Diagnostic performance of S100B assay for intracranial hemorrhage detection in patients with mild traumatic brain injury under antiplatelet or anticoagulant therapy.

The sampling of S100B protein has been proposed as a screening tool to identify patients with a low risk of post-traumatic intracranial hemorrhage. Its performance for patients on antiplatelet agents or anticoagulants is still debatable. This exploratory study evaluates the diagnostic accuracy of S100B concentrations, measured within 3 h of head trauma, to rule out intracranial hemorrhage in adults on antiplatelet or anticoagulant therapy. This prospective study enrolled adult patients presenting for head trauma within the last 3 h and under antiplatelets or anticoagulants. We hypothesized that a S100B concentration under 0,100 µg.L-1 rule out intracranial hemorrhage with a negative predictive value over 0,99. Sensitivity, specificity, positive predictive value and negative predictive value were analyzed. From June 2020 to January 2023, 155 patients were included. 119 patients had a S100B level at 0,100 µg.L-1 or over. 8 had an intracranial hemorrhage. The sensitivity of S100B was 1 (95%CI 0,68-1), specificity was 0,25 (95%CI 0,18 - 0,32), positive predictive value was 0,07 (95%CI 0.03-0.13), negative predictive value was 1 (95%CI 0,90 - 1). This study suggests that when performed in a 3-hour period after mild head trauma, S100B measurement is an accurate screening tool to rule out intracranial hemorrhage in patients treated with antiplatelet agents or anticoagulants.