Extreme Heat Related to Climate Change Could Triple Heart-Related Deaths in the US, Study Shows
Extreme heat can have a devastating impact on heart health, and a recent report reveals that the effects of climate change could make it even deadlier in the coming decades. Particularly vulnerable groups include Black adults, seniors, and people living in urban areas. According to a study published in the journal Circulation, between 2008 and 2019, the heat index in the US reached at least 90 degrees on an average of 54 days each summer. This extreme heat was associated with nearly 1,700 excess cardiovascular deaths annually.
The researchers found that if fossil-fuel development continues unchecked and minimal efforts are made to reduce planet-warming pollution, the US could experience 80 days of extreme heat each summer. This could result in over triple the number of heat-related cardiovascular deaths, reaching approximately 5,500 excess deaths per year. Even with plausible climate change mitigation measures in place, the study predicts a jump to 71 days of extreme heat per year and a 2.6 times increase in heart-related mortality by the middle of the century, leading to more than 4,300 excess cardiovascular deaths.
The National Institutes of Health’s National Heart, Lung, and Blood Institute, which partially funded the research, states that heart disease is already the leading cause of death in the US, and extreme heat currently accounts for a small percentage of cardiovascular deaths. However, as hot days become more prevalent, the importance of risk mitigation rises. Dr. Lawrence Fine, a senior adviser at the institute, explains, “Heat-related deaths are concentrated during very hot periods and in individuals who are already at greater risk due to their health conditions or other factors.”
The impact of heat waves extends beyond individual health, affecting emergency rooms and the broader healthcare system. Dr. Fine emphasizes the importance of addressing the root causes of temperature increase and heart disease. He also highlights the need for vulnerable individuals to have a specific plan in place when exposed to extreme heat. The study’s findings are based on projections of population growth and migration in the US, as well as trends in greenhouse gas emissions.
This summer provided a harrowing example of the dangers of extreme heat when Maricopa County, Arizona, reported a record number of heat-associated deaths. Over 469 people died from heat-related illness, making it the deadliest year since 2006. These deaths occurred during a period of record-breaking temperatures, with Phoenix experiencing 31 consecutive days at or above 110 degrees Fahrenheit. Heat-related fatalities have been on the rise in recent years, with deaths more than doubling since 2017.
The heart is particularly vulnerable to the effects of extreme heat. Dr. Sameed Khatana, an assistant professor of cardiovascular medicine at Penn Medicine and senior author of the study, explains that when the body detects an increase in temperature, the heart works harder to transport heat away from vital organs. For individuals with pre-existing cardiovascular conditions, their hearts may not be able to cope with these increased demands, leading to severe consequences.
The study also highlights disparities in the impact of extreme heat on different racial and age groups. Black adults in the US are projected to experience a six-fold increase in heat-related cardiovascular deaths, while White adults may see a 2.4 times increase in the worst-case scenario. Seniors aged 65 and older and those living in metropolitan areas are also expected to be disproportionately affected. Additionally, demographic shifts in the US, such as an aging population and urban growth, could exacerbate existing vulnerabilities.
Dr. Khatana stresses that vulnerable populations require targeted solutions, as they are likely to face multiple challenges beyond heat exposure, such as lack of tree cover or access to air conditioning. He also emphasizes that climate change and extreme heat are not just public health issues but also health equity issues. Efforts to mitigate the impacts of climate change and reduce emissions are crucial in addressing these disparities and preventing further widening of inequities.
