[1] Univ Texas SW Med Ctr Dallas, Div Cardiovasc, Dept Med, Dallas, TX 75390 USA
[2] Dallas VA Med Ctr, Dallas, TX USA
[3] Harvard Univ, Brigham & Womens Hosp, Sch Med, TIMI Study Grp,Cardiovasc Div,Dept Med, Boston, MA 02115 USA
[4] Duke Clin Res Inst, Durham, NC USA