1. Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen, Denmark
2. Heart Center, Turku University Hospital and University of Turku, 20520 Turku, Finland
3. Department of Medical Science, Cardiology, Uppsala University, Akademiska Sjukhuset, 751 85 Uppsala, Sweden
4. Department of Cardiology, Bichat Hospital, University Paris VII, Paris 75018, France