Fatal acute myocardial infarction during severe thrombocytopenia in a patient with idiopathic thrombocytopenic purpura.

Because platelets play a major role in most thrombotic events, it is not surprising that all cases of myocardial infarctions in patients with idiopathic thrombocytopenic purpura (ITP) have been reported to occur only when platelets counts begin to rise. We report on a 69-year-old man with ITP who had acute myocardial infarction while he was severely thrombocytopenic (2000/microL). We hypothesize that the pathogenesis of myocardial infarction in thrombocytopenic patients with ITP may result from endothelial damage induced by autoantibodies directed against antigens present on both platelets and coronary endothelial cells.