Heart disease medication is being massively over-prescribed with thousands of people being wrongly told that they are in danger of developing cardiovascular problems, according to a study.

A new and sophisticated approach to calculating risk has shed radical new light on the issue. A British Medical Journal study says that there are flaws in the traditional method and suggests that current estimates of the number of people in danger of the disease are 1.5 million too high.

Using the new test, the BMJ estimated that the number of people at risk had been overpredicted by 35 per cent.Consequently, many patients have likely been prescribed unnecessarily anti-cholesterol drug statins, inflating the annual £2 billion bill to the NHS.

The study prompted fears that the wrong type of people were being targeted for treatment with its discovery that white middle-aged men had a lower risk than previously thought and women from poorer backgrounds had a significantly higher risk.

It also found that one in three women in their 60s are at risk of heart disease. That figure was previously thought to be one in four.

Julia Hippisley-Cox, lead author of the study, told The Guardian: “We are potentially missing the right people for treatment. “If we use this new score it would increase treatment to deprived areas and especially to women. They are being under-treated across the board.”

The researchers tracked 1.28 million healthy men and women aged between 35 and 74 over 12 years to April this year and used GP records from 318 general practices. The overblown estimates of heart disease were derived from the traditional way of calculating risk, which involves a score based on smoking, blood pressure and “good” and “bad” cholesterol, along with age and sex.

The BMJ study used a new measure which also takes social deprivation, genetic factors and weight into account, reducing estimates.

As a result, it has concluded that 3.2 million adults under the age of 75 are at risk of developing cardiovascular illnesses compared with the 4.7 million previously estimated. A separate study by the Healthcare Commission says the number of people reported as having heart failure issues was 140,000 fewer than expected.

In another development, specialists warned that patients at high risk of a heart attack are often unsure when to dial 999.

They are so used to pain from angina that they cannot easily distinguish it from the pain of a heart attack, and may wait too long before calling an ambulance.

In an editorial in the BMJ, the authors said: “Ideally, patients would be able to distinguish stable angina from a potentially life-threatening acute coronary syndrome, but in reality they do not.”

The British Heart Foundation advises patients with angina that chest pain lasting more than 15 minutes is probably a heart attack. They are advised to use their glyceryl trinitrate (GTN) sprays three times at five minute intervals before calling an ambulance.

But for some high-risk patients, waiting 15 minutes could be too long, the authors of the editorial argue.

One study has shown that the average time from onset of symptoms to heart attack is 10 minutes, and manufacturers of sprays can offer different instructions — for example, recommending no more than three doses and leaving 15 minutes between treatments. The authors advise patients at high risk of an attack or with known ischaemic heart disease to carry a GTN spray at all times.

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