[1] Emory Univ, Sch Med, Div Cardiothorac Surg, Atlanta, GA USA
[2] Emory Univ, Sch Med, Div Cardiol, Atlanta, GA USA
[3] Emory Univ, Sch Med, Dept Cardiav Anesthesiol, Atlanta, GA USA
[4] Emory Ctr Outcomes Res, Atlanta, GA USA
[5] New England Res Inst, Watertown, MA 02172 USA