The new research highlights the fact that you still need to be taking COVID-19 precautions seriously.

By now, you likely know about all the symptoms of COVID-19dry cough, fever or chills, fatigue, sometimes diarrhea and vomiting. But the aftermath of COVID-19—those lingering effects the virus has on the body even after infection—is talked about less often, in part because scientists don’t fully understand the long-term effects of the new disease yet.

Now, in two new studies, both published Monday in JAMA Cardiology, researchers warn of some lasting effects COVID-19 could have on the body—specifically the cardiovascular system.

The first study, conducted by German researchers, found that SARS-CoV-2, the virus that causes COVID-19, can make its way to cardiac muscle tissue in the heart. Researchers evaluated the cardiac tissue of 39 people in Germany who had recently died from COVID-19 and were diagnosed with the virus postmortem. The patients’ ages at the time of death ranged from 78 to 89. The virus was present in the hearts of 24 of the 39 patients. The study clearly states that, while the virus was detected within the cardiac tissue of the evaluated patients, it wasn't necessarily associated with inflammation consistent with myocarditis.

While it was already known that preexisting cardiovascular conditions, like hypertension and coronary artery disease, can increase a person's risk for complications from COVID-19, the new study found evidence of the cardiovascular impact of SARS-CoV-2. In an editorial comment accompanying the new research, two physicians—Clyde Yancy, MD, chief of cardiology at Northwestern University Feinberg School of Medicine's Department of Medicine, and Gregg Fonarow, MD, a cardiologist at Ronald Reagan UCLA Medical Center—explained the significance of the study. "These new findings provide intriguing evidence that COVID-19 is associated with at least some component of myocardial injury, perhaps as the result of direct viral infection of the heart,” the doctors wrote.

The second study, this time from researchers in Germany, Italy, and Russia, evaluated 100 patients, aged 45 to 53 years old, who had recently recovered from COVID-19. The patients were selected from the University Hospital Frankfurt COVID-19 Registry between April and June 2020. Of the 100 patients, 82% were symptomatic, and 33% of the patients involved required hospitalization, while 67% were able to recover at home.

Regarding the cardiovascular health of those patients, 78% had abnormal findings from cardiovascular magnetic resonance (CMR) imaging—or testing that assesses the function and structure of the cardiovascular system—while 60% of the recovered patients had "ongoing myocardial inflammation." These results were independent of preexisting conditions, severity and course of the illness, and time since diagnosis of COVID-19.

Essentially, the new research establishes a link between COVID-19 and myocarditis, or inflammation in the heart caused by viral infection, but a relatively weak one, Daniel Cantillon, MD, a cardiologist at Cleveland Clinic, tells Health.

According to Dr. Cantillon, myocarditis sounds a lot more severe than it usually is. In fact, many viruses have been linked to myocarditis, and most people who develop the condition continue to be fully functioning, Dr. Cantillon says—that includes working full-time and exercising. Myocarditis resulting from causes other than COVID-19 has been linked to arrhythmias (which occur when a patient has an irregular heartbeat) that can be life-threatening; however, “that is extremely rare,” Dr. Cantillon adds. Most patients who have myocarditis “have a very good quality of life.”

It’s also worth noting that the chances of a COVID-19 survivor suffering from myocarditis are rare, given what we know so far, Dr. Cantillon adds. While 60% of the patients featured in the second study showed myocardial inflammation, it's important to remember that the study's sample size was small, with just 100 patients. Also, most of these patients were symptomatic, some bad enough to require hospitalization. That's an important distinction to make, since the World Health Organization suggests 80% of all COVID-19 infections are mild or asymptomatic. But that's not to say we shouldn't discount the research, only that further investigation of the topic is needed, Dr. Cantillon says.

Further research has the potential to help doctors treat COVID-19 patients both while they’re sick and long-term. “We have to continue to become better informed about what’s the optimal way to treat those patients [with] severe illness,” Dr. Cantillon says. For example, he explains, if myocarditis is a threat to certain patients who get COVID-19, doctors might consider treating them with anti-inflammatory treatment.

The new studies underscore how important it is for medical professionals to keep an eye on the multi-system effects of COVID-19, and serve as a reminder that there's still much more to lean about this virus. “This is a sobering reminder that the pandemic is likely going to have a long tail in terms of public health implications," Dr. Cantillon says. It's also important to remember that, with all of the newly-emerging research, it's imperative to continent taking all COVID-19 safety precautions seriously, while also remembering to keep calm about the situation. “We have to be careful that the message that the public receives is not that everybody who becomes ill with COVID is going to have long-lasting heart damage," Dr. Cantillon says.  "At the same time, we need to take the findings seriously."

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.

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