[1] Royal Infirm Edinburgh NHS Trust, Edinburgh, Scotland
[2] Univ Edinburgh, Anaesthesia Crit Care & Pain, Edinburgh, Scotland
[3] Barts Heart Ctr, London, England
[4] Golden Jubilee Natl Hosp, Clydebank, Scotland
[5] Univ Glasgow, Anaesthesia Crit Care & Perioperat Med, Glasgow, Scotland
[6] Queen Mary Univ London, London, England
[7] Aberdeen Royal Infirm, Aberdeen, Scotland
[8] Glasgow Royal Infirm, Glasgow, Scotland
[9] Hairmyres Hosp, East Kilbride, Scotland
[10] Ninewells Hosp, Dundee, Scotland
[11] Queen Elizabeth Univ Hosp, Glasgow, Scotland
[12] St Johns Hosp, Livingston, Scotland
[13] Victoria Hosp, Kirkcaldy, Scotland
[14] Wishaw Hosp, Wishaw, Scotland
[15] Univ Edinburgh, Usher Inst, Edinburgh, Scotland
[16] Univ Edinburgh, BHF Univ Ctr Cardiovasc Sci, Edinburgh, Scotland
[17] Royal Infirm Edinburgh NHS Trust, Anaesthesia Crit Care & Pain, 51 Little France Crescent, Edinburgh EH16 4SA, Scotland