[1] Royal Brompton & Harefield Natl Hlth Serv NHS Fdn, London, England
[2] Univ Hosp Birmingham NHS Fdn Trust, Birmingham, W Midlands, England
[3] James Cook Univ Hosp, Middlesbrough, Cleveland, England
[4] Univ Hosp S Manchester NHS Fdn Trust, Manchester, Lancs, England
[5] Bristol Heart Inst, Bristol, Avon, England
[6] Guys & St Thomas NHS Fdn Trust, London, England
[7] Univ Hosp Leicester NHS Trust, Leicester, Leics, England
[8] Kings Coll Hosp Kings Hlth Partners, London, England
[9] Brighton Univ Hosp, Sussex Cardiac Ctr, Brighton, E Sussex, England
[10] Sussex Univ Hosp, Sussex Cardiac Ctr, Brighton, E Sussex, England
[11] Leeds Gen Infirm, Leeds, W Yorkshire, England
[12] St Georges Hosp London, London, England
[13] Cent Cardiac Audit Database, London, England
[14] E Midlands Specialised Commissioning Grp, Leichester, England
[15] Southampton Univ Hosp NHS Trust, Southampton, Hants, England
[16] Univ Coll Hosp London NHS Fdn Trust, London, England