Very long-term follow-up of pulmonary vein isolation using cryoballoon for catheter ablation for atrial fibrillation

Cryoballoon pulmonary vein isolation (CB-PVI) has become an established treatment for atrial fibrillation (AF). However, data on long-term outcomes beyond 5-years is scarce.

This prospective analysis aimed to evaluate the very long-term outcome after CB-PVI.

Data from consecutive patients treated with CB-PVI for symptomatic AF between 2012 and 2018 in 13 institutions were analyzed. Patients with ≥5-year follow-up after the index procedure were included. Arrhythmia recurrence was defined as AF or atrial tachycardia (AT) lasting >30 seconds beyond a 3-month blanking period.

1330 patients were enrolled (28.4% female, mean age was 60.1±10.5 years). Median (IQR) CHA₂DS₂-VASc was 1.0 (0.0-2.0) while median (IQR) EHRA score was 2.0 (1.0-2.0). Paroxysmal AF patients were 73.1%, median AF duration was 36.0 (13.0-75.0) months. Overall, 4.4% of patients experienced a periprocedural complication with the most frequent being a transient diaphragmatic paralysis (2.3%). The rate of AF/AT recurrences progressively increased over time [event rate: 17.1% (15.2%-19.3%) at 1-year, 34.7% (32.2%-37.3%) at 5-year, 52.5% (49.4%-55.8%) at 8-year follow-up]. 78.3% patients were free from antiarrhythmic drug therapy at last available follow-up. Kaplan-Meier curves showing incidence of AF recurrences, stratified per AF pattern and per the use of AADs have been shown in Figure 1. Recurrences were mostly paroxysmal, with a low incidence of progression to permanent AF in the entire cohort (n=93; 7.0%). Importantly, 15.7% patients underwent a redo ablation for AF during follow-up. Among those, in 45.9% of cases all PVs were isolated; the median number of PVs isolated after the index procedure was 3 [1-4] veins. The only independent predictor of arrhythmia recurrences was AF type (Persistent AF: HR=1.37; CI 1.20-1.43, p<0.001) at multivariate analysis. In terms of adverse events during follow-up, there were 6 thromboembolic events (0.5%, including 4 strokes and 2 TIAs) and 4 major bleeding events (0.3%).

CB-PVI as the index procedure for AF ablation resulted in a favorable long-term outcome in patients with symptomatic AF, with limited progression towards persistent AF during follow-up. Persistent AF was the strongest predictor of recurrences at long-term follow-up.Figure 1