Some Covid-19 patients show signs of heart damage months later3 min read . Updated: 24 Sep 2020, 10:18 AM IST
Recent research suggests some people who recovered might have lingering heart inflammation and injury, even if their cases weren’t severe
The new coronavirus can leave some patients with signs of heart inflammation and injury months after they get sick with Covid-19, even in cases where their illness wasn’t severe, researchers say.
The findings could help explain the symptoms of recovered Covid-19 patients, some of whom are struggling with such issues as shortness of breath, chest pain and heart palpitations, scientists say.
And in some patients, the heart inflammation and damage could lead to serious problems years from now, including irregular heartbeats and even heart failure, though there hasn’t been enough time to study the long-term implications, according to researchers.
“We basically die with the heart-muscle cells we’re born with, so anything that results in the death of heart muscle has the potential to irreversibly damage the heart’s mechanical ability and the heart’s electrical function," said Charles Murry, director of the University of Washington’s Center for Cardiovascular Biology, who is studying Covid-19’s impact on the heart.
Heart inflammation can follow cases of the seasonal flu or other respiratory viruses and lead to irregular heartbeats or even heart failure in some cases, doctors and researchers say. The mounting evidence of Covid-19’s toll on the heart stems from studies probing the effect of the coronavirus on heart-muscle cells and autopsying people who died from the disease, as well as looking at the hearts of patients who have recovered.
The findings are still preliminary, researchers say, especially those gleaned from testing in lab-grown cells. More research, including studies in patients, needs to be done before scientists can reach any conclusions.
Researchers suspect there are two ways the coronavirus could cause heart inflammation and injure heart muscle.
One possibility is that the heart becomes collateral damage in a patient’s intense immune reaction to the virus. The other suspicion is that the virus invades heart tissue, which contains the molecular parts known as ACE2 receptors that the virus uses to enter cells.
Dr. Murry’s research team found that the coronavirus could infect and replicate in lab-grown heart-muscle cells, impairing their ability to contract and to conduct the electrical signals required for regulating heartbeat, eventually killing them. They reported their findings in a paper that was posted in August on a preprint server, but it hasn’t been peer-reviewed yet.
Muscle fibers in heart-muscle cells grown in a lab looked as though they had been diced into tiny pieces after being exposed to small doses of the coronavirus, according to a study by Gladstone Institutes that researchers posted on a preprint server in August.
Heart-muscle cells can’t contract properly and produce a normal heartbeat without those fibers functioning properly, said Todd McDevitt, senior investigator at the Gladstone Institutes and one of the lead authors of the study. The researchers also found that DNA seemed to be missing from the nuclei in many heart-muscle cells.
“A cell that can’t contract or that’s missing its nuclear DNA—it’s not going to function," Dr. McDevitt said. The study hasn’t yet been peer-reviewed.
His team found similar changes in heart autopsy samples they obtained from three Covid-19 patients. A study published in the journal JAMA Cardiology in July found detectable coronavirus in the hearts of 24 of 39 Covid-19 patients who were autopsied.
Scientists are trying to figure out whether their findings explain the heart symptoms of some Covid-19 patients, even months after they had appeared to recover from the disease.
Researchers studying 100 Covid-19 patients around two months after illness found heart-muscle inflammation in magnetic resonance imaging of the hearts of 60 of the people, according to a paper published in July by the journal JAMA Cardiology. The researchers also found abnormalities in magnetic resonance imaging of the hearts of 78 patients.
In some patients, symptoms lingered long after the illness, said Eike Nagel, one of the study’s lead authors and director of the Institute for Experimental and Translational Cardiovascular Imaging at University Hospital Frankfurt in Germany. Thirty-six patients had shortness of breath and reported general exhaustion, while 17 suffered chest pain and 20 had palpitations.
The group included patients who had been hospitalized, patients who recovered at home and patients who didn’t have any symptoms, the researchers said. The abnormalities didn’t appear related to whether a patient had a pre-existing condition such as diabetes or hypertension, or to the severity of the illness, the researchers said.
Such abnormalities are linked to an increased risk of heart failure, irregular heartbeats and other long-term health problems, Dr. Nagel said. The pandemic, he said, could be responsible for an uptick in heart-related disease and deaths years from now.
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