1. From the Departments of Cardiology (I.M.K., F.M., R.D.B., J.E.M., D.D.S., H.A., D.A.K., H.C., S.N.) and Radiology and Radiological Sciences (S.L.Z.), The Johns Hopkins University School of Medicine, Baltimore, MD; and Departments of Biostatistics (V.Z.) and Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.