[1] Univ Schleswig Holstein, Dept Cardiac & Thorac Vasc Surg, Ratzeburger Allee 160, D-23562 Lubeck, Germany
[2] Univ Cologne, Dept Internal Med 3, Cologne, Germany
[3] German Heart Ctr Munich, Clin Cardiovasc Surg, Munich, Germany
[4] Univ Giessen, Dept Cardiol, Giessen, Germany
[5] German Soc Thorac Cardiac & Vasc Surg, Berlin, Germany
[6] Robert Bosch Krankenhaus, Dept Cardiol, Stuttgart, Germany
[7] St Johannes Hosp, Dept Internal Med 1, Dortmund, Germany
[8] Goethe Univ Frankfurt, Dept Thorac Cardiac & Vasc Surg, Frankfurt, Germany
[9] BQS Inst Qual & Patient Safety, Dusseldorf, Germany
[10] Kerckhoff Heart & Thorax Ctr, Dept Cardiol, Bad Nauheim, Germany
[11] Univ Freiburg, Med Fac, Univ Heart Ctr Freiburg Bad Krozingen, Dept Cardiovasc Surg, Freiburg, Germany
[12] Heidelberg Univ, Dept Cardiol, Heidelberg, Germany
[13] Klinikum Braunschweig, Dept Cardiac Thorac & Vasc Surg, Braunschweig, Germany