1. From the Duke University Medical Center, Durham, NC (J.B.W., M.R.P., S.V.R.); Duke Clinical Research Institute, Durham, NC (L.A.K., D.M.W., M.R.P., S.V.R.); Piedmont Heart Institute, Atlanta, GA (A.J.K.); and Brown Medical School, Providence, RI (J.D.A.)