1. Department of Cardiovascular Medicine, University of Texas Medical Branch, Galveston, TX, USA
2. Division of Cardiovascular Medicine, University of Iowa, Iowa City, IA, USA
3. Division of Cardiovascular Medicine, University of Florida, Gainesville, FL, USA
4. Department of Internal Medicine, Rochester General Hospital, Rochester, NY, USA
5. Department of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
6. Division of Cardiac Surgery, University of Rochester Medical Center, Rochester, NY, USA
7. Division of Cardiology, University of Rochester Medical Center, Rochester, NY, USA