Affiliation: | a Department of Cardiac Surgery, Heartcenter, University of Leipzig, Leipzig, Germany b Department of Cardiac Surgery, Cardiocentro Ticino, Lugano, Switzerland c Department of Cardiac Surgery, Heart Center Dresden, Dresden, Germany d Department of Cardiovascular and Thoracic Surgery, Klinikum Braunschweig, Braunschweig, Germany e Department of Cardiovascular Medicine, Stanford University, Palo Alto, California |