1. From Cardiothoracic Surgical Research (J.S.I., J.A.J, J.R.B., R.E.S., L.L.C., B.S.K., F.G.S.), Division of Cardiothoracic Surgery, Medical University of South Carolina, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC; Division of Cardiothoracic Surgery (A.Z., J.E.B., J.H.G., R.C.G.), University of Pennsylvania, Philadelphia, Pa.