Marshall Vein Ethanol Infusion and Mitral Isthmus Ablation for Atrial Fibrillation With Durable Pulmonary Vein Isolation

BACKGROUND: The clinical significance of adding vein of Marshall ethanol infusion (VoM-EI) and mitral isthmus (MI) ablation to left atrial posterior wall isolation (LAPWI) during repeat ablation for atrial fibrillation (AF) despite durable pulmonary vein isolation (PVI) remains unclear. We assessed whether this combined strategy improves sinus rhythm maintenance. METHODS: We retrospectively analyzed 80 consecutive patients with AF who underwent repeat ablation despite durable PVI after prior PVI-only procedures and received either LAPWI plus VoM-EI and MI ablation or LAPWI alone. RESULTS: Of the 80 patients, 27 underwent LAPWI plus VoM-EI and MI ablation (VoM-EI group) and 53 underwent LAPWI alone (control group). During a median follow-up of 591.5 days, freedom from atrial tachyarrhythmia recurrence did not differ significantly in the overall cohort on unadjusted analysis but was higher in the VoM-EI group among patients with persistent AF (log-rank p = 0.041). After multivariable adjustment, the combined strategy was associated with a lower risk of atrial tachyarrhythmia recurrence in patients with persistent AF (hazard ratio [HR] 0.38; 95% confidence interval [CI] 0.14-0.92; p = 0.03) and in the overall cohort (HR 0.37; 95% CI 0.14-0.86; p = 0.02), mainly driven by persistent AF. Propensity score matching showed a similar association (HR 0.29; 95% CI 0.11-0.75; p = 0.01). Major complication rates did not differ between the groups. CONCLUSIONS: In patients with persistent AF despite durable PVI, adding VoM-EI and MI ablation to LAPWI was associated with lower atrial tachyarrhythmia recurrence than LAPWI alone. Because the two components were applied together, this finding is hypothesis-generating.