1. Department of Medicine, University of Colorado Anschutz Medical Campus, 12631 East 17th Avenue, Mail Stop B130, Aurora, CO 80045, USA
2. Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
3. Harvard Medical School, Boston, MA, USA
4. Division of Cardiology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
5. Department of Medicine, University of California San Francisco, USA