Optimal duration of anticoagulation in patients with venous thromboembolism.

The risk of recurrent venous thromboembolism (VTE) approaches 40 per cent of all patients after 10 yr of follow up. This risk is higher in patients with permanent risk factors of thrombosis such as active cancer, prolonged immobilization from medical diseases, and antiphospholipid syndrome; in carriers of several thrombophilic abnormalities, including deficiencies of natural anticoagulants; and in patients with unprovoked presentation. Patients with permanent risk factors of thrombosis should receive indefinite anticoagulation, consisting of subtherapeutic doses of low molecular weight heparin in cancer patients, and oral anticoagulants in all other conditions. Patients whose VTE is triggered by major surgery or trauma should be offered three months of anticoagulation. Patients with unprovoked VTE, including carriers of thrombophilia, and those whose thrombotic event is associated with minor risk factors (such as hormonal treatment, minor injuries, long travel) should receive at least three months of anticoagulation. The decision as to go on or discontinue anticoagulation after this period should be individually tailored and balanced against the haemorrhagic risk. Post-baseline variables, such as the D-dimer determination and the ultrasound assessment of residual thrombosis can help identify those patients in whom anticoagulation can be safely discontinued. As a few emerging anti-Xa and anti-IIa compounds seem to induce fewer haemorrhagic complications than conventional anticoagulation, while preserving at least the same effectiveness, these have the potential to open new scenarios for decisions regarding the duration of anticoagulation in patients with VTE.

Effect of hormone replacement therapy on hemostatic variables in post-menopausal women

Hormone replacement therapy [HRT] has been increasingly promoted over the last 40 years to improve quality of life, and to reduce the risks of osteoporotic fractures and coronary heart disease [CHD]. Recent randomized controlled clinical trials reported that HRT usage is associated with an increased risk of myocardial infarction [MI], stroke, and venous thrombosis. We conducted this study to evaluate the mean levels of some hemostatic parameters among groups that differ in estrogen levels and age. We studied 150 healthy women in an observational comparative study, divided into 3 groups. Forty women were post-menopausal using HRT for a period of 6 months to 17 years. Fifty-five women were post-menopausal and were not using HRT. Fifty-five women were younger pre-menopausal women with an age range of 20-54 years. The HRT group women were recruited from gynecologist private clinics while the other 2 groups were recruited in a random way from the society in Damascus, Syria between August 2002 and January 2003. We determined estradiol, fibrinogen, antithrombin III [AT III] and protein C in all women. When compared with post-menopausal non-users group, current HRT users had higher mean levels of estradiol, but lower mean levels of AT III and protein C, and similar mean levels of fibrinogen. When compared with pre-menopausal group, current users had similar mean levels of estradiol, AT III and protein C, but higher mean levels of fibrinogen. However, post-menopausal non-users women had higher mean levels of fibrinogen and lower mean levels of AT III and protein C when compared with pre-menopausal women. Hormone replacement therapy treatment did not change fibrinogen mean levels, but it caused a decrease in AT III and protein C mean levels