J Trauma Acute Care Surg. 2019 Jan;86(1):20-27. doi: 10.1097/TA.0000000000002061.

# Tranexamic acid administration is associated with an increased risk of posttraumatic venous thromboembolism.

Myers S, Kutcher M, Rosengart M, Sperry J, Peitzman A, Brown J, Neal M

BACKGROUND: Tranexamic acid (TXA) is used as a hemostatic adjunct for hemorrhage control in the injured patient and reduces early preventable death. However, the risk of venous thromboembolism (VTE) has been incompletely explored. Previous studies investigating the effect of TXA on VTE vary in their findings. We performed a propensity matched analysis to investigate the association between TXA and VTE following trauma, hypothesizing that TXA is an independent risk factor for VTE.

METHODS: This retrospective study queried trauma patients presenting to a single Level I trauma center from 2012 to 2016. Our primary outcome was composite pulmonary embolism or deep vein thrombosis. Mortality, transfusion, intensive care unit and hospital lengths of stay were secondary outcomes. Propensity matched mixed effects multivariate logistic regression was used to determine adjusted odds ratio (aOR) and 95% confidence intervals (95% CI) of TXA on outcomes of interest, adjusting for prespecified confounders. Competing risks regression assessed subdistribution hazard ratio of VTE after accounting for mortality.

RESULTS: Of 21,931 patients, 189 pairs were well matched across propensity score variables (standardized differences <0.2). Median Injury Severity Score was 19 (interquartile range, 12-27) and 14 (interquartile range, 8-22) in TXA and non-TXA groups, respectively (p = 0.19). Tranexamic acid was associated with more than threefold increase in the odds of VTE (aOR, 3.3; 95% CI, 1.3-9.1; p = 0.02). Tranexamic acid was not significantly associated with survival (aOR, 0.86; 95% CI, 0.23-3.25; p = 0.83). Risk of VTE remained elevated in the TXA cohort despite accounting for mortality (subdistribution hazard ratio, 2.42; 95% CI, 1.11-5.29; p = 0.03).

CONCLUSION: Tranexamic acid may be an independent risk factor for VTE. Future investigation is needed to identify which patients benefit most from TXA, especially given the risks of this intervention to allow a more individualized treatment approach that maximizes benefits and mitigates potential harms.

LEVEL OF EVIDENCE: Therapeutic, level III.