He performs more coronary bypasses than any other doctor, and his death rates are low. Yet what do these figures really tell us about Britain's busiest heart surgeon?

He is the busiest heart surgeon in Britain. Tony De Souza of the Royal Brompton Hospital, London, performed 660 coronary bypass operations in the last three years, more than any of his colleagues. His position at the top of the league is revealed in figures for all 244 heart surgeons in the UK, released for the first time under the Freedom of Information Act.

Malaysian by birth, he is 43 and has been at the Brompton for seven years. "We try to fly a full plane every day," he says, sweeping through swing doors towards the operating theatres. If a surgeon is on holiday another will step into his surgical clogs to ensure the flow of patients continues.

The figures show death rates for each surgeon, with De Souza's among the lowest at 0.9 per cent. Of his 660 patients, six died, five of whom were categorised as high risk. This is well below the average for all heart surgeons, which stands at just under 2 per cent. But what does this reveal? That he is a safe surgeon - or that he plays safe, by choosing the less risky patients? Publication of death rates for every individual named heart surgeon in Britain is supposed to usher in a new era of accountability in medicine. Patients will be able to check their surgeon's record before going under the knife. But heart surgeons are not doing their jobs properly unless some of their patients die. If a life-saving operation is only offered to patients who recover then we can never be sure it is genuinely life-saving.

"The history of coronary bypasses is that we didn't offer them initially to people over 75. Gradually they were extended to an older, sicker population. So if your mortality is too low you are probably not offering it to a wide enough sector of the population," says De Souza.

In his own case, 220 of his 660 patients were categorised as high risk, one in three, so he cannot be charged with "cream skimming". Since the publication of death rates he says he is more cautious about taking on high-risk cases. But his recent experience belies it.

"I operated on an 87-year-old man who was blind in one eye, partially sighted in the other and wheelchair-bound. I told him he had a 50 per cent chance of dying on the operating table and he replied "good". He said if he couldn't live a better life he preferred to die. A year previously he had been swimming." The man survived the operation but spent almost three months in intensive care. He is now back on a general ward but not out of hospital yet. It is a good example of what heart surgeons enjoy doing - playing for high stakes.

In New York, "gaming" of the system by surgeons who select the lowest risk patients is well known. It is the easy way to be top. But as with selective schools, selective surgeons and selective hospitals cannot claim their success is down to their skill. School exam league tables offer another comparison. They give pass rates, not failure rates. Yet the heart surgery tables give death rates, not survival rates.

"If we told patients the survival rate in Britain is better than 98 per cent, and that it is better than New York, they would be reassured by it. But by telling them the death rate they are worried. That is what irritates surgeons."

De Souza's productivity, while excellent for his patients, is less good for his managers and his colleagues. Every patient he treats has to be paid for, and the more he treats, the greater the cost. It also means less work for other surgeons, of whom there is a surplus. One reason is growing competition from cardiologists who offer the simpler, less invasive alternative to heart surgery, known as angioplasty. The rivalry between cardiac surgeons and cardiologists is legendary. Both treat damaged hearts but surgeons do it by opening up the chest and stitching new blood vessels on to the organ, while the cardiologists do it by inserting a catheter through an artery in the groin, threading it up to the heart and inflating a tiny balloon to stretch the narrowed artery - the process called angioplasty.

Naturally, patients prefer angioplasty because it is less invasive, involves less time in hospital and recovery is quicker. But the failure rate is 6-7 per cent.

"The cardiologists would like us to think the failure rate is zero but we know it isn't because we have to operate on them when they fail," De Souza says, laughing.

All the research shows that surgery is better - with a lower failure rate and longer lasting. But De Souza concedes that, sometimes, angioplasty is fine if the coronary artery affected is a less important one. The problem is that patients are referred by GPs for assessment to cardiologists who decide whether to book them for surgery, done by the surgeons, or angioplasty, done by themselves. The cardiologists are the gatekeepers. "When people talk about informed consent in medicine, I don't know how informed the consent is when people opt for angioplasty. If you go to a Mercedes garage and you ask how good a Mercedes is, they are not going to send you to the garage next door," he says.

Competition from cardiologists is one factor surgeons have to cope with. Another is that demand for heart surgery is plummeting as smoking rates have fallen, the population gets healthier and treatment with statins, cholesterol-reducing drugs, becomes more widespread. Deaths from heart disease in under 65s fell by 23 per cent between 1995-97 and 2002-3, prompting Health Secretary John Reid to predict last year that they would be virtually eliminated in 10 years' time.

The pace of the fall has caught managers by surprise. A review of the business plans for new cardiac centres by Roger Boyle, the Government's heart tsar, leaked this month to BMA News, the journal of the British Medical Association, suggested that up to 80 heart surgeons were being trained for whom there would be insufficient work.

De Souza works a 12-hour day, down from 14 hours since the birth of his daughter, now two and a half. "I insist on being home by 7.30 to bathe her," he says. He is married to a cardiac anaesthetist, who has some understanding of the pressures. He came to Britain at the age of 14 and was educated at Wrekin public school and Nottingham University. At the Brompton he has pioneered new types of coronary surgery, including a robotic technique through a key-hole incision less than two inches long, which speeds recovery.

A few years ago the hospital's waiting list was more than 12 months. For each of the last three years he and the nine other surgeons at the Brompton have done 15 months work in each year, reducing the waiting list to its current three months. "My agenda is to treat as many patients to the highest quality as quickly as possible. We should be able to slow down and maintain steady state now," he says.

Like most surgeons, he is an optimist. He is driven by the buzz of saving lives. "I always wanted to be a surgeon. Surgeons choose themselves. There is the action part of it and you want to see quick results. Cardiac surgery is exciting because it is about life and death. It is one of the toughest areas but when you are young you are never afraid of competition. Surgeons are competitive people by nature. We want to be the best."


* There are 244 heart surgeons working in 37 cardiac centres in the UK.

* Almost 25,000 coronary bypass operations were carried out in 2003.

* The average death rate was 1.8 per cent.

* The highest death rate for an individual surgeon was 5.5 per cent.

* The variation in mortality rates among UK surgeons is half that in New York, where it ranges up to 12.5 per cent.

* Death rates are higher among women, at 3 per cent, than men, because their coronary arteries are smaller and more difficult to repair.

* From April no patient will wait more than three months for a heart operation, the Government has said.

* There were almost 16,000 deaths in under 65s, 40,000 in under 75s, and 117,000 deaths in total from heart disease in 2002.

* Britain's death rate is still one of the highest in Western Europe. Only Ireland and Finland have higher rates.