Background

Pulmonary vein isolation (PVI) is an established therapy for symptomatic atrial fibrillation (AF) and

the cryoballoon (CB) has become a standard tool for PVI. But the technology is limited in certain ways. The novel multi-electrode balloon catheter (Heliostar^™, Biosense Webster, CA, USA) promises the advantages of a balloon technology in combination with 3D-mapping and more flexible energy delivery.

Purpose

There is very limit data available regarding the safety and efficacy of the Heliostar^™ RF-balloon. We therefore aimed to assess procedure characteristics, efficacy, and safety in direct comparison with the established CB.

Methods

All patients undergoing PVI using the Heliostar^™ between September 2021 and March 2022 were included in this single center registry. Procedural data and outcome were assessed and compared with data from consecutive patients undergoing initial PVI for paroxysmal AF with the CB from our specifically designed database.

Results

A total of 251 consecutive patients (63±13 years, 54% male) were included. Of those 28 patients undergoing RF-balloon and 223 patients CB PVI. Baseline parameters did not differ between groups. Acute PVI was achieved in all patients using CB and in 26/28 patients (93%) with the RF-balloon. In 2/28 patients an additional single tip catheter was needed.

A mean of 11.2±4.9 RF-applications with 2.8±1.4 applications per vein (LSPV 3.2±2.9, LIPV 2.6±2.5, RSPV 2.8±2.0 and RIPV 1.8±0.8) were necessary to achieve a durable isolation. Using the CB, significantly less applications (5.9±2.2;p=<0.001) were needed. While procedure duration (111±30min. vs. 70min.;p=<0.001) and fluoroscopy time (17.2±6.3min. vs. 11.5±4.8min.;<0.001) were longer in the Heliostar^™ group, time to isolation was significantly shorter using the RF-balloon: LSPV 23.5±12.3 sec. vs. 54.6±38.3 sec. (p=<0.001); LIPV 18.6±10.4 sec. vs. 61.2±46.5 sec. (p=0.002); RSPV 17.4±10.9 sec. vs. 62.5±53.9 (p=<0.001); RIPV 16.1±9.3 vs. 59.3±35.9 sec. (p=<0.001).

The mean maximum esophageal temperature was 40.2±0.8°C and the mean minimum temperature during cryoablation was 25.4±7.3°C.

One pericardial effusion occurred in the Heliostar^™ group due to complicated transseptal access. During CB PVI in 4/223 patients (1.8%) a phrenic nerve palsy was observed, which resolved in all patients within 12-month.
After 12-month 80% of patients in the Heliostar^™ and 79% of patients in the CB group (p=0.9) were free from atrial arrhythmias.

Conclusion

The novel multi-electrode RF-balloon has shown to be safe and effective with good long-term results. In comparison with the CB, time to isolation was significantly shorter but procedure durations were longer and fluoroscopy exposition was higher using the first generation Heliostar^™ without LassostarNav^®. This can be attributed to the learning curve applying a new ablation system and the necessity for separate 3D map preparation. More experience is needed in the future, especially with the new generation Heliostar^™ to determine the real benefits.