1. Department of Cardiology; Perelman School of Medicine at the University of Pennsylvania; Philadelphia Pennsylvania
2. Department of Surgery; University of Pennsylvania; Philadelphia Pennsylvania
3. Department of Pulmonary and Critical Care; University of Pennsylvania; Philadelphia Pennsylvania
4. Emory University School of Medicine; Atlanta Georgia
5. Cedars-Sinai Medical Center; Los Angeles California
6. Medstar Washington Hospital Center; Washington District of Columbia
7. St. Paul's Hospital; Vancouver British Columbia Canada
8. Medical City Dallas Hospital; Dallas Texas
9. Cleveland Clinic Foundation; Cleveland Ohio
10. Mayo Clinic; Rochester Minnesota
11. Cardiovascular Research Foundation; New York New York
12. Columbia University Medical Center/New York Presbyterian Hospital; New York New York