[1] Duke Univ, Med Ctr, Duke Clin Res Inst, Durham, NC USA
[2] Duke Univ, Med Ctr, Dept Med, Div Cardiol, Durham, NC 27710 USA
[3] Univ Brescia, Dept Med & Surg Specialties, Radiol Sci & Publ Hlth, Brescia, Italy
[4] Univ Groningen, Univ Med Ctr Groningen, Dept Cardiol, Groningen, Netherlands
[5] Canadian VIGOUR Ctr, Edmonton, AB, Canada
[6] Univ Alberta, Dept Med, Div Cardiol, Edmonton, AB, Canada
[7] Cleveland Clin, Heart & Vasc Inst, Cleveland, OH 44106 USA