1. Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
2. Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
3. Division of Cardiology; Wexner Medical Center at the Ohio State University; Columbus Ohio
4. Division of Cardiology; Pennsylvania State University; State College Pennsylvania
5. Division of Cardiology; University of Pittsburgh; Pittsburgh Pennsylvania
6. Division of Cardiology; Brigham and Women's Hospital; Boston Massachusetts USA