Background: In hypertrophic obstructive cardiomyopathy (HOCM) with medically-refractory symptoms, septal reduction therapy is indicated. Considerable debate exists regarding short- and long-term outcomes following alcohol septal ablation (ASA).
Methods: Pre-ASA clinical data, echocardiographic findings, intra-procedural findings, complications, and outcomes were recorded for all ASA procedures conducted at Mayo Clinic (Rochester, MN) between 2002-2014.
Results: 195 patients with HOCM underwent ASA; 112 (57%) female with age 67±12 years. 96% were NYHA class III-IV pre-ASA. 42 (22%) had pre-existing pacemaker. Right bundle branch block (11%), left bundle branch block (8%), and first degree atrioventricular block (25%) were seen on baseline electrocardiogram. Maximum pre-ASA gradient was 114±39 mmHg with 133 (69%) patients having resting gradient >30 mmHg. While 50 (26%) experienced intraprocedural heart block, only 21 (11%) required permanent pacemaker implantation. Immediately post-ASA, only 12/185 (6.4%) had resting gradient >30 mmHg while 24/185 (13%) had max rest/provocable (Valsalva, post-ectopic) gradient >50 mmHg. 12 (6.2%) patients experienced tamponade. Hospital length of stay was 3.9±2.8 days. There was no in-hospital mortality and 2 (1%) deaths within 30 days. At 6 months post-procedure, NYHA class decreased by 1 class in 131/148 (89%) patients and in 124/155 (80%) patients at last follow up (403 [2, 4892] days). 26 patients required repeat septal reduction: 11 (6%) underwent repeat ASA and 15 (8%) myectomy (380 [1, 2667] days from ASA).
Conclusions: ASA is associated with low procedural morbidity and mortality when performed in an experienced center. ASA is effective at reducing obstruction immediately post-procedure, resulting in sustained improvement in symptoms for a majority of patients.