Background:
Cryoballoon pulmonary vein (PV) isolation is an established anatomical single-shot procedure for the treatment of atrial fibrillation (AF). We compared a novel compliant to a non-compliant cryoballoon system regarding procedural characteristics and outcomes.

Methods:
122 consecutive paroxysmale and persistent AF patients were prospectively enrolled in our study. We treated them with either a new compliant (POLARx™, Boston Scientific) or a non-compliant (Arctic Front Advance Pro™, Medtronic) cryoballoon system. Procedural characteristics and outcomes of the two ablation systems were compared.

Results:
Mean age of patients was 67.0±12.0 years, 44% of the cohort were female (54 patients). Comparison of baseline characteristics regarding cardiovascular risk factors (hypertension, diabetes, hyperlipoproteinemia, CHADS-VASc score) and left atrial diameter revealed no significant difference between groups.

Total procedure duration and fluoroscopy time were shorter in patients treated with the non-compliant cryoballoon system (non-compliant vs. compliant: total procedure duration: 68.7±22.4 vs. 81.0±27.0 minutes, p=0.007; fluoroscopy time: 12.6±4.9 vs. 15.5±6.8 minutes, p=0.009). Total number of ablations per patient and per vein showed no significant difference (non-compliant vs. compliant: per patient: 5.9±2.1 vs. 6.3±1.9 ablations, p=0.282; per vein: 1.5±0.6 vs. 1.7±0.7, p=0.121). Mean follow-up was 8 months (240.3±127.5 days). Kaplan-Meier analysis showed no significant difference between groups regarding freedom from atrial fibrillation or atrial tachycardia recurrence (freedom from atrial arrhythmia: non-compliant vs. compliant: 68% vs. 65%, log rank p=0.903).

Conclusion:
Handling of the novel compliant cryo-balloon system results in longer procedure duration and fluoroscopy time. Regarding outcome there was no difference in atrial arrhythmia recurrence between the two cryoballoon ablation systems.