The American Society of Hematology (ASH) has conditionally recommended against using thromboprophylaxis in patients with COVID-19 who are being discharged from hospital and who do not have suspected or confirmed VTE or another indication for anticoagulation.
The draft recommendation is the latest update of the ASH guidelines on the use of anticoagulation in patients with COVID-19.
Previous recommendations were in favour of prophylactic-intensity anticoagulation over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19–related critical illness or acute illness who do not have confirmed or suspected VTE.
However all recommendations have been based on very low certainty in the evidence.
Regarding their latest recommendation, the ASH guidelines panel said while there was a suggestion of a trivial mortality benefit and reduction in VTE with post-discharge antithrombotic therapy, the evidence was of very low certainty.
“There was less uncertainty in the potential undesirable effects of antithrombotic therapy increasing the risk of major bleeding complications. Moreover, the panel considered that there was higher quality indirect evidence from non-COVID-19 critically ill patients for an increase in the risk of major bleeding with post-discharge anticoagulation, although the magnitude of this effect was uncertain in the COVID-19 population.”
“The panel however acknowledged the potential for benefit, and noted that an individualised decision is important for each patient based on an assessment of thrombotic and bleeding risk.”
They said post-discharge thromboprophylaxis may be reasonable in patients judged to be at high thrombotic risk and low bleeding risk.
However they also noted that validated risk assessment models to estimate thrombotic and bleeding risk in COVID-19 patients following hospital discharge are not available.
They said there was an urgent need for more high-quality prospective studies and randomised controlled trials examining the effect of post-discharge antithrombotic therapy.