1. From the Donald W. Reynolds Cardiovascular Clinical Research Center (J.A.d.L., A.K., D.K.M., G.S., H.S.L., R.P.), University of Texas Southwestern Medical Center, Dallas, Tex; and the Donald W. Reynolds Cardiovascular Clinical Research Center (A.Z., U.S., N.V., S.A.M., R.N., D.A.M., P.L.), Brigham and Women’s Hospital, Boston Mass.