Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: Lower alcohol dose reduces size of infarction and has comparable hemodynamic and clinical outcome

Patients with highly symptomatic hypertrophic obstructive cardiomyopathy (HOCM) are considered to be good candidates for percutaneous transluminal septal myocardial ablation (PTSMA). However, there is ongoing discussion regarding the optimal dose of alcohol injected into target septal artery and the impact of infarct sizes on the clinical and hemodynamic outcome. Thirty-four patients with symptomatic HOCM receiving maximum medical therapy were consecutively enrolled. Patients were randomized in a 1:1 ratio into one of the two arms according to dose of injected alcohol during echocardiography-guided PTSMA procedure. Clinical, electrocardiographic, and echocardiographic evaluation were performed 6 months after the procedure in all the patients. Both groups of patients matched in all clinical and echocardiographic data. The dose of alcohol injected was 1.6 +/- 0.4 and 3.4 +/- 0.9 (P0.001) with subsequent peak of CK-MB 1.9 and 3.2 microkat/L (P0.05) in group A and B, respectively. There was a correlation between amount of injected alcohol and the peak of CK-MB (r = 0.58; P0.01), whereas no significant relationship (r = 0.16; P = NS) was documented between the peak of CK-MB and left ventricular outflow gradient at follow-up. At 6-month follow-up, both groups of patients were not significantly different with regard to symptoms or electrocardiographic and echocardiographic findings. In conclusion, this study suggests that the low dose (1- 2 ml) of alcohol injected into target septal branch reduces size of necrosis. Moreover, the low dose is probably as safe and efficacious as usually used doses (2-4 ml).