1. The Heart Center, Nationwide Children’s Hospital, Columbus, OH (A.S., A.K.A., J.L.C., J.P.C., S.L.C.).
2. Biostatistics Resource at Nationwide Children’s Hospital, Columbus, OH (M.E.).
3. The Heart Institute, Joe DiMaggio Children’s Hospital, Hollywood, FL (B.A.B., T.F., J.A.-V.).
4. Seattle Children’s Hospital, WA (T.K.J., B.H.M., Z.L.S.).
5. Department of Pediatric Cardiology, Wilhelmina Children’s Hospital of the University Medical Center Utrecht, the Netherlands (G.J.K.).
6. Department of Medicine, Division of Cardiology, University of Washington, Seattle (Z.L.S.).
7. Department of Cardiology, University Medical Center Utrecht, the Netherlands (M.V.).
8. Heart Institute, Children’s Hospital Los Angeles, CA (D.P.B.).