1. University of Missouri, Cardiovascular Division; Columbia Missouri
2. University of California San Diego Sulpizio Cardiovascular Center; San Diego California
3. Prairie Cardiovascular Consultants; Springfield Illinois
4. Ochsner Medical Center; New Orleans Louisiana
5. Policlinico S. Orsola-Malpighi Hospital; Bologna Italy
6. Main Line Health Center; Philadelphia Pennsylvania
7. Brigham and Women's Hospital Heart & Vascular Center, Harvard Medical School; Boston Massachusetts