Cambridge Health Alliance (CHA) on January 8 announced that Assaad Sayah, M.D. is its new chief executive officer. Sayah, the system's chief medical officer, has served as the interim CEO since June, following the retirement of CEO Patrick Wardell. Prior to joining CHA, Sayah held leadership roles at several area hospitals, including director of EMS for Brigham and Women's Hospital. He received his medical doctorate from the University of Massachusetts Medical Center and completed his residency in emergency medicine at William Beaumont Hospital in Michigan.