1. Cardiothoracic Surgery Department Golden Jubilee National Hospital Glasgow UK
2. Cardiac Surgery Department, Massachusetts General Hospital Harvard Medical School Boston Massachusetts USA
3. Cardiac Surgery Department Università Campus Bio‐Medico di Roma Rome Italy
4. Cardiac Surgery Department Leiden University Medical Centrum Leiden The Netherlands
5. Cardiac Surgery Department, Lancashire Cardiac Centre Blackpool Victoria Hospital Blackpool UK
6. Cardiothoracic and Vascular Department Maria Cecilia Hospital (GVM) Cotignola Ravenna Italy