Full-dose blood thinners reduced moderately ill, hospitalized COVID-19 patients' need for organ support and improved their chances of leaving the hospital in a large clinical trial conducted worldwide and backed by the National Institutes of Health.
According to the study, published Aug. 4 in the New England Journal of Medicine, using the same treatment for critically ill COVID-19 patients didn't result in the same outcomes and may even harm those patients.
"These results make for a compelling example of how important it is to stratify patients with different disease severity in clinical trials. What might help one subgroup of patients might be of no benefit, or even harmful, in another," Gary Gibbons, MD, director of the National Heart, Lung, and Blood Institute, said in a news release.
The study included 1,098 critically ill and 2,219 moderately ill patients. They received either a low or full dose of heparin, a blood-thinning drug, for up to 14 days. Researchers defined moderately ill as those who were hospitalized but did not require organ support, and critically ill patients as those hospitalized and requiring intensive care levels of support.
For moderately ill patients, the likelihood of full-dose heparin to reduce the need for organ support, such as mechanical ventilation, compared to those who received low-dose heparin was 99 percent, the study found. A small number of patients experienced major bleeding, but that happened infrequently, the NIH said.
Researchers have observed in some people who have died from COVID-19 blood clots throughout their bodies, even in the smallest blood vessels. Blood thinners help prevent blood clot formation in certain diseases.
The drugs used in the study are familiar to physicians around the world and widely accessible, meaning the study's findings are "highly applicable to moderately ill COVID-19 patients," the researchers stated.
Read the NIH's full news release here.