[1] Hennepin Cty Med Ctr, Minneapolis, MN 55415 USA
[2] Mayo Clin, Rochester, MN USA
[3] Duke Clin Res Inst, Durham, NC USA
[4] Duke Univ, Med Ctr, Durham, NC USA
[5] Duke Univ, Med Ctr, Duke Heart Ctr, Durham, NC 27710 USA
[6] Brigham & Womens Hosp, Boston, MA 02115 USA
[7] Massachusetts Gen Hosp, Boston, MA 02114 USA
[8] Univ Utah, Salt Lake City, UT USA
[9] Michael E DeBakey VA Med Ctr, Houston, TX USA
[10] Baylor Coll Med, Houston, TX 77030 USA
[11] Univ Montreal, Montreal, PQ, Canada
[12] Montreal Heart Inst, Montreal, PQ H1T 1C8, Canada
[13] Univ Vermont, Burlington, VT 05405 USA
[14] Morehouse Sch Med, Atlanta, GA 30310 USA
[15] NHLBI, Bethesda, MD 20892 USA