Rheumatic heart disease burden from 1990 to 2021: an updated analysis based on the global burden of disease study 2021.

Background: Rheumatic heart disease (RHD) remains a significant contributor to cardiovascular morbidity and mortality, disproportionately affecting low- and middle-income countries. While global interventions have targeted the control of RHD, its burden and associated inequalities remain substantial. This study aims to evaluate temporal trends, socioeconomic disparities, and future projections of RHD burden across countries stratified by socio-demographic index (SDI). Methods: We analyzed data from the Global Burden of Disease Study spanning 1990 to 2021 to assess RHD incidence, prevalence, deaths, and disability-adjusted life years (DALYs). Inequality was quantified using the concentration index (CI) and slope index of inequality (SII). A decomposition analysis was conducted to attribute changes in RHD burden to population growth, population aging, and epidemiological change. Bayesian age-period-cohort models were used to forecast age-standardized rates of RHD burden through 2050. Results: From 1990 to 2021, the global age-standardized RHD burden declined substantially, particularly in high-SDI countries. However, concentration curves and inequality indices revealed persistent disparities, with low-SDI regions experiencing a disproportionately higher burden of disease. While inequalities in DALYs and mortality have improved modestly, the incidence and prevalence of the disease remain unequally distributed. Decomposition analysis showed that increases in absolute burden in low-SDI countries were primarily driven by population growth and aging, with minimal offset from epidemiological improvements. Future projections indicate continued declines in age-standardized death and DALYs rates, especially in high-SDI regions. In contrast, incidence and prevalence are expected to remain high in low-SDI countries. Conclusion: Despite global progress in reducing the overall burden of RHD, significant socioeconomic inequalities persist and are projected to continue. Strategies to reduce RHD must prioritize prevention, early intervention, and long-term care in low-resource settings.