1. Department of Cardiology, St.-Johannes-Hospital, 44137 Dortmund, Germany
2. Department of Cardiology, University of Oldenburg, 26129 Oldenburg, Germany
3. Department of Cardiovascular Surgery, University of Schleswig Holstein, Campus Kiel, 24118 Kiel, Germany
4. Department of Cardiology, University of Bonn, Heart Center Bonn, 53113 Bonn, Germany
5. Department of Cardiology, University of Gießen, 35390 Gießen, Germany