1. Heart Center; Turku University Hospital and University of Turku; Turku Finland
2. Department of Medicine; Turku University Hospital and University of Turku; Turku Finland
3. Department of Surgery; Turku University Hospital and University of Turku; Turku Finland
4. Department of Surgery; Oulu University Hospital and University of Oulu; Oulu Finland
5. Heart Center; Kuopio University Hospital and University of Eastern Finland; Kuopio Finland
6. Heart and Lung Center; Helsinki University Hospital and University of Helsinki; Finland