Both studies called for further investigations of long-term cardiac consequences of COVID-19.
One observational study involved 100 patients with recent COVID-19 illness. Cardiac magnetic resonance (CMR) imaging revealed cardiac involvement in 78 patients and heart muscle inflammation in 60 patients, independent of pre-existing conditions.
The patients were identified from the University Hospital Frankfurt COVID-19 Registry from April to June. Researchers said 33 patients were severely ill and needed hospitalization, while two of the patients underwent mechanical ventilation.
Detectable levels of troponin, a type of protein found in the muscles of the heart, were found in 71 patients, and high levels (indicating heart damage) were found in five patients. Biopsies of heart muscle tissue in patients with “severe findings” showed active inflammation, the study authors said.
In a second study involving autopsies from 39 COVID-19 cases, researchers found a presence of viral infection within the myocardium or the middle, muscular layer of the heart, in 24 patients.
The deceased patients were autopsied at the Institute of Legal Medicine at the University Medical Center Hamburg-Eppendorf from April 8 to 18.
The patients’ median age was 85 years, and pneumonia was listed as the cause of death for 90 percent of them. Study authors said current data show the presence of SARS-CoV-2 in heart tissue doesn’t necessarily cause an inflammatory reaction consistent with clinical myocarditis (an inflammation of the heart muscle).