Left Ventricular Systolic Function Following Alcohol Septal Ablation for Symptomatic Hypertrophic Cardiomyopathy

Abstract

Because alcohol septal ablation (ASA) for the treatment of symptomatic hypertrophic cardiomyopathy (HC) with left ventricular (LV) outflow tract (LVOT) obstruction results in a myocardial infarct of up to 10% of ventricular mass, LV systolic function could decline over time. We evaluated LV function during longitudinal follow-up in a cohort of patients who underwent ASA. We studied 145 consecutive patients with HC that underwent 167 ASA procedures from 2002 to 2011. Echocardiographic follow-up was available in 139 patients (96%). Echocardiographic indexes included LV ejection fraction (LVEF), mitral regurgitation severity, systolic anterior motion of the anterior mitral leaflet, and resting and provoked LVOT gradients. All patients had a baseline LVEF of >55%. LVEF was preserved in 97.1% of patients over a mean follow-up time of 3.1±2.3 years (maximum 9.7). Mild LV systolic dysfunction was observed (LVEF range 44% to 54%) in only 4 patients. Mitral regurgitation severity improved in 67% (n=112 of 138 with complete data). Resting LVOT gradient declined from a mean of 75 to 19 mm Hg (p<0.001), and provoked gradient declined from a mean of 101 to 33 mm Hg (p<0.001). New York Heart Association class improved from a mean of 2.9±0.4 to 1.3±0.5 (p<0.001). In conclusion, LV systolic function is only mildly reduced in a minority of patients after ASA for symptomatic HC; other echocardiographic and functional measures were significantly improved.