As researchers learn more about how COVID-19 affects the heart, they have learned that inflammation of the heart muscle, known as myocarditis, may not be the reason for heart injury in many COVID-19 cases.
After a study from the Mayo Clinic of the hearts of 15 patients who died but had been infected with COVID-19, researchers found that one-third of patients with active or cleared cases showed evidence of myocarditis. But, the study did not find evidence of SARS CoV-2 (which causes COVID-19) in the heart tissue.
Those patients were also compared to two groups: A control group of flu patients and a group of those without a viral infection.
Chemical staining tests as part of the study did reveal something important in the hearts of COVID-19 patients though.
"The study shows that COVID-19, unlike other viruses, seems to impact the heart's small blood vessels," Melanie Bois, M.D., a Mayo Clinic cardiovascular pathologist and first author of the study, said.
Those chemical staining tests showed that blood clotted in the heart’s small blood vessels, and that those blood clots didn’t always go away after the virus was cleared from the body. This suggests blood thinning therapy could be a treatment for COVID-19 patients.
"This study highlights the importance of an autopsy in understanding how diseases affect the body, which helps us to explore new and potentially more effective treatments," Joseph Maleszewski, M.D., a Mayo Clinic cardiovascular pathologist and senior author of the study, said.
