One-year outcome using a size-adjustable cryoballoon in patients with atrial fibrillation

Abstract Introduction The size-adjustable cryoballoon (SA-CB) has been recently introduced into clinical use for pulmonary vein (PV) isolation. The clinical data on long-term outcome is still limited. We sought to analyze real-world data on novel SA-CB. Methods This multi-center observational study included atrial fibrillation (AF) patients who underwent PV isolation using SA-CB and could be followed up for at least 3 months postoperatively. Results In 407 patients (68 ± 11 years, 279 men, 251 paroxysmal AF), 1,528 (95.9%) out of targeted 1,594 PVs were successfully isolated with SA-CB (43.2% with 31-mm balloon) with 76.3% of single shot isolation rate, and 4.1% of touch-up rate. In 61.7% of the patients, additional ablation (45.0% left atrial posterior wall isolation, 19.2% superior vena cava isolation, and 16.0% mitral isthmus ablation) underwent. At 1-year after single procedure, 91.7% of the patients were free from recurrent AF. Cox’s proportional models determined that nadir temperature in right superior PV (HR = 1.075; 95%CI = 1.023–1.129; P = 0.0039) and using 31-mm balloon for all PVs (HR = 3.238; 95%CI = 1.784–5.877; P 0.0001) were significantly associated with AF recurrence. Conclusion Combined with SA-CB ablation with additional ablation showed high success rate with more than 90% in patients with atrial fibrillation. However, all PV isolation using 31-mm balloon surprisingly showed worse outcome.