Effect of alcohol dosage on long‐term outcomes after alcohol septal ablation in patients with hypertrophic cardiomyopathy

OBJECTIVES: The aim of this study is to assess the long-term effects of alcohol dosage in alcohol septal ablation (ASA) on mortality and adverse arrhythmic events (AAE). BACKGROUND: ASA can be performed to reduce left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM). However, the effect of alcohol dosage on long-term outcomes is unknown. METHODS: This retrospective cohort study includes 296 HCM patients (age 60 ± 22 years, 58% male) who underwent ASA because of symptomatic LVOT obstruction. Twenty-nine patients (9.8%) were excluded because the alcohol dosage could not be retrieved. Primary endpoints were all-cause mortality and AAE. RESULTS: During 6.3 ± 3.7 years of follow-up, all-cause mortality and AAE rates were similar in patients who received ≤2.0 mL (n = 142) and >2.0 mL (n = 121) alcohol during ASA. Age was the only independent predictor of mortality (HR 1.1 95% CI 1.0-1.1, P < 0.001). Predictors of AAE were maximum CK-MB >240 U/L (HR 3.3 95% CI 1.5-7.2, P = 0.003), and sudden cardiac death survivor (HR 5.9 95% CI 1.7-20.3, P = 0.004). There was a mild to moderate correlation between CK-MB levels and amount of alcohol (Spearman's ρ 0.39, P < 0.001), cross-sectional area of the target septal branch ostium/ostia (Spearman's ρ 0.19, P = 0.003), and maximum ventricular wall thickness (Spearman's ρ 0.17, P = 0.006). CONCLUSIONS: Alcohol dosage appears not to have a long-term effect on mortality and AAE. A larger infarct size created by ASA increases the risk of AAE, and extended monitoring of these patients is advised.