1. Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School , Boston, MA , USA
2. Department of Medicine, University of Texas Southwestern Medical Center , Dallas, TX , USA
3. Department of Medicine and Mazankowski Heart Institute, Division of Cardiology, University of Alberta Hospital , Edmonton, Alberta , Canada
4. Inova Heart and Vascular Institute , Falls Church, VA , USA
5. Department of Medicine, Division of Cardiology, The Cardiovascular Center, Tufts Medical Center , Boston, MA , USA
6. Department of Medicine, Division of Cardiovascular Medicine, Duke University Medical Center , Durham, NC , USA
7. Department of Medicine, Cardiology Section, VA Boston Healthcare System , Boston, MA , USA