Central DuPage Hospital (CDH) is a 390-bed hospital in Winfield, Illinois. It is one of four hospitals operated by Northwestern Medicine in the Chicago area. CDH became one of the first hospitals in the Chicago area to perform open-heart surgery on a beating heart, and is ranked 6th out of Chicago Hospitals. The Central DuPage Hospital Association was established in 1958 when citizens from Glen Ellyn, Lombard, Wheaton, Warrenville, Winfield and West Chicago banded together to restore a sanitarium located on the hospitals current primary site. After an extensive million-dollar renovation project, Central DuPage Hospital opened on September 16, 1964 with 113 beds and 66 physicians. The hospital saw much change throughout the 1970s, with the opening of a 120-bed pavilion on December 13, 1970, small additions in 1971 and 1972, and a five-story 112-bed patient tower in 1976. Prior to the merger of Cadence Health (the then-parent company of CDH) with Northwestern Medicine in September 2014, CDH was the focal point of a network of health services that included a 50-physician medical group, a home health care agency, an occupational health center, and about half a dozen urgent care centers.