Flu, COVID, and Other Infections: Uncovering the Hidden Heart Risks
The symptoms of common viral infections like the flu or COVID-19 often fade within a week or so, but new research reveals a hidden danger lurking beneath the surface. A comprehensive review of 155 scientific studies published in the Journal of the American Heart Association has uncovered a startling connection: influenza and COVID infections significantly elevate the risk of heart attack and stroke by as much as three to five times in the weeks following the initial infection.
But the risks don't stop there. Viruses that linger in the body, such as HIV, hepatitis C, and varicella zoster (the virus causing shingles), can increase the long-term risk of serious, even life-threatening, heart problems. This revelation highlights the importance of understanding the intricate relationship between viral infections and cardiovascular health.
Dr. Graham Snyder, medical director of infection prevention and Hospital Epidemiology at UPMC and associate professor in the division of infectious diseases at the University of Pittsburgh School of Medicine, emphasizes the significance of this finding. "This gives us another reason to want to avoid influenza and [COVID-19], not just because they can make us sick and potentially even kill us, but because they can trigger other non-infectious related illnesses, and cardiovascular disease is a major concern."
The question arises: How do viral infections impact heart health? Researchers point to the body's immune response as the culprit. When the body fights off viral infections, it releases molecules that trigger and sustain inflammation and promote the tendency of blood to clot, both of which can persist long after the initial infection has resolved. These processes can significantly affect the heart's ability to function properly.
Dr. Snyder highlights some well-known examples of collateral damage from this natural immune response, such as Guillain-Barré syndrome, which can cause numbness or paralysis after an infection, and rheumatic fever, a post-strep condition that can inflame and damage the heart. The study's systematic review of existing studies reveals a broader range of pathogens associated with cardiovascular disease risk, heart disease, and stroke.
The short- and long-term effects of infections are profound. The review found that people with a laboratory-confirmed flu case were four times more likely to have a heart attack and five times more likely to have a stroke in the month after their infection. Similarly, those with COVID-19 faced a threefold increased risk of heart attack or stroke in the 14 weeks following infection. Chronic HIV infection carried a 60% higher risk of heart attack and a 45% higher risk of stroke over an average of five years, while hepatitis C increased the risk by 27% and 23%, respectively.
Lead study author Kosuke Kawai acknowledges that the elevated heart risks associated with HIV, hepatitis C, and the shingles virus are lower than the heightened short-term risks following the flu or COVID-19. However, he emphasizes the clinical relevance of these long-term risks, especially given the prevalence of shingles, which affects about one in three people in their lifetime. Kawai concludes, "The elevated risk associated with that virus translates into a large number of excess cases of cardiovascular disease."
