ABSTRACT
Background: Hospitalized patients with COVID-19 have shown a significant occurrence of thromboembolism and a heightened risk of death. It remains unclear whether factor Xa inhibitors are superior to enoxaparin in this context. Hence, there is a need for a direct comparison to assess the preventive effects and safety of factor Xa inhibitors versus enoxaparin in hospitalized COVID-19 patients. Methods: MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials (RCTs) or retrospective studies that compared the effectiveness or safety of factor Xa inhibitors and enoxaparin in preventing thromboembolism in hospitalized patients with COVID-19. Embolic incidence, incidence of bleeding, and all-cause mortality were among the outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95 percent CIs. Results: The analysis included six RCTs and two retrospective studies containing 4048 patients. Meta-analysis showed a statistically significant reduction among patients on factor Xa inhibitors compared with low-molecular-weight heparin (LMWH) in the embolic incidence [risk ratio (RR) 0.64 (95%, CI 0.42, 0.98); P=0.04, I2=12%]. Upon subgroup analysis by type of study design, no significant reductions were noted in patients on factor Xa inhibitors in RCTs (RR: 0.62; 95% CI: 0.33-1.17; P=0.14) or observational studies (RR: 0.53; 95% CI: 0.23-1.26; P=0.15) when compared with enoxaparin Factor Xa inhibitors were not significantly associated with incidence of bleeding [RR 0.76 (95% CI 0.36, 1.61); P=0.47, I2=0%] or all-cause mortality (RR: 0.81; 95% CI: 0.48-1.36; P=0.43). Consistent results were obtained upon subgroup analysis by the type of study design. Conclusion: Factor Xa inhibitors are more effective than enoxaparin in preventing thromboembolism among patients with COVID-19 who are not acutely ill and are hospitalized. Additional rigorous RCTs comparing factor Xa inhibitors with enoxaparin are warranted.
