1. Division of Cardiology, University Hospital Paolo Giaccone
2. Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (PROMISE) ‘G. D’Alessandro’, University of Palermo, Palermo
3. Department of General Surgery and Medical-Surgery Specialities (CHIRMED), University of Catania
4. Cardiology Unit, University Hospital G. Rodolico - San Marco, Catania, Italy