The struggling Antelope Valley Hospital has selected Dennis Knox as its new chief executive.

Knox previously worked as chief executive of Western Medical Center Anaheim, a for-profit facility owned by Integrated Healthcare Holdings Inc., a publicly traded company based in Santa Ana. While at Anaheim, he improved profitability and developed an affiliation with the University of California Irvine Medical Center for a neonatal intensive care department.

The new chief executive is taking over the 420-bed public hospital, operated by the Antelope Valley Healthcare District, at a tough time. Earlier this year, Moody’s conducted a “view for downgrade” of the hospital’s bond rating, but in July announced it would stay at Baa3, the lowest level of investment grade debt.

Moody’s Investor Services wanted new leadership in place at the hospital by November.

Antelope Valley Hospital lost its long-time chief executive, Ed Mirzabegian, in May, when he resigned to take another job. Since then, Pamela Hinson, former vice president of business administration, has run the hospital. Knox will take over in December.

“It is an honor to join the team at Antelope Valley Hospital,” Knox said in a statement. “I am looking forward to continuing the legacy of providing high quality patient-focused care to the community.”