Key Highlights
- Influenza and COVID-19 infections increase the risk of heart attack or stroke by 4 to 5 times in the weeks following infection.
- Chronic viral infections such as HIV, hepatitis C, and shingles can lead to long-term elevations in cardiovascular disease risks.
- The immune response to viral infections triggers inflammation and blood clotting, which persist even after the initial infection resolves.
- Vaccination against influenza, COVID-19, and shingles may reduce heart attack and stroke risk.
Acute and Chronic Viral Infections Linked to Increased Cardiovascular Risks
A new study published in the Journal of the American Heart Association has found that both acute and chronic viral infections significantly increase the risk of cardiovascular disease, including heart attacks and strokes. The research analyzed data from 155 scientific studies conducted between 1997 and 2024.
Short-Term Risks Following Infections
The study found that individuals are at a substantially higher risk of experiencing cardiovascular events in the weeks following an acute viral infection. Specifically, those who have contracted influenza or COVID-19 face a four to five times greater likelihood of suffering a heart attack or stroke compared to their baseline risk.
Kosuke Kawai, Sc.D., lead author and adjunct associate professor at the David Geffen School of Medicine at the University of California, Los Angeles, highlighted that “our study found acute viral infections are linked to both short- and long-term risks of cardiovascular disease.” He further noted that chronic infections such as HIV, hepatitis C, and shingles also elevate these risks in a more persistent manner.
Long-Term Risks of Chronic Infections
The research revealed that people living with certain chronic viral infections have an increased risk of heart attacks and strokes. For instance:
- A 60% higher risk of heart attack and a 45% higher risk of stroke for individuals infected with HIV.
- A 27% higher risk of heart attack and a 23% higher risk of stroke in those living with hepatitis C infection.
- A 12% higher risk of heart attack and an 18% higher risk of stroke for patients who have experienced shingles.
Kawai explained, “The elevated risks are lower than the heightened short-term risk following influenza and COVID. However, they remain clinically relevant because these infections persist over a long period.” He also pointed out that shingles affect about one in three people during their lifetime, translating into significant public health implications.
Role of Inflammation and Blood Clotting
The immune system’s response to viral infections involves the release of molecules that trigger inflammation and promote blood clotting. These effects can linger even after the initial infection has resolved, contributing to long-term cardiovascular risk. “Inflammation plays a key role in the development and progression of cardiovascular disease,” Kawai stated.
Vaccination as Prevention
According to the findings, preventive measures such as vaccination against influenza, COVID-19, and shingles could significantly reduce heart attack and stroke risk. A 2022 review cited in the study reported a 34% lower risk of major cardiovascular events among participants receiving a flu shot compared to those who received a placebo.
Kawai emphasized that “preventive measures against viral infections, including vaccination, may play an important role in decreasing the risk of cardiovascular disease. Prevention is especially important for adults already at increased risk due to pre-existing heart conditions or other cardiovascular risk factors.”
