Regulators have determined that North Carolina Children’s Hospital is in compliance with federal rules but markedly changed since doctors, department heads and a top administrator expressed concerns three years ago about patients undergoing heart surgery there.

Inspection records released on Thursday cited no deficiencies with the hospital’s operations. But a spokesman for the Centers for Medicare and Medicaid Services, which oversaw an investigation with the state health agency, said the institution’s heart surgery program “is significantly different than it was during 2016-17.”

The North Carolina secretary of health had called for the investigation after a May article in The New York Times gave a detailed look inside the hospital during those years. In secret audio recordings provided to The Times, cardiologists grappled with whether to keep sending patients to their own hospital for surgery and pressed administrators to provide mortality data they said they had not been able to get for several years.

The health secretary dispatched investigators from the state’s Division of Health Service Regulation. They were on site at the hospital for about two weeks in June and later conducted interviews with doctors before preparing a report for federal regulators.