1. Heart and Lung Center, Helsinki University Hospital, Haartmaninkatu 4 P.O. Box 340, 00029 Helsinki, Finland
2. Research Unit of Surgery, Anesthesiology and Critical Care, Faculty of Medicine, University of Oulu, Oulu, Finland
3. Department of Surgery, University of Turku, Turku, Finland
4. Department of Thoracic and Cardio-Vascular Surgery, University Hospital Jean Minjoz, Besançon, France
5. Division of Cardiothoracic and Vascular Surgery, Robert Debré University Hospital, Reims, France
6. Department of Intensive Care Medicine and Cardiac Surgery, Glenfield Hospital, University Hospitals of Leicester, Leicester, UK
7. Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
8. Department of Cardiac Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
9. Department of Cardiothoracic Surgery, Münster University Hospital, Münster, Germany
10. Department of Cardiac Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
11. Department of Cardiothoracic Surgery, University of Lund, Lund, Sweden
12. Division of Cardiothoracic and Vascular Surgery, Pontchaillou University Hospital, Rennes, France
13. Division of Cardiac Surgery, Ospedali Riuniti, Trieste, Italy
14. Prince Sultan Cardiac Center, Al Hassa, Saudi Arabia
15. Department of Cardiothoracic, Transplantation and Vascular Surgery, S. Orsola Hospital, University of Bologna, Bologna, Italy
16. Cardiothoracic Department, University Hospital of Udine, Udine, Italy
17. Institute of Clinical and Experimental Medicine, Prague, Czech Republic
18. Department of Cardiothoracic Surgery, Golden Jubilee National Hospital, Glasgow, UK
19. Department of Cardiovascular Surgery, Ziekenhuis Oost-Limburg, Genk, Belgium
20. Department of Cardiothoracic Surgery, Henri Mondor University Hospital, AP-HP, Paris-Est University, Créteil, France