Reassessing the risk of hemorrhage progression in mild traumatic brain injury: the role of anticoagulant and antiplatelet therapy.

Abstract

In patients with mild traumatic brain injury (TBI; Glasgow Coma Scale scores 13-15), the presence of anticoagulant or antiplatelet therapy, collectively referred to as blood thinners (BTs), has been presumed to elevate the risk of intracranial hemorrhage (ICH) progression. Current Brain Injury Guidelines (BIG) automatically classify all patients receiving BTs as high-risk (modified BIG [mBIG] 3), requiring hospital admission and repeat imaging. The aim of this study was to evaluate whether BTs independently increase the risk of hemorrhage progression, surgical intervention, or mortality in mild TBI with ICH, and whether risk varies by specific BT agent. The authors conducted a retrospective cohort study of 2312 adult patients presenting with mild TBI and traumatic ICH at a level 1 trauma center (2016-2021). Patients were categorized by mBIG criteria and then reclassified using hemorrhage characteristics (reclassified mBIG [RmBIG]), excluding BT status. Outcomes included radiographic progression, surgical intervention, and in-hospital mortality. A subgroup analysis was performed to assess outcomes by specific BT type. Radiographic progression occurred in 14.1% of mBIG 3 patients versus 1.7% and 6.8% of mBIG 1 and 2 patients, respectively. Among reclassified patients, those receiving BTs had similar progression rates to non-BT patients within the same RmBIG category. Patients classified as mBIG 3 based only on BT use had significantly lower progression rates (11.9%) compared with those classified based on hemorrhage severity (18.1%, p < 0.001). Mortality and surgical intervention rates did not differ overall by BT status. In the BT subgroup analysis, warfarin was the only agent significantly associated with increased radiographic progression (OR 1.93, p = 0.01). Anticoagulant and antiplatelet therapy might not warrant automatic classification of all patients with mild TBI as high risk. While warfarin represents the upper end of the risk spectrum, most agents did not increase adverse outcomes. Refining BIG to incorporate hemorrhage features and agent-specific risk might improve patient care and resource utilization.