1. Cardiology Department, Cardiovascular Institute, Hospital Universitario Clínico San Carlos , Calle del Prof Martín Lagos, S/N, Moncloa - Aravaca, 28040 Madrid , Spain
2. Cardiology Department, Hospital Universitario Principe de Asturias , Alcalá de Henares , Spain
3. Cardiac Surgery Department, Cardiovascular Institute, Hospital Universitario Clínico San Carlos , Madrid , Spain