According to a study supported by the National Institutes of Health, cardiovascular-related deaths due to extreme heat are expected to increase between 2036 and 2065 in the United States. Researchers whose work is published circulationpredicts that adults age 65 and older and black adults are likely to be disproportionately affected.
Although extreme heat currently accounts for less than 1% of heart-related deaths, modeling analyzes predict that this will change as summer days feel at least 90 degrees. This heat index, which factors in how temperature feels relative to humidity, measures extreme temperatures. Older adults and black adults will be most at risk because many have underlying medical conditions or may face socioeconomic barriers that can affect their health — such as living in areas that lack air conditioning or can absorb and trap heat, which ” Known as “heat island”.
The health burden from extreme heat will continue to increase over the next few decades. Because of the disproportionate impact of extreme heat on different populations, it is also an issue of health equity and may exacerbate already existing health disparities.”
Samid A. Khatana, MD, MPH, study author, is a cardiologist and assistant professor of medicine at the University of Pennsylvania, Philadelphia.
To make these predictions, the researchers evaluated county-level data from the 48 contiguous states between May and September of 2008-2019. Over 12 million deaths related to cardiovascular disease occurred during that time. Using environmental modeling estimates, they also found that the heat index rose by at least 90 degrees about 54 times per summer. Researchers linked extreme temperatures that occur each summer to a national average of 1,651 annual cardiovascular deaths. Some areas, such as the South and Southwest, were more affected than others, such as the Northwest and Northeast.
Using modeling analyzes to predict environmental and demographic changes, the researchers looked to 2036-2065 and estimated that each summer, about 71 to 80 days will feel 90 degrees or hotter. Based on these changes, they predicted that the number of annual heat-related cardiovascular deaths would increase by 2.6 times that of the general population -; 1,651 to 4,320. This assumption is based on greenhouse gas emissions, which trap the sun’s heat, being kept to a minimum. If emissions rise significantly, deaths could more than triple, to 5,491.
For older adults and black adults, the estimates were more pronounced. Among those age 65 and older, deaths would nearly triple if greenhouse gas emissions were held constant, from 1,340 to 3,842, or 4,894 if they were not. Among black adults, deaths more than tripled, rising from 325 to 1,512 or 2,063.
In comparing current and future populations, researchers account for multiple factors, including age, underlying health conditions, and where a person lived.
Most people adapt to extreme heat, as the body finds ways to cool itself, such as through sweating. However, people with underlying health conditions, including diabetes and heart disease, may have different reactions and be at increased risk of heart attack, irregular heart rhythm or stroke.
“Heat-related cardiovascular events affect a small proportion of adults, but this study shows how important it is for those at risk to take extra steps to avoid extreme temperatures,” said Lawrence J. Fine, MD, is a senior advisor in the Clinical Applications and Prevention Branch, Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute (NHLBI), part of the NIH.
The authors describe cooling methods that some cities are using—planting trees for shade, adding cooling centers with air conditioning, and using heat-reflective materials to pave streets or paint roofs. However, more research is needed to understand how these methods may affect population health.
“In addition to thinking about the impact of extreme temperatures in the United States, this type of modeling predicts the impact of extreme heat around the world, particularly in regions with warmer climates and disproportionately affected by health disparities,” said Flora N., director of the Division of International Training and Research at the NIH Fogarty International Center. . Katz, Ph.D.
The research was supported in part by NHLBI grant K23 HL153772.