1. Duke University Medical Center Durham NC
2. Duke Clinical Research Institute Durham NC
3. Wayne State University Detroit MI
4. Yale School of Medicine New Haven CT
5. National Heart, Lung and Blood Institute Bethesda MD
6. University of North Carolina Chapel Hill NC
7. University of Alberta Edmonton Alberta Canada
8. Thomas Jefferson University Philadelphia PA
9. Massachusetts General Hospital Boston MA
10. Inova Heart and Vascular Institute Falls Church VA