One-Year Clinical Outcomes of Novel Dual-Sized Cryoballoon Ablation for Atrial Fibrillation.

Background: Clinical outcomes after atrial fibrillation (AF) ablation using the novel dual-sized cryoballoon (DS-CB) are limited. This study aimed to analyze real-world data on the DS-CB.

Methods: This multicenter observational study included consecutive AF patients who underwent pulmonary vein (PV) isolation (PVI) using a DS-CB catheter (28-mm/31-mm).

Results: In 407 patients (68 ± 11 years, 279 men, 251 paroxysmal AF[PAF]), 1528 (95.9%) out of 1594 targeted PVs were successfully isolated with DS-CBs. The total application number and application time were 5 [4-6] and 812 ± 207 s, respectively. Cryoballoon-related phrenic nerve injury (PNI) occurred in 23 (5.6%) patients, with 4.7% in the right superior PV (RSPV) and 1.0% in the right inferior PV. All but one patient recovered within 12 months. Additional ablation beyond CB-PVI was performed in 251 (62%) patients. The 1-year arrhythmia freedom was 91.7% (93.3% for PAF and 89.5% for non-PAF, p = 0.08), with antiarrhythmic drug use in 23 (9.2%) and 32 (20.6%) PAF and non-PAF patients, respectively. Forty-three patients experienced early recurrence of AF (ERAF) within 2 months of follow-up. In a multivariate Cox regression analysis, including baseline and procedural parameters, a higher nadir balloon temperature in the RSPV (hazard ratio[HR] = 1.076, 95% confidence interval[CI] = 1.024-1.130, p < 0.01) and all 4 PVI with 31-mm balloons (HR = 3.085, 95% CI = 1.701-5.595, p < 0.01) were significantly associated with arrhythmia recurrence. In the multivariate analysis including all parameters, ERAF (HR = 5.066, 95% CI = 2.928-8.767, p < 0.01) was the strongest predictor of arrhythmia recurrence.

Conclusions: The 1-year arrhythmia freedom post-DS-CB ablation was 91.7% in real-world clinical practice; however, right PNI remained a common complication, even with the balloon size adjustability.