Anticoagulation in COVID-19

Expert consensus from Mayo Clinic

Findings from analysis of real-world data from more than 1 million patients from 859 US hospitals.


  • The incidence of coagulopathy and thrombotic events were higher in those patients with COVID-19 who presented with more severe forms of the disease
    • Thrombotic outcomes are associated with augmented morbidity and mortality; therefore, venous thromboembolism (VTE) prophylaxis requires a balanced approach between the risk of thrombosis versus the risk of major bleeding


  • The Mayo Clinic experts’ consensus will aid clinicians in the health care management of patients with COVID-19
    • The consensus assimilates current data on thrombosis risk, prognostic implications, and anticoagulation effects in the therapeutic landscape of COVID-19


  • Systematic review (in accordance with the PRISMA statement): provide a description of coagulopathy and the role of anticoagulants in patients with COVID-19
    • Literature search and data extraction: Ovid databases (November 2019 to May 2020)
      • 4070 unique citations were identified; 37 of these studies were included
      • Study cohorts ranged from 24 to 2773 patients with a diagnosis of COVID-19; overall mortality was up to 56%
    • Key inclusion criteria: prospective/retrospective primary studies reporting
      • a. frequency of coagulation abnormalities
      • b. laboratory values of coagulation parameters
      • c. efficacy of pharmacological anticoagulation
    • Key exclusion criteria: non-interventional studies with <100 participants (that only reported the prevalence of coagulopathy)
    • Outcomes of interest: mortality, VTE, disseminated intravascular coagulation (DIC), and major bleeding


  • Laboratory findings:
    • Elevated D-dimer = 42%
    • Coagulopathy (prolongation of either prothrombin time [PT] or activated thromboplastin time [aPTT]) = 28%
    • Thrombocytopaenia = 20%
    • Prolonged aPTT = 11% and prolonged PT = 7%postpartum period)
    • Incidence of thrombotic events and comparison with non-COVID patients: overall heterogeneity was moderate to high
    • Prognosis: elevated D-dimer values, thrombocytopaenia, and DIC
  • Expert consensus: prevention of thrombosis
    • a. patients on prior anticoagulation therapy should be transitioned to unfractionated heparin or low-molecular-weight heparin
    • b. for patients not receiving anticoagulants, VTE prophylaxis should be determined based on bleeding risk assessment
    • c. baseline laboratory assessment should include a complete blood cell count with differential, PT/aPTT, fibrinogen, and D-dimer
    • d. a distinction between patients requiring medical care in hospital wards versus intensive care unit (ICU) care should be considered
  • Expert consensus: treatment of thrombosis
    • If VTE is identified, unfractionated heparin or LMWH should be initiated (patient management approach should be the same as for non-COVID patients)
    • After stabilisation, patients can be transitioned to oral anticoagulant therapy (direct oral anticoagulants or vitamin K antagonists, depending on patient-specific variables)


  • Consensus is based on low-certainty evidence and the guidance lacked the typical process of clinical guideline development
    • Limited data on VTE prevalence for patients hospitalised on the medical ward, apart from the ICU setting
    • Lack of estimates of VTE rates in ambulatory patients with COVID-19 recovering in the home setting
    • Only few reports are available for bleeding outcomes for the hospitalised patients receiving either prophylaxis or therapeutic anticoagulation
    • Requirement for ideal screening strategies for VTE in the ICU setting
    • The evaluation strategies relying on pretest probability of disease evaluation may not be valid for patients with COVID-19
    • Using D-dimer value as a negative predictive assay may be of less value

    McBane RD 2nd, Torres Roldan VD, Niven AS, Pruthi RK, Franco PM, Linderbaum JA, et al. Anticoagulation in COVID-19: A systematic review, meta-analysis, and rapid guidance from Mayo Clinic. Mayo Clin Proc. 2020;95(11):2467-2486. doi: 10.1016/j.mayocp.2020.08.030.

MAT-BH-2100643/v1/Jul 2021