1. Department of Cardiology, Royal Brompton Hospital, London SW3 6NP, UK
2. Department of Cardiology, Azienda Sanitaria Universitaria Integrata Giuliano Isontina (ASUGI), University of Trieste, 34123 Trieste, Italy
3. Cardiovascular Sciences Research Centre, St. George’s, University of London, London SW17 0RE, UK