Global burden of ischemic heart disease attributable to temperature extremes in adults aged 40 years and older: Trends, inequalities, and projections (1990-2050).

Ischemic heart disease (IHD) remains the leading cause of global mortality. Apart from traditional risk factors like hypertension and dyslipidemia, ambient temperature extremes-both cold and heat-have increasingly been recognized as important but underexplored contributors to IHD burden, with the impact of climate change necessitating a deeper understanding of temperature-related cardiovascular risks. Here we performed a cross-sectional analysis of Global Burden of Disease 2021 data stratified by region, sex, age, and Socio-Demographic Index (SDI) aiming to demonstrating the burden of temperature extremes-related IHD. Temporal trends were quantified using estimated annual percentage change (EAPC), inequalities were assessed via the slope index and concentration index, and autoregressive integrated moving average models were used to project burden through 2050. In 2021, cold-related IHD accounted for 505,300 deaths and 9.96 million disability-adjusted life years (DALYs) worldwide. Cold-related mortality and DALYs declined since 1990 (EAPC = -1.73), whereas heat-related IHD-although smaller in absolute terms-rose over time (EAPC = 1.68). High-SDI regions experienced the largest reductions in cold-related IHD, while low-SDI regions exhibited the steepest increases in heat-related burden. Age- and sex-specific patterns differed: in males both cold- and heat-related burdens peaked at 60-69 years; in females cold-related burden peaked at 80-84 years and heat-related burden at 65-69 years. Projections suggest a continued decline in cold-related IHD but a rising heat-related burden. These findings underscore the need for climate-sensitive public health strategies to mitigate temperature-related cardiovascular risk, particularly in less developed regions.