1. Department of Cardiology, Castle Hill HospitalHull York Medical School (at University of Hull) Kingston upon Hull UK
2. Robertson Institute of Biostatistics and Clinical Trials UnitUniversity of Glasgow Glasgow UK
3. Faculty of Medical ScienceAnglia Ruskin University Chelmsford UK
4. National Heart & Lung Institute and National Institute of Health Research Cardiovascular Biomedical Research UnitRoyal Brompton & Harefield Hospitals, Imperial College London London UK