[1] Harvard Med Sch, Boston, MA 02115 USA
[2] Beth Israel Deaconess Med Ctr, Richard A & Susan F Smith Ctr Outcomes Res Cardiol, Dept Med, Boston, MA 02215 USA
[3] New York Univ, Med Ctr, Dept Med, Div Cardiol, New York, NY USA
[4] Beth Israel Deaconess Med Ctr, Dept Med, Div Cardiol, Boston, MA USA