ABSTRACT
Objective: To compare Anti-Xa directed thromboprophylaxis using low molecular weight heparin (LMWH) (anti-Xa peak goal 0.2-0.5â IU/mL) to alternative anticoagulation strategies in critically ill COVID-19 patients. Methods: This was a retrospective, multicenter, single health-system study. Primary outcomes were thromboembolic events and clinically important bleeding events. Secondary outcomes included dosing comparisons between LMWH cohorts. Main Results: A total of 695 patients were included. No differences were found in the incidence of thrombotic events with any of the dosing strategies. The incidence of major bleeding was significantly higher in the standard dose thromboprophylaxis, intermediate dose subcutaneous heparin (SQH), and therapeutic anticoagulation cohorts. Forty-nine percent of patients within the anti-Xa directed group had their first anti-Xa peak at goal, while 43% were above goal. Patients who had levels above goal had dose modifications made, therefore anti-Xa directed LMWH resulted in significantly lower total daily doses compared to intermediate dose LMWH. Conclusions: Anti-Xa directed LMWH dosing provided comparable thromboprophylaxis with lower total daily doses of LMWH in critically ill COVID-19 patients. Further randomized controlled trials are needed to confirm our findings.