NIH Record - National Institutes of Health

Full-Dose Blood Thinners Improve Outcomes in Hospitalized Covid Patients

Patient lays down on a hospital bed
Full-dose blood thinner may decrease need for life support in moderately ill Covid patients.

Photo:  Credit TEMPURA/GETTY

In large clinical trials, full-dose anticoagulation (blood thinner) treatments given to moderately ill patients hospitalized for Covid-19 reduced the need for vital organ support, such as ventilation. A trend in reduced mortality was also observed and is under further study. With large numbers of Covid-19 patients requiring hospitalization, these outcomes could also help reduce the overload on intensive care units around the world.

Early in the pandemic, physicians observed increased rates of blood clots and inflammation, which affected multiple organs and led to such complications as lung failure, heart attack and stroke. Low-dose blood thinners are routinely administered to these patients but it was unknown whether larger doses would be safe and effective.

Three clinical trial platforms spanning 5 continents in more than 300 hospitals have been collaborating to test the possible benefit of giving full doses of the blood thinner heparin to moderately ill hospitalized adults with Covid-19.

Based on interim results of more than 1,000 moderately ill patients, full doses of blood thinners were safe and superior to the doses normally given to prevent blood clots in hospitalized patients. These trial results complement the group’s findings announced in December that routine use of full-dose anticoagulation, when started in the ICU in critically ill Covid-19 patients, was not beneficial and may have been harmful in some patients. 

The three international trials are REMAP-CAP, ACTIV-4 and ATTACC. In the United States, the ACTIV-4 trial is an NIH-led collaborative effort with several universities.

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The NIH Record, founded in 1949, is the biweekly newsletter for employees of the National Institutes of Health.

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Assistant Editor: Eric Bock (link sends e-mail)

Staff Writer: Amber Snyder (link sends e-mail)