[1] Polytech Univ Marche, Lancisi Cardiovasc Ctr, Cardiac Surg Unit, Ancona, Italy
[2] European Interbalkan Med Ctr, Dept Cardiac Surg, Thessaloniki, Greece
[3] Med Univ Innsbruck, Dept Cardiac Surg, Innsbruck, Austria
[4] German Heart Ctr Berlin, Dept Cardiothorac & Vasc Surg, Berlin, Germany
[5] Univ Heart Ctr Dresden, Ctr Minimally Invas Cardiac Surg, Dresden, Germany
[6] Careggi Univ Hosp, Cardiac Surg Unit, Florence, Italy
[7] Hartctr OLV Aalst, Dept Cardiac Surg, Aalst, Belgium
[8] Univ Miami, Div Cardiothorac Surg, Miami, FL USA
[9] Franciscan Hlth Indianapolis, Indianapolis, IN USA
[10] Univ Bologna, St Orsola Malpighi Hosp, Dept Cardiac Surg, Bologna, Italy
[11] Royal Prince Alfred Hosp, Dept Cardiothorac Surg, Sydney, Australia
[12] Univ Turin, Cardiac Surg Unit, Turin, Italy
[13] S Bortolo Hosp, Div Cardiac Surg, Vicenza, Italy
[14] Univ Paris, Henri Mondor Hosp, Paris, France
[15] Jena Univ Hosp, Dept Cardiothorac Surg, Jena, Germany
[16] Univ Med & Pharm, Ho Chi Minh City, Vietnam
[17] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Dept Cardiothorac & Vasc Surg, Houston, TX USA