People who recover from COVID-19 may have lingering heart damage and inflammation months after their initial infection, even if they were not hospitalized, a small new study suggests.
The study, published Monday (July 27) in the journal JAMA Cardiology, involved 100 adults ages 45 to 53 in Germany who had recently recovered from COVID-19. About one-third of participants required hospitalization while the other two thirds were able to recover at home. On MRI scans taken more than two months after their diagnosis, about three-quarters of these patients showed signs of heart abnormalities, including inflammation of the heart muscle, or myocarditis. Many patients also had detectable levels of a protein in their blood called troponin that can indicate heart injury, such as damage after a heart attack. (Troponin is a protein found in heart cells that is released into the blood when the heart muscle is damaged, according to the University of Rochester Medical Center.)
However, exactly what these findings mean for patients' heart health in the long term is unclear, the authors said. The heart abnormalities seen in the study occasionally occur with other respiratory diseases such as influenza and may be temporary — indeed, mild cases of heart inflammation may not show symptoms and often get better on their own, according to the National Heart, Lung and Blood Institute.
But given how common heart abnormalities were in this study group, the findings "urgently require confirmation" in a larger population, the authors concluded.
The findings are potentially worrisome because heart inflammation and damage may give rise to heart failure, a potentially life-threatening condition that occurs when the heart muscle can't pump enough blood to meet the body's normal demands.
Both the researchers and the patients were surprised by the prevalence of these heart abnormalities, and that they were still pronounced weeks after the patients had recovered, study lead author Dr. Valentina Puntmann, of the University Hospital Frankfurt, told UPI.
"While we do not yet have the direct evidence for [long-term] consequences yet, such as the development of heart failure ... it is quite possible that in a few years this burden will be enormous," Puntmann said.
Although initially recognized mainly as a lung infection, COVID-19 has now been linked with damage to multiple other organs in the body, including the brain and heart. But many of these complications were observed in patients ill enough to be hospitalized.
Of the 100 patients in the new study, 67 were not hospitalized, and most of these people experienced mild or moderate symptoms. Some patients had underlying conditions such as high blood pressure, diabetes or asthma, but most did not. Patients were followed up with an MRI scan about two to three months after their initial diagnosis. At this time, about one-third of patients reported experiencing ongoing COVID-19 symptoms, such as shortness of breath and general exhaustion. A few patients had heart palpitations and chest pain after their diagnosis, but none thought they had a heart problem related to COVID-19, STAT reported.
The researchers compared scans from recovered COVID-19 patients to those of people who were similar in age and health status but were not infected with COVID-19.
Overall, 78% of recovered COVID-19 patients showed signs of some type of heart abnormality. The most common heart problem was inflammation of the heart muscle, or myocarditis, experienced by 60% of patients. Some patients also showed signs of inflammation of the pericardium, the tissue that surrounds the heart. Myocarditis occasionally occurs with influenza, adenovirus and other respiratory viruses, though it's much less common, for instance showing up in less than 10% of cases of flu, according to a 2012 study in the journal Influenza Research and Treatment.
The presence of heart abnormalities was not related to the severity of the study participants' COVID-19 illness or whether they had underlying conditions.
"Our findings demonstrate that participants with a relative paucity of preexisting cardiovascular [conditions] and with mostly home-based recovery had frequent cardiac inflammatory involvement" after COVID-19, the authors said.
Another study, also published Monday in JAMA Cardiology, analyzed autopsy findings from 39 older adults who died from COVID-19, and found evidence of SARS-CoV-2, the virus that causes COVID-19, in the heart tissue of 61% of patients.
In an editorial accompanying these studies, Dr. Clyde Yancy, a cardiologist at Northwestern's Feinberg School of Medicine, and Dr. Gregg Fonarow, a cardiologist at UCLA's Geffen School of Medicine, said that together, these two studies raise worries that the COVID-19 pandemic could spur an increase in cases of heart failure.
"We are inclined to raise a new and very evident concern that cardiomyopathy [heart muscle disease] and heart failure related to COVID-19 may potentially evolve as the natural history of this infection becomes clearer," the editorial said.
The editorial authors added that they do not want to "generate additional anxiety," but call for rigorous studies to confirm or refute the new findings.
Originally published on Live Science.