[1] BAYLOR COLL MED, METHODIST HOSP, HOUSTON, TX 77030 USA
[2] CLEVELAND CLIN FDN, CLEVELAND, OH USA
[3] JOHNS HOPKINS UNIV HOSP, BALTIMORE, MD 21205 USA
[4] LOYOLA UNIV, MED CTR, MAYWOOD, IL USA
[5] VIRGINIA COMMONWEALTH UNIV MED COLL VIRGINIA, MCGUIRE VET AFFAIRS HOSP, RICHMOND, VA USA
[6] ST LOUIS UNIV, MED CTR, ST LOUIS, MO USA
[7] STANFORD UNIV, SCH MED, STANFORD, CA USA
[8] TAMPA GEN HOSP, TAMPA, FL USA
[9] ST LUKES EPISCOPAL HOSP, TEXAS HEART INST, HOUSTON, TX USA
[10] UNIV ALABAMA, BIRMINGHAM, AL USA
[11] UNIV MINNESOTA, MINNEAPOLIS, MN USA
[12] UNIV OTTAWA, OTTAWA, ON, CANADA
[13] UNIV UTAH, SALT LAKE CITY, UT USA