Timing and Type of Venous Thromboembolic Chemoprophylaxis Is Associated with Acute Traumatic Brain Injury Outcomes

Venous thromboembolic (VTE) prophylaxis in acute traumatic brain injury (TBI) is a controversial topic with wide practice variations. This study examined the association of VTE chemoprophylaxis with inpatient mortality and VTE events among isolated TBI patients. This was a retrospective cohort study of 87 trauma centers within a large hospital system in the United States analyzing 23,548 patients with isolated TBI, 7977 of whom had moderate-to-severe TBI. Primary outcomes were inpatient mortality and VTE events. The control group received no chemoprophylaxis. Other groups received low-molecular-weight heparin (LMWH), unfractionated heparin (UFH), and combined LMWH and UFH chemoprophylaxis. Multi-variable regression accounted for confounders. Outcomes were stratified by timing of administration, body mass index (BMI), and TBI type. Patients without VTE prophylaxis had the least VTE events. LMWH had the lowest mortality for both all-isolated and moderate-to-severe isolated TBI populations at adjusted odds ratio (aOR) 0.24 (95% confidence interval [CI], 0.14–0.43) and aOR 0.25 (95% CI, 0.14–0.44), respectively. Clinically significant progression of TBI was lowest among the LMWH group (0.1%; p value, 0.001). After stratifying by timing of VTE chemoprophylaxis, only patients with subdural hematoma and LMWH between 6 and 24 h (N = 62), as well as patients with ≥35 BMI and LMWH between 6 and 24 h (N = 65) or >24–48 h (N = 54), had no VTE events. VTE chemoprophylaxis timing may have prevented VTE in certain subgroups of isolated TBI patients. Though VTE chemoprophylaxis did not prevent VTE for most TBI patients, LMWH VTE chemoprophylaxis was associated with reduced mortality.