Efficacy and safety of cryoballoon ablation combined with vein of Marshall ethanol infusion for persistent atrial fibrillation: a comparative cohort study.

Background: Ablation strategies for persistent atrial fibrillation (AF) remain controversial. Vein of Marshall ethanol infusion (VOM-EI) has been proposed to improve outcomes of catheter ablation for AF. This study aimed to evaluate the efficacy and safety of combining cryoballoon ablation (CBA) with VOM-EI in patients with persistent AF. Methods: This was a single-center, real-world, non-randomized cohort study including consecutive patients with persistent AF who underwent CBA with or without VOM-EI between March 2021 and May 2024.Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were applied retrospectively to balance baseline characteristics between groups. The primary endpoint was freedom from atrial tachyarrhythmia at 12 months postablation. Safety outcomes included procedural complications and all-cause mortality. Results: After PSM, 47 patients in the CBA + VOM-EI group and 94 in the CBA-alone group were included in the analysis. At 12 months, freedom from atrial tachyarrhythmia was higher in the CBA combined with VOM-EI group (78.7%) compared with the CBA-alone group [57.4%; hazard ratio (HR): 0.42; 95% confidence interval (CI): 0.20-0.87; Conclusion: CBA combined with VOM-EI is a feasible, effective, and safe strategy for treating persistent AF, with approximately 80% of patients remaining free from atrial arrhythmia recurrence at 1-year follow-up and a low incidence of complications. In addition, elevated LAD and longer AF duration were considered risk factors for atrial arrhythmia recurrence. These findings necessitate large-scale randomized controlled studies for further validation.