Department of Anaesthesia, Royal Sussex County Hospital, Brighton, UK. Electronic address: robert.kong@nhs.net. Department of Anaesthesia, Royal Sussex County Hospital, Brighton, UK. University Hospitals Sussex NHS Foundation Trust, Clinical Research Facility, Cardiac Research, Brighton, UK. Brighton and Sussex Clinical Trials Unit, Brighton & Sussex Medical School, University of Sussex, Brighton, UK. Brighton and Sussex Medical School, Brighton, UK. Department of Cardiac Surgery, Royal Sussex County Hospital, Brighton, UK. School of Health Sciences, University of London, London, UK. Department of Haematology, Royal Sussex County Hospital, Brighton, UK. Department of Cardiology, Royal Sussex County Hospital, Brighton, UK.