Preventing Thrombohemorrhagic Complications of Heparinized COVID-19 Patients Using Adjunctive Thromboelastography: A Retrospective Study

Background: The treatment of COVID-19 patients with heparin is not always effective in preventing thrombotic complications, but can also be associated with bleeding complications, suggesting a balanced approach to anticoagulation is needed. A prior pilot study supported that thromboelastography and conventional coagulation tests could predict hemorrhage in COVID-19 in patients treated with unfractionated heparin or enoxaparin, but did not evaluate the risk of thrombosis. Methods: This single-center, retrospective study included 79 severely ill COVID-19 patients anticoagulated with intermediate or therapeutic dose unfractionated heparin. Two stepwise logistic regression models were performed with bleeding or thrombosis as the dependent variable, and thromboelastography parameters and conventional coagulation tests as the independent variables. Results: Among all 79 patients, 12 (15.2%) had bleeding events, and 20 (25.3%) had thrombosis. Multivariate logistic regression analysis identified a prediction model for bleeding (adjusted R-2 = 0.787, p < 0.001) comprised of increased reaction time (p = 0.016), decreased fibrinogen (p = 0.006), decreased D-dimer (p = 0.063), and increased activated partial thromboplastin time (p = 0.084). Multivariate analysis of thrombosis identified a weak prediction model (adjusted R-2 = 0.348, p < 0.001) comprised of increased D-dimer (p < 0.001), decreased reaction time (p = 0.002), increased maximum amplitude (p < 0.001), and decreased alpha angle (p = 0.014). Adjunctive thromboelastography decreased the use of packed red cells (p = 0.031) and fresh frozen plasma (p < 0.001). Conclusions: Significantly, this study demonstrates the need for a precision-based titration strategy of anticoagulation for hospitalized COVID-19 patients. Since severely ill COVID-19 patients may switch between thrombotic or hemorrhagic phenotypes or express both simultaneously, institutions may reduce these complications by developing their own titration strategy using daily conventional coagulation tests with adjunctive thromboelastography.