1. Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center, Medical Faculty, University Hospital Essen , Hufelandstraße 55, 45147 Essen, Germany
2. Division of Hematology and Division of Experimental Pathology, Mayo Clinic , Rochester, MN 55901, USA
3. Department of Cardiovascular Disease, Mayo Clinic , Rochester, MN 55901, USA