Warning over medication ‘which may increase risk of heart attacks in hot weather’

People who take certain heart medications are at greater risk of heart attack during extremely hot weather, according to a new study.

Researchers at Yale University in Connecticut found coronary heart disease patients who take both beta-blockers and aspirin or other antiplatelet medications are more likely to suffer non-fatal heart attacks during heatwaves.

Kai Chen, an assistant professor in the Department of Epidemiology at the Yale School of Public Health said: “Patients taking these two medications have higher risk. During heat waves, they should really take precautions.”

For the study, researchers looked at 2,494 non-fatal heart attack cases in Augsburg, Germany during the hotter months of May to September between 2001 and 2014.

They found that those who took beta-blockers or antiplatelet medications were more more likely to have a heart attack during hotter days compared to days they were not exposed.

For those who took antiplatelet medication, there was a 63 per cent increase in the risk of having a non-fatal heart attack. For beta-blockers users, there was a 65 per cent increase in risk. For people taking both drugs, they had a 75 per cent higher risk.

People who did not use such medications were not as likely to have a heart attack during hotter weather.

The study does not directly prove the link between the use of beta-blockers and antiplatelet medication and an increase chance of having a heart attack, as patients’ underlying heart disease could explain the higher risk of heart attacks during hot weather.

However, researchers found that younger patients aged between 25 to 59 taking such medications were more likely to have heat-related heart attacks.

Dr Chen from the Yale School of Public Health said: “We hypothesise that some of the medications may make it hard to regulate body temperature.”

The study was published in Nature’s Cardiovascular Research journal.

Previous research has shown that exposure to either heat or cold made heart attacks more likely, with scientists estimating that heat-related heart-attack rates would increase once the planet has warmed by 2C to 3C due to the climate crisis.