1. Columbia University Medical Center; New York New York
2. Cardiovascular Research Foundation; New York New York
3. Hôpital Du Sacré-Coeur De Montréal; Université De Montréal; Montréal Québec Canada
4. Sahlgrenska University Hospital; Gothenburg Sweden
5. The Cardiac & Vascular Institute; Gainesville Florida
6. Utah Cardiology; Layton Utah
7. UCLA Medical Center; Los Angeles California
8. St. Francis Hospital-the Heart Center; Roslyn New York
9. Mercy Hospital; Metropolitan Heart and Vascular Institute; Minneapolis Minnesota