1. University of Cologne, Faculty of Medicine and University Hospital Cologne, Clinic III for Internal Medicine , Cologne , Germany
2. Department of Cardiology and Aortic Centre, Guy’s and St. Thomas’ Hospitals NHS Trust, Royal Brompton and Harefield Hospitals , London SW3 6NP , UK
3. Department of Cardiac Surgery, Guy’s and St. Thomas’ Hospitals NHS Trust, Royal Brompton and Harefield Hospitals , London , UK