1. Department of Thoracic and Cardiovascular Surgery, Herz- und Diabeteszentrum NRW, University Hospital Ruhr-University Bochum, Bad Oeynhausen, Germany
2. Department of Cardiovascular Surgery, Heart Center Duisburg, Duisburg, Germany
3. Institute of Anesthesiology and Pain Therapy, Herz- und Diabeteszentrum NRW, University Hospital Ruhr-University Bochum, Bad Oeynhausen, Germany
4. Institute of Laboratory and Transfusion Medicine, Herz- und Diabeteszentrum NRW, University Hospital Ruhr-University Bochum, Bad Oeynhausen, Germany