Aims: Data regarding hypertrophic cardiomyopathy (HCM)-related mortality in United States young adults, defined as those aged between 25 and 44 years, are lacking. We sought to assess the trends in HCM-related mortality among US young adults between 1999 and 2019 and determine differences by sex, race, ethnicity, urbanization and census region. Methods: Mortality data were retrieved by the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiologic Research (WONDER) dataset from January 1999 to December 2019. Age-adjusted mortality rates (AAMRs) were assessed using the Joinpoint regression modeling and expressed as estimated average annual percentage change (AAPC) with relative 95% confidence intervals (95% CIs). Results: Over 20-year period, the AAMR from HCM in US young adults linearly decreased, with no differences between sexes [AAPC: -5.3% (95% CI -6.1 to -4.6), P < 0.001]. The AAMR decrease was more pronounced in Black patients [AAPC: -6.4% (95% CI -7.6 to -5.1), P < 0.001], Latinx/Hispanic patients [AAPC: -4.8% (95% CI -7.2 to -2.36), P < 0.001] and residents of urban areas [AAPC: -5.4% (95% CI -6.2 to -4.6), P < 0.001]. The higher percentages of HCM-related deaths occurred in the South of the country and at the patient's home. Conclusion: HCM-related mortality in US young adults has decreased over the last two decades in the United States. Subgroup analyses by race, ethnicity, urbanization and census region showed ethnoracial and regional disparities that will require further investigation.
