1. Herzchirurgie, Herz- und Gefäßklinik Bad Neustadt, Bad Neustadt, Germany
2. Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, NRW, Germany
3. Herzzentrum Dresden, Dresden, Germany
4. Herz-, Thorax- und herznahe Gefäßchirurgie, Regensburg, Germany
5. Department of Cardiac and Thoracic Surgery, University of Jena, Jena, Germany
6. Herzchirurgie, Robert-Bosch-Krankenhaus GmbH, Stuttgart, Baden-Württemberg, Germany
7. Herzchirurgie, Herzzentrum Leipzig, Leipzig, Germany
8. Department of Cardiovascular Surgery, University Heart Center Hamburg, Hamburg, Germany
9. Department of Cardiac Surgery, Albertinenkrankenhaus, Hamburg, Germany
10. HELIOS Klinik fur Herzchirurgie Karlsruhe, Karlsruhe, Baden-Württemberg, Germany
11. Department of Cardiothoracic Surgery, Ruhr-University Bochum, Bochum, Germany
12. Department of Cardiovascular Surgery, University Hospital Giessen, Giessen, Germany