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TIZIANA FABI / AFP via Getty Images
From images of cloudy chest scans and gasping patients hooked up to ventilators, we have been conditioned to think of Covid-19 as a respiratory disease. But it’s not just about the lungs. Even from the early days of the pandemic, doctors discovered that a new coronavirus infection could devastate other parts of the body, including the brain, blood vessels, and heart. Data from the initial outbreaks in China, New York City, and Washington state suggested that 20 to 30 percent of hospitalized Covid-19 patients showed signs of heart injury.
The fact that these patients tended to get sicker and die more often than patients without heart complications did not immediately sound the alarm bells. After all, these were people with severe cases of Covid-19, severe enough to end up in hospital. Most people who contract the virus experience a spectrum of less severe symptoms. One in three never feels sick. But now, evidence is emerging that the virus can cause heart damage even in people who have had mild symptoms or none at all, especially if those people exercise while infected.
Last month, when league commissioners from the Big Ten and Pac-12 college conferences announced that they would be postponing the 2020 fall sports season, one of the main factors they cited was concern about something called myocarditis. That’s what happens to cardiologists when the muscular walls of the heart become inflamed, weakening the organ and making it difficult to pump blood. It is not a new-found condition and it rarely appears, but when it does, it is most often triggered by an infection. Viruses, bacteria, even invasive amoebae, yeasts, and worms have been shown to cause it.
What they have in common is that they put the body’s immune system into attack mode, causing inflammation. If a person rests while sick and during recovery, most of the time the inflammation recedes and the heart muscle heals on its own. But vigorous activity while the heart is weakened can cause swelling in the legs, dizziness, shortness of breath, and, in severe cases, irregular heartbeat, cardiac arrest, and sudden death.
These more extreme results are seen more often in competitive athletes. That’s why cardiologists have been asking for caution about the return of the sports pandemic. Last month, former Florida State basketball player Michael Ojo died of apparent heart complications while playing in a professional league in Serbia, shortly after the 27-year-old recovered from Covid-19.
To prevent the pandemic from causing equally tragic heart injuries among student athletes, doctors at Ohio State University developed a new protocol, says Saurabh Rajpal, a cardiologist and assistant professor of internal medicine at OSU. The protocol requires that any player diagnosed with Covid-19 receive a clinical exam, blood test, EKG and MRI, an expensive and sparingly used imaging technology, before returning to play. Between June and August, 26 men and women from the school’s soccer, football, lacrosse, basketball, and track teams showed up for testing after they recovered from Covid-19. MRIs revealed inflammation of the heart muscle, a sign of myocarditis, in four of them. Of them, two had never experienced any symptoms of Covid-19. The case series was reported Friday in the magazine. JAMA Cardiology.
Because pictures of the athletes’ hearts were not taken prior to their Covid-19 infections, and because similar people who did not contract the virus were not compared to controls, it is impossible to say for sure whether the virus caused the observed damage. . But Rajpal, one of the study’s co-authors, says that other viral infections cause myocarditis, and SARS-CoV-2 is no different. “It is important for people to know that Covid-19 can affect the heart,” he says.
And these problems don’t just affect athletes. A larger observational study conducted in Germany earlier this summer followed 100 non-athletic Covid-19 patients and found persistent cardiac inflammation and other heart abnormalities in 78 of them. According to Eric Topol, a US cardiologist who corresponded with the study authors, 12 of those people did not have any symptoms of Covid-19. And although the study was later corrected for statistical errors, its authors confirmed that the main conclusions still hold: even a mild course of Covid-19 could damage the heart.
Exactly how much and how often, well, no one knows yet, says Topol, who runs the Scripps Research Translational Institute in La Jolla, California. “That is an unexplored border,” he says. The evidence remains mostly anecdotal. He would like governments and other research sponsors to set aside money to more systematically study large cohorts of people to see what happens to their hearts after receiving Covid-19. But so far, it doesn’t seem like a big priority. Maybe it’s because many other viruses can also cause myocarditis, Topol speculates. But the difference here, and what should prompt a more urgent study, he believes, is that most viruses do not infect tens of millions of people in the span of six months.
“In the United States right now, it is estimated that more than 50 million people have been infected with this virus,” he says. (There have been 6.5 million confirmed cases, but due to the unstable testing infrastructure in the US, experts estimate the true number to be closer to ten times that.) Even if only 1 percent of Americans experience some kind of heart problem, that’s still 500,000 people. “That is what people are losing here,” says Topol. “It doesn’t matter much when this virus has gone through so many people to be a huge burden. That is why we need to wrap our arms around this and understand it as soon as possible. “
Scientists also do not know if the inflammation seen in Covid-19 patients is collateral damage to the body’s immune response or if the virus directly infects heart tissue. Cardiac muscle cells express ACE2, the molecular gate that coronavirus uses to invade new hosts. And autopsy studies have discovered the virus within the hearts of deceased Covid-19 patients. (Although, in particular, they are not the types of immune cells associated with an inflammatory response.) Earlier this month, scientists at the San Francisco-based Gladstone Institutes discovered that the virus, when added to human heart cells in a Petri dish, shredded the long muscle fibers that keep hearts beating. Bruce Conklin, one of the study’s co-authors, said STAT the “carnage” was unlike anything seen with other diseases. But more research is needed to better understand whether that is representative of what is actually happening inside the bodies of people with Covid-19 infections.
The need is especially critical because many people who become infected with the coronavirus do not know it. And they may unknowingly do things, like exercise, that could damage their hearts during or immediately after infection. Amateur athletes, such as marathoners, ultra runners, triathletes, and others who run long miles but do not have access to regular cardiac examinations, may not be sufficiently aware of the risks to make judgments about the safety of their training regimens .
That is why Rajpal suggests paying more attention to your body if you are going to go for a run, bike ride or other sports activity, especially if you have any signs of illness. “If you experience any suspicious symptoms (chest pain, shortness of breath, or heart palpitations), contact your doctor,” he says. And if you’ve tested positive for Covid-19, he says, you should take a few weeks off before gradually returning to the level of training you had before.
At OSU, athletes who showed signs of myocarditis on their MRI scans received a mandatory three-month break. At the end of that, they’ll be re-scanned to make sure the inflammation has subsided, and only then, Rajpal says, will they be allowed to play.
This story was originally published on U.S
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