1. Department of Medicine, St George’s University of London, Cranmer Terrace, Tooting, London, United Kingdom
2. Department of Medicine, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
3. Department of Cardiothoracic Surgery, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
4. Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool, Heart and Chest Hospital, Liverpool, United Kingdom