1. From the Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Scottsdale, Ariz (K.S.S.), and Rochester, Minn (T.J.B., S.J.A., P.A.F., T.M.M., S.C.H., Y.-M.C., P.A.B., A.J., D.J.B., R.F.R., D.L.P., W.-K.S.), and the Division of Anatomic Pathology, Mayo Clinic, Rochester, Minn (W.D.E.).