1. Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
2. Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark
3. Section of Cardiac Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT, USA
4. Department of Cardiothoracic surgery, Karolinska University Hospital, Stockholm, Sweden
5. Department of Surgery, Heart Center, Turku University Hospital, University of Turku, Turku, Finland
6. Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
7. Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
8. Department of Cardiothoracic Surgery, Landspitali University Hospital, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
9. Department of Cardiothoracic Surgery, Heart Center Tampere University Hospital and University of Tampere, Tampere, Finland
10. Department of Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden
11. Department of Cardiothoracic Surgery, Lund University, Skåne University Hospital, Lund, Sweden
12. Department of Cardiothoracic and Vascular Surgery, Orebro University Hospital, Orebro, Sweden
13. Statistiska konsultgruppen, Gothenburg, Sweden
14. Department of Ophthalmology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden