1. British Heart Foundation, Greater London House, 180 Hampstead Road, London, UK
2. Department Cardiovascular Sciences, KU Leuven, Herestraat 49, Leuven, Belgium
3. Department of Cardiac & Vascular Diseases, John Paul II Hospital, Jagiellonian University Medical College, Krakow, Poland; and
4. Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands