1. From the Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas (A.K.); and the Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, and the Intramural Research Program, National Institute on Minority Health and Health Disparities — both at the National Institutes of Health, Bethesda, MD (T.M.P.-W.).