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Effect of Antithrombotic Therapy on Outpatients with Clinically Stable Symptomatic COVID-19

November 24, 2021

Researchers including UPMC’s Frank Sciurba, MD, recently found that adding antithrombotic therapy does not reduce major cardiopulmonary adverse outcomes with symptomatic but clinically stable COVID-19 patients. The results were published in JAMA

Though the risks and benefits of antithrombotic therapy have not been established, acutely ill inpatients with COVID-19 typically receive that therapy. In this study, researchers assessed whether antithrombotic therapy can safely reduce major adverse cardiopulmonary outcomes. 

Participants were given aspirin, prophylactic-dose apixaban, therapeutic-dose apixaban, or placebo for 45 days. 

The primary outcome was the combination of symptomatic deep venous thrombosis, pulmonary embolism, arterial thromboembolism, myocardial infarction, ischemic stroke, hospitalization for cardiovascular or pulmonary events, and all-cause mortality for up to 45 days after treatment initiation.

Researchers found that there were no significant differences between the active and placebo groups, meaning treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome. However, the study was terminated after enrollment of 9% of participants because of an event rate lower than anticipated.

Read the full study here.


Connors JM, Brooks MM, Sciurba FC, et al. Effect of Antithrombotic Therapy on Clinical Outcomes in Outpatients With Clinically Stable Symptomatic COVID-19: The ACTIV-4B Randomized Clinical Trial. JAMA. Published online October 11, 2021. doi:10.1001/jama.2021.17272

About Dr. Sciurba

Frank Sciurba, MD, is a professor of Medicine and Education in the Division of Pulmonary, Allergy and Critical Care Medicine, director of the Emphysema/COPD Research Center, and director of the Pulmonary Function Exercise Physiology Laboratory. 

Dr. Sciurba’s clinical focus is on individual patient-focused approaches for advanced COPD patients. His long-term research interest includes volume reduction strategies in patients with advanced emphysema and the use of exercise testing as a diagnostic and outcome tool in lung disease.