Comprehensive Summary
This retrospective multicenter study investigated the association between antithrombotic (AT) medication and intracranial hemorrhage (ICH) risk among older patients (≥65 years old) with mild traumatic brain injury (mTBI). Data from 5,948 patients across 103 emergency departments (ED) who underwent CT imaging were analyzed. Natural language processing models were applied to extract data from emergency physician and radiology reports. Multivariable regression assessed associations between antiplatelet or anticoagulant use and ICH occurrence. No antithrombotic class, including antiplatelets (odds ratio [OR] 0.98, 95% CI 0.81-1.18), direct oral anticoagulant (OR 0.82, 95% CI 0.60-1.09), or vitamin K antagonist (OR 0.66, 95% CI 0.37-1.10) was significantly associated with higher ICH risk. In contrast, factors including high-level fall, amnesia, vomiting, cutaneous head impact, suspected skull vault or facial bone fractures, and a Glasgow coma scale score of 14 were associated with increased ICH risk.
Outcomes and Implications
Older patients with mTBI are traditionally considered high-risk for ICH, but whether antithrombotic therapy modifies this risk has remained uncertain. This study found no association between any AT class and increased ICH risk. Although limited by its retrospective design, potential missing or incomplete data, and exclusion of patients without CT imaging, the study challenges the assumption that AT use alone necessitates routine neuroimaging. Instead, clinical features such as mechanism of injury and neurologic signs should guide imaging decisions in this population. Future multicenter prospective studies should refine neuroimaging decision rules that integrate high-risk clinical variables with AT status in older patients with mTBI.