1. Department of Medicine, NewYork-Presbyterian Brooklyn Methodist Hospital, Brooklyn (J.F.H., A.I., C.H., T.J.S.).
2. Department of Medicine, Duke Cardiovascular Magnetic Resonance Center, Durham, NC (A.S., J.K.H., I.K., M.H.S., L.V.A., J. White, J. Washam, M.R.P., R.J.K.).
3. Department of Medicine, Maastricht University Medical Center, the Netherlands (S.C.A.M.B., M.W.S.).