As athletes begin returning to spring sports, epidemiologist Jodie Guest and sports cardiologist Jonathan Kim discuss the impacts of COVID-19 on the heart.

How can COVID-19 affect heart health? What is myocarditis and what are the symptoms? When do athletes need to be evaluated for cardiac complications?

To address the impact of COVID-19 on the heart and provide guidance for athletes, Jodie Guest, professor and vice chair of the department of epidemiology at Emory University’s Rollins School of Public Health, spoke with Jonathan Kim, associate professor of medicine in the division of cardiology and chief of sports cardiology at Emory University School of Medicine.

You can watch a video of the conversation and get answers questions related to the COVID-19 pandemic here.

And below, you can read some highlights from the conversation:

Who is most at risk for heart complications due to COVID-19?

Patients who are older, have underlying comorbidities, or have been severely ill and hospitalized with COVID-19 are at greatest risk for developing cardiac injury.

“A recent study found that COVID-19 may cause heart damage in hospitalized patients with severe infection,” says Guest. “This particular study included data from the United States, China, Italy, and Spain, and found that rates of cardiac damage were somewhere between 10 to 25% of people hospitalized with COVID-19.”

From the beginning, sports cardiologists have been concerned about reports of cardiac damage in patients hospitalized with COVID-19.

“Upwards of around 20% of hospitalized patients having evidence of cardiac injury is much higher than you typically see for patients hospitalized with other common respiratory viral illnesses,” says Kim.

“Take patients who are very ill with influenza, and maybe ill enough to be hospitalized—you don’t see as much cardiac injury to the level that we were seeing, and certainly still see, among patients admitted with severe COVID-19.”

Younger patients with COVID-19 are generally at less risk of developing cardiac injury.

“Certainly, the younger you are and the healthier you are, you’re probably going to experience milder forms of COVID-19,” Kim says. “We are not seeing high burden of cardiac injury and inflammatory heart disease, that being myocarditis, in younger patients with COVID-19.”

What is myocarditis? What causes it?

“Myocarditis is a general term,” Kim says. “It’s a disease characterized by inflammation within the heart cells. Importantly, you really need to have symptoms. The classic symptoms of myocarditis are chest pain, shortness of breath, feeling your heart race inappropriately—we call these palpitations—other irregular heartbeats, and passing out of unexplained causes.”

Blood tests for cardiac inflammatory biomarkers such as troponin, a protein that can indicate heart damage, and changes on an electrocardiogram are also evidence of myocarditis.

“One of the most common causes of myocarditis is actually viral infections,” Kim continues, noting that myocarditis existed prior to COVID-19. “Common respiratory viral illnesses, even the common cold in certain situations, can actually lead to myocarditis in patients. There’s a wide spectrum in terms of how sick patients who are afflicted with myocarditis can present.”

Can COVID-19 vaccines cause myocarditis?

Myocarditis related to vaccination is very rare.

“It’s incredibly helpful to balance the risks of vaccination-related myocarditis against the risks of myocarditis due to COVID-19 as people are making decisions and being concerned about their health,” Guest says.

When talking to his athletic patients about vaccination, Kim shares data about the prevalence of myocarditis among competitive athletes.

“We have benefited quite a bit from studies of athletes who have returned to play. That’s where we’ve gathered all this information about how common this cardiac injury after COVID-19 is,” he says. Data from large registries of collegiate and professional athletes indicate that the prevalence of cardiac injury after COVID-19 is 0.6% among this group, or around one in 200.

Data have also shown that those at most risk for vaccine-related myocarditis are adolescent and young adult males. Some studies suggest the prevalence of myocarditis among this group is around 40 cases per million.

“That’s about one in 20,000 to one in 25,000 individuals that may have vaccine-related myocarditis, and we know that these are primarily milder cases of myocarditis,” Kim says.

“If you compare that one-in-200 risk from having COVID myocarditis versus a one-in-20,000 to one-in-25,000 risk, specifically in this target epidemiologic range, it’s not even really comparable,” he continues. “That’s why within sports medicine we continue to advocate for vaccination, because it’s not just the risk of severe ramifications of having COVID—it’s long haul, right? We know that the risk of having long-haul phenomena in even young individuals is not trivial.”

