Differences in thromboelastometry parameters A10EXTEM and A10FIBTEM –as independent risk factors for mortality during bleeding

Purpose During bleeding, the decrease A10 EXTEM and A10 FIBTEM (the clot firmness at 10 min) measured by rotational thromboelastometry (Rotem) can detect alterations in the fibrin contribution to clot firmness (FIBTEM) and in the extrinsic pathway (EXTEM). However, the significance of a decrease of A10 FIBTEM and A10 EXTEM for risk stratification in patients with bleeding remains unclear. Methods 1942 consecutive patients were retrospectively examined between 2014 and 2020. All patients were tested with Rotem during a hemorrhage at Saarland University Hospital. A10 EXTEM and A10 FIBTEM and their association with mortality at 30 days were tested using C statistic. A threshold value for A10 EXTEM reaching a specificity > 90% for 30-day mortality was selected and for A10 FIBTEM was fixed at <6 mm. Adjusted hazard ratios (adjHR [95% confidence interval]) were calculated with multivariable Cox models. Results A10 EXTEM (C statistic 0.57, selected threshold≤39 mm) had a predictive power for 30-day mortality, whereas A10 FIBTEM did not. The 30-day mortality rate was significantly increased in patients with A10 EXTEM ≤39 mm (A10 EXTEM ≤39 mm: 32% versus A10 EXTEM >39 mm: 16%, p < 0.001) and A10 FIBTEM <6 mm (A10 FIBTEM <6 mm: 25% versus A10 FIBTEM ≥6 mm: 18%, p = 0.03). The selected threshold values of A10 EXTEM ≤39 mm (adjHR 1.7 [1.3–2.3], p < 0.001) and A10 FIBTEM <6 mm (adjHR 1.6 [1.1–2.2], p = 0.009) remained independent risk predictors for 30-day mortality even after adjustment for confounding factors. The leading cause of death in these populations were uncontrolled bleeding. Patients with A10 FIBTEM <6 mm had significant more fibrinogen administration (A10 FIBTEM <6 mm: 2.7 ± 3.7 g versus A10 FIBTEM ≥6 mm: 0.5 ± 1.6 g, p < 0.001). Conclusion Our results indicate that A10 EXTEM -detected alterations in the extrinsic pathway might be independent predictors for 30-day mortality in patients with bleeding. Nevertheless, A10 FIBTEM measurements to optimize treatment with fibrinogen is required.