1. Department for Cardiac Rehabilitation, Schüchtermann-Klinik Bad Rothenfelde, Bad Rothenfelde, Germany
2. Department of Preventive and Rehabilitative Sport and Exercise Medicine, Institute for Cardiology and Sports Medicine, German Sports University Cologne, Cologne, Germany
3. Department for Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
4. Department for Cardiac Surgery, Schüchtermann-Klinik Bad Rothenfelde, Bad Rothenfelde, Germany