RABAAF Study With Protocol-Mandated Repeat Electrophysiology Studies

INTRODUCTION: Pulmonary vein isolation (PVI) is the cornerstone in atrial fibrillation (AF) ablation but achieving durable PVI remains a challenge. The radiofrequency balloon (RFB) is a "single-shot" ablation catheter for PVI that offers selective energy titration from 10 surface electrodes and 3D mapping system integration. The durability of RFB PVI has not been investigated.

METHODS: The objective of this study was to evaluate the durability of RFB PVI by protocol-mandated remaps in patients with paroxysmal or persistent AF referred for AF ablation at a high-volume center. RFB procedures were performed under conscious sedation, PVI assessed by high-density mapping, bidirectional block confirmed after a waiting period of ≥ 20 min, and dormant conduction assessed by adenosine injections. After 4-6 months patients underwent a remap study for assessment of PVI durability by high-density mapping and assessment of bidirectional block.

RESULTS: Forty-five patients were enrolled, 43 completed the RFB PVI, and 35/43 (81%) completed the remap study: 26% female, 43% persistent AF, median age 65 (interquartile range: 61-69) years, median CHA2DS2-VASc score 1 (0-2), and median left atrial volume 31 (25-42) mL/m2. Acute PVI was achieved in 99% of pulmonary veins (PVs) but focal radiofrequency touch-up lesions were required in 31% of patients. After 5.4 (4.9-6.1) months, 71% of PVs were durably isolated, and 29% of patients had all PVs durably isolated; 86% of patients were free from documented atrial tachyarrhythmias.

CONCLUSION: The durability of RFB PVI achieved under conscious sedation was relatively low. However, medium-term freedom from clinical recurrent arrhythmia was favorable.

TRIAL REGISTRATION: URL: https://www.

CLINICALTRIALS: gov. Unique Identifier: NCT06296888.