1. Department of Thoracic and Cardiovascular Surgery, German Cardiac Competence Center, Eberhard-Karls-University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
2. Department of Anesthesiology and Intensive Care Medicine, Eberhard-Karls-University of Tuebingen, 72076 Tuebingen, Germany
3. Department of Cardiothoracic Surgery, University Hospital of Jena, Friedrich-Schiller-University, 07747 Jena, Germany
4. Department of Cardiac Surgery, Ludwig-Maximilians-University, 80539 Munich, Germany
5. German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 81377 Munich, Germany
6. Department of Cardiothoracic Surgery, Heart Center, University of Cologne, 50923 Köln, Germany
7. Institute for Clinical Epidemiology and Applied Biostatistics, Eberhard-Karls-University of Tuebingen, 72074 Tuebingen, Germany