Thromb Haemostasis
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Comparative Study
Therapeutic action of tranexamic acid in hereditary haemorrhagic telangiectasia (HHT): regulation of ALK-1/endoglin pathway in endothelial cells.
Recurrent epistaxis is the most frequent clinical manifestation of hereditary haemorrhagic telangiectasia (HHT). Its treatment is difficult. Our objective was to assess the use of tranexamic acid (TA), an antifibrinolytic drug, for the treatment of epistaxis in HHT patients and to investigate in vitro the effects of TA over endoglin and ALK-1 expression and activity in endothelial cells. ⋯ Cultured endothelial cells incubated with TA exhibited increased levels of endoglin and ALK-1 at the protein and mRNA levels, enhanced TGF-beta signaling, and improved endothelial cell functions like tubulogenesis and migration. In summary, oral administration of TA proved beneficial for epistaxis treatment in selected patients with HHT. In addition to its already reported antifibrinolytic effects, TA stimulates the expression ofALK-1 and endoglin, as well as the activity of the ALK-1/endoglin pathway.
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Comparative Study
High post-treatment platelet reactivity is associated with a high incidence of myonecrosis after stenting for non-ST elevation acute coronary syndromes.
High post-treatment platelet reactivity (HPPR=adenosine diphosphate [ADP] 10 microM-induced platelet aggregation >70%) identifies low responders to dual antiplatelet therapy with increased risk of recurrent cardiovascular (CV) events after stenting for non-ST elevation acute coronary syndromes (NSTE-ACS). This study was designed to compare the incidence of periprocedural myocardial infarction (MI) after stenting for NSTE-ACS patients between non-responders to dual antiplatelet therapy defined by HPPR and normo-responders. One hundred ninety NSTE-ACS consecutive patients undergoing coronary stenting were included in this prospective study. ⋯ HPPR was present in 22% of patients (n=42). Periprocedural MI occurred significantly more frequently in patients with HPPR than in the normo-responders (43% vs. 24%, p=0.014). After being correlated with recurrent ischemic events after stenting for NSTE-ACS, the HPPR seems to be also a marker of increased risk of periprocedural MI for NSTE-ACS patients.
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Comparative Study
Accuracy of compression ultrasound in screening for deep venous thrombosis in acutely ill medical patients.
The value of vein ultrasonography for diagnosis of symptomatic deep vein thrombosis (DVT) is widely accepted. We are unaware of published data comparing ultrasonography with the "gold standard" of venography for DVT diagnosis in asymptomatic persons in the patient group of acutely ill medical patients. It was the objective of this study to evaluate sensitivity and specificity of compression ultrasound (CUS) examinations in the diagnosis of proximal and distal DVT in acutely ill medical patients [with congestive heart failure (NYHA class III and IV), exacerbations of respiratory disease, infectious disease, and inflammatory diseases] considered to be at moderate risk of venous thromboembolism (VTE). ⋯ In two of seven patients with venographically proven calf DVT, the diagnosis was confirmed by CUS (sensitivity 28.6%, 95%CI=[8%-64%]) and in two patients, CUS was false positive (specificity 98.6, 95%CI=[95%-99%]). PPV and NPV of CUS in diagnosis of distal DVT were 50% (95%CI=[15-85%]) and 96% (95% CI=[92%-98%]), respectively. In conclusion, CUS underestimates the incidence of proximal and distal DVT compared to contrast venography in acutely ill medical patients without thrombosis symptoms.
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A safe and effective management strategy is pivotal in excluding pulmonary embolism (PE). The combination of Wells' simplified dichotomous clinical decision rule and D-dimer test is non-invasive and could be highly efficient, though its safety has not been widely studied. We evaluated safety and efficiency of this combination in excluding PE. ⋯ The diagnostic protocol could be completed and allowed a decision to be made in 90% of the study patients. This study has prospectively established the safety of a combination of a dichotomized clinical decision rule and D-dimer test in ruling out PE. The strategy proved highly efficient, since more than 50% of patients could be managed without the need for more invasive and expensive tests.
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Controlled Clinical Trial
Inhibition of clot formation process by treatment with the low-molecular-weight heparin nadroparin in patients with carotid artery disease undergoing angioplasty and stenting. A thromboelastography study on whole blood.
Low-molecular-weight heparins (LMWHs) have become the corner stone of antithrombotic treatment but their administration protocol needs to be optimized for certain groups of patients. In this paper, we studied the influence of nadroparin treatment on clot formation process assessed by thromboelastography in patients with carotid artery disease undergoing angioplasty and stenting. Standard thromboelastography assays (in-TEM and ex-TEM) and minimal TF-triggered thromboelastography assay in citrated whole blood were performed in normal volunteers (n = 20), in patients with carotid artery disease receiving only antiplatelet treatment (n = 30), and in patients undergoing angioplasty receiving nadroparin 5750 anti-Xa IU s.c. twice daily (n = 60). ⋯ There was no statistical correlation for any other parameter in all tests. In conclusion, the present study shows that nadroparin treatment in patients with carotid artery disease undergoing endovascular procedures induces significant modification of the thrombus kinetics assessed by minimal TF-triggered whole blood thromboelastography. The clinical relevance of these findings has to be evaluated in future studies.