Hospitalized COVID-19 patients may be more likely to develop clotting in their major organs, which researchers say may explain why some with the virus suffer heart attacks despite having no prior coronary damage.
A series of 18 autopsies performed on NYU Winthrop Hospital patients who tested positive for COVID-19 discovered abnormal clotting and deposits of cells and proteins that cause clots in small blood vessels in their hearts, kidneys, lungs and livers. The findings were published Thursday in Lancet.
Clotting was also found in the heart veins rather than arteries, causing heart muscle damage. Researchers believe that findings may help to explain why some patients with COVID-19 have heart attacks but do not show signs of having blocked arteries on coronary angiography.
Most of the patients autopsied for the study show no signs of having previous significant coronary damage, according to Dr. Amy Rapkiewicz, the study's co-author, chair of pathology at NYU Winthrop Hospital, and associate professor and autopsy director at NYU Long Island School of Medicine. The majority of the patients were obese and had hypertensive disease. But Rapkiewicz said more research was needed in order to learn what are the factors that put some coronavirus patients at higher risk for clotting
"I think that's the one open-ended question," Rapkiewicz said.
Respiratory failure has been cited as the main cause of death for COVID-19 patients. Previous research has found widespread lung clots in deceased COVID-19 patients compared to influenza patients.
Rapkiewicz said the blood clots could likely explain why multiple organ failure is found in some COVID-19 deaths. COVID-infected organs in the patients studied were found to have a high number of bone marrow cells called megakaryocytes, which produce platelets necessary for blood to clot.
"The clotting complications in these patients is really not limited to the lungs, it' s systemic and it's multi-organ," Rapkiewicz said. "In the heart, we see cells that we normally would not be present."
In some patients, clots had formed in the lungs despite them receiving anti-clotting medication therapies.
The findings raise the question to whether anti-platelet therapy should become a standard treatment given to hospitalized COVID-19 patients as a means of reducing the risk of multi-organ clotting. But researchers need to understand how clinicians could predict which patients are most likely to need the therapy, Rapkiewicz said.
"We're rapidly coming to some idea around what makes a person potentially be in that poor prognostic category," she said.
The study is the latest evidence on how COVID-19 can cause cardiac trauma even in patients without coronary disease. A research letter published in April in the New England Journal of Medicine found patients had vital signs usually associated with having a heart attack, yet most showed no signs of having arterial blockage.
The latest study's findings suggest clinicians may need to think differently how they approach ways to reduce the risk clotting among COVID-19 patients compared to patients without the virus.
"It has to be a therapeutic option that treats the whole body and not just the patient that has stasis and immobility and develops clotting in the legs that just embolizes to the lungs," Rapkiewicz said.