[1] Framingham Heart Dis Epidemiol Study, Framingham, MA USA
[2] Brigham & Womens Hosp, Dept Med, Div Cardiovasc Med, Boston, MA 02115 USA
[3] Boston Univ, Sch Med, Sect Prevent Med, Boston, MA 02215 USA
[4] Boston Univ, Sch Med, Cardiol Sect, Boston, MA 02215 USA
[5] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA 02215 USA