1. Cardiac Surgery Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
2. Regional Agency for Health and Social Care, Emilia-Romagna, Italy
3. Cardiac Surgery Unit, Surgery Department, Parma Hospital, Parma, Italy
4. Cardio-Thoracic-Vascular Department, University Hospital S. Orsola-Malpighi, Bologna, Italy
5. Department of Clinical Cardiology and Thoraco Vascular Surgery, Hesperia Hospital, Modena, Italy
6. Department of Cardiology and Cardiac Surgery, Villa Maria Cecilia Hospital, Lugo, Ravenna, Italy