[1] Johns Hopkins Univ Hosp, Dept Med, Div Cardiol, Baltimore, MD 21287 USA
[2] Brigham & Womens Hosp, Dept Med, Div Cardiovasc Med, 75 Francis St, Boston, MA 02115 USA
[3] Brigham & Womens Hosp, Dept Radiol, 75 Francis St, Boston, MA 02115 USA
[4] Massachusetts Gen Hosp, Dept Med, Cardiol Div, Boston, MA 02114 USA
[5] Mayo Clin, Dept Med, Div Cardiovasc Dis, Rochester, MN USA