Myocarditis isn't new, but since the coronavirus became a global pandemic, the condition's connection to athletes who recovered from COVID-19 has been in the headlines as sports programs continue to return to play.
Researchers have been studying COVID-19 and the rare myocarditis heart condition to discover the risks. Since one challenge of the condition is that it lacks specific symptoms, and in many cases, people who have myocarditis are asymptomatic, studies also look at how to best detect it in athletes post-COVID.
As researchers continue to track COVID's long-term effects after recovery, they'll uncover more about the connection between the virus and myocarditis. The longer we wait, the more we learn. Given that symptom-less heart conditions can still be fatal, the industry is looking for answers with great urgency.
Sudden death in youths
Myocarditis is caused by inflammation of the heart muscle. Inflammation of the heart from viral infections like COVID-19 can enlarge it, weaken it, create scar tissue and force it to work harder.
Although heart conditions are sometimes affiliated with older populations, myocarditis can affect anyone, including young adults and children. According to the Myocarditis Foundation, the disease most often affects otherwise healthy, young, athletic people. The age group at highest risk includes individuals from puberty through their early 30s, affecting males at twice the rate of females. Myocarditis is the third-leading cause of sudden death in children and young adults, the foundation says.
Around fall 2020, the fear about myocarditis was not what researchers knew about it, but what they didn't. The director of the University of Washington Medicine Center for Sports Cardiology, Dr. Jonathan Drezner, told ESPN in early August 2020 that the concern about myocarditis in collegiate athletes should "make all of us sort of press pause and do some due diligence so that we can feel the athlete is safe to exercise. ... We have to ensure that the risk on the playing field is not necessarily higher than the risk they're dealing with the rest of their college experience."
Since then, researchers have learned more through several studies about the risks and have been publishing data as they get it. Here are three recent studies and what researchers say they can conclude so far:
JAMA Cardiology on Pro Athletes, March 2021
A study published March 4, 2021, in the JAMA Cardiology journal looked at the prevalence of inflammatory heart disease in professional athletes who had COVID-19 and were returning to play. Of the 789 pro athletes with COVID-19, five (0.6 percent) were restricted from play because of evidence of inflammatory heart disease.
The study reviewed return-to-play cardiac testing performed between May and October 2020 on professional athletes who had tested positive for COVID-19. The pro sports leagues implemented mandatory cardiac screening requirements for all players who tested positive for COVID-19 before resuming organized team activities.
The study concluded that, "While long-term follow-up is ongoing, few cases of inflammatory heart disease have been detected, and a safe return to professional sports activity has thus far been achieved."
American Heart Association on College Athletes, May 2021
In a small study published by the American Heart Association in May, researchers investigated if symptom severity was associated with heart inflammation or poor recovery after COVID-19.
Less than 4 percent of 137 athletes showed heart abnormalities on initial screening tests. Only five participants who had abnormal test results received a cardiac MRI. Of the five, no heart damage or inflammation was seen. After COVID-19 recovery, all athletes were able to resume full training and competition without complications.
The study concluded that college athletes with COVID-19 rarely had heart complications and could safely return to playing sports after recovery.
JAMA Cardiology on Competitive Collegiate Athletes, May 2021
A study published by JAMA Cardiology in May looked at 1,597 competitive collegiate athletes in the United States undergoing cardiovascular testing. Cardiovascular testing was performed on 964 men and 633 women representing 13 universities.
A total of 37 — 10 women and 27 men — were diagnosed with COVID-19-related myocarditis (2.3 percent). According to researchers, if cardiac testing was based on cardiac symptoms alone, only five athletes in the study would have been detected (detected prevalence was noted as 0.31 percent). Using cardiac magnetic resonance imaging, or CMR, to test all athletes yielded a 7.4-fold increase in detection of myocarditis.
The study concluded that testing protocols were closely tied to the detection of myocarditis in college athletes. According to its authors, "The role of CMR in routine screening for athletes' safe return to play should be explored further."
This article originally appeared in the October 2021 issue of Athletic Business with the title "What Do Those Myocarditis-COVID-Connection Studies Even Mean?" Athletic Business is a free magazine for professionals in the athletic, fitness and recreation industry. Click here to subscribe.