Thrombosis research
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Thrombosis research · Aug 2014
Comparative StudyComparison of Von Willebrand factor (VWF) activity VWF:Ac with VWF ristocetin cofactor activity VWF:RCo.
Ristocetin cofactor activity of Von Willebrand factor (VWF:RCo) and the ratio VWF:RCo to its antigen VWF:Ag are used as routine screening to estimate VWF function and to detect types of Von Willebrand disease (VWD) caused by loss of high molecular weight multimers. However, the VWF:RCo test is prone to analytic imprecisions due to various reasons. We compared an assay for VWF activity (VWF:Ac) with VWF:RCo putting emphasis on the ratios to VWF:Ag. ⋯ The data suggest that the results obtained with the VWF:Ac assay are comparable to that of the VWF:RCo assay. An AVWS was more reliably detected by VWF:Ac/VWF:Ag. We assume that the VWF:Ac assay could replace VWF:RCo for routine screening for AVWS, especially when prompt evaluation is required.
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Thrombosis research · Aug 2014
The prothrombotic paradox of severe obesity after cardiac surgery under cardiopulmonary bypass.
Obesity is suggested to reduce postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) but perioperative hemostasis variations have not been studied. Therefore, we investigated the effects of severe obesity (body mass index [BMI] ≥35kg/m(2)) on chest tube output (CTO) and hemostasis in patients undergoing cardiac surgery with CPB. ⋯ Severe obesity is associated with a prothrombotic postoperative state that leads to a reduction of postoperative blood loss in patients undergoing cardiac surgery with CPB.
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Thrombosis research · Aug 2014
Weight-adjusted LMWH prophylaxis provides more effective thrombin inhibition in morbidly obese pregnant women.
Low molecular weight heparin (LMWH) prophylaxis has been recommended for morbidly obese pregnant women (>40kg/m(2)). There is very little data on the anticoagulant effects of LMWH in this group. We investigated two different dosing regimens; fixed dose and weight-adjusted dose on the anticoagulant effects of the LMWH tinzaparin used for thromboprophylaxis in obese pregnant women. ⋯ Morbidly obese pregnant women have increased thrombin generation and reduced natural anticoagulant in third trimester. This prothrombotic state was more effectively attenuated by weight-adjusted than fixed LMWH doses.
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Thrombosis research · Aug 2014
The predictive ability of the CHADS2 and CHA2DS2-VASc scores for bleeding risk in atrial fibrillation: the MAQI(2) experience.
Guidelines recommend the assessment of stroke and bleeding risk before initiating warfarin anticoagulation in patients with atrial fibrillation. Many of the elements used to predict stroke also overlap with bleeding risk in atrial fibrillation patients and it is tempting to use stroke risk scores to efficiently estimate bleeding risk. Comparison of stroke risk scores to bleeding risk scores to predict bleeding has not been thoroughly assessed. ⋯ The CHADS2 and CHA2DS2-VASc scores did not perform as well as formal bleeding risk scores for prediction of major bleeding in non-valvular atrial fibrillation patients treated with warfarin. All three bleeding risk scores (HAS-BLED, ATRIA and HEMORR2HAGES) performed moderately well.
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Thrombosis research · Aug 2014
Verification of the guidelines for lupus anticoagulant detection: usefulness of index for circulating anticoagulant in APTT mixing test.
Lupus anticoagulant (LA) is an antibody that interferes with one or more in vitro coagulation reactions, which are dependent on interactions with protein-phospholipid complexes. For LA diagnosis, a mixing test is considered useful for differentiating the inhibitor from a factor deficiency. However, the usefulness and the index of circulating anticoagulant (ICA) in a mixing test with activated partial thromboplastin time (APTT) has not been adequately investigated, and there is scant information regarding the effects of warfarin, heparin, and hemophilia plasma on ICA. We evaluated the usefulness of ICA by investigating the correlation of that index with international normalized ratio (INR), heparin concentration, and factor VIII activity in hemophilia patients. ⋯ ICA was able to distinguish LA-positive samples from the normal, warfarin, and hemophilia samples, but not heparin samples. ICA calculated from APTT clotting time is useful for LA diagnosis.