[1] Emory Univ, Sch Med, Dept Med, Div Cardiol, 101 Woodruff Circle,Woodruff Mem Bldg, Atlanta, GA 30322 USA
[2] Wake Forest Sch Med, Dept Internal Med, Winston Salem, NC USA
[3] Wake Forest Sch Med, Div Cardiol, Dept Internal Med, Winston Salem, NC USA
[4] Wake Forest Sch Med, Dept Epidemiol & Prevent, Epidemiol Cardiol Res Ctr, Winston Salem, NC USA