1. From the Division of Cardiology, Department of Medicine (K.W., G.S.P., K.S., A.S., G.G., S.D.R., R.G.W.) and Division of Magnetic Resonance Research, Department of Radiology (K.W., M.S., P.A.B.), Johns Hopkins University School of Medicine, Baltimore, MD; Philips Healthcare Germany, Hamburg, Germany (K.W.); Heart Failure and Circulatory Support Program, George Washington University School of Medicine, DC (G.S.P.); and Johns Hopkins School of Public Health, Baltimore, MD (A.G.).