L'antiagrégation a-t-elle une place en cas de thrombopénie tardive induite par l'héparine ?

We report a case of type II heparin-induced thrombocytopenia, which occurred after heart surgery in a 71-year-old female patient with several cardiovascular risk factors. The diagnosis of heparin-induced thrombopenia was suspected because association of multifocal arterial and venous thrombosis and detection of antiplatelet-factor 4 antibodies with a drop of more than 50% in the platelet count. Until diagnostic of heparin-induced thrombocytopenia was made, clopidogrel was introduced because of well-documented ischemia in middle-cerebral artery territory. The platelets subsequently increased by near 30%. The diagnosis of heparin-induced thrombocytopenia was finally confirmed a few days later by detection of antiplatelet-factor 4 antibodies associated with a positive platelet aggregation test for unfractionated heparin. Heparin was replaced by sodium danaparoid. These measures did not change the unfavorable outcome and death of the patient. The increase in the platelet count after fortuitous clopidogrel introduction raises the question of the role of antiaggregant agents in association with anticoagulants for the treatment of type II heparin-induced thrombocytopenia. (J Mal Vasc 2005; 30: 94-97).