 Between March 2005 and October 2006, 844 patients median age range: 65 18-98 years; 547 women were included. At inclusion, confirmed deep-vein thrombosis andor symptomatic pulmonary embolism was associated with ST in 24.9 n210 of patients. Among the 600 patients with isolated ST i.e. without deep-vein thrombosis or pulmonary embolism at inclusion, 10.4 n56 developed venous thromboembolic complications at three months, including the following symptomatic events: pulmonary embolism 0.4, n2, deep-vein thrombosis 2.8, n15, extension of ST 3.1, n17 and recurrence of ST 1.9, n10. These complications occurred despite the use of various anticoagulant strategies in 90.5 n540 of patients; four independent risk factors increased the risk of these complications: male sex, cardiac or respiratory insufficiency, history of deep-vein thrombosis or pulmonary embolism and no history of varicose veins. 