Characterization of the Benefits and Risks of Therapeutic Anticoagulation in Patients Admitted with Severe COVID-19 (CRITAC).

Background Severe COVID-19 is associated with increased rates of thrombotic complications. Recent provincial recommendations in British Columbia have suggested providing thromboprophylaxis with therapeutic anticoagulation for hospital inpatients with severe COVID-19 who do not have a high risk of bleeding. Objectives To characterize the rates of major bleeding, thrombotic events, complications from COVID-19, and adverse effects among patients with severe COVID-19 treated with therapeutic anticoagulation. Methods This retrospective chart review involved patients with laboratory-confirmed COVID-19 who were admitted to 3 sites within a local health authority between April 1 and December 31, 2021, and received therapeutic anticoagulation for thromboprophylaxis. Results After screening of 1036 patients, 72 patients were included in the study. The mean age of participants was 54 years, 63% (n = 45) were male, and 92% (n = 66) were receiving supplemental oxygen by nasal prongs on admission. The primary outcome, major bleeding, was experienced by 1 patient (1%). Increasing oxygen requirements resulting in progression to high-flow nasal cannula occurred in 11 patients (15%), and 5 patients (7%) required admission to the intensive care unit. One patient (1%) experienced a thrombotic event, and 1 patient (1%) had a minor bleed. The mean duration of hospitalization was 10 (standard deviation 10.8) days. One death occurred during the study period, and no cases of heparin-induced thrombocytopenia were observed. Conclusions In this study of hospital inpatients with severe COVID-19 who were deemed to be at low risk of bleeding and who received therapeutic anticoagulation, there were low rates of both major bleeding and thrombotic events.