1. Northeast Georgia Physicians Group, Gainesville, GA USA
2. Northwestern University, Feinberg School of Medicine, Chicago, IL USA
3. Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, MN USA
4. East Bay Cardiac Surgery Center, Oakland, CA USA
5. Penn Presbyterian Medical Center, Philadelphia, PA USA
6. The Toledo Hospital, Toledo, OH USA
7. The Heart Hospital Baylor Plano, Plano, TX USA
8. University of Virginia, Charlottesville, VA USA
9. Saint Elizabeth's Medical Center, Brighton, MA USA
10. Gulf Coast Cardiothoracic & Vascular Surgeons, Ft. Myers, FL USA
11. Holy Spirit Northside Hospital, Chermside, Australia
12. New York University School of Medicine, New York, NY USA
13. Temple University, Philadelphia, PA USA
14. Swedish Heart and Vascular Institute, Seattle, WA USA
15. Penrose St. Francis Hospital, Colorado Springs, CO USA
16. Emory St. Joseph's Hospital, Atlanta, GA USA
17. St. Thomas Hospital, Nashville, TN USA
18. Weill Cornell Medical College/New York Presbyterian Hospital, New York, NY USA
19. South Florida Heart & Lung Institute, Doral, FL USA
20. David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA USA
21. TriHealth Heart Institute, Cincinnati, OH USA
22. Central Maine Heart and Vascular Institute, Lewiston, ME USA
23. Department of Cardiothoracic Surgery, Princeton Baptist Hospital, Birmingham, AL USA
24. Lankenau Medical Center, Wynnewood, PA USA.