Aging is an independent risk factor, without any clear explanation. The primary aim of the study is to depict the effect of aging on the coagulation fibrinolysis parameters and microparticles.

Patients older than 40, without any acute disease and not receiving any antiaggregant and anticoagulant therapy will be included in the study. Blood tests will be performed for coagulation, fibrinolysis and microparticles measurement.

Inclusion Criteria:

• age <40 2 groups : 1 : no history of VTE 2 : history of VTE

Exclusion Criteria:

• antiaggregant or anticoagulant therapy at curative dose
• arterial or thrombotic event in the last month

Stable patients without overt acute clinical event, not receiving antiplatelet or anticoagulant treatment