1. Department of Cardiac Surgery, Aerospace Center Hospital, Beijing, China
2. Department of Cardiac Surgery, Peking University People’s Hospital, Beijing, China
3. Department of Cardiovascular Surgery, German Heart Centre Munich, Technische Universität München, Munich, Germany
4. Department of Thoracic and Cardiovascular Surgery, West German Heart and Vascular Centre Essen, University Hospital Essen, Essen, Germany
5. Department of Cardiovascular Surgery, Henan Provincial People’s Hospital, Zhengzhou, China