Empirical superior vena cava cryoballoon ablation fails to improve freedom from atrial fibrillation in paroxysmal atrial fibrillation: 2-year outcomes of a randomized trial

Background Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for atrial fibrillation (AF). However, non-pulmonary vein triggers, particularly from the superior vena cava (SVC), may contribute to AF recurrence. While observational studies have suggested potential benefit of empirical SVC isolation (SVCI) in paroxysmal AF (PAF), randomized data are limited. Aim To compare 2-year efficacy outcomes of PVI alone versus PVI plus empirical SVCi using a fourth-generation cryoballoon in patients with PAF. Methods This unblinded, prospective, single-centre randomized trial enrolled consecutive patients with PAF. Participants were assigned 1:1 to PVI-only or PVI+SVCi. Procedures were performed with a fourth-generation cryoballoon. The primary endpoint was freedom from any documented AF episode >30 seconds after a single procedure at 2-year follow-up. Acute and safety outcomes have been reported previously [1]. Results A total of 149 patients (62.4% male; median age 63 years; median CHA2DS2-VASc score 2) were randomized (PVI-only: n=74; PVI+SVCi: n=75). At 2 years, overall freedom from AF was 76.5% (95% CI, 69.1–82.6%), with median time to recurrence 9.5 months (IQR, 6–15). Freedom from AF was higher in the PVI+SVCi group (81.3%, 95% CI, 70.8–88.9%) versus PVI-only (71.6%, 95% CI, 60.2–80.9%), but the difference was not statistically significant (log-rank p=0.139). The hazard ratio for AF recurrence with PVI+SVCi was 0.61 (95% CI, 0.31–1.19; p=0.146). Conclusion Empirical SVC isolation did not significantly improve 2-year freedom from atrial fibrillation when added to PVI using a fourth-generation cryoballoon. The trend toward improved outcomes suggests potential clinical benefit that merits further investigation in larger multicentre studies.Freedom from AF in PVI-only vs. PVI+SVCi