1. Department of Cardiology, University Leipzig-Heart Center, Leipzig
2. West German Heart Center Essen, Department of Cardiology
3. Bayer HealthCare, Wuppertal
4. Institute of Clinical Chemistry and Laboratory Medicine, University of Duisburg-Essen
5. Institute of Pathophysiology, West German Heart Center, University Hospital Essen, Essen
6. Clinic of Cardiology, Klinikum Links der Weser, Bremen, Germany