1. Department of Medicine II Heart Center, University Hospital Bonn Bonn Germany
2. Division of Cardiology University Hospital of Duesseldorf Duesseldorf Germany
3. Division of Cardiology Cardiovascular Research Institute Duesseldorf Düsseldorf Germany
4. Department of Cardiology, Heart Center University of Cologne Cologne Germany
5. Department of Cardiac Surgery Heart Center, University Hospital Bonn Bonn Germany