Viral Infections Linked to Increased Heart Attack and Stroke Risks

A recent analysis highlights a concerning link between viral infections and an increased risk of heart attacks and strokes. Researchers found that individuals diagnosed with the flu or COVID-19 face heightened cardiovascular risks in the weeks following their illness. This comprehensive study examined data from 155 studies, revealing that infections from a variety of viruses, including influenza, COVID-19, HIV, and hepatitis C, can negatively impact heart health.

The research indicates that the risks associated with these infections extend beyond immediate effects. According to the findings, published in the Journal of the American Heart Association, individuals are four times more likely to experience a heart attack and five times more likely to suffer a stroke within one month of a flu diagnosis. Following a COVID-19 infection, the likelihood of heart attack or stroke increases threefold in the subsequent 3.5 months, with risks remaining elevated for up to a year.

Long-Term Implications of Viral Infections

The analysis also draws attention to individuals with chronic viral infections. For example, heart attack risks for people living with HIV are 60 percent higher, while those with hepatitis C face a 27 percent increased risk. Additionally, individuals with shingles have a 12 percent higher risk of cardiovascular events at least five years post-infection.

Kosuke Kawai, the lead author of the study and an epidemiologist at the University of California, Los Angeles, emphasized the clinical relevance of these findings, especially given the global prevalence of such infections. In 2024, there were approximately 1.3 million new HIV infections, and about one million new hepatitis C infections are reported each year. Furthermore, estimates suggest that across Europe, there are roughly six to ten new shingles cases annually for every 1,000 people. Kawai remarked, “The elevated risk associated with that virus translates into a large number of excess cases of cardiovascular disease at the population level.”

Understanding the Mechanism

The underlying mechanism for these increased risks stems from the body’s immune response to viral infections. When the body fights off a virus, it releases molecules that enhance blood flow, leading to inflammation and blood clotting. While these reactions are beneficial for addressing infections, they can also impair heart function, potentially explaining the lingering elevated risks of heart attacks and strokes.

The study notes that while evidence is clear for the viruses discussed, it remains uncertain whether other viruses, such as dengue, human papillomavirus (HPV), cytomegalovirus, and herpes simplex 1, also elevate heart health risks.

To mitigate these risks, vaccination emerges as a promising strategy. Vaccines for the flu, COVID-19, and shingles may significantly reduce the chances of developing cardiovascular issues. A review from 2022 found that individuals who received a flu shot had a 34 percent lower risk of dying or being hospitalized due to cardiovascular problems compared to those who received a placebo. Kawai highlights that preventive measures, particularly vaccinations, may play a crucial role in reducing cardiovascular disease risk, especially for individuals already facing heart disease or other risk factors.

In conclusion, the findings of this analysis underscore the importance of understanding the relationship between viral infections and heart health. As the global burden of viral diseases continues to rise, proactive measures, including vaccination, may be essential in protecting cardiovascular health.