1. Department of Cardiothoracic Surgery, Leiden University Medical Centre, Leiden, Netherlands
2. Department of Cardiac Surgery, San Raffaele Hospital, Milan, Italy
3. Department of Thoracic and Cardiovascular Surgery, University Hospital Homburg, Homburg, Germany
4. Department of Thoracic and Cardiovascular Surgery, Saarland University Medical Center, Homburg/Saar, Germany
5. Department of Cardiovascular and Thoracic Surgery, Hokkaido University Hospital, Sapporo, Japan
6. Department of Cardiology, University Paris Diderot, Paris, France
7. Department of Cardiac Surgery, Louis Pradel Hospital, Lyon, France
8. Department of Cardiovascular Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
9. Department of Cardiovascular Surgery, University Heart Centre, Freiburg, Germany