Institute of Anaesthesiology, University of Zurich and University Hospital Zurich, Zurich, Switzerland. Electronic address: donat.spahn@usz.ch. Department of Cardiothoracic and Vascular Surgery, German Heart Centre Berlin, Berlin, Germany; German Centre for Cardiovascular Research, partner site Berlin, Germany. Institute of Anaesthesiology, University of Zurich and University Hospital Zurich, Zurich, Switzerland. Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Switzerland. Department of Anaesthesiology, University of Zurich and University Hospital Balgrist, Zurich, Switzerland. Division of Haematology, University of Zurich and Zurich University Hospital, Zurich, Switzerland. Institute of Anaesthesiology, University of Zurich and University Hospital Zurich, Zurich, Switzerland; School of Surgery, University of Western Australia and School of Public Health Research, Curtin University, Perth, Western Australia, Australia. Department of Cardiovascular Surgery, University of Zurich and University Hospital Zurich, Zurich, Switzerland. Department of Cardiothoracic and Vascular Surgery, German Heart Centre Berlin, Berlin, Germany; German Centre for Cardiovascular Research, Berlin, Germany; Department of Cardiothoracic Surgery, Charité - Universitätsmedizin Berlin Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.