Heart patients at Oxford's John Radcliffe Hospital can be assured that death rates at its cardiac unit are not high, NHS investigators said today.

But following a 16-month review into the department, surgeons have once again been criticised for failing to work together and putting their own ambitions above the good of the team.

The hospital, part of the Oxford Radcliffe Hospitals NHS Trust, has also been criticised for poor data collection, bad auditing and out-of-date policies, and warned it will need to take action to reclaim its reputation as a centre of excellence.

The JR heart unit has been plagued by a history of investigations into its performance, and the Healthcare Commission launched the latest review in December 2005 when statistics were published highlighting a high mortality rate among adult heart patients treated at the hospital.

Managers and surgeons claimed the data was skewed because it did not take into account the high number of very ill patients at the unit.

Following the investigation, a report published by the Commission has confirmed the trust's heart operation mortality rate is within "acceptable levels".

But it highlighted concerns that staff did not use data to pinpoint problems and make improvements for the future.

The report stated: "Data can provide an early indicator of potential problems. Where clinical performance appears to be outside the norm, or close to it, this should be explored."

Although mortality rates were deemed to be normal, surgeons Mr Ravi Pillai, Mr Steve Westaby, Prof David Taggart and Mr Chandi Ratnatunga were once again told to work together.

A report in 2000 compared heart surgeons' behaviour to "drinking club mentality" .

The Healthcare Commission report stated: "The development of the cardiothoracic surgical services has been hindered by difficult working relationships among the consultant cardiothoracic surgeons.

"There is no doubt that there is a wealth of experience, innovation and knowledge in the surgical team at the trust, but the personal ambitions of some seem to override the duty to work collaboratively for the development of the unit."

Nigel Ellis, of the Healthcare Commission, said: "If the trust doesn't act on our recommendations, we're going to have concerns."

ORH chief executive Trevor Campbell Davis was pleased with the report and said the trust, in collaboration with Oxford University, would now start £27m plans to build an improved cardiac unit.

He added: "We've done a lot of work with (surgeons) in the last six years and I'm satisfied they understand the systems of the hospital, but the Healthcare Commission has made some recommendations and I'll make sure they follow them."