1. Duke University Medical Center, Durham, NC
2. Duke Clinical Research Institute, Durham, NC
3. New York University School of Medicine Lenox Hill Hospital, New York, NY
4. Division of Cardiology, University of California Los Angeles, Los Angeles, CA
5. Mayo Clinic, Rochester, MN
6. Lankenau Institute for Medical Research, Wynnewood, PA
7. Stanford University School of Medicine, Palo Alto, CA
8. Harvard Medical School and Massachusetts General Hospital, Boston, MA