1. Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
2. Medical Clinic III, Department of Cardiology, University Hospital Frankfurt, Frankfurt, Germany
3. Department of Cardiac Surgery, University Hospital Oldenburg, Oldenburg, Germany
4. Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany
5. Department of Cardiac Surgery, INCCI National Heart Institute, Luxembourg, Luxembourg
6. Department of Anesthesiology, Emergency and Intensive Care Medicine, University Medical Center, University of Goettingen, Goettingen, Germany
7. Division of Thoracic and Cardiovascular Surgery, University Hospital Frankfurt, Frankfurt, Germany