Efficacy of Vein of Marshall Ethanol Infusion in Persistent Atrial Fibrillation Ablation: A Meta-Analysis of RCTs

Catheter ablation for persistent atrial fibrillation (AF) exhibits suboptimal outcomes after pulmonary vein isolation (PVI) alone. The vein of Marshall (VOM) has emerged as an adjunctive ablation target, through which ethanol infusion can achieve transmural lesions in regions resistant to radiofrequency ablation.

To evaluate the efficacy and safety of adjunctive VOM ethanol infusion in patients undergoing catheter ablation for persistent AF.

We conducted a meta-analysis of randomized controlled trials (RCTs) comparing PVI ± linear ablation with versus without VOM ethanol infusion for persistent AF. The primary outcome was freedom from AF recurrence, analyzed using odds ratios and hazard ratios for time-to-event data. Secondary outcomes included procedural metrics and complications. Data were pooled using random-effects models.

Four RCTs (n = 1045 patients) were included. VOM ethanol infusion significantly improved sinus rhythm maintenance (65.8% vs. 48.6%; absolute difference 17.2%; OR: 1.68, 95% CI: 1.13-2.49, p = 0.025). Time-to-event analysis showed consistent benefit of maintaining sinus rhythm during the first post-procedure year (pooled HR: 0.73, 95% CI: 0.59-0.91, p = 0.005) with high mitral isthmus block rates (90%). Subgroup analysis showed consistent sinus rhythm maintenance whether ethanol was added to PVI alone (OR: 1.66) or PVI with linear ablation (OR: 1.69). Fluoroscopy time was longer (+10.3 min, p = 0.0009) with VOM ethanol infusion. Complication rates were similar (OR: 1.55, p = 0.46).

Adjunctive VOM ethanol infusion significantly improves ablation outcomes in persistent AF without increasing major complications. It represents a promising strategy to enhance durable rhythm control. Further research is required to evaluate long-term outcomes.