Comparing Therapeutic versus Prophylactic Enoxaparin Therapy in Severe COVID-19 Patients: A Randomized Clinical Trial

Coronavirus disease 2019 (COVID-19) has been associated with a hypercoagulopathy state; however, the efficacy of different anticoagulant regimens in preventing thrombotic events is not clear. We aimed to compare therapeutic versus prophylactic enoxaparin therapy in severe COVID-19 patients. In this single-center, open-label, randomized controlled trial, adult patients with severe COVID-19 presentations and an increased D-dimer level of more than 4 times the normal upper limit were randomly assigned to receive either prophylactic or therapeutic dose of enoxaparin. All patients were observed for at least 4 months regarding the overall survival as the primary outcome. Hospitalization duration, the need for intensive care unit (ICU) admission, the need for mechanical ventilation, and major adverse events (MAEs) were also analyzed as the secondary outcomes. Survival analysis was done via Kaplan-Meier curves and the Log-rank test. Cox regression was used, adjusting for baseline variables. Overall, 237 patients (152 men and 85 women) were randomized to either arm (121 to prophylactic and 116 to therapeutic groups). The mortality rate was 27 (22.3%) and 52 (44.8%) in prophylactic and therapeutic arms, respectively. Prophylactic enoxaparin was associated with better survival in the log-rank test ( < 0.001; HR, 0.42). Additionally, a significantly lower rate of ICU admission, a lower rate of MAEs, and shorter hospitalization were observed in the prophylactic arm ( < 0.001, = 0.009, and = 0.028, respectively). The results of the current study were in favor of anticoagulant treatment with prophylactic doses of enoxaparin. Still, due to the limitations of this paper, we suggest that these findings be treated cautiously.