1. Department of Cardiovascular Medicine, Gill Heart and Vascular Institute University of Kentucky Lexington Kentucky USA
2. Department of Cardiovascular Medicine, Harrington Heart & Vascular Institute University Hospitals Cleveland Ohio USA
3. Department of Cardiovascular Medicine, Tulane University Heart and Vascular Institute Tulane University School of Medicine New Orleans Louisiana USA
4. Vascular Medicine Outcomes Program, Section of Cardiovascular Medicine Yale University New Haven Connecticut USA
5. Division of Cardiology Alpert Medical School of Brown University Providence Rhode Island USA
6. Smith Center for Outcomes Research in Cardiology, Division of Cardiology Beth Israel Deaconess Hospital Boston Massachusetts USA