Background: Alcohol septal ablation (ASA) is an alternative treatment for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients refractory to pharmacological therapy. We sought to evaluate the immediate and long-term incidence of death and changes in life quality in a consecutive cohort submitted to ASA. Methods and Results: Between October 1998 and December 2013, a total of 56 patients (mean age 53.2 +/- 15.5) with symptomatic refractory HOCM were treated with ASA and followed during 15 years (mean 864 years). There were 7 (12.5%) deaths, 2 (3.6%) being of cardiac cause. The Kaplan-Meier survival probability estimate was 96.4% at 1 year, 87.7 at 5 years and 81.0% at 12 years post-ASA. Significant improvement was observed in life quality assessed by DASI index and NYHA functional class as well as in the left ventricle outflow tract (LVOT) gradient reduction (from 92.8 +/- 3.3 mm Hg to 9.37 +/- 6.7 mm Hg, P<0.001) and septum thickness (from 23.9 +/- 0.6 mm to 12.9 +/- 1.0 mm, P<0.001). Only one patient (1.7%) required permanent pacemaker immediately after ASA. During follow-up, one patient had a repeated ASA, three patients underwent myectomy and other four required ICD/pacemaker. In the multivariate model only postASA LVOT residual gradient and left ventricle mass were associated with worse prognosis. Conclusions: In this long-term clinical follow-up without losses, ASA was effective in improving quality of life and NYHA functional class, with relatively low mortality and very low need for immediate permanent pacemaker implantation. (C) 2016 Wiley Periodicals, Inc.