1. From the Perelman School of Medicine, University of Pennsylvania, Philadelphia (K.B.M., T.P.C.); Duke Clinical Research Institute, Durham, NC (K.J.A., A.F.H.); Mayo Clinic, Rochester, MN (M.M.R.); Division of Cardiovascular Sciences, National Heart, Lung and Blood Institute, Bethesda, MD (M.R.S.); and Harvard Medical School, Boston, MA (E.B.).