1. Department of Cardiology, University Hospital of Wales, Cardiff, United Kingdom (T.K., S.G., R.A.).
2. Department of Cardiology, Sussex Cardiac Centre, Brighton and Sussex University Hospitals, United Kingdom (J.C., D.H.-S.).
3. Department of Cardiology, University College Hospital, London, United Kingdom (A.S.).
4. Department of Cardiology, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom (P.L.).
5. Department of Cardiology, The James Cook University Hospital, Middlesbrough, United Kingdom (M.d.B.).
6. Department of Cardiology, St Bartholomew’s Hospital, London, United Kingdom (E.S.).
7. Department of Cardiology, Bristol Royal Infirmary, United Kingdom (J.S.).
8. Keele Cardiovascular Research Group, Institute of Applied Clinical Sciences, University of Keele, Stoke-on-Trent and Royal Stoke Hospital, University Hospital of North Midlands, United Kingdom (M.M.).