Anticoagulation strategies and risk of bleeding events in critically ill COVID-19 patients

ABSTRACT

Background: Previous reports describe high rates of venous thromboembolism (VTE) in critically ill COVID-19 patients. Consequently, intermediate and therapeutic doses anticoagulation have been used in clinical practice, potentially exposing patients to a higher risk of bleeding. Aims: To evaluate the rate of thrombosis, bleeding and mortality comparing prophylactic, intermediate or therapeutic doses in critically ill COVID-19 patients. Methods: All COVID-19 patients admitted to the intensive care unit of a tertiary hospital between March and April 2020 were included. Patients were categorized into three groups according to the highest anticoagulant dose received prophylactic, intermediate and therapeutic. Incidence of VTE, bleeding and mortality were compared between groups. We performed two logistic multivariable regressions to test the association between VTE and bleeding with clinical characteristics and the anticoagulant regimen. Results: 201 patients were included. 78 (39%) received prophylactic, 94 (47%) intermediate and 29 (14%) therapeutic doses. There were no differences in VTE and mortality between groups. In contrast, bleeding events were more frequent in patients receiving therapeutic (31%) and intermediate (15%) doses than in those receiving prophylactic doses (5%) ( P < 0.001 and P < 0.05 respectively). Major bleedings were also more frequent in patients with anticoagulant doses ( P < 0.01). The anticoagulant dose was the strongest determinant for bleeding (odds ratio [OR] 2.4, 95% confidence interval (CI) 1.26-4.58, P = 0.008) but had no impact on VTE (OR 0.97, 95%CI 0.58-1.68, P = 0.92). Conclusions: Critically ill COVID-19 patients receiving intermediate or therapeutic doses of heparin appear to have a higher risk of bleeding without a decrease of VTE events and mortality.