Prevention and Treatment of Venous Thromboembolism Key Clinical Questions
08. How should D-dimer be interpreted in the setting of COVID-19?
a. HOMERuN institutions
Fourteen percent of protocols recommended consideration of empiric therapeutic anticoagulation based on elevated D-dimer alone. Nineteen percent recommended against empiric therapeutic dosing of anticoagulation based on lab values in the absence of other clinical indications such as proven VTE. Forty-three percent recommended escalation from standard to higher-dose prophylactic anticoagulation based on laboratory findings in combination with clinical variables. For diagnostic decision-making, 14% recommended that elevated or rising D-dimer should prompt additional imaging to evaluate for VTE, while 10% instead recommended that D-dimer elevation alone should not lead to VTE work-up or empiric treatment. Several protocols mentioned that D-dimer below the upper limit of normal could still be used to exclude VTE.
b. What is Known
In data describing coagulation parameters among COVID-19 patients, D-dimer is elevated in approximately half. D-dimer at admission and markedly increasing D-dimer levels (3- to 4-fold) over time were associated with high mortality, likely reflecting coagulation activation from infection/sepsis, cytokine storm and impending organ failure.5
c. What is Not Known
Although D-dimer elevation is common in COVID-19, the implications remain unknown, including its association with hypercoagulability or overt thrombosis. In addition, how to integrate D-dimer in decisions about pharmacologic prophylaxis, diagnosis and treatment of VTE remain unknown.
Key Clinical Questions
- Tang N, Li D, Wang X, Sun Z. Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia. J Thromb Haemost JTH. 2020;18(4):844-847. doi:10.1111/jth.14768