Letter by Maron et al Regarding Article, "Genotype and Lifetime Burden of Disease in Hypertrophic Cardiomyopathy: Insights From the Sarcomeric Human Cardiomyopathy Registry (SHaRe)".

March 19, 2019 1557 Barry J. Maron, MD Ethan J. Rowin, MD Martin S. Maron, MD To the Editor: As experienced hypertrophic cardiomyopathy (HCM) clinical investigators, we are compelled to ask Ho et al1: How did HCM suddenly become a bad disease...again? We were very surprised to encounter data from the SHaRe registriy (Sarcomeric Human Cardiomyopathy Registry) in Circulation1 that promote a vision of HCM we no longer recognize (ie, grim, unrelenting, incompletely treated, and with poor outcomes). Indeed, it is difficult to align the high mortality reported for HCM by Ho et al1 with the very low mortality rates (0.5% per year)2 associated with good quality of life and the data reporting the substantial impact that highly effective contemporary treatment interventions have made in this disease, including implantable defibrillators for sudden death prevention, low risk:high benefit surgical myectomy to reverse progressive heart failure, and atrial fibrillation catheter-ablation (and Maze procedure) and anticoagulation for stroke prevention.2–5 Therefore, we present 2 specific questions for consideration. First, what is the explanation for 2 polar opposite views of prognosis and outcome for the same disease, and could the outcome data of Ho et al1 have been skewed unfavorably by using less robust therapeutic initiatives? For example, the SHaRe data seem to extend back almost 60 years to the inception of HCM and well before many effective treatments were available (although, paradoxically, the authors report a median follow-up period of only 2.9 years). The confusion potentially created by these data for a disease too often mischaracterized to patients could adversely affect attitudes of clinicians in the contemporary practicing cardiovascular community, a particularly unfortunate possibility in this modern treatment era for HCM. Second, the management initiatives specifically for obstructive HCM in the SHaRe registry are unclear, although almost one-third of all patients had outflow gradients (including many with limiting symptoms). Remarkably, treatments for symptomatic obstructive HCM, such as surgical myectomy (or alternatively, alcohol septal ablation), are not mentioned, even though these interventions are known to reliably reverse heart failure symptoms and extend longevity.5 Hence, could the high HCM mortality reported by Ho et al1 be attributable in part to the authors’ less aggressive treatment of obstructive HCM? These questions are posed here so that clinicians may fully understand the limitations of the SHaRe data, in contrast to the comprehensive contemporary treatment-oriented studies that have created a much more realistic and optimistic appraisal of clinical course, treatment, and prognosis for patients with HCM.2–5