1. Unit of Quality Improvement, Department of Cardiothoracic Surgery, University of Thessaly, Biopolis, 41110 Larissa, Greece
2. Department of Cardiology, University of Thessaly, Biopolis, 41110 Larissa, Greece
3. Department of Cardiothoracic Surgery, University of Thessaly, Biopolis, 41110 Larissa, Greece
4. Department of Surgery and Cancer, Imperial College London, St Mary’s Hospital, London W2 1NY, UK
5. Department of Anesthesiology, University of Thessaly, Biopolis, 41110 Larissa, Greece
6. Department of Therapeutics, Faculty of Medicine, National and Kapodistrian University of Athens, 10679 Athens, Greece