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For people with coronary heart disease, beta-blockers can improve survival and quality of life, while aspirin and other antiplatelet medications can reduce the risk of heart attack.
But these protections could backfire during hot weather events, a time when heart attacks are more likely. A new study has found that among people who suffer non-fatal heart attacks associated with hot weather, a large proportion take these heart medications.
“Patients taking these two medications are at higher risk,” said Kai Chen, assistant professor in the Department of Epidemiology (Environmental Health) at the Yale School of Public Health and first author of the study. “During heat waves, they really should take precautions.”
These precautions include cooling strategies such as using air conditioning or visiting a public cooling center.
External environmental factors such as air pollution and cold can trigger heart attacks. Growing evidence suggests hot weather can do it, too. But epidemiologists are still working to identify which groups of people are most vulnerable to these environmental extremes.
methods
Using a registry, the authors analyzed 2,494 cases in which people experienced nonfatal heart attacks in Augsburg, Germany, during the hot weather months (May through September) between 2001 and 2014.
In previous research, they had shown that exposure to heat or cold made heart attacks more likely, and calculated that rates of heat-related heart attacks would increase once the planet warmed between 2 and 3 degrees Celsius.
The current study builds on that research by examining patients’ medication use before their heart attack.
They analyzed the data in a way that allowed the patients to serve as their own controls, comparing heat exposure on the day of the heart attack with the same days of the week during the same month. That is, if a person had a heart attack on the third Thursday in June, the authors compared their temperature exposure on that day with their temperature exposure on other “control” Thursdays in June.
Two drugs related to risk
It turned out that users of beta-blockers or antiplatelet drugs were more likely to have heart attacks on the hottest days compared to control days. Antiplatelet medication use was associated with a 63% increased risk, and beta blockers with a 65% increased risk. People taking both drugs had a 75% higher risk. Non-users of these medications were not more likely to have a heart attack on hot days.
The study does not show that these drugs cause heart attacks, or that they make people more vulnerable to heart attack. While it is possible that they increase the risk of heart attacks caused by hot weather, it is also possible that patients’ underlying heart disease explains both the prescriptions and the increased susceptibility to heart attack during hot weather.
Still, one clue suggests that medications could be to blame.
When researchers compared younger patients (aged 25 to 59) with older patients (aged 60 to 74), they found, as expected, that the younger group was healthier, with lower rates of coronary disease. However, younger patients taking beta-blockers and antiplatelet drugs were more susceptible to heat-related heart attack than older patients, despite older patients having more heart disease.
Another clue that these two types of drugs may make people more vulnerable: For the most part, other heart drugs didn’t show a connection to heat-related heart attacks. (An exception was statins. When taken by younger people, statins were associated with a more than threefold risk of heart attack on hot days.)
“We hypothesize that some of the medications may make it difficult to regulate body temperature,” Chen said. He plans to try to unravel these relationships in future studies.
The findings suggest that as climate change progresses, heart attacks may become a greater risk for some people with cardiovascular disease.
Study finds strong association between prediabetes and heart attack risk. More information: Kai Chen et al, Activation of myocardial infarction by heat exposure is modified by drug intake, Nature Cardiovascular Research (2022). DOI: 10.1038/s44161-022-00102-z Provided by Yale School of Public Health
Citation: Two heart drugs linked to increased risk of heart attack during very hot weather (2022, August 1) Retrieved August 2, 2022, from
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