Hypertrophic cardiomyopathy: The need for randomized trials

Hypertrophic cardiomyopathy (HCM) is a complex cardiac condition characterized by variable degrees of asymmetric left ventricular (LV) hypertrophy, generally associated with mutations in sarcomere protein genes. While generally perceived as rare, HCM is the most common genetic heart disease with over one million affected individuals in Europe alone and represents a prevalent cause of sudden cardiac death in the young. To date, HCM remains an orphan disease, as recommended treatment strategies are based on the empirical use of old drugs with little evidence supporting their clinical benefit in this context. In the six decades since the original description of the disease, less than fifty pharmacological studies have been performed in HCM patients, enrolling little over 2,000 HCM patients, mostly comprising small non-randomized cohorts. No specific agent has been convincingly shown to affect outcome, and critical issues such as prevention of myocardial energy depletion, microvascular ischemia, progressive myocardial fibrosis and the peculiar mechanisms of arrhythmogenesis in HCM still need to be addressed in a systematic fashion. However, there is increasing evidence that a variety of drugs may counter the effects of sarcomere protein mutations and the resulting pathophysiological abnormalities at the molecular, cellular and organ level. Following major advances in our understanding of HCM and increasing opportunities for networking among large international referral centres, the opportunity now exists to identify potentially effective treatments and implement adequately designed pharmacological trials, with the ultimate aim to impact the natural course of the disease, alleviate symptoms and improve quality of life in our patients.