[1] Duke Univ, Sch Med, Dept Med, Div Cardiol, Durham, NC 27715 USA
[2] Duke Clin Res Inst, Durham, NC USA
[3] Duke Univ, Duke Translat Med Inst, Durham, NC 27715 USA
[4] Johns Hopkins Univ, Berman Inst Bioeth, Baltimore, MD USA
[5] Johns Hopkins Sch Med, Dept Med, Baltimore, MD USA