1. Department of Cardiac Surgery, Medical University of Innsbruck , Innsbruck , Austria
2. Institute of Clinical and Functional Anatomy, Medical University of Innsbruck , Innsbruck , Austria
3. Department of Thoracic and Cardiovascular Surgery, West-German Heart and Vascular Center Essen, University Duisburg-Essen , Essen , Germany
4. University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck , Innsbruck , Austria
5. Central Institute of Clinical Chemistry and Laboratory Medicine, Medical University of Innsbruck , Innsbruck , Austria
6. Department for Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck , Innsbruck , Austria