[1
]Boston Children’s Hospital and Harvard Medical School, MA (J.W.N., L.A.S., C.D.-M.).
[2
]Children’s Hospital of Philadelphia and University of Pennsylvania Medical School,
Philadelphia (J.W.G.).
[3
]New England Research Institutes, Watertown, MA (D.H.-P., S.C., P.S.).
[4
]Children’s Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee (P.C.F.,
N.S.G.).
[5
]North Carolina Consortium, Duke University, Durham (J.S.L.).
[6
]East Carolina University, Greenville, NC (J.S.L.).
[7
]Wake Forest University, Winston-Salem, NC (J.S.L.).
[8
]Children’s Healthcare of Atlanta and Emory University, GA (W.T.M.).
[9
]Morgan Stanley Children’s Hospital of New York-Presbyterian, Columbia College of Physicians
and Surgeons, NY (I.A.W.).
[10
]Medical University of South Carolina, Charleston (A.M.A.).
[11
]National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda,
MD (KM.B.).
[12
]Cincinnati Children’s Medical Center, OH (J.C.).
[13
]University of Michigan Medical School, Ann Arbor (C.S.G., R.G.O.).
[14
]Congenital Heart Institute of Florida, St. Petersburg (J.P.J.).
[15
]Children’s Hospital Los Angeles, CA (A.B.L.).
[16
]Hospital for Sick Children, Toronto, Ontario, Canada (S.M.).
[17
]Nemours Cardiac Center, Wilmington, DE (C.P.).
[18
]Primary Children’s Hospital and the University of Utah, Salt Lake City (A.E.).