[1] Univ Arkansas Med Sci, Dept Internal Med, Little Rock, AR USA
[2] Duke Univ, Dept Med, Div Cardiol, Durham, NC USA
[3] Duke Clin Res Inst, Durham, NC USA
[4] Cardiovasc Res Fdn, New York, NY USA
[5] Cardiovasc Res Fdn, 1700 Broadway, New York, NY 10019 USA