Preinjury warfarin, but not antiplatelet medications, increases mortality in elderly traumatic brain injury patients.

BACKGROUND: Previous studies of traumatic brain injury (TBI) outcomes in elderly patients on oral antithrombotic (OAT) therapies have yielded conflicting results. Our objective was to examine the effect of premorbid OAT medications on outcomes among elderly TBI patients with intracranial hemorrhage.

METHODS: We performed a retrospective analysis of elderly TBI patients (≥65 years) with closed head injury and evidence of brain hemorrhage on computed tomography scan from 2006 to 2010. Patient demographics, injury severity, clinical course, hospital and intensive care unit length of stay, and disposition were collected. Comparison of patients stratified by premorbid OAT use was performed using nonparametric Kruskal-Wallis and Fisher's exact tests. Multivariable logistic regression was used to compare groups and identify predictors of primary outcomes, including mortality, neurosurgical intervention, hemorrhage progression, complications, and infection.

RESULTS: A total of 1,552 patients were identified: 543 on aspirin only, 97 on clopidogrel only, 218 on warfarin only, 193 on clopidogrel and aspirin, and 501 on no antithrombotic agent. Blood products were administered to reverse coagulopathy in 77.3% of patients on antithrombotic medications. After adjusting for covariates, including medication reversal, OAT use was associated with increased mortality (p = 0.04). Warfarin use was identified as a key predictor (odds ratio, 2.27; p = 0.05), in contrast to the preinjury use of antiplatelet medications, which was not associated with increased risk of in-hospital death. Rates of neurosurgical intervention differed between groups, with patients on warfarin undergoing intervention more frequently. Survivor subset analysis demonstrated that hemorrhage progression was not associated with preinjury antithrombotic therapy, nor were rates of complication or infection, hospital and intensive care unit lengths of stay, or ventilator days.

CONCLUSION: Preinjury use of warfarin, but not antiplatelet medications, influences survival and need for neurosurgical intervention in elderly TBI patients with intracranial hemorrhage; hemorrhage progression and morbidity are not affected. The importance of antithrombotic therapy may lie in its impact on initial injury severity.

LEVEL OF EVIDENCE: Epidemiologic study, level III.