1. Department of Surgery Duke University Durham North Carolina USA
2. Rocky Mountain Regional Veterans Affairs Medical Center Aurora Colorado USA
3. Division of Cardiology University of Colorado School of Medicine Aurora Colorado USA
4. Department of Surgery Clement J. Zablocki Veterans Affairs (VA) Medical Center Milwaukee Wisconsin USA
5. Department of Surgery, Division of Cardiothoracic Surgery Medical College of Wisconsin Milwaukee Wisconsin USA
6. Department of Surgery, Division of Cardiac Surgery VA Boston Healthcare System Boston Massachusetts USA
7. Department of Surgery, Division of Cardiothoracic Surgery University of Colorado School of Medicine Denver Colorado USA
8. Cooperative Studies Program Coordinating Center Veterans Affairs Medical Center Perry Point Maryland USA
9. Department of Cardiology Veterans Affairs Greater Los Angeles Healthcare System Los Angeles California USA
10. Department of Medicine University of California Los Angeles Los Angeles California USA
11. Northport Veterans Affairs Medical Center Research and Development Office Northport New York USA