Surgical myectomy versus alcohol septal ablation for obstructive hypertrophic cardiomyopathy. Will there ever be a randomized trial?

Dynamic left ventricular outflow tract obstruction is an important pathophysiologic feature of hypertrophic cardiomyopathy (HCM) and a predictor of clinical deterioration and cardiovascular mortality. Patients with marked obstruction and severe limiting symptoms refractory to maximum medical management are considered candidates for invasive septal reduction therapy, which includes surgical myectomy and alcohol septal ablation (ASA). Availability of both surgical myectomy and ASA has polarized the cardiovascular community concerning the most appropriate implementation of these two interventions. The ensuing controversy of whether myectomy and ASA are truly equivalent options has resulted in calls for a prospective randomized trial. However, upon analysis, such a myectomy versus ASA trial, adequately powered to compare the key issue of long-term outcome, poses a myriad of practical problems that seem virtually insurmountable. Therefore, it is appropriate to revisit this evolving debate at this time, identify the unique obstacles to a randomized study design, and achieve some clarity concerning the most realistic clinical strategies for symptomatic patients with HCM and outflow obstruction.