A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy - The Baylor experience (1996-2002)

Background: There is a paucity of data on the long-term outcome of alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). Hypothesis: The study was undertaken to evaluate the longer-term outcome of ASA therapy for symptomatic HOCM. Methods: In all, 137 patients were enrolled consecutively (1996-1999) and 130 (95%) (74 men, 56 women, aged 51 ± 17 years) underwent ASA and had serial prospective follow-up for up to 5 years (mean follow-up 3.6 ± 1.4 years). Evaluation included angina (Canadian Cardiovascular Society [CCS] score), dyspnea (New York Heart Association [NYHA] class), duration of exercise on treadmill, and echocardiographic indices. Results: Ethanol (3.5 ± 1.5 cc), injected into 1.5 ± 0.6 arteries, induced a mean peak plasma creatine kinase (CK) of 1676 ± 944 units. Complications of procedures included death 1.5% (2/130), heart block requiring permanent pacemaker 13% (17/130), and coronary dissection 4.4% (6/130). Baseline versus last follow-up visit: NYHA class decreased from 3.0 ± 0.4 to 1.2 ± 0.6 (p < 0.01); CCS angina score from 2.0 ± 0.8 to 0.08 ± 0.4 (p < 0.01); and duration of exercise increased from 322 ± 207 to 443 ± 200 s (p < 0.01). Resting left ventricular outflow tract gradient at baseline versus last follow-up visit showed a decrease from 74 ± 30 to 4 ± 13 (p < 0.01), and the dobutamine-provoked gradient of 88 ± 29 decreased to 21 ± 21 (p < 0.01) mmHg. All-cause mortality over the duration of follow-up was 7.7% (10) giving an annual rate of 2.1%, and cardiac mortality was 2.3% (3) reflecting an annual rate of 0.6%. Conclusions: Alcohol septal ablation decreased symptoms and improved exercise performance, indicating that it is an effective procedure for symptomatic HOCM.