A Dynamic, D-dimer-based Thromboprophylaxis Strategy in Patients with COVID-19 [version 2; peer review: 2 approved]

Background COVID-19 pandemics increases venous thromboembolism (VTE) risk during hospitalization, despite prophylactic anticoagulation. Limited radiological diagnosis in pandemic requires a guided protocol for anticoagulant adjustment. Methods This retrospective cohort study was conducted at a single center as part of a quality improvement program evaluating the efficacy and safety of anticoagulation protocols. The study focused on implementing a guideline for anticoagulant dosing protocol based on dynamic changes in D-dimer levels in COVID-19 hospitalized patients. The dosing guideline allowed for dose escalation from standard prophylactic levels to escalated prophylactic or therapeutic levels, depending on the patient's risk profile for VTE. The primary endpoints included in-hospital survival comparing between fix and dynamic adjustment treatment groups. Secondary endpoints encompassed major and clinically relevant non-major bleeding (CRNMB) events, incidence of breakthrough thrombosis, length of hospitalization and ICU stay, days of mechanical ventilator use, and survival duration. Findings Among the 260 COVID-19-infected patients hospitalized between March 15th and June 15th, 2020. The patients received fixed anticoagulant dosage in 188, 72.3%) patients, while 72 (27.7%) were up-titrated according to the protocol. In-hospital survival at 30 days demonstrated superiority among patients whose anticoagulation was up-titrated to either escalated prophylactic or therapeutic (80.2%) compared to receiving fixed anticoagulant dosage (51.3%) (p=0.01). Bleeding events were significantly higher in up-titrate group (12.5%) compared to fixed anticoagulant dosage group (2.13%). Most of them are CRNMB. Conclusion A dynamic, D-dimer-based dose escalation of anticoagulation for hospitalized patients with COVID-19 holds promise in improving in-hospital mortality rates without a significant increase in fatal bleeding events.