1. Department of Medicine, Division of Cardiovascular Medicine, Maine Medical Center, Portland, ME, USA
2. Division of Cardiovascular Critical Care Services, Maine Medical Center, Portland, ME, USA
3. Department of Medicine, Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
4. Cardiovascular Outcomes, Quality, and Evaluative Research Center, University of Pennsylvania, Philadelphia, PA, USA
5. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA
6. Department of Medicine, Division of Pulmonary and Critical Care Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
7. Department of Medicine, Division of Vascular Medicine, Massachusetts General Hospital, Boston, MA, USA
8. Department of Medicine, Harvard Medical School, Boston, MA, USA