Duke Clinical Research Institute, Durham, North Carolina. Electronic address: robert.mentz@duke.edu. Duke Clinical Research Institute, Durham, North Carolina. Department of Medicine, Division of Cardiology, Brigham and Women's Hospital, Boston, Massachusetts; Department of Medicine, Division of Cardiology, New York University Langone Medical Center, New York University School of Medicine, New York, New York. Department of Medicine, Division of Cardiology, Washington University School of Medicine, St. Louis, Missouri. Department of Medicine, Division of Cardiology, Mayo Clinic, Rochester, Minnesota. Department of Medicine, Division of Cardiology, Brigham and Women's Hospital, Boston, Massachusetts. Department of Medicine, Division of Cardiology, Hennepin County Medical Center, Minneapolis, Minnesota.