Abstract Number: PB0475
Meeting: ISTH 2020 Congress
Background: Up to 20% of severely injured patients on prophylactic anticoagulation experience venous thromboembolism (VTE). Our previous work shows that acquired antithrombin III (ATIII) deficiency [ATIII< 80%] occurs in approximately 20% of trauma patients upon admission and drives poor responsiveness to enoxaparin. However, changes in ATIII over time and its association with VTE remain unknown.
Aims: To determine the relationship between acquired ATIII deficiency and VTE in severely injured patients.
Methods: A secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) clinical trial was performed. Demographics, mechanism and severity of injury, transfusions, and outcomes were compared between patients who did and did not develop VTE. Kruskal Wallis and Chi square tests analyzed continuous and categorical data, respectively. Logistic regression analyses were performed to identify significant contributions to VTE risk, controlling for ATIII deficiency (over first 72 hours), age, gender, race, and injury severity. Cox proportional hazards modeling determined the contribution of ATIII deficiency to the cumulative incidence of VTE.
Results: Of the 680 patients enrolled in PROPPR, 87 (13%) developed VTE. The median time to VTE was 6 days (IQR 3, 13). No differences in demographics, injuries, or transfusions were identified. Multivariable modeling demonstrated that ATIII deficiency at 72 hours post-admission was independently associated with the development of VTE. Patients who experienced ATIII deficiency at this time point had a 2.5 fold increased risk of VTE [p< 0.01; 95% CI 1.28-4.71]. Lastly, patients who developed VTE had worse outcomes as displayed by significantly fewer hospital-free days compared to non-VTE patients [0 (0, 8) vs 4 (0, 18), respectively].
Conclusions: Acquired ATIII deficiency is an important risk factor for VTE in severely injured patients. These data indicate that intervening, perhaps through ATIII supplementation, in the first three days after injury could mitigate the risk of VTE and improve patient outcomes.
To cite this abstract in AMA style:Rahbar E, Cotton B, Wade C, Cardenas J. Acquired Antithrombin III Deficiency Is a Risk Factor for Venous Thromboembolism after Severe Injury [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/acquired-antithrombin-iii-deficiency-is-a-risk-factor-for-venous-thromboembolism-after-severe-injury/. Accessed January 27, 2022.
« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/acquired-antithrombin-iii-deficiency-is-a-risk-factor-for-venous-thromboembolism-after-severe-injury/