Two heart drugs linked to increased risk of heart attack in very hot weather

heart attack

Credit: public domain CC0

For people with coronary heart disease, beta-blockers can improve survival and quality of life, while aspirin and other antiplatelet drugs can reduce heart attack risk.

But those protections could backfire during hot weather events, a time when heart attacks are more likely. A new study has found that among people with non-fatal heart attacks associated with hot weather, an inordinate portion take these heart medications.

“Patients taking these two drugs have a 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 like air pollution and cold can trigger heart attacks. A growing body of evidence suggests that hot weather can do it too. But epidemiologists are still struggling to identify the groups of people most vulnerable to these environmental extremes.


Using a registry, the authors looked at 2,494 cases in which people suffered nonfatal heart attacks in Augsburg, Germany, during the warm 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 they had calculated that rates of heat-related heart attacks would increase once the planet warmed by 2 at 3 degrees Celsius.

The current study builds on that research by looking at patients’ medication use before their heart attack.

They analyzed the data in a way that allows patients to serve as their own controls, comparing heat exposure on the day of the heart attack versus the same weekdays 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 to their temperature exposure on other “control” Thursdays in June.

Two drugs linked to risk

It turned out that users of beta-blockers or anti-platelet drugs were more likely to have heart attacks on hotter days than on control days. The use of antiplatelet drugs was associated with a 63% increased risk and beta-blockers with a 65% increase. People taking both drugs had a 75% higher risk. Non-users of these drugs were no more likely to have a heart attack in hot weather.

The study does not prove that these drugs caused the heart attacks, nor that they make people more susceptible to heart attacks. Although it is possible that they increased the risk of heart attacks triggered by hot weather, it is also possible that the patients’ underlying heart disease explains both the prescriptions and the greater susceptibility to heart attacks by warm weather.

Yet one clue suggests that drugs might be to blame.

When the researchers compared younger patients (25 to 59 years old) with older patients (60 to 74 years old), they found, as expected, that the younger ones were a healthier group, with lower rates. of coronary diseases. Still, younger patients taking beta-blockers and antiplatelet drugs were more susceptible to heat-related heart attacks than older patients, although older patients had more heart disease.

Another clue that these two types of drugs may make people more vulnerable: for the most part, other heart medications have not been shown to be linked to heat-related heart attacks. (An exception was statins. When taken by younger people, statins were associated with a more than three times greater risk of heart attack in hot weather.)

“We hypothesize that some of the drugs may make it difficult to regulate body temperature,” Chen said. He plans to try to untangle these relationships in future studies.

The results suggest that as climate change progresses, heart attacks may become a greater danger for some people with cardiovascular disease.

Study finds strong association between prediabetes and heart attack risk

More information:
Kai Chen et al, Onset of myocardial infarction by exposure to heat is modified by taking medication, Nature Cardiovascular research (2022). DOI: 10.1038/s44161-022-00102-z

Provided by Yale School of Public Health

Quote: Two heart medications linked to increased risk of heart attack in very hot weather (August 1, 2022) Retrieved August 2, 2022 from -hot.html

This document is subject to copyright. Except for fair use for purposes of private study or research, no part may be reproduced without written permission. The content is provided for information only.

Leave a Comment