University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen - Department of Cardiology and Vascular Medicine, University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen, University of Duisburg-Essen - Department of Thoracic and Cardiovascular Surgery and University of Duisburg-Essen