Cardiomyopathy-related mortality in the United States, 1999 to 2023: A national population-based observational study.

Cardiovascular disease remains a major global public health burden. In recent years, advances in cardiac imaging and molecular genetics have renewed clinical attention to the diagnosis, treatment, and prevention of cardiomyopathies. However, a comprehensive quantitative assessment of the overall mortality burden associated with cardiomyopathy (CM) remains limited. To address this gap, we analyzed trends and disparities in CM-related mortality in the United States between 1999 and 2023, drawing on data from the Centers for Disease Control and Prevention (CDC WONDER) database. This was a population-based retrospective observational study using U.S. national mortality data from CDC WONDER. Deaths among individuals aged ≥ 25 years were identified using ICD-10 code I42 listed as the underlying cause of death. Crude and age-adjusted mortality rates (AAMRs) were computed using the 2000 U.S. standard population, and age-specific mortality rates were used for predefined age-group analyses. Joinpoint regression analysis (version 5.1.0.0) was used to estimate annual percent changes (APCs) and average annual percent changes (AAPCs), with statistical significance set at P < .05. From 1999 to 2023, 576,693 CM-related deaths were recorded among U.S. adults aged ≥ 25 years. The AAMR declined from 15.14 to 7.11 per 100,000 population. Joinpoint regression identified no statistically significant joinpoints, with an APC and AAPC of -3.21% (95% CI: -3.34 to -3.08; P < .001) over the entire study period. Mortality remained higher among men and non-Hispanic Black individuals, and geographic heterogeneity persisted, with higher burdens observed in the Midwest and South. Age-specific mortality rates declined overall across all predefined age groups but remained highest among adults aged ≥ 85 years. In the urbanization-specific analysis limited to 1999 to 2020, AAMRs were higher in metropolitan counties at baseline, whereas a modest nonmetropolitan excess had emerged by 2020. Cardiomyopathy-related mortality in the United States declined substantially between 1999 and 2023, although important population-level disparities remained by sex, race/ethnicity, region, and age. Urban-rural disparities evolved during 1999 to 2020, with mortality initially higher in metropolitan counties and a modest nonmetropolitan excess emerging by 2020. Because this study used aggregated mortality data, these findings should be interpreted as national population-level patterns rather than individual-level risks, prognostic differences, or causal effects.