Two-Year Functional Outcomes following Moderate-to-Severe TBI in Patients on Antithrombotics: Propensity-Matched Case-Controlled Study

OBJECTIVE Traumatic brain injury (TBI) is a major cause of morbidity in the United States. Elderly patients are more likely to have pre-trauma anticoagulation and antiplatelet therapy (ACAP), which theoretically increases morbidity risk in TBI. Currently, this interaction is not well characterized in moderate-to-severe TBI patients (msTBI) at long term endpoints and this study sought to address this clinical need. METHODS A total of 664 consecutive cases of msTBI from two Level-1 trauma centers 2017-2024 were included in a retrospective case-controlled analysis. A 1:1 nearest neighbor propensity scoring matching between ACAP use and controls was performed using a tight 0.05 caliper with age, sex, admission GCS, and rates of multicompartment hemorrhage and polytrauma as covariates. Sub-group analysis was performed for direct oral anticoagulants (DOACs) and Vitamin K antagonists (VKAs). Outcomes were assessed serially. Discharge disposition was assessed as an early clinical endpoint; GOSE at six months, one year, and two years was the primary long-term outcome of interest. A chi-square or Cochran-Mantel-Haenszel test was used for categorical variables, and a one-way ANOVA for inter-group averages. R and SPSS 29.0 were used for statistical analysis. RESULTS 248 patients were eligible following matching: 20 patients on DOACs, 31 patients on VKAs, 63 patients on antiplatelets agents (APs), 10 patients on dual therapies (VKA and aspirin), and 124 controls. No significant differences were observed across cohorts in hospital mortality (p = 0.374) or discharge to home (p = 0.254). GOSE scores at six months (p = 0.262), one year (p = 0.227), and two years (p = 0.381) were comparable for all survivors. Patients in the VKA group had the highest mortality at all time points (p > 0.05). Subgroup analysis demonstrated no differences in functional outcomes between DOAC and VKAs at all time points (p = 0.236). Rates of neurosurgical interventions were highest in the ACAP group (p = 0.079). CONCLUSION While antithrombotic medications increased the radiographic severity of a msTBI in this population, they did not necessarily dictate poor long-term functional outcomes. These findings suggest that, in the context of current reversal protocols, pre-TBI antithrombotic use may not carry independent prognostic weight at long-term functional endpoints in msTBI patients.