The purpose of this study is to determine how often heart surgery patients who receive heparin develop an immune response (heparin-induced thrombocytopenia) that leads to clots forming in different parts of the body. These clots usually occur in the legs (deep venous thrombosis or DVT) or lungs (pulmonary embolism or PE) or cause heart attacks (myocardial infarction or MI) and strokes.

The purpose of this study is to determine how often heart surgery patients who receive heparin develop an immune response (heparin-induced thrombocytopenia) that leads to clots forming in different parts of the body. These clots usually occur in the legs (deep venous thrombosis or DVT) or lungs (pulmonary embolism or PE) or cause heart attacks (myocardial infarction or MI) and strokes.