Long-term Outcomes of Pediatric-Onset Hypertrophic Cardiomyopathy and Age-Specific Risk Factors for Lethal Arrhythmic Events

Question What is the long-term outcome of pediatric-onset hypertrophic cardiomyopathy, and are there age-specific risk factors for lethal arrhythmic events? Findings In this cohort study, 24 of 100 patients with hypertrophic cardiomyopathy diagnosed between age 1 and 16 years had major events in 9.2 years (mean rate, 1.9%per year), including 19 lethal arrhythmic events (at a mean [SD] age of 23.1 [11.5] years and up to 33 years after diagnosis) and 5 heart failure–related events. Risk was predicted by limiting symptoms at initial evaluation and Troponin I or T gene mutations. Meaning Pediatric-onset hypertrophic cardiomyopathy is characterized by adverse outcomes driven mainly by arrhythmic events; risk extends well beyond adolescence, requiring unchanged levels of surveillance into adulthood, and predictors of risk in this age group differ from those of adult populations