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

OBJECTIVE: To evaluate the rate of thrombosis, bleeding and mortality comparing anticoagulant doses in critically ill COVID-19 patients. DESIGN: Retrospective observational and analytical cohort study. SETTING: COVID-19 patients admitted to the intensive care unit of a tertiary hospital between March and April 2020. PATIENTS: 201 critically ill COVID-19 patients were included. Patients were categorized into three groups according to the highest anticoagulant dose received during hospitalization: prophylactic, intermediate and therapeutic. INTERVENTIONS: The incidence of venous thromboembolism (VTE), bleeding and mortality was compared between groups. We performed two logistic multivariable regressions to test the association between VTE and bleeding and the anticoagulant regimen. MAIN VARIABLES OF INTEREST: VTE, bleeding and mortality. RESULTS: 78 patients received prophylactic, 94 intermediate and 29 therapeutic doses. No differences in VTE and mortality were found, while bleeding events were more frequent in the therapeutic (31%) and intermediate (15%) dose group than in the prophylactic group (5%) (p < 0.001 and p < 0.05 respectively). The anticoagulant dose was the strongest determinant for bleeding (odds ratio 2.4, 95% confidence interval 1.26–4.58, p = 0.008) but had no impact on VTE. CONCLUSIONS: Intermediate and therapeutic doses appear to have a higher risk of bleeding without a decrease of VTE events and mortality in critically ill COVID-19 patients.