A heavily promoted heart drug endorsed by the National Institute for Health and Clinical Excellence (NICE) may be worthless, according to a newly published trial.

Ezetimibe (Ezetrol) was recommended by NICE last year for patients with inherited high cholesterol, to be used in conjunction with a statin drug such as simvastatin. But results published in the New England Journal of Medicine and presented yesterday at the American College of Cardiology annual scientific session in Chicago show that it may add nothing to the effectiveness of the statin.

The trial is highly controversial, with claims that it was deliberately suppressed by the drug’s manufacturers and released only in response to congressional pressures. The data were made public in January by Merck and Schering-Plough, which makes the drug, but this is the first formal publication.

Ezetrol is hugely successful. It is advertised heavily in America, where its sales exceed $5 billion. In the United Kingdom in 2006 – before the NICE endorsement – more than a million prescriptions for Exetrol were written out, worth more than £40 million. The trial does not show that Ezetrol is damaging, and confirms that it reduces “bad” LDL cholesterol. The assumption was that it would add to the benefits already proven for simvastatin, producing a double-drug with even better lifesaving effects.

The new trial was designed to compare the effects of simvastatin alone with simvastatin plus Ezetrol in slowing the progression of coronary artery disease in patients with familial hyper-cholesterolaemia – a condition in which a tendency to high cholesterol levels is inherited.

This was done by measuring the degree of blockage of the arteries in more than 600 patients given either plain simvastatin, or simvastatin plus Ezetrol, for two years.

The result was that adding Ezetrol did nothing to slow the progress of the disease. Plaque build-up on the artery walls was the same in patients who took the combination as it was in those who took simvastatin alone.

Earlier studies have shown that plaque build-up is a good proxy for death rates. The more plaque, the more deaths. So most cardiologists will conclude that prescribing Ezetrol is unlikely to prolong the lives of their patients.

Other trials are in progress that will measure actual outcomes, such as deaths or heart attacks, but they are not likely to be published before 2011.

Until then, says an editorial in the New England Journal of Medicine, it seems prudent to encourage patients whose cholesterol levels remain high despite an optimal dose of statins “to redouble their efforts at dietary control and regular exercise”.

Other drugs such as niacin, fibrates and resins should be considered if diet, exercise and a statin have failed.

The results throw the whole science of cholesterol reduction into question. Until now the greater the reduction, the better. But the trial has shown that it is possible to reduce bad cholesterol significantly and yet come out no better, and maybe worse. That is a shock.

In the US the waters have been muddied by claims that Merck and Schering-Plough completed the trial two years ago but did not publish the results until a congressional inquiry was launched. The trial was completed in April 2006, but both companies say it is time-consuming to analyse scans taken of carotid arteries and they only knew of the results early in January. Executives have denied selling shares in the companies before the trial was made public.

Peter Kim, president of Merck Research Laboratories, said: “We stand behind ezetimibe and our science, which has brought these cholesterol-lowering medications to millions of patients around the world.”

A spokesman for NICE said that it would be looking at the results of the study.

NICE work

— NICE decides which drugs are available on the NHS

— In June 2000 it decided not to recommend that beta interferon should be available to every patient with multiple sclerosis

— Last year it reversed a decision limiting the availability of Lucentis, used to combat blindness, after 13,000 complaints

— A Commons committee said in January that its decisions were slow, arbitrary and made too little use of expert opinion

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