1. Duke University Medical Center, Durham, NC
2. Duke Clinical Research Institute, Durham, NC
3. New Hanover Regional Medical Center, Wilmington, NC
4. Mount Sinai Saint Luke's Hospital, New York, NY
5. Cardiovascular Center for Clinical Research, Danville, PA
6. South Denver Cardiology Associates, Denver, CO
7. Sanger Heart and Vascular Institute, Carolinas HealthCare System, Charlotte, NC
8. University of North Carolina, Chapel Hill, NC