1. Cardiology Department, Hospital Universitario La Princesa, 28006 Madrid, Spain
2. Cardiology Department, Hospital Universitario Puerta del Mar, 11009 Cádiz, Spain
3. Cardiology Department, Hospital Clinic, 08036 Barcelona, Spain
4. Cardiology Department, Hospital Universitario Doce de Octubre, 28041 Madrid, Spain
5. Cardiology Department, Hospital Universitario Río Hortega, 47012 Valladolid, Spain