Adjunctive Vein of Marshall Ethanol Infusion During Atrial Fibrillation Ablation: A Systematic Review and Meta-Analysis

INTRODUCTION: Catheter ablation (CA) for atrial fibrillation (AF) can be associated with limited efficacy. Due to its autonomic innervation, the vein of Marshall (VOM) is an attractive target during AF ablation. In this meta-analysis, we aimed to evaluate the efficacy and safety of adjunctive ethanol infusion of VOM (VOM-EI) in AF ablation. METHODS: We performed a comprehensive literature search for studies that evaluated the efficacy and safety of VOM-EI in AF ablation compared to AF catheter ablation alone. The primary outcome of interest was late (≥3 months) AF or atrial tachycardia (AT) recurrence. The secondary outcomes included acute mitral isthmus bidirectional block (MIBB) and procedural complications (pericardial effusion, stroke, or atrio-esophageal fistula). Pooled relative risk (RR) and corresponding 95% confidence intervals (CIs) were calculated using the random-effects model. RESULTS: A total of four studies, including 804 AF patients (68.2% with persistent AF, the mean age of 63.5±9.9 years, 401 patients underwent VOM-EI plus CA vs. 403 patients who had CA alone), were included in the final analysis. VOM-EI group was associated with a lower risk of late AF/AT recurrence (RR:0.63; 95% CI:0.46-0.87; P = 0.005), and increased probability to achieve acute MIBB (RR:1.39; 95% CI:1.08-1.79; P = 0.009) without an increase in procedural complications (RR:1.05; 95% CI:0.57-1.94; P = 0.87). CONCLUSIONS: Our meta-analysis demonstrated that adjunctive VOM-EI strategy is more effective than conventional catheter ablation with similar safety profiles.