1. From the Department of Bioengineering (G.E.R.W., W.R.W.) and McGowan Institute for Regenerative Medicine (G.E.R.W., W.R.W.), University of Pittsburgh, Pa; Cardiovascular Institute (E.L., M.M.C., D.F., F.S.V.), University of Pittsburgh School of Medicine, Pa; and Cardiovascular Imaging Center (A.L.K.), University of Virginia, Charlottesville, Va.