9. More than mild valvular heart disease or clinically significant congenital heart disease. Allowable conditions include bicuspid aortic valve without clinically significant stenosis or regurgitation; spontaneously closed ventricular septal defects; patent foramen ovale, small (≤ 2 mm) restrictive ventricular septal defects with normal ventricular size, and other minor defects that are considered allowable after [review and consensus by participating pediatric cardiologists, overall study PI and] adjudication by the echocardiographic core laboratory.