1. Department of Cardiology, Royal Brompton and Harefield Hospital, Imperial College London, Sydney Street, SW3 6NP London, UK
2. Division Of Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
3. School of Cardiovascular Disease, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy