Viscoelastic Hemostatic Assays are Associated With Mortality and Blood Transfusion in a Multicenter Cohort

Objectives: Trauma-induced coagulopathy (TIC) carries significant risks, including increased mortality. Traditional TIC definitions rely on laboratories that result slowly and do not highlight therapeutic targets. We hypothesized that a TIC score, based on thromboelastography (TEG) and rotational thromboelastometry (ROTEM), collectively termed viscoelastic hemostatic assays, is associated with in-hospital mortality and packed red blood cell (pRBC) transfusion. Methods: This retrospective cohort study used a database of adult patients undergoing institutional massive transfusion at seven level 1 trauma centers (2013-2018). A “TIC score” was developed, with 1 point assigned for abnormal TEG R-time (≥ 9 min) or ROTEM clot time (≥ 80 sec), ɑ-angle (< 65^o), or maximum amplitude (< 55 mm). TIC+ patients (TIC score 1-3) were compared with TIC− patients (TIC score 0). TIC Score composition and abnormal cutoff values were adjusted to investigate optimal weighting and thresholds. Multiple logistic and negative binomial regression was used to control confounders while evaluating the association between abnormal TIC values, in-hospital mortality, and 24-hour pRBC transfusion. Results: Of 1499 patients in the final analysis, 591 (39.4%) were TIC+. Each 1-point increase in TIC score was associated with a 53% increase in the odds of mortality (odds ratio [OR], 1.53, 95% CI, 1.33-1.76, P < .001) and a 25% increase in pRBC transfusion volumes (incidence rate ratio, 1.25, 95% CI, 1.16-1.34, P < .001). Abnormal maximum amplitude was associated with both mortality (OR 1.50, 95% CI, 1.03-2.19, P = .034) and pRBC transfusion volumes (P < .001), whereas abnormal ɑ-angle was associated with mortality (OR, 1.59, 95% CI, 1.09-2.32, P = .015). The unequal weighting of TIC score components and adjustments to normal/abnormal cutoff thresholds were maintained but did not improve the model's predictive power. Conclusion: A viscoelastic hemostatic assay-based TIC score is independently associated with mortality and pRBC transfusion volumes. This association persists with unequal weighting and adjustment of normal/abnormal cutoff thresholds of TEG components.