Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Apr 2015
Experimental model of hyperfibrinolysis designed for rotational thromboelastometry in children with congenital heart disease.
We assessed an in-vitro model of hyperfibrinolysis using rotational thromboelastometry (ROTEM) by the addition of increasing concentrations of tissue-type plasminogen activator (t-PA) on whole blood obtained from children undergoing cardiac surgery. We assessed the relevance of this model by repeating the tests in the same population after tranexamic acid (TXA) infusion. In addition, we determined the sensitivity and specificity of ROTEM parameters to detect the different degrees of fibrinolysis. ⋯ Lysis-onset time (LOT) and degree of fibrinolysis measured at 30 min (LI30) best assessed the degree of fibrinolysis. This in-vitro model of t-PA-induced hyperfibrinolysis using the EXTEM test of ROTEM may represent a promising tool to assess hyperfibrinolysis in the pediatric population. In addition, we observed that LOT and LI30 should be considered as the best parameters to detect different degrees of fibrinolysis.
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Blood Coagul. Fibrinolysis · Mar 2015
Observational StudyResults of rotational thromboelastometry, coagulation activation markers and thrombin generation assays in orthopedic patients during thromboprophylaxis with rivaroxaban and enoxaparin: a prospective cohort study.
A prospective observational study was conducted in two clinical cohorts of patients to compare the effect of enoxaparin and rivaroxaban on rotational thromboelastometry (ROTEM), coagulation activation markers and thrombin generation. ⋯ Data show that prolonged CT in the extrinsic ROTEM and thrombin generation assays reflecting initiation and propagation of thrombin may be useful for detecting treatment with rivaroxaban. The significance of observed differences in markers of coagulation needs to be investigated further.
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Blood Coagul. Fibrinolysis · Mar 2015
Clinical TrialBariatric patients have plasmatic hypercoagulability and systemic upregulation of heme oxygenase activity.
Morbid obesity is associated with significant thrombophilia. Of interest, adipocytes obtained from obese patients have increased heme oxygenase (Hmox) activity, the endogenous enzyme responsible for carbon monoxide (CO) production. Given that CO enhances plasmatic coagulation, we determined whether morbidly obese patients undergoing bariatric surgery had an increase in endogenous CO and plasmatic hypercoagulability. ⋯ Nonsmoking bariatric patients (n = 20, BMI 47 ± 8 kg/m, mean ± SD) had abnormally increased COHb concentrations of 2.7 ± 1.9%, indicative of Hmox upregulation. When coagulation kinetics of these bariatric patients were compared with values obtained from normal individuals' (n = 30) plasma, 70% (95% confidence interval 45.7-88.1%) had abnormally great velocity of clot formation, abnormally large clot strength, and COHF formation. Future investigation of Hmox-derived CO in the pathogenesis of obesity-related thrombophilia is warranted.
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Blood Coagul. Fibrinolysis · Mar 2015
Case ReportsRivaroxaban for arterial thrombosis related to heparin-induced thrombocytopenia.
Heparin-induced thrombocytopenia (HIT) may be a critical condition in intensive care patients. Diagnosis of HIT is often difficult, and management too, as physicians have usually a limited experience with alternative anticoagulants. A 36-year-old man was admitted for orthopaedic surgery after a trauma causing a fracture of the sacrum and right ankle. ⋯ Fondaparinux was transiently administered but was replaced 3 days later by rivaroxaban (15 mg twice a day during 21 days then 20 mg/day), after the demonstration of an acute thrombosis of the left radial artery. Platelet count returned to normal range and a partial recanalization of arterial thrombosis was noted. The use of rivaroxaban in this indication is of theoretical interest but requires further experience.
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Blood Coagul. Fibrinolysis · Mar 2015
Impact of nonsynonymous mutations of factor X on the functions of factor X and anticoagulant activity of edoxaban.
Edoxaban is an oral direct factor Xa (FXa) inhibitor and its efficacy as an oral anticoagulant is less subject to drug-food and drug-drug interaction than existing vitamin K antagonists. Although this profile of edoxaban suggests it is well suited for clinical use, it is not clear whether genetic variations of factor X influence the activity of edoxaban. Our aim was to investigate a possible impact of single-nucleotide polymorphisms (SNPs) in the factor X gene on the functions of factor X and the activity of edoxaban. ⋯ Michaelis-Menten kinetic parameters of FXas, Km and Vmax values, PT and aPTT were not influenced by either mutation indicating these mutations do not affect the FXa catalytic and coagulation activities. The Ki values of edoxaban for the FXas and the concentrations of edoxaban required to double PT and aPTT were not different between wild type and mutated FXas indicating that both mutations have little impact on the activity of edoxaban. In conclusion, these data suggest that edoxaban has little interpatient variability stemming from SNPs in the factor X gene.