[1] Creighton Univ1, Omaha, NE 68178 USA
[2] MercyOne Med Ctr, Des Moines, IA USA
[3] Med Univ Vienna, Vienna, Austria
[4] Keele Univ, Keele Cardiovasc Res Grp, Stoke On Trent, Staffs, England
[5] Cornell Univ, Brooklyn, NY USA
[6] Minneapolis Heart Inst, Dept Internal Med, Div Cardiol, Minneapolis, MN USA
[7] Brown Univ, Dept Internal Med, Div Cardiol, Providence, RI 02912 USA
[8] Brigham & Womens Hosp, Div Cardiol, Dept Internal Med, 75 Francis St, Boston, MA 02115 USA
[9] Univ Nebraska Med Ctr, Dept Internal Med, Div Cardiol, Omaha, NE USA