1. Division of Surgery and Interventional Science; University College London; London UK
2. Department of Anaesthesia and Intensive Care; Papworth Hospital; Cambridge UK
3. Department of Cardiovascular Sciences and NIHR Cardiovascular Biomedical Research Unit; University of Leicester, and Glenfield General Hospital; Leicester UK
4. Department of Innovative Clinical Trials; University Medical Centre Göttingen (UMG); Göttingen Germany