1. Department of Medicine, University of Chicago, Chicago, Illinois
2. Department of Medicine, Columbia University, New York, New York
3. Baptist Health Heart and Transplant Institute, Little Rock, Arkansas
4. Department Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
5. Department of Medicine, Duke University, Durham, North Carolina
6. Department of Surgery, Johns Hopkins Hospital, Baltimore, Maryland
7. Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
8. Christ Hospital, Cincinnati, Ohio
9. Inova Heart and Vascular Institute, Falls Church, Virginia
10. University of Colorado, Aurora, Colorado
11. Health Sciences Division, Cardiovascular Research Institute, Loyola University Medical Center, Maywood, Illinois
12. Abbott (Formerly St Jude Medical), Chicago, Illinois.