[1] Univ Hosp Hamburg Eppendorf, Univ Heart Ctr, Martinistr 52, D-20246 Hamburg, Germany
[2] Ruhr Univ Bochum, Heart & Diabet Ctr NRW, Clin Thorac & Cardiovasc Surg, Bad Oeynhausen, Germany
[3] Goethe Univ Frankfurt, Dept Cardiac & Thorac Surg, Frankfurt, Germany
[4] Heart Ctr Freiburg Univ, Dept Cardiovasc Surg, Freiburg, Germany
[5] Heinrich Heine Univ, Dept Cardiovasc Surg, Dusseldorf, Germany
[6] Univ Hosp Leipzig, Heart Ctr Leipzig, Dept Cardiac Surg, Leipzig, Germany
[7] Univ Regensburg, Dept Cardiac & Thorac Surg, Regensburg, Germany
[8] Kerckkoff Clin, Bad Nauheim, Germany
[9] Heidelberg Univ, Cardiac Surg Clin, Heidelberg, Germany
[10] Hannover Med Sch, Dept Cardiac Thorac Transplantat & Vasc Surg, Hannover, Germany
[11] German Heart Inst, Dept Cardiac Thorac & Vasc Surg, Berlin, Germany
[12] Ludwig Maximilians Univ Munchen, Clin Cardiac Surg, Munich, Germany
[13] Childrens Hosp, Dept Cardiac Surg, Zurich, Switzerland
[14] Univ Hosp Zurich, Clin Cardiovasc Surg, Zurich, Switzerland
[15] Med Univ Vienna, Dept Cardiac Surg, Vienna, Austria