1. Division of Cardiac Surgery, University of Verona Medical School , Verona, Italy
2. Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg , Hamburg, Germany
3. Department of Cardiac Surgery, Centre Cardiologique du Nord de Saint-Denis , Paris, France
4. Department of Cardiac Surgery, LMU University Hospital, Ludwig Maximilian University , Munich, Germany
5. German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance , Munich, Germany
6. Department of Cardiac Surgery, Hôpitaux Universitaires Henri Mondor, Assistance Publique-Hôpitaux de Paris , Creteil, France
7. Department of Thoracic and Cardiovascular Surgery, University of Franche-Comte , Besancon, France
8. Department of Cardiothoracic Surgery, University Hospital Muenster , Muenster, Germany
9. Cardiovascular Surgery Department, University Hospital Gregorio Marañón , Madrid, Spain
10. Department of Cardiac Surgery, Third Faculty of Medicine, Charles University and University Hospital Kralovske Vinohrady , Prague, Czech Republic
11. Division of Cardiac Surgery, Cardio-Thoracic and Vascular Department, Azienda Sanitaria Universitaria Giuliano Isontina , Trieste, Italy
12. Cardiothoracic Department, University Hospital , Udine, Italy
13. Cardiac Surgery, Molinette Hospital, University of Turin , Turin, Italy
14. Department of Cardiovascular Surgery, Hospital Clínic de Barcelona, University of Barcelona , Barcelona, Spain
15. Department of Cardiac Surgery, Centre Hospitalier Annecy Genevois , Epagny Metz-Tessy, France
16. Department of Cardiac Surgery, Glenfield Hospital , Leicester, UK
17. Liverpool Centre for Cardiovascular Sciences, Liverpool Heart and Chest Hospital , Liverpool, UK
18. Department of Cardiac Surgery, Ziekenhuis Oost Limburg , Genk, Belgium
19. National Center for Global Health, Istituto Superiore di Sanitá , Rome, Italy
20. Heart and Lung Center, Helsinki University Hospital, University of Helsinki , Helsinki, Finland
21. Department of Medicine, South-Karelia Central Hospital, University of Helsinki , Lappeenranta, Finland
22. Research Unit of Surgery, Anesthesia and Critical Care, University of Oulu , Oulu, Finland