1. From the National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA;1,2 the Cardiology Division1 and Department of Medicine,1,2Massachusetts General Hospital, Harvard Medical School, Boston, MA; the Department of Preventive Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA;2 and the National Heart, Lung, and Blood Institute, Bethesda, MD1