1University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
2Cardiovascular Research Foundation and Lenox Hill Heart and Vascular Institute, New York, New York
3Brigham and Women's Hospital, Boston, Massachusetts
4St. Vincent Hospital and Health Center of Indiana, Indianapolis, Indiana
5Munroe Regional Medical Center, Ocala, Florida
6Providence Hospital, Columbia, South Carolina
7Carolinas Healthcare, Charlotte, North Carolina
8Buffalo General Hospital, Buffalo, New York
9Morton Plant Mease Medical Center, Clearwater, Florida
10St. Joseph's Hospital Health Center, Syracuse, New York
11Presbyterian HealthCare, Charlotte, North Carolina