Thromb Haemostasis
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A pregnant woman has a two- to five-fold higher risk of venous thromboembolism (VTE) than a non-pregnant woman of the same age and, in developed countries, she is more likely to die from fatal pulmonary embolism (PE) than from obstetric haemorrhage. The increased VTE risk is mediated through normal physiological changes of pregnancy including alterations in haemostasis that favour coagulation, reduced fibrinolysis and pooling and stasis of blood in the lower limbs. Thrombophilia, smoking, obesity, immobility and postpartum factors such as infection, bleeding and emergency surgery (including emergency caesarian section) also increase the risk of pregnancy-related VTE. ⋯ Emerging data support antepartum LMWH prophylaxis for women with previous VTE if the event was unprovoked or in the presence of thrombophilia. On the other hand, women with prior provoked VTE and no thrombophilia or women with asymptomatic thrombophilia (but a family history of VTE) can safely be managed with antepartum surveillance. Postpartum prophylaxis is recommended for women with prior VTE or thrombophilia (and a family history of VTE).
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Randomized Controlled Trial Multicenter Study Comparative Study
Desmoteplase in acute massive pulmonary thromboembolism.
Alteplase is standard therapy for patients with acute, massive pulmonary embolism. The novel plasminogen activator desmoteplase displays high fibrin specificity and selectivity for fibrinbound plasminogen. In a preclinical model desmoteplase was twice as potent with a shorter lysis time and lower reocclusion rate. ⋯ Safety did not differ among the 4 groups. The study results suggest that desmoteplase at doses of 180 and 250 microg/kg had similar or greater efficacy compared to alteplase 100 mg. Onset of action was faster, safety was comparable.
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The objective of this study was to evaluate the rate of stroke associated with aspirin and warfarin in routine clinical practice. The study included patients aged 40+ with chronic atrial fibrillation (cAF) registered in the UK General Practice Research Database. The outcome was the rate of stroke during current, past and no use of aspirin and warfarin. ⋯ The effectiveness of warfarin was dependent on the level of anticoagulation, with optimal risk reduction occurring within the recommended international normalised ratio (INR) range of 2.0 to 3.0. The proportion of patients achieving a stable INR within the target therapeutic range was at its lowest during the first three months of warfarin treatment. In conclusion, the results of this study support the effectiveness of warfarin treatment to reduce the rate of stroke in cAF patients in the general clinical practice setting, however the risk reduction is lower than that reported in clinical trials.
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Subtherapeutic anticoagulation levels increase both the risk and severity of thromboembolism. The aim of this study was to determine the cumulative incidence of subtherapeutic international normalised ratios (INRs) and to identify risk factors associated with a low INR. We performed a cohort study in 7,419 patients from a Dutch anticoagulation clinic. ⋯ A subtherapeutic INR occurred twice as often in patients using acenocoumarol as in those using phenprocoumon (hazard ratio [HR] 2.1, 95% confidence interval [95%CI]:2.0 - 2.3) and was more common in patients with a high therapeutic range compared to a low therapeutic range (HR 1.8, 95%CI:1.5 - 2.2). Occurrence of a low INR also depended on indication for anticoagulant therapy, with the highest risk in patients who used anticoagulants as prophylaxis and the lowest risk in patients with mechanical heart valves. In 30% of cases the subtherapeutic INR was preceded by an event necessitating vitamin K or discontinuation of the anticoagulant drug.