1. Keele Cardiovascular Research Group, Centre for Prognosis Research, Institute for Primary Care and Health Sciences, Keele University (A.S., M.R., C.S.K., J.N., M.A.M.).
2. Cardiology Department, University Hospital of Wales, Cardiff, United Kingdom (T.K.).
3. Faculty of Medicine, University of Southampton, United Kingdom (N.C.).
4. Institute for Primary Care Sciences, University of Manchester (E.K.)
5. Cardiology Department, Queen Elizabeth Hospital Birmingham, United Kingdom (P.L.).
6. Cardiology Department, James Cook University Hospital, Middlesbrough, United Kingdom (M.d.B.).
7. Academic Cardiology Department, Newcastle University, United Kingdom (A.Z.).