1. From the Department of Internal Medicine, Divisions of Nephrology and Hypertension (X.-Y.Z., E.D., A.R.C., L.O.L.) and Cardiovascular Diseases (M.R.-P., A.L., L.O.L.), Mayo Clinic, Rochester, Minn; the Research Center of Excellence in Cardiovascular Diseases and Departments of General Pathology and Medicine (C.N.), University of Naples, Italy; and the Evans Department of Medicine and Whitaker Cardiovascular Institute (C.N.), Boston University, Boston, Mass.