1. Imperial Weight Centre, St Mary's Hospital Imperial College Healthcare NHS Trust London UK
2. Imperial Centre for Endocrinology, Charing Cross Hospital Imperial College Healthcare NHS Trust London UK
3. Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction Imperial College London, Hammersmith Campus London UK
4. West London NHS Trust Southall UK
5. Cardiothoracic, Transplantation and Mechanical Circulatory Support Service, Harefield Hospital Royal Brompton and Harefield NHS Foundation Trust Harefield UK
6. National Heart and Lung Institute Imperial College London London UK
7. Department of Surgery and Cancer Imperial College London London UK