A sweeping analysis of 155 observational studies has found that several common viral infections are associated with a steep increase in the risk of major cardiovascular events including heart attack and stroke. The research, led by scientists at University of California, Los Angeles and published in the American Heart Association (AHA) journal, reveals that infections such as influenza, COVID‑19, hepatitis C and shingles (herpes zoster) raise the odds of cardiovascular problems both shortly after infection and, in some cases, over the long term.
In self-controlled case series, the study found that people who recently had influenza faced about 4 times the usual risk of heart attack and about 5 times the risk of stroke within the first month. Cohort data also showed that hepatitis C raised the risk of coronary heart disease by roughly 27 per cent and stroke by about 23 per cent. For long-standing viruses like HIV, the risk remains elevated over time: HIV was tied to a 60 per cent increased risk of coronary heart disease and 45 per cent higher stroke risk.
The mechanisms behind these findings appear to involve inflammation and clotting. Viral infections trigger the immune system, prompting the release of substances that inflame the blood-vessel lining and make clot formation more likely. These changes may persist for weeks, months or even longer raising the odds of heart attacks and strokes.
The authors stress that while some risks such as those after influenza or COVID-19 are more acute and dramatic, the persistent risks tied to viruses like hepatitis C and herpes zoster remain clinically meaningful because of how common these infections are. For example, shingles affects about one in three people during their lifetime, meaning the added cardiovascular risk translates into a large number of excess cardiovascular events at the population level.
Importantly, the research highlights the potential role of vaccines and preventive medical care in reducing cardiovascular risk. The authors urge health practitioners to consider integrated approaches: vaccinating against influenza, shingles and possibly other viruses, and closely monitoring cardiovascular health in patients who have had serious viral infections. They also call for more studies to explore links between cardiovascular disease and other viruses such as cytomegalovirus, herpes simplex 1, hepatitis A, respiratory syncytial virus (RSV), dengue and human papillomavirus (HPV).
This research suggests that viral infections don’t just pose an immediate health threat they may also deliver a long-term cardiovascular effect. As viral outbreaks arise and seasonal illnesses return, paying attention to heart health in the wake of infection may be more important than ever.
