1. Department of Medicine, Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
2. Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA.
3. Department of Medicine, Center for Research on Health Care Data Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
4. Department of Medicine, Division of Cardiology, Ohio State University, Columbus, USA.
5. Department of Medicine, Division of Cardiology, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA.
6. Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina, USA.
7. Department of Medicine, Division of Palliative Care, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.