1. Imperial College London (National Heart and Lung Institute), Hammersmith Hospital, Du Cane Road, London, UK
2. Department of Cardiac Technology, College of Applied Medical Sciences, Imam Abdulrahman Bin Faisal University, 2835 King Faisal Street, Dammam, Kingdom of Saudi Arabia
3. Department of Population Science & Experimental Medicine, Institute of Cardiovascular Science, University College London, Gower street, London, UK
4. MRC Unit for Lifelong Health and Ageing, University College London, London, UK
5. Cardiology Department, Hammersmith Hospital, Du Cane Road, London, UK