[1] Helsinki Univ Hosp, Heart & Lung Ctr, Helsinki, Finland
[2] South Karelia Cent Hosp, Dept Med, Lappeenranta, Finland
[3] Univ Oulu, Res Unit Surg Anesthes & Crit Care, Oulu, Finland
[4] CPE Inst Cardiol, Dept Cardiac Surg, Paediat Cardiac Surg, Multan, Pakistan
[5] Univ Franche Comte, Dept Thorac & Cardiovasc Surg, Besancon, France
[6] Ctr Cardiol Nord St Denis, Dept Cardiac Surg, Paris, France
[7] Ctr Hosp Annecy Genevois, Pringy, France
[8] Ziekenhuis Oost Limburg, Dept Cardiac Surg, Genk, Belgium
[9] Ludwig Maximilians Univ Munchen, LMU Univ Hosp, Munich, Germany
[10] German Ctr Cardiovasc Res DZHK, Partner Site Munich Heart Alliance, Munich, Germany
[11] Muenster Univ Hosp, Dept Cardiothorac Surg, Munster, Germany
[12] Univ Heart & Vasc Ctr Hamburg, Dept Cardiovasc Surg, Hamburg, Germany
[13] Charles Univ Prague, Fac Med 3, Dept Cardiac Surg, Prague, Czech Republic
[14] Univ Hosp Kralovske Vinohrady, Prague, Czech Republic
[15] Univ Verona, Med Sch, Div Cardiac Surg, Verona, Italy
[16] Univ Hosp, Cardiothorac Dept, Udine, Italy
[17] Univ Turin, Molinette Hosp, Cardiac Surg, Turin, Italy
[18] Azienda Sanit Univ Giuliano Isontina, Cardiothorac & Vasc Dept, Div Cardiac Surg, Trieste, Italy
[19] Natl Hlth Inst, Ctr Global Hlth, Rome, Italy
[20] Univ Barcelona, Dept Cardiovasc Surg, Hosp Clin Barcelona, Barcelona, Spain
[21] Univ Hosp Gregorio Maranon, Cardiovasc Surg Dept, Madrid, Spain
[22] Glenfield Hosp, Dept Cardiac Surg, Leicester, England
[23] Liverpool Heart & Chest Hosp, Liverpool Ctr Cardiovasc Sci, Liverpool, England