Journal of thrombosis and haemostasis : JTH
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J. Thromb. Haemost. · May 2016
A single test to assay warfarin, dabigatran, rivaroxaban, apixaban, unfractionated heparin, and enoxaparin in plasma.
Essentials Simple and fast assaying of different anticoagulants (ACs) is useful in emergent situations. We used highly diluted prothrombin time (dPT) or highly diluted Fiix-PT (dFiix-PT) to assay ACs. Both tests could quantify target specific anticoagulants and warfarin anticoagulation. Improved results were consistently observed with the dFiix-PT compared with the dPT. ⋯ Background Assaying anticoagulants is useful in emergency situations or before surgery. Different specific assays are currently needed depending on the anticoagulant. Objectives We hypothesized that levels of warfarin, dabigatran, rivaroxaban, apixaban, and heparins could be measured with use of the diluted prothrombin time (dPT) and diluted Fiix-PT (dFiix-PT), using highly diluted thromboplastin (TP). The latter test is affected only by reduced levels of active factors II and X but corrects test plasma for other deficiencies Methods Increasing TP dilutions were used to identify suitable dilutions to measure dabigatran, rivaroxaban, apixaban, unfractionated heparin (UFH), and enoxaparin. Calibrators containing known amounts of direct oral anticoagulants (DOACs) were used to make standard curves. Citrated plasma samples were obtained from patients taking warfarin or DOACs with known drug concentrations as determined by specific assays. Results The dFiix-PT at a TP dilution of 1:1156 could be used to measure all of the drugs tested at therapeutic concentrations except for fondaparinux. The dPT achieved the same but required two TP dilutions (1:750 and 1:300). The warfarin effect could be assessed by using dFiix-PT at 1:1156 with a PT ratio identical to the international normalized ratio. Six different TPs yielded similar results, but two were less sensitive. Dabigatran, rivaroxaban, and apixaban could be accurately measured in patient samples using both dilute PT assays, but a better correlation was consistently observed between the dFiix-PT and specific assays than with the dPT. Conclusion The dFiix-PT using a single dilution of TP may be suitable to assess the anticoagulant effects of warfarin, dabigatran, rivaroxaban, apixaban, heparin, and enoxaparin.
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J. Thromb. Haemost. · Apr 2016
Observational StudyImpact of point-of-care international normalized ratio monitoring on quality of treatment with vitamin K antagonists in non-self-monitoring patients: a cohort study.
Point-of-care (POC) international normalized ratio (INR) monitoring by healthcare professionals could eliminate the need for venous blood sampling in non-self-monitoring (NSM) patients on vitamin K antagonists (VKA). However, few studies have investigated the impact of POC INR monitoring on the quality of treatment in these patients and real-world data on this issue are lacking. ⋯ Although associated with lower TTR, POC INR monitoring is a safe and effective alternative to laboratory INR monitoring in NSM patients on VKA.
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J. Thromb. Haemost. · Mar 2016
Multicenter StudyRapid quantitative D-dimer to exclude pulmonary embolism: a prospective cohort management study.
ESSENTIALS: It is not known if D-dimer testing alone can safely exclude pulmonary embolism (PE). We studied the safety of using a quantitative latex agglutination D-dimer to exclude PE in 808 patients. 52% of patients with suspected PE had a negative D-dimer test and were followed for 3 months. The negative predictive value of D-dimer testing alone was 99.8%, suggesting it may safely exclude PE. ⋯ A negative latex agglutination D-dimer assay is seen in about one-half of patients with suspected PE and reliably excludes PE as a stand-alone test.
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J. Thromb. Haemost. · Mar 2016
Neutrophil elastase-deficient mice form neutrophil extracellular traps in an experimental model of deep vein thrombosis.
ESSENTIALS: Neutrophil elastase (NE) plays a role in extracellular trap formation (NETosis) triggered by microbes. The contribution of NE was evaluated in mouse NETosis models of sterile inflammation and thrombosis. NE is not required for mouse neutrophil NET production in vitro with non-infectious stimuli. NE deficiency had no significant effect on thrombosis in the inferior vena cava stenosis model. ⋯ Neutrophil elastase is not required for NET formation in mice. NE(-/-) mice, which form pathological venous thrombi containing NETs, do not phenocopy PAD4(-/-) mice in in vitro NETosis assays or experimental venous thrombosis. Our study suggests that NET-targeted therapies need to be highly effective to have an impact on DVT.