[1] Columbia Univ, Med Ctr, Div Cardiol, New York, NY USA
[2] Yale New Haven Med Ctr, Ctr Outcomes Res & Evaluat, 20 York St, New Haven, CT 06504 USA
[3] Hosp Ramon & Cajal, Resp Dept, Madrid, Spain
[4] Hosp Badalona Germans Trias & Pujol, Badalona, Spain
[5] Brigham & Womens Hosp, Div Cardiovasc Med, 75 Francis St, Boston, MA 02115 USA