1. University Hospital Aachen; Department of Cardiothoracic Surgery; Pauwelsstrasse 30 Aachen North Rhine Westphalia Germany 52074
2. RWTH Aachen University; Department of Intensive Care Medicine; Pauwelsstrasse 30 Aachen North Rhine Westphalia Germany 52074
3. Heart Center, University of Cologne; Department of Cardiothoracic Surgery; Kerpener Str. 62 Cologne Germany 50937
4. University Hospital RWTH Aachen; Department of Anaesthesiology; Pauwelsstrasse 30 Aachen Germany
5. University of Leipzig; Institute for Medical Informatics, Statistics & Epidemiology (IMISE); Haertelstrasse 16-18 Leipzig Germany
6. University Hospital Frankfurt; Department of Anaesthesiology, Intensive Care and Pain Therapy; Theodor-Stern-Kai 7 Frankfurt am Main Germany 60590