1. Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio
2. Department of Cardiac Surgery, Heart and Vascular Institute, Cleveland Clinic, Ohio
3. Department of Cardiology, DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, Texas
4. Division of Cardiology, Department of Medicine,University of Colorado Hospital, Denver
5. Department of Cardiac Surgery, Medstar Heart and Vascular Institute and Georgetown University School of Medicine, Washington, DC
6. Department of Medicine, Columbia University Medical Center, New York Presbyterian Hospital, New York
7. Duke University Clinical Research Institute, Duke Medical Center, Durham, North Carolina