COVID-19 and the Heart: A Look at Recent Research

Researchers and physicians are still learning about the many ways COVID-19 can impact the heart. Severe COVID-19 may lead to a heart attack, blood clots in the heart, heart failure, or heart injury. 

But people who experience mild symptoms of COVID-19 or who are asymptomatic may also experience myocarditis, or heart inflammation, new research shows.

“We know that COVID is a terrible stress test for the heart,” Eric Adler, MD, a cardiologist at UC San Diego Health, tells Verywell. 

What the American Heart Association Says 

The American Heart Association (AHA) says that at the start of the coronavirus pandemic, hospitalized patients with severe COVID-19 were showing signs of heart involvement and damage, and those with underlying heart conditions were most at risk.

The AHA says healthcare experts are now concerned in the face of new research. Recent studies have shown some COVID-19 survivors who had mild to no symptoms, or no underlying cardiovascular conditions, are also exhibiting evidence of heart damage on imaging.

Here’s What Research is Finding

Researchers at the Icahn School of Medicine at Mount Sinai report that about a quarter of patients who are hospitalized with COVID-19 develop myocardial injury. Heart damage can be associated with fatal conditions, such as heart attack, pulmonary embolism, and heart failure.

Patients who develop heart damage are typically older and have higher rates of high blood pressure diabetes mellitus, coronary artery disease, and heart failure than those without damage markers, according to the study published in the Journal of the American College of Cardiology.

The researchers detected the damage by measuring COVID-19 patients’ troponin levels when they were admitted to the hospital. An elevated troponin level usually indicates the heart has been injured. They also looked at echocardiographic and electrocardiographic data and found that nearly two-thirds of the patients had structural abnormalities.

The study explains various ways COVID-19 potentially damages the heart. In some cases, the virus is actually invading the heart tissue and causing damage to the heart muscle. In other cases, the extreme stress the virus places on the heart causes the injury. Inflammation can also affect the small blood vessels within the heart, cause tiny blood clots that block blood flow, or cause plaque ruptures that can lead to a heart attack.

People With Mild Illness Are Also at Risk

A study out of Frankfurt, Germany, raises the alarm on heart inflammation or damage after COVID-19 recovery in patients who had mild illness or who were asymptomatic. The study, published in JAMA Cardiology, looked at cardiac magnetic resonance (CMR) imaging in 100 patients who had recently recovered from COVID-19.

The study reports that 67% of the patients were able to recuperate from their infection at home, while 33% were admitted to the hospital. The results showed cardiac involvement in 78% of patients and ongoing heart inflammation in 60% of patients. And the researchers say the results were independent of disease severity or pre-existing conditions.

“Those who have pre-existing coronary disease, heart failure, those who have rhythm disturbances—those people will tend to do worse if they get infected with COVID,” Raymond Benza, MD, director of the Division of Cardiovascular Medicine at The Ohio State University Wexner Medical Center, tells Verywell. “This is clear, and this is still non-arguable.” 

But he says research is indicating that previously healthy people and those who fare well in the face of a COVID-19 infection are also at risk for heart complications. He points to a new study out of Ohio State University, Columbus, published in JAMA Cardiology, where researchers also looked at CMR imaging, this time in 26 college athletes. They found that 15% showed inflammation of the heart muscle.

“People, even with mild symptoms or even asymptomatic, could have myocarditis and they don’t know it,” Benza says. “And that’s important because myocarditis, if it doesn’t go away, it can lead to heart failure and because the damage itself can lead to heart-rhythm abnormalities, which can be very dangerous.”

What Health Professionals Are Seeing

Physicians on the front lines of the COVID-19 pandemic echo the various studies’ findings with what they’re seeing in patients. Satjit Bhusri, MD, FACC, cardiologist and founder of Upper East Side Cardiology, says the SARS-CoV-2 virus has been causing heart damage directly. “We’re seeing the virus actually itself going into the inner lining of the heart muscle cells,” he tells Verywell. 

Hal Skopicki, MD, PhD, a cardiologist at Stony Brook Heart Institute in New York, describes the way COVID-19 harms tissue at the cell level, causing organ damage. “There’s a little protein on the top of cells,” he tells Verywell. “COVID has figured out a way to hop onto that protein. And then the cell says, ‘Oh, I think I need to bring that protein into the cell.’ And so it brings COVID into the cell, where then COVID replicates and causes cell damage when it gets released into the bloodstream again.”

Bhusri, who previously ran the cardiac COVID unit at Lenox Hill Hospital in New York, says he’s seeing “broken heart syndrome,” a condition resulting from extreme heart inflammation that’s occurring in COVID-19 patients. 

“The acute inflammatory response, or what people now know as the cytokine storm is so overwhelming that it actually breaks the patients’ heart," he says. The condition’s formal name is takotsubo cardiomyopathy. “Tako-tsubo is actually a Japanese bowl used to catch octopus,” he explains. “It’s called that because the heart fails and, under angiography, it looks like that.”

At the start of the pandemic, Benza says physicians were worried about acute coronary syndromes like heart attacks and angina. But he adds that the incidence of those issues has been much less than anticipated. Instead, he says heart failure is the problem he is most worried about.

“About 52% of those who have died from COVID have some element of heart failure,” he says, “and even 12% of those who’ve recovered from COVID have some element of heart failure. So I think that is something that we are very worried about.”

Adler reiterates Benza’s concern about the potential for people who weren’t hospitalized to be unaware they have heart inflammation after recovering for COVID-19.

“We’re seeing patients, where they seem to have no symptoms of COVID,” he says, “but when we take pictures of their heart, we see inflammation of the heart. We’re worried about whether we could be creating a wave of heart problems that we won’t see for a year or two.”

Bhusri recommends that people who have had COVID-19 follow up with their doctor to get an echocardiogram. “The doctor can actually see your heart in three-dimensions to make sure there are no new signs of asymptomatic heart failure,” he explains. “You want to catch it before you start getting symptoms. And if you do have them, you can start treating them with certain medicines.”

Preventive Measures 

Physicians also express concern that people who need health care aren’t accessing it during the pandemic out of fear of contracting the virus in a clinic or emergency room. “Cancer diagnoses are down 30%,” Adler says. “It's not because there’s less cancers; it’s because no one goes to doctor.”

Bhusri shares that worry, especially regarding heart health. “We have seen a 400% increase in out-of-hospital cardiac arrest because people didn’t call 911,” he says. 

Skopicki adds, “If you have cardiovascular risk factors, we need to get those taken care of.” He recommends working with your primary care physician to make sure your health is optimized.

Many patients who have developed severe COVID-19 have had untreated underlying cardiovascular issues that were perhaps unknown, Adler cautions. “We’re seeing untreated high blood pressure, obesity—the kind of risk factors for heart disease,” he explains. “It’s kind of unmasking inequities in our healthcare system.”

One of the lasting impacts of the pandemic will be the increase in telehealth availability, Adler adds. So if you have concerns about your heart health or otherwise, don’t hesitate to reach out to your physician. 

“Patients who are wary of going to the doctor or can’t go to the doctor because they have trouble with transportation or maybe they’re at work can do some kind of telehealth visit to get quickly screened to make sure they’re okay,” he says.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.