Traumatic intracranial lesion prevalence in CT-imaged adults with mild traumatic brain injury receiving dual versus single antiplatelet therapy: a two-center cohort study

Abstract Among adults with mild traumatic brain injury (mTBI) who are already receiving antiplatelet therapy, evidence comparing radiographic lesion prevalence between dual and single therapy remains limited. We conducted a retrospective two-center cohort study in two French university hospital emergency departments including adults receiving antiplatelet therapy who presented with mTBI and underwent initial head computed tomography during the index visit. The primary exposure was dual versus single antiplatelet therapy, and the primary outcome was any traumatic intracranial lesion on initial computed tomography. Relative risks were estimated using modified Poisson regression with robust variance; sensitivity analyses additionally adjusted for study center and used propensity score overlap weighting with doubly robust adjustment. Among 1,912 patients, 159 received dual antiplatelet therapy and 1,753 single therapy. Lesions were identified in 31/159 patients (19.5%) receiving dual therapy and 251/1,753 (14.3%) receiving single therapy, yielding an absolute risk difference of 5.2% (95% confidence interval, − 0.5% to 12.2%) and an adjusted relative risk of 1.33 (95% confidence interval, 0.95–1.87). A targeted sensitivity analysis restricted to clearly classified intracranial lesions yielded an adjusted relative risk of 1.26 (95% confidence interval, 0.86–1.85). Within this selected CT-imaged population, dual therapy showed a numerically higher but imprecisely estimated lesion prevalence. The study cannot determine excess risk relative to no antiplatelet therapy or whether this numerical difference represents clinically meaningful hemorrhagic risk.