1. From the Hatter Cardiovascular Research Institute, Department of Medicine, Faculty of Health Sciences, University of Cape Town ( K.S., K.T.), and Soweto Cardiovascular Research Unit, Department of Cardiology, University of the Witwatersrand, Johannesburg, South Africa (K.S., K.T., E.L., A.B.); Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minn (L.B.); Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa (K.T.); Netcare N1 City Hospital, Cape Town, South Africa (J...