[1] Natl Heart Lung & Blood Inst, Clin Trials Grp, Bethesda, MD 20892 USA
[2] Univ Texas, Hlth Sci Ctr, San Antonio, TX USA
[3] Fresno VAMC, Fresno, CA USA
[4] Cardiac Ctr Louisiana, Shreveport, LA USA
[5] Univ Utah, Ctr Hlth Sci, Salt Lake City, UT USA
[6] George Washington Univ, Div Cardiol, Washington, DC USA
[7] Univ Colorado, Div Cardiol, Denver, CO USA
[8] St Louis VAMC, St Louis, MO USA
[9] Baptist Mem Hosp, Memphis, TN USA