1. Cardiology Unit, Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT (Istituto Mediterraneo per i Trapianti e Terapie ad alta specializzazione), Palermo, Italy
2. Service of Clinical Epidemiology & Biometry, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
3. Division of Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Veruno, Italy
4. Cardiac, Thoracic and Vascular Department, University of Pisa, Pisa, Italy
5. Section of Cardiology, Department of Medicine, University of Verona, Verona, Italy
6. Division of Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
7. Division of Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Montescano, Italy