As doctors continue to piece together information about COVID-19, a new study involving Major League Baseball and five other United States-based sports leagues provides important data and, perhaps, some comfort for professional athletes who contract the virus.
Just five of 789 -- or 0.6 percent -- of professional athletes infected with COVID-19 in 2020 were later found to have suffered inflammatory heart disease, according to a study published Thursday in JAMA Cardiology. The study, which was the largest to date on the cardiac impact of COVID-19 in pro sports, involved athletes from MLB, the NFL, the NBA, the WNBA, the NHL and Major League Soccer.
“This is the first time these leagues and their players’ associations have collaborated on a study,” said Dr. Gary Green, MLB’s medical director. “The leagues have different seasons and demands and challenges. To find a common ground was important.”
Though statistics suggest that young athletes who contract COVID-19 are less likely to experience the virus’ most serious symptoms than some other segments of the population, the potential for cardiac damage loomed as an unknown. The case of Red Sox pitcher Eduardo Rodriguez, who was diagnosed with myocarditis -- or inflammation of the heart -- after a bout with COVID-19 last year was a source of particular concern within MLB.
The study, therefore, is a first step toward understanding this particular issue more deeply. Before returning to action, the athletes, who had contracted COVID between May and October last year and were both symptomatic and asymptomatic, underwent three noninvasive tests to track their heart rhythms, took an ultrasound of their hearts and measured a protein in their blood that can be a signal of heart damage.
Of the five diagnosed cases of inflammatory heart disease, three were identified as myocarditis and two as pericarditis. They will continue to be monitored by MRIs over time.
All names of those involved in the study were kept private.
With the NCAA currently compiling a similar study, sports leagues are helping the medical community, at large, better understand the virus.
“We’re trying to use our information we gain to add to the general scientific knowledge on this,” Green said. “We also saw this last year where we contributed to Stanford’s antibody study. We make it a point to try to give back to the community and gather information that’s not only going to help baseball but the general public as well.”
Green expressed cautious optimism as MLB reconvenes for the 2021 season and the COVID-19 vaccination rate in the United States improves.
“There are things that could derail us,” Green said. “Variants resistant to the vaccine or vaccine hesitancy, where people are reluctant to get the vaccine, or just failure to follow the protocols until we achieve herd immunity. But I definitely feel better than last year at this time.”
MLB’s initial intake testing at the start of Spring Training found just 13 positive tests, or 0.3% of the 4,336 total samples taken and tested.
“In our offseason, our players did a very good job of keeping safe,” Green said. “But the thing that’s a note of caution is that, even though [infection] rates [nationwide] are relatively low, they’re still relatively high in the communities where we’re playing, in Florida and Arizona. And while community rates are lower than they were a few months ago, the number of daily cases in most states is still higher than any point in our season last year. That’s really important to keep in mind.”