1. Department of Cardiac and Thoracic Vascular Surgery, University of Schleswig-Holstein, Luebeck Campus , Lübeck, Germany
2. Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum , Bad Oeynhausen, Germany
3. German Center for Cardiovascular Research (DZHK), Partner Site Hamburg-Kiel-Luebeck , Luebeck, Germany