[1] Norfolk & Norwich Univ Hosp, Norwich, Norfolk, England
[2] James Paget Univ Hosp, Great Yarmouth, Norfolk, England
[3] George Inst Global Hlth, Sydney, NSW, Australia
[4] West Wales Hosp, Dept Med, Carmarthen, Wales
[5] Regina Qu Appelle Hlth Reg, Regina, SK, Canada
[6] Univ East Anglia, Norwich Med Sch, Norwich Res Pk Cardiovasc Grp, Norwich, Norfolk, England