Thrombosis research
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Thrombosis research · Aug 2015
The impact of thrombin generation and rotation thromboelastometry on assessment of severity of factor XI deficiency.
The phenotype of bleeding in patients with severe FXI deficiency is unpredictable and unlike other bleeding disorders, it is not directly correlated with levels of FXI. In this study we analyzed whether the global coagulation assays can serve as a clinical tool in predicting bleeding tendency in patients with severe FXI deficiency undergoing surgery, taking into account the large inter-individual variability of FXI levels and genotypes. Thrombin generation (TG) was measured in 39 platelet-poor plasma with or without tissue factor (TF) and in the presence or absence of corn trypsin inhibitor (CTI). ⋯ ROTEM assays failed to distinguish bleeding from non-bleeding patients but could do so between different FXI activity levels and genotypes. In conclusion, in the current study we found a sensitive tool to distinguish between bleeding and non-bleeding patients. In order to recommend TG as a predictive tool for treatment tailoring, a larger patient group is required.
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Thrombosis research · Aug 2015
Determinants of oral anticoagulation control in new warfarin patients: analysis using data from Clinical Practice Research Datalink.
The safety and effectiveness of warfarin therapy depends critically on the quality of anticoagulation control, often assessed using the percentage time in therapeutic International Normalised Ratio (INR) range (TTR). We aimed to identify patient characteristics related to anticoagulation control with warfarin, measured by TTR. ⋯ In a real world clinical practice there is a high amount of unpredictable inter-individual TTR variability and in some patients good anticoagulation control is more challenging than in others. These findings may help to identify patients who will require closer monitoring or innovative strategies to optimise the outcomes of oral anticoagulant therapy.
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Thrombosis research · Aug 2015
Clinical TrialThe temporal pattern of postoperative coagulation status in patients undergoing major liver surgery.
After major liver surgery, there are risks of both postoperative bleeding and thrombosis. Routine coagulation monitoring is indicated, but may not provide adequate clinical guidance. Thus, we described the clotting status in a pilot study using broader coagulation testing. We analysed the temporal pattern of coagulation tests to assess whether thromboelastometry (ROTEM®) would improve the quality of the postoperative monitoring of the coagulation status in patients undergoing major hepatic resections. ⋯ Despite the abnormalities observed in routine coagulation monitoring, thromboelastometry indicated a balanced coagulation status following major hepatic surgery. The levels of both pro- and anticoagulant proteins changed over time during this period. The exact clinical role for thromboelastometry in major hepatic surgery remains to be established.
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Thrombosis research · Aug 2015
Clinical TrialIn vitro thromboelastometric evaluation of the efficacy of frozen platelet transfusion.
Although frozen platelets are extensively used in remote locations and military environments, scientific evidence of their efficacy is scarce. The objective of this study was to evaluate the in vitro hemostatic efficacy of frozen versus fresh platelet transfusions by rotational thromboelastometry (ROTEM) to ascertain whether the freezing and thawing process impaired platelet contribution to clot strength. ⋯ The ROTEM analysis assessment indicates a dual effect in frozen platelet transfusion: it produces a hypercoagulable state (shortening of CT), and a second, more predominant effect of frozen platelets' functionality impairment compared with fresh platelets (shorter MCF/MCE and longer CFT).
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Thrombosis research · Aug 2015
Controlled Clinical TrialProcoagulant activity induced by transcatheter closure of atrial septal defects is associated with exposure of phosphatidylserine on microparticles, platelets and red blood cells.
The mechanism of hypercoagulable state following transcatheter closure of atrial septal defects (ASDs) remains unclear. We evaluated the exposure of phosphatidylserine (PS) on released microparticles (MPs) and also the cells of their origin from peripheral blood, and the associated increase in procoagulant activity (PCA) following transcatheter ASD closure. We demonstrate that PS(+) MP levels were elevated immediately after device implantation (P <0.002), peaked at 24hour (P <0.002), and persisted at high levels for 1-week post procedure (P <0.002). ⋯ Intrinsic factor Xa and prothrombinase were produced abundantly by platelets, RBCs, and MPs leading to materialization of fibrin by 24hours. Additionally, Xase complex formation and thrombin generation was inhibited by about 74% by the addition of lactadherin to the assays. Our results thus demonstrate that PS exposure on MPs, platelets, and RBCs play an important role in hypercoagulability following transcatheter ASD closure.