Prospective study including all the consecutive patients admitted at the Department of Cardiology, Timone Hospital wih a definite diagnosis of IE according to the modified Duke criteria. The period of inclusion will be for 24 months. Eighty patients and age-matched control subject will be included. Primary end point are EE occurring during the antimicrobial treatment and secondary end points will be 6-month mortality, vegetation length and the impact of antimicrobial treatment on inflammation-induced procoagulant changes and endothelial cell activation.