Differences in Disease Trajectory, Comorbidities, and Mortality in Sarcomeric and Nonsarcomeric Hypertrophic Cardiomyopathy

BACKGROUND: Sarcomere gene variants are a key cause of hypertrophic cardiomyopathy (HCM), and have been associated with worse prognosis. However, it is unclear how comorbidities influence clinical trajectories, the timing of events, and causes of death in sarcomeric and nonsarcomeric HCM. METHODS: We conducted a multicenter longitudinal cohort study of genotyped patients with HCM in the Sarcomeric Human Cardiomyopathy registry (SHaRe). Patients were classified as sarcomeric HCM (pathogenic/likely pathogenic sarcomere variant) or nonsarcomeric HCM (genetically elusive). The influence of genetic classification and comorbidities on the sequence of cardiovascular events were assessed in time-varying Cox proportional hazards models. RESULTS: Among 6120 patients (40% women; 87% probands; 50% sarcomeric HCM), followed for a median of 5.3 years, sarcomeric HCM (n=3082) was associated with a younger age at diagnosis (median 38.1 versus 54.3 years; P