SEATTLE — A new study is further underscoring the importance of the annual flu shot. Researchers from the University of Washington School of Medicine say there is strong evidence linking severe influenza disease and sudden, serious heart complications.
The study by the Centers for Disease Control and Prevention uses data from more than 80,000 adult patients who were hospitalized with influenza over the course of eight flu seasons from 2010 to 2018. The results show serious cardiovascular events are common, occurring in almost 12 percent of these patients. That’s one out of every eight individuals.
‘Our study shows just how common it is’
The most common cardiovascular events in the report are acute heart failure and acute ischemic heart disease, which typically involves a drop in blood flow to the heart. Each of these complications occur in approximately six percent of the study participants. Other cardiac events were also recorded, although their incidence was just one percent or less.
According to the study, approximately 30 percent of those who developed any heart complication were admitted to the ICU and seven percent died in the hospital. Scientists also report that older age, tobacco use, diabetes, renal disease, and underlying cardiovascular disease all have a significant connection to the risk of these events.
Strikingly, the study finds that five percent of hospitalized patients with influenza have cardiac complications despite no evidence of any underlying health issues.
“Previous to our study, there had been suggestions between the link, but our study shows just how common it is,” says lead author Eric Chow in a media release.
Will the flu season make the COVID pandemic even worse?
This finding is timely, in light of the recent reports of heart complications in previously healthy patients recovering from COVID-19. Chow says SARS-CoV-2, the virus which causes this disease, can damage the lungs and other organs, including the heart. The resulting inflammation puts stress on the body and can lead to potentially fatal cardiovascular outcomes.
As the Northern Hemisphere gears up for its flu season, health experts worry about the potential for a “twindemic” of coronavirus and influenza occurring at the same time. In order to reduce the chance of overwhelming hospitals, the CDC recommends that everyone age six months and older receive a flu shot. This is an important protection for people who are at high risk for developing serious flu complications, including people with preexisting heart disease.
“There are few respiratory viruses we have a vaccine for,” emphasizes Chow. “Our team motto is ‘get a flu shot.'”
The study is published in the Annals of Internal Medicine.