1 Heart Centre Heidelberg, Department of Cardiac Surgery, University Hospital Heidelberg, University Heidelberg, Heidelberg, Germany.
2 Department of Cardiothoracic Surgery, Heart Centre, University Hospital Cologne, Cologne, Germany.
3 Department of Cardiac Surgery, University Hospital Oldenburg, European Medical School Oldenburg-Groningen, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
4 Department of Thoracic and Cardiovascular Surgery, Thoracic Transplantation, West German Heart and Vascular Centre Essen, University Hospital Essen, Essen, Germany.
5 Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Royal Brompton & Harefield NHS Foundation Trust, Harefield Hospital, Harefield, Middlesex, UK.
6 Department of Thoracic and Cardiovascular Surgery, University Medical Centre Tübingen, Tübingen, Germany.