[1] Univ Pittsburgh, Med Ctr, Pittsburgh, PA 15213 USA
[2] Univ So Calif, Los Angeles, CA USA
[3] Intermt Med Ctr, Salt Lake City, UT USA
[4] Vanderbilt Univ, Nashville, TN 37235 USA
[5] Cleveland Clin, Cleveland, OH 44106 USA
[6] Washington Univ, St Louis, MO USA
[7] Louisiana State Univ, Hlth Sci Ctr, Shreveport, LA 71105 USA
[8] Univ Rochester, Sch Med & Dent, Rochester, NY USA
[9] Univ Maryland, Baltimore, MD 21201 USA
[10] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Boston, MA USA
[11] Columbia Univ, New York, NY USA
[12] Emory Univ, Atlanta, GA 30322 USA
[13] Univ Pittsburgh, Sch Publ Hlth, Pittsburgh, PA 15213 USA
[14] Univ Pittsburgh, Heart Lung Blood & Vasc Med Inst, Pittsburgh, PA 15213 USA
[15] Mayo Clin, Rochester, MN USA