1. From Division of Cardiology, Children’s National Health System, Department of Pediatrics (M.L.O.), and Division of Cardiothoracic Surgery, Children’s National Health System, Department of Surgery (R.A.J.), George Washington University of Health Sciences, Washington, DC; Duke Clinical Research Institute (S.K., C.P.H., B.A.Y., R.A.M.) and Department of Pediatrics (C.P.H.), Duke University School of Medicine, Durham, NC; Department of Biostatistics and Bioinformatics, Duke University, Durham, NC (R.A.M...