1. Department of Cardiology, Royal Brompton Hospital, Imperial College London, London, UK
2. Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
3. Department of Cardiology, Oslo University Hospital, Postboks 4950 Nydalen, 0424 Oslo, Norway
4. Faculty of Medicine, University of Oslo, Postboks 1171, Blindern, 0318 Oslo, Norway
5. Department of Cardiology, Centrum voor Hart en Vaatziekte (CHVZ), Universitair Ziekenhuis Brussel, Free University of Brussels, 101 Laarbeeklaan, 1090 Brussels, Belgium