1. Department of Cardiac and Thoracic Vascular Surgery, University of Schleswig-Holstein, Lübeck Campus, Lübeck, Germany
2. Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum, Bad Oeynhausen, Germany
3. Department of Cardiovascular Surgery, First Faculty of Medicine, General University Hospital in Prague, Charles University, Prague, Czech Republic
4. Department of Pathology, Academic Teaching Hospital Bielefeld, Bielefeld, Germany