[1] Univ Texas Southwestern Med Ctr Dallas, Dallas, TX 75390 USA
[2] VA North Texas Hlth Care Syst, 4500 S Lancaster Rd,111a, Dallas, TX 75216 USA
[3] Cardiothorac & Vasc Surg, Austin, TX USA
[4] Univ Oklahoma, Hlth Sci Ctr, Oklahoma City, OK USA
[5] Seton Med Ctr, Austin, TX USA
[6] Arkansas Heart Hosp, Little Rock, AR USA
[7] Walnut Hill Med Ctr, Dallas, TX USA
[8] Univ Texas San Antonio, San Antonio, TX USA
[9] Denver VA Med Ctr, Denver, CO USA
[10] Midwest Cardiovasc Res Fdn, Davenport, IA USA