1. From the Framingham Heart Study (J.P.Z., V.X., M.G.L., D.L., R.S.V.), Framingham, MA; Department of Cardiology (J.P.Z.), Children's Hospital Boston, Boston, MA; Department of Pediatrics (J.P.Z.), Harvard Medical School, Boston, MA; Cardiovascular Engineering Inc (G.F.M.), Norwood, MA; Department of Biostatistics (V.X.), Boston University School of Public Health, Boston, MA; Department of Mathematics (M.G.L.) and Section of Preventive Medicine and Epidemiology, School of Medicine (V.X., R.S.V.),...