Single-Center Investigation of Brain Injury Guidelines (BIG)-3 Classification in Traumatic Brain Injury: A Retrospective Analysis of the Role of Pre-injury Antithrombotic Therapy.

Background Traumatic brain injuries (TBIs) are sometimes classified using the Brain Injury Guidelines (BIG) into categories BIG-1, BIG-2, and BIG-3, which determine management strategies. The BIG is a validated tool that triages patients with TBI into those who can be safely managed by the trauma service and those who require neurosurgical consultation and repeat imaging. Patients receiving pre-injury antithrombotic therapy, including anticoagulants and antiplatelet agents, are commonly upgraded to higher BIG classifications despite otherwise low-risk clinical and imaging features. This study evaluates whether pre-injury antithrombotics alone warrant BIG-3 classification and assesses associated clinical outcomes. Methods We conducted a retrospective analysis of TBI patients classified as BIG-3 solely due to antithrombotic use, with no other BIG-3 criteria met. We selected patients who would have otherwise been a BIG-1 had it not been for antithrombotics. Data were collected from 8/19/2019 to 7/24/2024, including demographics, injury characteristics, antithrombotic regimen, and clinical outcomes, at Bon Secours Mercy Health St. Vincent Hospital, Toledo, USA. Pre-injury antithrombotic therapy was defined as documented use of anticoagulant agents (e.g., warfarin, apixaban, and rivaroxaban) or clinically significant antiplatelet therapy, including dual antiplatelet regimens (e.g., aspirin and clopidogrel), at the time of injury. Patients receiving low-dose aspirin monotherapy ("baby aspirin") were excluded from the study cohort. Primary outcomes included CT progression, neurological decline, neurosurgical intervention, and mortality. Data are presented as numbers and percentages or means ± standard deviations. Results A total of 375 patients were screened, of whom 69 patients (18.4%) met the inclusion criteria, with a mean age of 77.9 years and 50.7% female. Falls were the predominant mechanism of injury, accounting for 64 cases (92.8%). Sixty-one patients (88.4%) presented with a Glasgow Coma Scale (GCS) score of 15. Thirty-three patients (47.8%) were receiving single-agent therapy, and 36 patients (52.2%) were receiving dual therapy, with aspirin and clopidogrel being the most common combination (43.5%). None required intubation, had skull fractures, or were intoxicated. CT progression occurred in only two patients (2.9%), both of whom remained neurologically stable and did not require neurosurgical intervention. Three patients (4.3%) required intensive care admission. There were no cases of neurological decline or surgical intervention. One patient (1.5%) died, but the death was unrelated to brain injury. Conclusion In our single-center retrospective cohort of 69 patients, we found that anticoagulated TBI patients, who would have otherwise been classified as BIG-1, had minimal CT progression, no neurological decline, and no neurosurgical interventions. These findings support further investigation and a potential area of study for prospective validation.