1. From the Division of Heart and Vascular Diseases, The National Heart, Lung, and Blood Institute (J.T.B., T.R.H.), Bethesda, Md; the Departments of Bioengineering, Surgery, and McGowan Institute for Regenerative Medicine, The University of Pittsburgh (H.S.B.), Pittsburgh, Pa; the Departments of Pediatric and Congenital Heart Surgery and Biomedical Engineering, The Cleveland Clinic Foundation (B.W.D.), Cleveland, Ohio; Ension, Inc (M.J.G.), Pittsburgh, Pa; Jarvik Heart, Inc (R.K.J.), New York, NY; and...