[1] Univ Mississippi, Med Ctr, Dept Med, 2500 North State St, Jackson, MS 39216 USA
[2] Duke Univ Hosp, Div Cardiol, 2301 Erwin Rd, Durham, NC 27710 USA
[3] Baylor Scott & White Res Inst, 3434 Oak St,Ste 501, Dallas, TX 75204 USA
[4] 2301 Erwin Rd, Durham, NC 27710 USA