Redo Pulmonary Vein Isolation After Index Cryoballoon Ablation: Cryoballoon Versus Radiofrequency Redo Ablation for Recurrent Atrial Fibrillation.

Background: Data guiding the choice of energy source for redo pulmonary vein isolation (PVI) after index cryoballoon (CB) PVI are limited. We compared procedural findings, pulmonary vein (PV) reconnection patterns, and reported clinical outcomes after CB-redo versus radiofrequency (RF)-redo ablation in patients with recurrent atrial fibrillation (AF) following an index CB-PVI. Methods: We included a retrospective single-center cohort of 61 consecutive patients with symptomatic recurrent AF after prior CB-PVI who underwent redo ablation between 2019 and 2020 (CB redo, n = 32 vs. RF redo, n = 29). All patients had an index CB PVI (28 mm balloon). The primary reported outcome was freedom from atrial tachyarrhythmia after the blanking period. Results: Mean age was 66 ± 10 years; 41 (67%) were men. Time from index procedure to redo: CB redo 323 ± 72 days vs. RF redo 238 ± 48 days (p < 0.001). All patients had ≥1 PV at redo. Mean reconnected PVs per patient: CB 2.1 ± 1.1 vs. RF 1.7 ± 0.6 (p = 0.08). Right inferior PV reconnection was more frequent after CB redo (69% vs. 41%; p = 0.03). Early recurrence during the 90-day blanking period was CB 8/32 (25.0%) vs. RF 9/29 (31.0%) (p = 0.54). At 12 months, recurrence was CB 7/32 (21.9%) vs. RF 6/29 (20.7%) (unadjusted p = 0.75). Kaplan-Meier log-rank p = 0.88. Adjusted Cox HR (CB vs. RF) = 1.05 (95% CI 0.40-2.76; p = 0.92). Total outcome events = 13. No major periprocedural complications were observed. Conclusions: No statistically significant difference in arrhythmia recurrence between CB redo and RF redo strategies was detected. However, the small sample size, limited event count, non-random treatment selection, and wide statistical uncertainty preclude conclusions regarding equivalence.