1. The Cardiovascular Division, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (T.N., G.E.D., A.K., R.M.J., G.F.M., W.G.S.).
2. The Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Boston, MA (T.N., B.S., S.T., R.G.M., U.B.T.).