1. Cape Heart Institute, Faculty of Health Sciences, University of Cape Town, South Africa
2. Department of Medicine, Division of Cardiology, Groote Schuur Hospital, University of Cape Town, South Africa
3. Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
4. Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, USA
5. Medical Faculty of the Philipps University Marburg, Marburg, Germany