Effect of Ethanol Infusion via the Vein of Marshall on Atrial Tachyarrhythmia With Mitral Valve Surgical History

BACKGROUND: It is unclear whether ethanol infusion via the vein of Marshall (EIVOM) could help block mitral isthmus conduction and improve prognosis in atrial fibrillation/tachycardia (AF/AT) patients with mitral valve (MV) surgical history. METHODS: This was a multicenter, retrospective, propensity-matched study from January 2022-April 2024. AF/AT patients with MV surgical history were divided into two groups according to ablation strategies: catheter ablation (CA) alone or combined with EIVOM. Efficacy and safety outcomes were analyzed. RESULTS: 53 patients underwent CA plus EIVOM (49 patients had successful EIVOM), and 53 patients were selected through the population who underwent CA alone through propensity score matching. There was no significant difference in baseline characteristics between the two groups. Bidirectional conduction block was achieved in 42 patients (79.2%) for the mitral isthmus in CA+EIVOM group, which was significantly higher than that in CA alone group (30, 56.6%) (p = 0.013). After 12 months, 36 of 53 patients (67.9%) assigned to undergo CA plus EIVOM and 24 of 53 patients (45.3%) assigned to undergo CA alone remained free from atrial arrhythmias without taking antiarrhythmic drugs. The HR was 0.53 (95% CI, 0.30-0.95; p = 0.029). The incidence of complications was similar between the two groups (CA + EIVOM: 4, 7.5% vs. CA: 3, 5.7%; p = 1.000). CONCLUSIONS: Among AF/AT patients with MV surgical history, addition of EIVOM to CA, compared with CA alone, significantly improved the blocking rate of mitral isthmus, as well as freedom from atrial arrhythmias within 12 months.