[1] Washington Univ, Sch Med, Div Cardiovasc, Dept Med, St Louis, MO 63110 USA
[2] Univ Maryland, Dept Med, Baltimore, MD 21201 USA
[3] Axio Res Corp, Seattle, WA USA
[4] Univ Penn, Dept Med, Philadelphia, PA 19104 USA
[5] Univ Penn, Dept Biostat & Epidemiol, Philadelphia, PA 19104 USA
[6] Rush Presbyterian St Lukes Med Ctr, Dept Med, Chicago, IL 60612 USA
[7] Univ Massachusetts, Dept Med, Worcester, MA 01605 USA
[8] British Hosp, Dept Cardiol, Buenos Aires, DF, Argentina
[9] Cardiol Associates, Elk Grove, IL USA
[10] E Carolina Univ, Sch Med, Dept Med, Greenville, NC USA