1. Division of Cardiology, A.O.U. Policlinico "G. Rodolico ‐ San Marco" University of Catania Catania Italy
2. National Centre for Global Health Istituto Superiore di Sanità Rome Italy
3. Department of Surgery University of Oulu Oulu Finland
4. Department of Surgery University of Turku Turku Finland
5. Heart and Lung Center Helsinki University Hospital Helsinki Finland
6. Italian National Agency for Regional Healthcare Services Rome Italy