[1] Keele Univ, Keele Cardiovasc Res Grp, Stoke On Trent, Staffs, England
[2] Royal Stoke Univ Hosp, Stoke On Trent, Staffs, England
[3] Cleveland Clin, Heart & Vasc Inst, Dept Cardiovasc Med, Cleveland, OH 44106 USA
[4] Univ Nebraska Med Ctr, Div Cardiovasc Med, Omaha, NE USA
[5] Univ Florida, Div Cardiovasc Med, Gainesville, FL 32611 USA
[6] Wayne State Univ, Detroit Med Ctr, Detroit Heart Hosp, Detroit, MI 48202 USA
[7] Univ Washington, Heart Inst, Div Cardiol, Seattle, WA 98195 USA