1. Department of Medicine, Duke University School of Medicine, Durham, NC (M.F.C., A.V., J.H., R.J.M., S.J.G.).
2. Duke Clinical Research Institute, Durham, NC (J.-L.S., B.A., R.J.M., S.J.G.).
3. Department of Medicine, University of Mississippi Medical Center, Jackson (J.B.).
4. Baylor Scott and White Research Institute, Dallas, TX (J.B.).
5. Department of Cardiovascular Medicine, Heart and Vascular Institute, Kaufman Center for Heart Failure, Cleveland Clinic, OH (R.C.S.).