A heart condition, myocarditis, has been found in a number of U.S. college athletes who have had COVID-19, a new study finds.
Myocarditis has also been linked in some young people to the COVID-19 vaccine. But the odds are far greater that this inflammation of the heart muscle will occur in those who get COVID-19 infection itself, experts said.
"We're still learning about how the virus attacks the heart," said lead researcher Dr. Jean Jeudy, a professor of radiology at the University of Maryland School of Medicine.
"Myocarditis is part of the body's reaction to fighting the infection, but it's also in response to the virus trying to attack the heart," Jeudy said.
Myocarditis is usually caused by a viral or bacterial infection. It can affect the heart's rhythm and ability to pump. It can also cause lasting scarring of the heart muscle, Jeudy's team noted.
The risk for myocarditis among people with COVID-19 is 16 times higher than among those without the infection, according to the U.S. Centers for Disease Control and Prevention.
Jeudy and his colleagues said that myocarditis has been linked to up to 20% of sudden deaths in young athletes.
Concern had been raised that myocarditis can occur after being vaccinated for COVID-19, especially among young males like those in this study.
According to the CDC, however, there are approximately 50 cases of myocarditis for every 1 million young men vaccinated, far below the risk of myocarditis from COVID-19 itself.
Based on its data, the CDC says the benefit from the vaccine far outweighs the risk of getting myocarditis.
"We know that COVID-19 can affect the heart, and we know there's no reason to risk the potential for the kind of long-term effects of COVID-19," Jeudy said.
"So getting vaccinated is probably the No. 1 thing to think about," he stressed.
For this study, Jeudy's team took advantage of the Big Ten Athletic Conference's ability to get data on the frequency of myocarditis in student athletes recovering from COVID-19.
The conference required all athletes who had COVID to get a series of heart tests before returning to play. Tests included cardiac MRIs, echocardiograms, ECGs and blood tests.
Jeudy reviewed the results of nearly 1,600 cardiac MRIs from 13 participating universities.
Thirty-seven of these athletes -- 2.3% -- had myocarditis related to COVID-19. What was surprising, however, was that few had symptoms.
Twenty of these patients with COVID-19 myocarditis -- 54% -- had no cardiac symptoms or heart abnormalities seen on other tests. Only MRIs found the problem.
For some of the athletes studied, myocarditis was limited and went away within a month, but others continued to show abnormalities on MRIs, Jeudy said.
MRIs are expensive, and most patients hospitalized for COVID-19 don't get them, so it's likely that many cases of myocarditis go undiagnosed, he said.
The long-term consequence of myocarditis among those infected with COVID-19 will only become clear over time, Jeudy said.
He noted that persistent inflammation or heart scarring can increase the risk of an irregular heartbeat known as arrhythmia.
When can athletes resume play?
"At the very least, this athlete is going to be out for six months, with evaluation, making sure that they have a gradual return to play," Jeudy said.
"It's largely connected with symptoms. If there are signs of decreased function or underlying arrhythmia, that would be a concern for that particular athlete," Jeudy said.
The findings were released Monday at the annual meeting of the Radiological Society of North America. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
Dr. Marc Siegel, a clinical professor of medicine at NYU Langone Medical Center in New York City, said COVID-19 can affect many parts of the body.
"It's a virus that sets off a lot of alarms around the body, inflammatory alarms that go off," said Siegel, who was not involved with the study.
"Those inflammatory alarms occur in organs where the virus isn't even present," he said. "It's the body fighting back against the virus systemically. We're seeing it in the brain. We're seeing it in the heart. We're seeing it in the lungs. It's a multi-system organ risk of inflammation."
Siegel said the best way to prevent getting COVID-19 and its complications is to get vaccinated.
"This study is yet another motivation to get vaccinated before you ever get COVID-19," he said.
For more on COVID-19, see the U.S. Centers for Disease Control and Prevention.
Copyright © 2021 HealthDay. All rights reserved.