1. Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK
2. Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
3. Department of Cardiology, University Hospital Southampton NHS Foundation Trust, Southampton, UK
4. Department of Cardiac Surgery, South Tees Hospitals NHS Trust, Middlesbrough, UK
5. Department of Cardiology, Royal Sussex County Hospital, Brighton, UK
6. National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
7. National Institute for Cardiovascular Outcomes Research, NHS Arden & GEM, Leicester, UK