Viral Infections Significantly Increase Heart Attack and Stroke Risk, Study Finds
New research reveals that both acute infections like influenza and COVID-19 and chronic viral infections including HIV and hepatitis C substantially elevate cardiovascular disease risks, highlighting the importance of preventive measures including vaccination.
A comprehensive review of 155 scientific studies published in the Journal of the American Heart Association reveals that viral infections significantly increase both short-term and long-term risks of cardiovascular events including heart attacks and strokes. The analysis found that influenza and COVID-19 infections raise cardiovascular risk dramatically in the weeks following infection, while chronic infections such as HIV, hepatitis C and varicella zoster virus lead to sustained elevations in cardiovascular risk over years.
According to the research, 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 infection. Similarly, COVID-19 infection increases heart attack risk threefold and stroke risk threefold in the 14 weeks following infection, with elevated risk persisting for up to one year. The study's lead author, Kosuke Kawai, Sc.D., of UCLA's David Geffen School of Medicine, noted that while the link between viruses and cancer is well-established, the connection to cardiovascular disease has been less understood.
The immune system's response to viral infections appears to drive this increased cardiovascular risk through mechanisms involving inflammation and blood clotting. Viral infections trigger the release of inflammatory molecules that can persist long after the initial infection resolves, contributing to plaque formation and rupture in arteries. This inflammatory response, combined with increased blood clotting tendency, reduces heart function and elevates cardiovascular event risk.
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. Hepatitis C infection increases heart attack risk by 27% and stroke risk by 23%, while shingles infection raises heart attack risk by 12% and stroke risk by 18%. Kawai emphasized that while these percentage increases are lower than the dramatic short-term spikes following acute infections, they remain clinically significant because they persist over long periods and affect large population groups.
The findings suggest that preventive measures, particularly vaccination, could play a crucial role in reducing cardiovascular disease burden. The researchers cite evidence from randomized clinical trials showing a 34% lower risk of major cardiovascular events among participants receiving influenza vaccination compared to those receiving placebo. The American Heart Association recommends that individuals with cardiovascular disease or risk factors consult healthcare professionals about appropriate vaccinations, as detailed in their health information available at https://www.heart.org/en/health-topics/patient-carecoronavirus/covid-19-resources-for-health-care-providers/vaccines.
The study, which screened more than 52,000 publications before selecting 155 high-quality studies for meta-analysis, represents one of the most comprehensive examinations of the virus-cardiovascular disease connection to date. Most studies were conducted in North America, Europe and East Asia, with publication dates spanning from 1997 to 2024. While the analysis has limitations as it was based on observational studies rather than randomized controlled trials, the researchers note that most studies adequately accounted for potential confounding factors.
Overall financial information about the American Heart Association is available at https://www.heart.org/en/about-us/aha-financial-information. The association receives more than 85% of its revenue from sources other than corporations, including individual contributions, foundations, estates, investment earnings and educational material sales, with strict policies to prevent corporate donations from influencing scientific content.