Beta blockers cost more lives than they save, study claims

At least 800,000 deaths may have been caused worldwide in the past decade by preventive drugs which are routinely given to patients undergoing surgery to reduce the risk of heart attacks, researchers said yesterday.

The huge death toll was compared to that "from a world war" by the leader of the international study, carried out in 23 countries, who said it had been caused by "well-meaning physicians" handing out the drugs without considering the side-effects. The result was that they had cost more lives than they saved.

The drugs, called beta blockers, are recommended for patients undergoing surgery, to reduce the risk of heart attacks after operations. Guidelines published in 1996 by the American College of Cardiology and adopted worldwide, recommend they be used in all non-cardiac surgery – all operations except those on the heart. But a randomised trial involving 8,350 patients who had surgery in 190 hospitals across the world has found that those given beta blockers doubled their risk of a stroke (from 0.5 per cent to 1 per cent) and increased their overall risk of death by a third (from 2.3 per cent to 3.1 per cent) compared with a placebo, in the 30 days after their operation.

The drugs did lower the incidence of heart attacks by more than a quarter (from 5.7 per cent to 4.2 per cent), but the benefit was outweighed by the "side effects" of increased stroke and death, the researchers said.

There are an estimated 100 million non-cardiac operations a year globally, so although the absolute numbers affected were low, the cumulative impact is large.

Dr Philip Devereaux, a cardiologist and epidemiologist at McMaster University, Hamilton, Canada, who led the study published in The Lancet, said: "Even if only 10 per cent of doctors followed the guidelines, and that is a conservative estimate, 100 million patients would have been given beta- blockers during surgery in the past decade. On the basis of our findings, that means 800,000 would have died prematurely and 500,000 would have suffered a stroke. If our findings are true, that is death on the scale of a world war."

Dr Devereaux said there was evidence that up to 40 per cent of doctors were routinely using beta blockers in surgery in some parts of the world, which would quadruple the death toll in those areas.

"The doctors who gave these drugs were caring and knowledgeable physicians. But, every so often, we discover that what we were trying to prevent, we were making worse. Although beta blockers have benefits, they end up causing death and strokes because they lower blood pressure. They end up doing more good than harm."

The body can go into a state of shock after surgery in which the blood pressure falls, and that effect may be amplified by the beta blocker, Dr Devereaux said.

A commentary in The Lancet said those already taking beta blockers for a heart condition should continue through surgery, and for those without heart conditions it suggests a lower dose, started a week before surgery, may still help.

Dr Devereaux criticised the commentary for suggesting a lower dose on the basis of a small trial of just over 100 patients compared with his own trial of more than 8,000 patients. "The people who wrote the commentary are the people who wrote the guidelines. It is uncomfortable for them," he said.

Professor Lee Fleisher, an author of the commentary and of the original guidelines, from the University of Pennsylvania, disputed Dr Devereaux's claim that beta blockers had caused 800,000 deaths. "I believe that is an overestimate," he said.

But he accepted that when the guidelines were published a decade ago, doctors had applied the guidelines unthinkingly which could have resulted in deaths.

How beta blockers work

*For 30 years, beta blockers have been the cornerstone of treatment for heart disease. They are given to reduce blood pressure and treat angina and other heart conditions. They were so safe and effective that some specialists said that everyone over 55 should be taking them. They work by slowing the heart rate, and the force with which it pumps. Two years ago a major review of 13 trials suggested they were less effective than other drugs at preventing heart attacks among those with high blood pressure but without existing heart disease. And today's study in The Lancet raises serious doubts about the use of beta blockers to reduce the risk of heart attack in surgery.

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