1. Department of Internal Medicine, Karl Bremer Hospital, Mike Pienaar Boulevard, Cape Town 7530, South Africa
2. Division of Cardiology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University & Tygerberg Academic Hospital, Francie van Zijl Avenue, Cape Town 7505, South Africa
3. Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Tygerberg Academic Hospital, Francie van Zijl Avenue, Cape Town 7505, South Africa