Clinical Guidance from the Anticoagulation Forum on Thromboembolism & Anticoagulant Therapy During COVID-19

Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19- induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.


  • Many patients with COVID-19 are at increased risk of venous thromboembolism (VTE). Therefore, we recommend pharmacologic prophylaxis for patients with COVID-19 when hospitalized.

  • We recommend that dosing of VTE pharmacologic prophylaxis be evidence-based, whenever possible. Escalated doses can be considered for critically ill patients.

  • We recommend that post-hospital pharmacologic prophylaxis be used selectively for patients at highest risk for VTE based on existing evidence from randomized trials.

  • We recommend the use of anti-Xa assay rather than aPTT to monitor unfractionated heparin dosing due to potential baseline abnormlaities in aPTT for patients with COVID-19.

  • We recommend a full 3 month course of therapeutic anticoagulation for patients with COVID-19 who are presumed to have a hospital-associated VTE event.