[1] Wake Forest Univ, Sch Med, Cardiol Sect, Dept Med, Winston Salem, NC 27157 USA
[2] Univ Calif Irvine, Dept Med, Div Cardiol, Irvine, CA 92717 USA
[3] St Francis Hosp, Roslyn, NY USA
[4] Univ Washington, Dept Biostat, Seattle, WA 98195 USA
[5] NHLBI, Div Epidemiol & Clin Applicat, Bethesda, MD 20892 USA
[6] Univ Massachusetts, Med Ctr, Dept Med, Boston, MA 02125 USA
[7] Univ Vermont, Burlington, VT USA
[8] Univ Arizona, Tucson, AZ USA