1. Division of Cardiology, Rocky Mountain Regional VA Medical Center, University of Colorado, Denver, CO, USA
2. Vascular Center and Division of Cardiovascular Medicine, University of California, Davis, Sacramento, CA, USA
3. Department of Medicine, Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center, Boston, MA, USA
4. Penn Cardiovascular Outcomes, Quality and Evaluative Research Center, Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA
5. Cardiovascular Medicine Division, University of Pennsylvania, Philadelphia, PA, USA
6. Department of Medicine-Cardiology, Vanderbilt University Medical Center, Nashville, TN, USA