1. Department of Cardiac Surgery, Complejo Hospitalario Universitario de Vigo, Vigo, Spain
2. Department of Cardiology, Complejo Hospitalario Universitario de Vigo, Vigo, Spain
3. Department of Geriatric Medicine, Complejo Hospitalario Universitario de Vigo, Vigo, Spain
4. Department of Surgery, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
5. University of Lincoln, Lincoln, UK