1. Division of Cardiac Surgery, Ospedali Riuniti
2. Department of Thoracic and Cardio-Vascular Surgery, University Hospital Jean Minjoz
3. Hamburg University Heart Center
4. Division of Cardiovascular Surgery, Verona University Hospital
5. Department of Molecular Medicine and Surgery, Department of Cardiothoracic Surgery and Anesthesiology, Karolinska Institute, Karolinska University Hospital
6. Cardiovascular Center, Paracelsus Medical University
7. Department of Cardiac Surgery, St. Anna Hospital
8. Centro Cuore Morgagni
9. Division of Cardiac Surgery, Department of Cardiothoracic Sciences, Second University of Naples
10. Division of Cardiac Surgery, University of Genoa
11. Division of Cardiac Surgery, University of Parma
12. Department of Cardiovascular Sciences, Cardiac Surgery Unit, S. Camillo-Forlanini Hospital
13. Department of Cardiovascular Sciences, Clinical Sciences Wing, University of Leicester, Glenfield Hospital
14. Department of Surgery, Oulu University Hospital
15. Division of Cardiothoracic and Vascular Surgery, Pontchaillou University Hospital
16. Department of Cardiac Surgery, Centro Cardiologico-Fondazione Monzino IRCCS, University of Milan