Predictors of arrhythmia recurrence after cryoballoon ablation in paroxysmal atrial fibrillation: a comparative analysis from the CONTRAST-CRYO trial.

BACKGROUND: Factors associated with arrhythmia recurrence after atrial fibrillation (AF) ablation with different cryoballoon systems remain unclear. We sought to assess the predictors of arrhythmia recurrence after cryoballoon ablation using two different cryoballoon systems. METHODS: This substudy of the CONTRAST-CRYO trial compared the novel cryoballoon (NCB) with the conventional cryoballoon (CCB) for pulmonary vein (PV) isolation (PVI) in patients with paroxysmal AF. A total of 198 patients (66 ± 12 years; 152 men; 22 with structural heart disease [SHD]) underwent ablation (CCB, 101; NCB, 97) and were followed for 12 months. RESULTS: Early recurrence of atrial tachyarrhythmias (ERATs) occurred in 17(8.6%) patients within the blanking period. The 1-year arrhythmia-free survival was 90.6%, with no significant difference between groups (p = 0.60). The prevalence of SHD was significantly higher among patients with recurrence (25.0% vs. 9.6%, p = 0.037). In multivariable analysis, SHD (hazard ratio [HR] = 3.88, 95% confidence interval [CI] = 1.36–11.09, p = 0.011) and ERATs (HR = 4.83, 95%CI = 1.69–13.80, p = 0.003) independently predicted recurrence. In the CCB subgroup, a longer time-to-isolation in the left superior PV (LSPV) was the only factor associated with recurrence (HR = 1.03, 95% CI = 1.01–1.06, p = 0.007). In the NCB subgroup, a greater number of right superior PV (RSPV) applications, longer time to − 40 °C in the RSPVs and right inferior PVs, and the presence of ERATs were significantly associated with recurrence. CONCLUSIONS: In this CONTRAST-CRYO sub-analysis, SHD and ERATs were independent predictors of arrhythmia recurrence. LSPV factors were associated with recurrence in the CCB system, whereas right PV factors were associated in the NCB system.