The thrombelastometry parameter CT_EXTEM as an independent risk factor for mortality in bleeding patients

PURPOSE: Pathologic thromboelastometric results may indicate a coagulation disorder. During bleeding, the prolongation of CTEXTEM (Clotting Time) measured by rotational thromboelastometry (ROTEM) can detect alterations in the extrinsic pathway. However, the significance of a prolonged CTEXTEM for risk stratification in patients with bleeding remains unclear. METHODS: A total of 2035 consecutive patients were retrospectively examined between 2014 and 2020 from a bleeding database at Saarland University Hospital. The database includes patients tested with ROTEM during bleeding. The study population was split into three groups: Cardiothoracic surgery with cardiopulmonary bypass (CPB, n = 753), trauma (n = 206) and medical bleeding (n = 1076). The impact of CTEXTEM on 30-day mortality was assessed using C-statistic. Threshold values for CTEXTEM reaching a specificity > 90% for 30-day mortality were selected. Adjusted hazard ratios (adjHR [95% confidence interval]) were calculated with multivariable Cox models. RESULTS: The C-statistic showed that CTEXTEM (C-statistic for groups 1–3: 0.62, threshold ≥ 110 s (CPB); 0.65, threshold ≥ 98 s (trauma); 0.63, threshold ≥ 99 s (medical bleeding)) had a predictive power for 30-day mortality in all groups. The determined threshold value of CTEXTEM reaching a specificity > 90% remained an independent risk predictor for 30-day mortality even after adjustment for confounding factors (CPB: adjHR 2.5 [1.5–4.2], p < 0.001; trauma: adjHR 3.9 [1.8–8.7], p = 0.001; medical bleeding: adjHR 1.8 [1.4–2.5], p < 0.001). The 30-day mortality rate was significantly increased (CPB: CTEXTEM ≥ 110 s, 26% versus 9%, p < 0.001; trauma: CTEXTEM ≥ 98 s, 41% versus 11%, p < 0.001; medical bleeding: CTEXTEM ≥ 99 s, 41% versus 22%, p < 0.001). CONCLUSION: Our results indicate that CTEXTEM-detected alterations in the extrinsic pathway may be an independent predictor of 30-day mortality in patients with bleeding.