Early Tranexamic Acid Administration after Traumatic Brain Injury Is Associated with Reduced Syndecan-1 and Angiopoietin-2 in Patients with Traumatic Intracranial Hemorrhage

Objective: To evaluate the effect of early tranexamic acid (TXA) administration on circulating markers of endotheliopathy. Setting: Twenty trauma centers in the United States and Canada. Participants: Patients with moderate-to-severe traumatic brain injury (TBI) (MS-TBI) and intracranial hemorrhage who were not in shock (systolic blood pressure ≥90 mm Hg). Design: TXA (2 g) or placebo administered prior to hospital arrival, less than 2 hours postinjury. Blood samples and head computed tomographic scan collected upon arrival. Plasma markers measured using Luminex analyte platform. Differences in median marker levels evaluated using t tests performed on log-transformed variables. Comparison groups were TXA versus placebo and less than 45 minutes versus 45 minutes or more from time of injury to treatment administration. Main Measures: Plasma levels of angiopoietin-1, angiopoietin-2, syndecan-1, thrombomodulin, thrombospondin-2, intercellular adhesion molecule 1, vascular adhesion molecule 1. Results: Demographics and Injury Severity Score were similar between the placebo (n = 129) and TXA (n = 158) groups. Levels of syndecan-1 were lower in the TXA group (median [interquartile range or IQR] = 254.6 pg/mL [200.7-322.0] vs 272.4 pg/mL [219.7-373.1], P =.05. Patients who received TXA less than 45 minutes postinjury had significantly lower levels of angiopoietin-2 (median [IQR] = 144.3 pg/mL [94.0-174.3] vs 154.6 pg/mL [110.4-209.8], P =.05). No differences were observed in remaining markers. Conclusions: TXA may inhibit early upregulation of syndecan-1 and angiopoietin-2 in patients with MS-TBI, suggesting attenuation of protease-mediated vascular glycocalyx breakdown. The findings of this exploratory analysis should be considered preliminary and require confirmation in future studies.