Should anticoagulation be used in the treatment of severe COVID-19?
Background. The progression of COVID-19 to its acute (pneumonia) phase occurs during the 7th to 14th day of illness. During this highly inflammatory phase, a proportion of patients with severe COVID-19 develop a hypercoagulable state associated with poor prognosis. Hence, anticoagulation is seen as a potentially beneficial intervention due to its antithrombotic effect, anti-inflammatory function, and anti-viral properties.
Objective. This review aims to determine the efficacy and safety of anticoagulation in severe COVID-19.
Methods. A rapid review was done on April 11, 2020 and updated on April 23, 2020. PubMed, MEDLINE, and medRxiv.org were searched. The review included studies on the association between the use of anticoagulants on top of other interventions, and disease progression and/or mortality among adults >18 years old with severe COVID-19 infection, as well as studies on patients with disseminated intravascular coagulopathy (DIC) of sepsis investigating bleeding complications with anticoagulant use. Four ongoing registered clinical trials on anticoagulants for COVID-19 were also found.
Results. Current evidence shows that the use of low-molecular weight heparin (LMWH) in COVID-19 is associated with the following: (1) improved surrogate markers for disease progression (increase in lymphocyte & platelet counts and decrease in D-dimer, fibrinogen degradation products, and IL-6); and (2) reduced 28-day mortality in high risk patients. Studies on DIC related to bacterial sepsis did not show significant increase in bleeding complications with anticoagulation.
Conclusion. The use of anticoagulants appears to be beneficial for severe COVID-19 due to a reduction in 28-day mortality and improvement in inflammatory and coagulation markers. However, these findings come from low-quality studies, and confirmation of the effect is needed through randomized controlled trials.