1. Cardiology Department, Gaia/Espinho Hospital Centre and Cardiovascular Research Centre, Faculty of Medicine, University of Porto, Rua Conceicao Fernandes, 4434-502 Vila Nova de Gaia, Portugal
2. Cardiovascular Research Centre, Faculty of Medicine of the University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
3. Royal Papworth Hospital, Papworth Road, CB2 0AY Cambridge, UK
4. Department of Cardiology, Complejo Hospitalario Universitario de A Coruña, CIBER-CV, University of A Coruña, Lugar Jubias de Arriba 84, 15006 A Coruña, Spain
5. European Heart House, Les Templiers 2035 route des colles, CS 80179 Biot, 06903 Sofia-Antipolis Cedex, France
6. Royal Brompton and Harefield Hospitals and Imperial College, Sydney Street, SW3 6NP London, UK