Kim warns that misinformation related to vaccines continues to spread online.

“A lot of misinformation out there has been circulated about, ‘Oh, I’m hearing about athletes who have been vaccinated and are dropping dead after vaccination.’ These reports, if you see any of these out there, are clear disinformation,” he says.

“Many of these cases are from individuals that had an adverse event before COVID even existed, that get put into these scare-tactic videos trying to prove that vaccinations are bad. I’m just not aware of cases out there of somebody being vaccinated and ‘dropping dead’ after a COVID vaccination in an athlete.”

How soon after COVID-19 infection would a patient expect to see signs of cardiac injury? What symptoms might they experience?

Signs of cardiac injury can surface at any time. Symptoms include chest tightness, shortness of breath, fluttering or racing of the heart, dizziness, or passing out, particularly during exertion.

“In general, those are the symptoms—we call these cardiopulmonary symptoms—that really dictate potential clinical concern and the need for an evaluation for cardiac injury to the heart after COVID-19,” Kim says.

“What we’ve seen primarily in some of the athletes we’ve cared for is that the majority of this population—and I think you could probably include most young, healthy people in this mix—have mild COVID and they don’t have these symptoms,” he continues.

“They’re going to have the upper respiratory symptoms, the GI symptoms, fatigue, headache, the loss of taste and smell. These are not cardiopulmonary symptoms. It’s those cardiopulmonary symptoms that, if experienced and if you’re a competitive athlete, for sure are the ones that need to be addressed prior to returning to competitive exercise.”

While competitive athletes experiencing these symptoms should seek medical evaluation, most people will not require cardiac testing before returning to moderate exercise.

“Most people aren’t engaging in the intense training regimens and the competitive environment that highly competitive and recreational athletes are engaging in,” Kim explains. These individuals should simply allow time for their symptoms to resolve and remain vigilant about returning to exercise slowly.

How can competitive athletes who have had COVID-19 safely return to their sports? Should they be screened for potential cardiac injury?

“We’re trying to get away from that concept of ‘screening.’ It’s really the clinical evaluation of an athletic patient, recovered from COVID-19, getting back to training,” says Kim, who served on a committee to update the American College of Cardiology’s guidelines for athletes returning to sports after COVID-19. The new guidelines will be published in March.

“Instead of screening, who needs to be clinically evaluated? And it’s those that have those cardiopulmonary symptoms,” he says. “If you don’t have those, then you don’t need to be screened for anything.”

Competitive athletes who had COVID-19 and do experience symptoms of cardiac injury should be evaluated by a sports cardiologist before returning to training.

“Similar to pre-COVID, if you had a bad flu and you got back to training and you started having chest tightness, guess what? You’re going to be evaluated by a sports cardiologist before getting back to your competitive training, because a doctor is going to be worried about myocarditis,” Kim explains. “And the evaluation that would be recommended would be seeing a specialist, an EKG imaging of the heart with an ultrasound called an echocardiogram, and a blood test called troponin.”

“For everybody else who has mild or asymptomatic COVID, once you recover, you can get back to training without any sort of testing,” he emphasizes. “Usually, we recommend a little bit of a slow ramp-up just to make sure that symptoms don’t occur with the initiation of training.” If an individual begins experiencing chest tightness or other cardiopulmonary symptoms during that ramp-up, Kim says they should then see a doctor for evaluation.

What are the potential long-term effects of COVID-19 on the heart?

Researchers still need to learn more about the long-term effects of COVID-19. Kim says he is reassured by the fact that most people seem to recover from the virus without any long-term cardiac complications. Most people who develop myocarditis will recover, as well.

“Again, myocarditis is a disease that has been around before COVID,” Kim says. While myocarditis can cause severe illness or even death in some cases, “there is a wide spectrum, and most individuals who have myocarditis get better.”

“For those that have more severe forms of myocarditis and maybe have scarring in the heart that may be a long-lasting remnant of the myocarditis, it’s going to require long-term follow-up to see outcomes in these individuals,” he adds. “But I’ve been reassured, just taking care of competitive athletes for the last two years who have had COVID, that the vast majority get better and have returned to competitive play with no long-lasting effects, and are really back to baseline, to where they were before COVID-19.”

Source: Emory University