[1] Helsinki Univ Hosp, Heart & Lung Ctr, Haartmaninkatu 4 POB 340, Helsinki 00029, Finland
[2] Univ Oulu, Fac Med, Res Unit Surg Anesthesiol & Crit Care, Oulu, Finland
[3] Univ Turku, Dept Surg, Turku, Finland
[4] Univ Hosp Jean Minjoz, Dept Thorac & Cardio Vasc Surg, Besancon, France
[5] Robert Debre Univ Hosp, Div Cardiothorac & Vasc Surg, Reims, France
[6] Univ Hosp Leicester, Glenfield Hosp, Dept Intens Care Med & Cardiac Surg, Leicester, Leics, England
[7] Karolinska Univ Hosp, Karolinska Inst, Dept Mol Med & Surg, Stockholm, Sweden
[8] Karolinska Univ Hosp, Karolinska Inst, Dept Cardiac Surg, Stockholm, Sweden
[9] Munster Univ Hosp, Dept Cardiothorac Surg, Munster, Germany
[10] Sahlgrens Univ Hosp, Dept Cardiac Surg, Gothenburg, Sweden
[11] Lund Univ, Dept Cardiothorac Surg, Lund, Sweden
[12] Pontchaillou Univ Hosp, Div Cardiothorac & Vasc Surg, Rennes, France
[13] Osped Riuniti, Div Cardiac Surg, Trieste, Italy
[14] Prince Sultan Cardiac Ctr, Al Hasa, Saudi Arabia
[15] Univ Bologna, S Orsola Hosp, Dept Cardiothorac Transplantat & Vasc Surg, Bologna, Italy
[16] Univ Hosp Udine, Cardiothorac Dept, Udine, Italy
[17] Inst Clin & Expt Med, Prague, Czech Republic
[18] Golden Jubilee Natl Hosp, Dept Cardiothorac Surg, Glasgow, Lanark, Scotland
[19] Ziekenhuis Oost Limburg, Dept Cardiovasc Surg, Genk, Belgium
[20] Paris Est Univ, Henri Mondor Univ Hosp, AP HP, Dept Cardiothorac Surg, Creteil, France