1. Heart Failure and Vascular Risk Unit, Internal Medicine Department; Hospital Universitario Ramón y Cajal, Universidad de Alcalá; Madrid Spain
2. Cardiology Department; Hospital Universitario La Paz; Madrid Spain
3. Department of Cardiology; Castle Hill Hospital, Hull York Medical School, University of Hull; Kingston upon Hull HU16 5JQ UK
4. Department of Medicine; University of East Anglia, Norwich Research Park; Norwich NR4 7TJ UK