1. Division of Cardiology, New Main Building, Groote Schuur Hospital, University of Cape Town, Anzio Road, Observatory 7925, Cape Town, South Africa
2. Department of Medicine, Old Main Building, Groote Schuur Hospital, University of Cape Town, Anzio Road, Observatory 7925, Cape Town, South Africa
3. Hatter Institute for Cardiovascular Research in Africa and Cape Heart Institute, Chris Barnard Building, Faculty of Health Sciences, University of Cape Town, Observatory 7925, Cape Town, South Africa
4. Klinik für Innere Medizin III, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Saarland University Hospital, Homburg/Saar, Deutschland, Germany