Viral Infections Significantly Increase Cardiovascular Disease Risk, Study Finds

A comprehensive review of 155 scientific studies published in the Journal of the American Heart Association reveals significant connections between viral infections and increased cardiovascular disease risk. The research found that influenza and COVID-19 infections dramatically raise the likelihood of heart attacks and strokes in the weeks following initial infection, while chronic viral infections such as HIV, hepatitis C, and varicella zoster virus (which causes shingles) lead to long-term elevations in cardiovascular event risk.

According to the study, people are four times as likely to have a heart attack and five times more likely to have a stroke in the month after laboratory-confirmed influenza. Similarly, individuals face three times higher risk of both heart attack and stroke in the 14 weeks following COVID infection, with the elevated risk persisting for up to a year. The findings underscore the substantial cardiovascular implications of common viral infections that affect millions of people worldwide.

The research team, led by Kosuke Kawai, Sc.D., adjunct associate professor at the David Geffen School of Medicine at UCLA, screened more than 52,000 publications before identifying 155 high-quality studies appropriate for meta-analysis. Kawai noted that while the connection between certain viruses and cancer is well-established, the relationship between viral infections and cardiovascular disease has been less understood until now.

The biological mechanisms behind this increased risk involve the immune system's natural response to viral infections. When fighting viruses, the body releases molecules that trigger inflammation and promote blood clotting, both of which can persist long after the initial infection resolves. Inflammation plays a crucial role in cardiovascular disease development by contributing to plaque formation and rupture in arteries, while increased clotting tendency can lead to blocked blood vessels causing heart attacks and strokes.

For chronic viral infections, the study found people with HIV face a 60% higher risk of heart attack and 45% higher risk of stroke compared to similar individuals without the infection. Those with hepatitis C infection experience a 27% higher heart attack risk and 23% higher stroke risk, while individuals who have had shingles show a 12% increased heart attack risk and 18% higher stroke risk. Although these percentages are lower than the short-term risks following acute infections, they remain clinically significant because they persist over many years.

The population-level implications are substantial, particularly for shingles, which affects approximately one in three people during their lifetime. The elevated cardiovascular risk associated with this common virus translates into a large number of excess cardiovascular disease cases across the general population. The study suggests that increased vaccination rates for influenza, COVID-19, and shingles could potentially reduce the overall incidence of heart attacks and strokes.

Supporting this preventive approach, the researchers cite a 2022 review showing a 34% lower risk of major cardiovascular events among participants receiving flu shots in randomized clinical trials compared to those receiving placebos. The American Heart Association recommends that individuals with cardiovascular disease or cardiovascular disease risk factors consult healthcare professionals about appropriate vaccinations, as these preventive measures offer critical protection to those already at increased risk. Additional information about cardiovascular health and prevention strategies is available at https://www.heart.org.

While the current analysis provides compelling evidence for several common viruses, researchers note that more studies are needed to understand potential links between heart disease risk and other viruses including cytomegalovirus, herpes simplex 1, dengue, and human papilloma virus. The study's limitations include its basis on observational studies rather than randomized controlled trials, though most studies adequately accounted for potential confounding factors. The research did not examine how infection with multiple viruses or bacteria might affect cardiovascular risk, nor did it identify high-risk groups that might be disproportionately affected.