[Risk factors of venous thromboembolism]

Authors discussed the known risk factors of venous thromboembolism (VTE), which is complex disease with two manifestations: deep venous thrombosis (DVT) and pulmonary embolism (PE). Acquired risk factors of VTE are following: age over 40 years, bed rest, surgery, trauma, cancer, myocardial infarction, ischemic stroke, use of oral contraceptives, hormone-replacement therapy, pregnancy and puerperium, previous VTE, long lasting travel and presence of antiphospholipid antibodies. Group of genetic defects predisposing to thromboembolic events are called thrombophilia. The best known causes of thrombophilia are: resistance to activated protein C (factor V Leiden), the prothrombin 20210A, protein C deficiency, protein S deficiency, antithrombin deficiency, hyperhomocysteinemia and abnormality in the fibrinolytic system. Genetic predisposition to thrombosis may be detected in up to one-third of patients with VTER and more than 50% of patients with familial thrombosis. Detection of factor V Leiden is important for patients: with recurrent incidences of VTE, with other known causes of thrombophilia and in members of families with frequent occurrence of VTE. It is important also to detect deficiency of: protein C, protein S and especially of antithrombin in patient with previous VTE, because such patients have 8 to 10 fold increase risk of next incident of VTE. Chronic prevention of thrombosis should be used in all these cases.