1. From the Division of Cardiology (R.D.), Johns Hopkins Hospital, Baltimore, Md; General Internal Medicine Section (M.G.S.), Veterans Affairs Medical Center, and Departments of Medicine, Epidemiology, and Biostatistics (F.L., E.V., S.B.H., M.G.S.), and the Division of Cardiology (Z.H.T.), University of California School of Medicine, San Francisco.