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