There is new evidence that COVID-19 may have long-lasting effects on heart health, which may go unnoticed in patients who presume they have recovered from the infection.
Two studies from Germany, published Tuesday in the journal JAMA Cardiology, show how the virus can stay in the heart for months, even without causing symptoms.
The first study included 100 patients with coronavirus from the COVID-19 Registry of the University Hospital of Frankfurt. Most were healthy adults in their 40s and 50s.
They all had MRIs of their heart two to three months after the virus was diagnosed, when many seemed to have fully recovered. Those images were compared to people who had never had COVID-19.
Of those 100 COVID-19 patients, 78 still had visual signs that the virus had an impact on the heart. Sixty of those patients had signs of continued inflammation of the heart muscle.
“That is really compelling,” Dr. Clyde Yancy, chief of cardiology in the department of medicine at Northwestern Medicine in Chicago, told NBC News. “It indicates that months after exposure to COVID-19, we can still detect evidence of a heart that is not completely normal.”
The problem may not cause physical symptoms, but it could indicate a risk of further heart damage.
“Once the heart muscle has been injured, there is a possibility of progressive injury,” Yancy wrote in an editorial accompanying the studies.
Because the virus is so new, the long-term cardiovascular risks of COVID-19 are still unknown.
According to the study authors, no pre-existing condition would have explained the damage, and only a third had been hospitalized with COVID-19. The rest were able to remain at home during the course of their illness.
“Our findings may provide an indication of a potentially considerable burden of inflammatory disease in large and growing parts of the population,” the study authors wrote.
The second study included 39 autopsies of people who had died from COVID-19. Those patients tended to be older, in their 80s. The researchers found evidence of the virus in heart tissue in 24 of the 39 patients.
Also, five of those patients had signs that the virus was replicating in heart tissue.
“We know that the virus is reaching the heart muscle and appears to cause an inflammatory response that we still don’t fully understand,” said Dr. Matthew Belford, an interventional cardiologist at Wake Forest Baptist Health in Winston-Salem, North Carolina, said. Belford was not involved in any of the studies.
Doctors have known for some time that COVID-19 can wreak havoc on the circulatory system, which can lead to dangerous blood clots. A study published in the journal Cell in March showed that the virus infiltrates the body by binding to a type of receptor on cells called ACE2.
ACE2 receptors are often found on endothelial cells, located in the lining of the heart and blood vessels. One of the main jobs of cells is to help control blood clotting and platelets.
It is unclear how long such damage will persist.
The research “catches my eye,” Yancy said.
“It makes me say, ‘We’re not done yet,'” he said. “We must respect COVID-19.”
“There is still a lot we don’t know,” he added. “We have to be on guard.”
This story was originally published on NBC News.
