1. Herz und Gefass-Klinik, Bad Neustadt/Saale, Bayern, Germany
2. Departmentof XVII –Cardiovascular Surgery, Bundeswehrzentralkrankenhaus Koblenz, Koblenz, Rheinland-Pfalz, Germany
3. Department of Cardiac Surgery, Sana HerzchirurgischeKlinik Stuttgart GmbH, Stuttgart, Baden-Württemberg, Germany
4. Department of Cardiology, St. MarienKrankenhaus, Siegen, Germany
5. Department of Cardiology, KatholischesKlinikum Koblenz Montabaur, Koblenz, Rheinland-Pfalz, Germany
6. Department of Cardiovascular Surgery, Universitatsklinikum Dusseldorf, Dusseldorf, Nordrhein-Westfalen, Germany
7. Department of Cardiology, St. Marien Hospital, Bonn, Germany
8. Department of Cardiac Surgery, Kerckhoff Klinik, Bad Nauheim, Germany