Plans to publish death rates for individual heart surgeons could lead to the sickest patients being turned away, experts have warned.

The Society of Cardiothoracic Surgeons says some specialists will be discouraged from operating on the riskiest cases because of fears it will affect their ratings.

We need to be very cautious about not destroying innovative surgery in this country

Bruce Keogh, report author

The warning comes as performance figures for named cardiac units in all NHS hospitals are published for the first time.

Mortality rates for adult coronary artery bypass graft surgery in some hospitals, such as London's Middlesex Hospital, were found to be more than twice the national average.

But Professor Peter Hutton, Chairman of the Academy of Medical Royal Colleges, said this was because the hospital was operating on high-risk patients.

It was "almost a case of congratulation rather than vilification", he said.

'World class'

Coronary artery bypass graft mortality rates

Highest: Middlesex, London - 4.7% Walsgrave, Coventry - 3.6% Queen Elizabeth, Birmingham - 3.5% St George's, London - 3.5% St Mary's, London - 3.3%

Robert Naylor, chief executive of University College London Hospitals NHS Trust, said The Middlesex Hospital was a central London teaching hospital and surgeons were expected to take on more complex cases.

He said the trust had taken major steps to continue to improve the quality of cardiac care, including the transfer of all cardiac surgery from the Middlesex to a new heart hospital.

"Patients are now cared for in world class facilities and the arrangements for heart surgery are greatly improved," he said.

"Information collected over the past six months suggests that survival rates have continued to improve and are now favourable in comparison to other cardiac units in the NHS."

Controversy

Coronary artery bypass graft mortality rates

Lowest: Royal Infirmary, Bristol - 0.9% City, Nottingham - 1.2% Bart's & London Chest Hospital - 1.2% Southampton General - 1.3% Derriford, Plymouth - 1.3%

The debate centres on a government pledge to publish mortality rates for individual heart surgeons in 2004. It follows an inquiry into the deaths of 35 children at Bristol Royal Infirmary.

Professor Hutton said that while surgeons were signed up to the idea of individual ratings, the real debate to be had was whether it was in the best interest of patients.

According to a recent survey, 90% of surgeons believe high-risk patients are already being denied operations in the drive to measure performance.

Dr Roger Boyle, a government advisor and the National Heart Director, said patients needed to have the best possible data available to them.

"The key is not whether we should have this data but how we should present that data," he said.

US comparison

Bruce Keogh, the report's author, said surgeons needed to be given credit for taking on high-risk cases to ensure patients who would benefit from an operation are given surgery.

"We need to be very cautious about not destroying innovative surgery in this country," he said.

"In this country some of the best surgeons have the highest mortality rates."

The report reveals that cardiac surgery in the UK compares favourably with the United States as a whole.

National mortality rates for adults undergoing coronary artery bypass graft surgery - the most common form of heart surgery - are 2.1% in the UK (for 1999-2001) compared with 2.6 % (in 2001) in the USA.

Death rates were improving in female heart patients and in those with co-existing conditions such as diabetes and high blood pressure.

The death rates for the 42 different units varied between 0.9% and 4.7%.