Low-molecular-weight heparin is associated with lower venous thromboembolism events than factor Xa inhibitors in patients with severe blunt trauma: a cohort study from the Trauma Quality Improvement Program

BACKGROUND: Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common complication of major trauma. Pharmacological VTE prophylactics are widely used, and low-molecular-weight heparin (LMWH) is recommended. Factor Xa inhibitors are increasingly being used for VTE prophylaxis in both medical and surgical patients. Evidence comparing LMWH and factor Xa inhibitors as VTE prophylactics for severe blunt trauma is lacking. This study aims to compare the efficacy and safety of factor Xa inhibitors and LMHW in VTE prophylaxis.

MATERIALS AND METHODS: Patients with severe blunt trauma who received LMWH or a factor Xa inhibitor for VTE prophylaxis in the Trauma Quality Improvement Program between 2017 and 2019 were included. The comparison was performed after using propensity score matching. The outcomes included mortality and incidence of DVT, PE, post-prophylactics haemorrhage control procedures and length of stay.

RESULTS: After 2:1 propensity score matching, 1128 patients ( n =752, LMHW group; n =376, factor Xa inhibitor group) were included in the analysis. Patients in the LMWH group had fewer VTE events than those in the factor Xa inhibitor group (DVT, 3.7% vs. 7.2%, P =0.013; PE, 0.4% vs. 3.2%, P <0.001). VTE risk was higher in the factor Xa group (DVT: odds ratio, 1.97; 95% CI, 1.12-3.44; P =0.018 and PE: odds ratio, 9.65; 95% CI, 2.91-44.12; P =0.001). The mortality rate was higher in the LMWH group; however, there was no significant difference (4.0% vs. 1.9%; P =0.075). The difference in the risk of undergoing haemorrhage control surgery after VTE prophylaxis between both groups was insignificant (0.3% vs. 0.0%; P =0.333).

CONCLUSIONS: LMWH was associated with a lower risk of VTE than factor Xa inhibitors in patients with severe blunt trauma. The mortality rate was higher in the LMWH group; however, there was no statistically significant difference observed.