Personalizing Antithrombotic Therapy in COVID-19: Role of Thromboelastography and Thromboelastometry
Rahul Chaudhary, Rolf P. Kreutz, Kevin P. Bliden, Udaya S. Tantry, Paul A. Gurbel
Abstract
Coronavirus-2019 (COVID-19) infection is responsible for the pandemic outbreak across the world. The pathophysiology of COVID-19 has been characterized by endothelial dysfunction, and a thromboinflammatory state. Severe infection and poor clinical outcomes have been associated with diffuse endothelial dysfunction and a hyperinflammatory state leading to a cytokine storm which further enhances thrombotic complications.[1] [2] The pathophysiology uniquely affects the lungs in its early stages as evidenced by autopsy reports of diffuse alveolar damage along with pulmonary intravascular microthrombi in the absence of known venous thromboembolism (VTE).[3] Multiple retrospective and prospective clinical trials have evaluated thromboinflammatory biomarkers linking them to poor prognosis among patients with COVID-19 infection.[4] [5] [6] The thrombotic biomarkers evaluated include D-dimer levels, fibrinogen levels, prothrombin time (PT), and activated partial thromboplastin time (aPTT). There have been several reports and meta-analyses linking elevated D-dimer levels with poor prognosis including severity and mortality with COVID-19 infection.[5] [7] However, several concerns have been raised with the use of D-dimer as a biomarker among COVID-19 infected patients. D-dimer has low specificity and elevated levels are often seen with advanced age, African American race, female sex, active malignancy, surgery, pregnancy, immobility, cocaine use, connective tissue disorders, end-stage renal disease, and prior thromboembolic disease.[8] Also, D-dimer reflects a later stage in the hemostatic process and is released when a clot is degraded by the fibrinolytic processes. Other standard laboratory tests including PT and aPTT measure the clotting activity from the plasma and ignore other components of the coagulation such as the platelets and the fibrinolysis. The platelet count and fibrinogen concentration also have the caveat of providing static measures with no information regarding their functionality.