Follow-Up of Alcohol Septal Ablation for Symptomatic Hypertrophic Obstructive Cardiomyopathy. The Baylor and Medical University of South Carolina Experience 1996 to 2007

Objectives: This study sought to determine the long-term outcome of alcohol septal ablation (ASA). Background: There are inadequate data on the long-term outcome of ASA for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). Methods: Six hundred and twenty-nine patients were enrolled consecutively (1996 to 2007) and 98.4% (n = 619) underwent ASA with 92% follow-up in 2007. Evaluation included deaths, procedural complications, pacemaker requirement, repeat ASA, and myectomy/valve surgery. Follow-up parameters included angina (Canadian Cardiovascular Society score), dyspnea (New York Heart Association functional class), exercise time, and echocardiographic indices (septal thickness, ejection fraction, resting and provoked gradients). Results: Ethanol (2.6 ± 1.0 ml) was injected into 1.3 ± 0.5 septal arteries, inducing a septal infarct. Complications included death 1% (n = 6), permanent pacemaker requirement 8.2% (n = 52), coronary dissection 1.3% (n = 8), and worsening mitral regurgitation 0.3% (n = 2). The mean follow-up was 4.6 ± 2.5 years (range: 3 months to 10.2 years). During follow-up, New York Heart Association functional class decreased from 2.8 ± 0.6 to 1.2 ± 0.5 (p < 0.001); Canadian Cardiovascular Society angina score decreased from 2.1 ± 0.9 to 1.0 ± 0 (p < 0.001); and exercise time increased from 4.8 ± 3.3 to 8.2 ± 1.0 (p < 0.001) min. The resting and provoked left ventricular outflow tract gradients decreased progressively (p < 0.001) and remained low during follow-up. The septal thickness decreased from 2.1 ± 0.5 cm to 1.0 ± 0.1 cm (p < 0.001) and the ejection fraction decreased from 68 ± 9% to 62 ± 3% (p < 0.001). The survival estimates at 1, 5, and 8 years were 97%, 92%, and 89%, respectively. Conclusions: The initial benefits of ASA were maintained during follow-up.