Viral Infections Significantly Increase Heart Attack and Stroke Risk, Study Finds

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, with implications for public health strategies and preventive care. The analysis found that people are four times more likely to have a heart attack and five times more likely to have a stroke in the month following laboratory-confirmed influenza infection. Similarly, COVID-19 infection increases heart attack and stroke risk threefold in the 14 weeks following infection, with elevated risk persisting for up to a year.

The research, led by Kosuke Kawai, Sc.D., adjunct associate professor at the David Geffen School of Medicine at UCLA, examined more than 52,000 publications before identifying 155 high-quality studies for meta-analysis. "It is well recognized that human papillomavirus (HPV), hepatitis B virus and other viruses can cause cancer; however, the link between viral infections and other non-communicable diseases, such as cardiovascular disease, is less well understood," Kawai explained. "Our study found acute and chronic viral infections are linked to both short- and long-term risks of cardiovascular disease, including strokes and heart attacks."

The biological mechanism behind this increased risk involves the immune system's 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.

Chronic viral infections also demonstrate significant long-term cardiovascular risks. The analysis found people with HIV infection 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 (caused by varicella zoster virus) elevates heart attack risk by 12% and stroke risk by 18%. Kawai noted that while these percentages are lower than the dramatic short-term increases following acute infections, they remain clinically relevant because they persist over extended periods.

The findings have substantial public health implications, particularly regarding vaccination. 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. "Preventive measures against viral infections, including vaccination, may play an important role in decreasing the risk of cardiovascular disease," Kawai emphasized. "Prevention is especially important for adults who already have cardiovascular disease or cardiovascular disease risk factors."

The American Heart Association recommends that individuals with cardiovascular disease consult healthcare professionals about appropriate vaccinations, as they face more severe complications from viruses like influenza, COVID-19, RSV, and shingles. Additional information about the Association's health recommendations and financial disclosures is available at https://www.heart.org. While the current analysis has limitations as it was based on observational studies, the findings underscore the importance of considering viral infections in cardiovascular risk assessment and prevention strategies.