1. Division of Cardiology, University of Texas Southwestern Medical Center, Dallas
2. Saint Luke's Mid America Heart Institute, Kansas City, Missouri3Division of Cardiology, Department of Internal Medicine, University of Missouri–Kansas City, Kansas City
3. Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina5Duke Clinical Research Institute, Durham, North Carolina
4. Saint Luke's Mid America Heart Institute, Kansas City, Missouri
5. Minneapolis Heart Institute, Minneapolis, Minnesota
6. Division of Cardiology, Department of Internal Medicine, University of Iowa, Iowa City