1. Department of Hemostasis and Transfusion Medicine, Heinrich Heine University Medical Center Dusseldorf, Dusseldorf, Germany,
2. Department of Hemostasis and Transfusion Medicine, Heinrich Heine University Medical Center Dusseldorf, Dusseldorf, Germany
3. Department of Angiology, University Clinic Essen, Essen, Germany
4. West German Heart Center Essen, University Clinic Essen, Essen, Germany