1. Cardiovascular Division, University of California, San Diego, CA
2. Cardiology Division, Veterans Affairs Medical Center and University of Colorado, Denver, CO
3. Faculty of Health Sciences, University of Linköping, Linköping, Sweden
4. Children's Hospital Boston and Harvard Medical School, Boston, MA
5. Pfizer Pharmaceuticals Group, New York, NY
6. Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
7. Cardiovascular Division, San Francisco General Hospital and University of California, San Francisco, CA
8. Cardiovascular Division, Veterans Affairs Boston Healthcare System, West Roxbury, Harvard Medical School, Boston, MA