[1] Columbia Univ, Div Cardiol, Irving Med Ctr, New York, NY 10032 USA
[2] Univ Penn, Dept Med, Perelman Sch Med, Div Cardiol, Philadelphia, PA 19104 USA
[3] Harvard Med Sch, Div Cardiovasc Med, Brigham & Womens Hosp, Boston, MA 02115 USA
[4] Vanderbilt Heart & Vasc Inst, Nashville, TN USA
[5] Amer Heart Assoc, Dallas, TX USA