Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: Safe and Apparently Efficacious But Does Reporting of Aggregate Outcomes Hide Less-Favorable Results, Experienced by a Substantial Proportion of Patients?

Aims: To describe individual and aggregate outcomes for patients undergoing alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM).

Methods: Retrospective case series reviewing all patients undergoing ASA at a United Kingdom tertiary referral center from 2000-2012. Aggregate and individual outcomes are described in terms of symptomatic and hemodynamic response.

Results: Eighty-eight patients were reviewed. Alcohol was delivered in 84, with clinical status data available in 82 and hemodynamic data available in 74. All patients had resting or exercise stress left ventricular outflow tract (LVOT) gradient >50 mm Hg. Mean age was 60.3 ± 14.3 years. Follow-up period was 4.2 ± 3.3 years. Twenty-four patients (27%) required ≥2 procedures. Complete heart block was observed in 17%. New York Heart Association (NYHA) class pre ASA was 2.80 ± 0.46, improving to 1.92 ± 0.84 post ASA (P<.001). Fifty-eight out of 82 patients (71%) had improved NYHA class. Resting peak gradient was 99.80 ± 45.86 mm Hg. Post-ASA peak gradient fell to 23.77 ± 41.87 mm Hg (P<.001). Sixty-one out of 74 patients (82%) had successful treatment of LVOT gradient. A successful outcome in both symptomatic and gradient treatment was seen in 66% of patients. No patient who received alcohol suffered sudden cardiac death. Fifteen patients had implantable cardioverter defibrillator implantation; no appropriate therapy was delivered.

Conclusions: ASA is safe, with few major complications. Aggregate outcomes are good, but can hide individual failure. There is a need to refine case selection, procedure planning, and performance to secure more uniform favorable outcomes.