• Posted October 29, 2025

Flu, COVID Increase Risk of Heart Attack, Stroke

People’s risk of heart attack or stroke skyrockets after a bout with the flu or COVID, a new evidence review says.

Folks are four times more likely to have a heart attack and five times more likely to have a stroke within a month of infection with influenza, researchers reported today in the Journal of the American Heart Association.

Likewise, people are three times more likely to have a heart attack or stroke within 14 weeks of being afflicted with COVID, and their risk remains elevated for up to a year, researchers said.

Results show heart risk also increases when people have chronic infections like HIV, hepatitis C and shingles.

“The elevated risks for cardiovascular disease risks are lower for HIV, hepatitis C and herpes zoster than the heightened short-term risk following influenza and COVID,” said lead researcher Kosuke Kawai,  an adjunct associate professor of general internal medicine and health services research at the David Geffen School of Medicine at UCLA.

“However, the risks associated with those three viruses are still clinically relevant, especially because they persist for a long period of time,” Kawai continued in a news release. “Moreover, shingles affects about 1 in 3 people in their lifetime. Therefore, the elevated risk associated with that virus translates into a large number of excess cases of cardiovascular disease at the population level.”

For their review, researchers pooled data from 155 prior studies related to viral infections and their impact on heart health. The studies were published between 1997 and 2024.

Besides the increased risk from the flu and COVID, researchers also found:

• People with HIV infection had a 60% higher risk of heart attack and 45% higher risk of stroke.

• Folks with hepatitis C had a 27% higher risk of heart attack and 23% higher risk of stroke.

• People with shingles had a 12% higher risk of heart attack and 18% higher risk of stroke.

Researchers also found that vaccination for flu, COVID and shingles might reduce heart attacks and strokes. For example, a 2022 review they cited found a 34% lower risk of such major events among people who got flu shots in randomized clinical trials.

“Preventive measures against viral infections, including vaccination, may play an important role in decreasing the risk of cardiovascular disease,” Kawai said. “Prevention is especially important for adults who already have cardiovascular disease or cardiovascular disease risk factors.”

More information

The American Heart Association has more on RSV and heart health.

SOURCE: American Heart Association, news release, Oct. 29. 2025