HEAT exposure could drive a dramatic rise in cardiovascular disease (CVD) burden across the USA over the next 25 years, with researchers warning that climate change and population ageing may combine to reverse decades of progress in heart health.
Heat Exposure Threatens Future Heart Health
A new modelling study estimated that heat-attributable CVD burden could more than triple by 2050 under a high greenhouse gas emissions scenario, disproportionately affecting older adults and economically disadvantaged communities.
CVD remains the leading cause of death in the USA, and growing evidence suggests that rising temperatures are becoming an increasingly important contributor to heart-related illness and mortality. Excessive heat places additional strain on the cardiovascular system, increasing the risk of conditions such as myocardial infarction, stroke, and heart failure.
To assess the potential impact of climate change on cardiovascular health, researchers analysed county-level data from 3,108 counties across the contiguous USA. Baseline estimates were derived from data collected between 2010–2016 and used to project future heat-attributable CVD burden in 2030 and 2050 under moderate and high greenhouse gas emissions scenarios.
Cardiovascular Disease Burden Set to Rise
The analysis found that the national median heat-attributable CVD burden during the baseline period was 138.5 disability-adjusted life-years (DALYs) per 100,000 population.
Under the high-emissions scenario, this burden was projected to increase to 418.2 DALYs per 100,000 by 2050, representing a threefold rise. Researchers estimated that this increase could correspond to approximately 50,000–70,000 additional cardiovascular deaths each year.
Regional differences were also observed. Although the Pacific Northwest recorded the highest baseline heat-attributable burden, Southern and Midwestern states were projected to experience the steepest increases by mid-century.
Population Ageing Adds Further Risk
The study found that demographic ageing would independently contribute to future cardiovascular burden, increasing heat-attributable DALYs by an additional 34% by 2050 regardless of temperature changes.
Older adults are particularly vulnerable to heat-related cardiovascular complications because of reduced thermoregulatory capacity and higher rates of chronic disease. As the US population continues to age, the interaction between demographic change and climate change is expected to place increasing pressure on healthcare systems.
Disproportionate Impact on Lower-Income Communities
Researchers also identified substantial socioeconomic disparities.
Middle-income and low-income counties experienced approximately twice the relative increase in heat-related cardiovascular burden compared with high-income counties.
The findings suggest that factors such as access to cooling, housing quality, healthcare availability, and community resources may influence vulnerability to extreme heat.
While the projections rely on future emissions scenarios and modelling assumptions, the authors concluded that heat mitigation strategies should become a central component of CVD prevention efforts, particularly for ageing populations and economically vulnerable communities.
Reference
Parameswaran G et al. Projected US cardiovascular disease burden from heat exposure for future greenhouse gas scenarios. JAMA Cardiol. 2026;DOI: 10.1001/jamacardio.2026.1240.
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