Application of Activators Ecarin and Factor Xa in Thrombelastography for Measurement of Anticoagulant Effect of Direct Oral Anticoagulants Using TEG 5000

Nomogram model combined thrombelastography for venous thromboembolism risk in patients undergoing lung cancer surgery

Background: The aim of this study was to develop a nomogram model in combination with thromboelastography (TEG) to predict the development of venous thromboembolism (VTE) after lung cancer surgery. Methods: The data of 502 patients who underwent surgical treatment for lung cancer from December 2020 to December 2022 were retrospectively analyzed. Patients were then randomized into training and validation groups. Univariate and multivariate logistic regression analyses were carried out in the training group and independent risk factors were included in the nomogram to construct risk prediction models. The predictive capability of the model was assessed by the consistency index (C-index), receiver operating characteristic curves (ROC), the calibration plot and decision curve analysis (DCA). Results: The nomogram risk prediction model comprised of the following five independent risk factors: age, operation time, forced expiratory volume in one second and postoperative TEG parameters k value(K) and reaction time(R). The nomogram model demonstrated better predictive power than the modified Caprini model, with the C-index being greater. The calibration curve verified the consistency of nomogram between the two groups. Furthermore, DCA demonstrated the clinical value and potential for practical application of the nomogram. Conclusion: This study is the first to combine TEG and clinical risk factors to construct a nomogram to predict the occurrence of VTE in patients after lung cancer surgery. This model provides a simple and user-friendly method to assess the probability of VTE in postoperative lung cancer patients, enabling clinicians to develop individualized preventive anticoagulation strategies to reduce the incidence of such complications.

Bleeding management in patients with direct oral anticoagulants

Bleeding events in patients under direct oral anticoagulation (DOAC) can be life-threating but are commonly not related to drug overdose. However, a relevant DOAC plasma concentration impairs the hemostasis and should therefore be ruled out immediately after hospital admission. The effect of DOAC is typically not visible in standard coagulation tests such as activated partial thrombin time or thromboplastin time. Specific anti-Xa or anti-IIa assays allow a specific drug monitoring, but they are too time-consuming in critical bleeding events and typically not available 24 h/7 d in routine care. Recent advantages in point-of-care (POC) testing might improve patient care by early exclusion of relevant DOAC levels, but sufficient validation is still lacking. POC urine analysis help to exclude DOAC in emergency patients, but does not provide a quantitative information about plasma concentration. POC viscoelastic testing (VET) can determine the DOAC effect on clotting time and helps further to reveal other concomitant bleeding disorders in emergency, e.g., factor deficiency or hyperfibrinolysis. If a relevant plasma concentration of the DOAC is assumed or was proven by either laboratory assays or POC testing, restoration of factor IIa or factor IIa activity is key for effective hemostasis. Limited evidence suggests that specific reversals for DOAC, e.g., idarucizumab for dabigatran and andexanet alfa for apixaban or rivaroxaban, might be superior to increasing thrombin generation by administration of prothrombin complex concentrates. To determinate, if DOAC reversal is indicated or not, time from last intake, anti-Xa/dTT values or results from POC tests can be considered. This experts' opinion provides a feasible decision algorithm for clinical practice.