1. Department of Cardiac Surgery, Nottingham University Hospitals NHS Trust, Nottingham NG5 1PB, UK
2. Medical Horizons, 15562 Cholargos, Greece
3. Department of Cardiac Surgery, Evangelismos Hospital, 11527 Athens, Greece
4. Department of Cardiothoracic Surgery, Larissa General University Hospital, 41334 Larissa, Greece
5. Department of Cardiac Surgery, Oxford University Hospitals, Oxford OX3 9DU, UK
6. Department of Cardiac Surgery, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London W2 1NY, UK
7. Department of Surgery and Cancer, Imperial College London, London W2 1NY, UK