[1] Oulu Univ Hosp, Dept Surg, Oulu, Finland
[2] Oulu Univ Hosp, Dept Internal Med, Oulu, Finland
[3] Landspitali Univ Hosp, Dept Cardiothorac Surg, Reykjavik, Iceland
[4] Sahlgrens Univ Hosp, Dept Cardiothorac Surg, Gothenburg, Sweden
[5] Univ Catania, Policlin Vittorio Emanuele, AOU, Cardiac Surg Unit, Catania, Italy
[6] Turku Univ Hosp, Ctr Heart, FIN-20520 Turku, Finland
[7] Univ Turku, Turku, Finland
[8] Vaasa Cent Hosp, Dept Anesthesiol, Vaasa, Finland
[9] Vaasa Cent Hosp, Dept Surg, Vaasa, Finland
[10] Vaasa Cent Hosp, Dept Internal Med, Vaasa, Finland
[11] Univ Verona, Sch Med, Div Cardiac Surg, I-37100 Verona, Italy
[12] Univ Verona, Sch Med, Dept Med, Div Cardiol, I-37100 Verona, Italy
[13] Univ Iceland, Fac Med, Dept Cardiol, Reykjavik, Iceland
[14] Satakunta Cent Hosp, Ctr Heart, Pori, Finland
[15] Tampere Univ Hosp, Ctr Heart, Tampere, Finland
[16] V Monaldi Hosp, Dept Cardiothorac & Resp Sci, Naples, Italy