1. Department of Cardiovascular Surgery, University Medical Center Hamburg-Eppendorf University Heart & Vascular Center, Hamburg, Hamburg, Germany
2. Department of Cardiothoracic Surgery, University Hospital Augsburg, Augsburg, Bayern, Germany
3. Department of Cardiology, University Medical Center Hamburg-Eppendorf University Heart & Vascular Center, Hamburg, Hamburg Germany
4. Department of Internal Medicine, Itzehoe Hospital, Itzehoe, Schleswig-Holstein, Germany