Background: Traumatic injury is associated with an increased risk of coagulopathy and venous thrombosis. plasminogen activator inhibitor-1 (PAI-1) is a procoagulant molecule that inhibits tPA/uPA, thrombomodulin, and activated protein C. We hypothesized that elevated PAI-1 levels would be associated with increased Injury Severity Score (ISS) in injured patients with and without traumatic brain injury and that PAI-1 levels would vary with injury type.
Methods: We retrospectively analyzed demographic, ISS, and hemodynamic data from a prospectively collected database. Patients with traumatic injury requiring intensive care unit admission (n = 268) were classified as multiple injuries, isolated body, or isolated head based on Abbreviated Injury Severity score. Admission PAI-1 levels were quantified using a Luminex analyte platform. Univariate tests for association informed the construction of a multivariate model of the relationship between PAI-1 and ISS.
Results: Plasminogen activator inhibitor-1 positively associated with ISS (p < 0.0001) and was highest in patients with ISS greater than 35 (p < 0.0001). Plasminogen activator inhibitor-1 was significantly different between multiple injuries, isolated body, and isolated head patients (p < 0.0001). On univariate analysis, age (p = 0.0011), hypotension (p = 0.0076), and alcohol intoxication (p = 0.0024) were all positively associated with PAI-1 level. Admission international normalized ratio was not associated with PAI-1 level (p = 0.638). After adjusting for age, sex, hypotension, and alcohol intoxication, higher PAI-1 levels were associated with higher ISS (p < 0.0001).
Conclusion: Elevated PAI-1 at admission is associated with higher ISS. This association is more pronounced in patients with hypotension. These findings suggest that PAI-1 levels may reflect the burden of endothelial damage and platelet activation after injury.
Level of evidence: Prognostic, level III.