1. Department of Cardiology, Leiden Univesity Medical Center , Albinusdreef 2, 2300 RC, Leiden , The Netherlands
2. Department of Cardiology, Germans Trias i Pujol Hospital , Carretera de Canyet s/n. 08916 Badalona, Barcelona , Spain
3. Division of Cardiovascular Imaging, Weill Cornell Medical College, Houston Methodist DeBakey Heart & Vascular Center , 6565 Fannin St, Houston, TX 77030 , USA
4. Department of Cardiovascular Medicine, Mayo Clinic , 200 First St. SW, Rochester, MN 55905 , USA
5. Department of Cardiology, Barts Heart Centre and University College London , West Smithfield, London EC1A 7BE , UK
6. Department of Cardiology, Minneapolis Heart Institute at Abbott Northwestern Hospital , 800 E 28th St, Minneapolis, MN 55407 , USA