London: Tens of thousands of NHS patients are having operations to clear their arteries in the false belief that it will cut their chance of a heart attack or even extend their life, a leading expert has warned.

Doctors are failing to tell patients that angioplasty is not a magic bullet to stop heart attacks, said consultant cardiologist Aseem Malhotra.

Each year some 30,000 people with a condition called stable angina opt to have the procedure, in which a tiny balloon is inserted into clogged arteries to help clear them.

A metal ring called a stent is then put in to keep the artery wide.

The theory is that widening the artery will improve blood flow and reduce the odds of a blockage.

But Dr Malhotra said such patients were rarely told that the invasive procedure made no difference to their chance of having a heart attack, nor did it improve their odds of long life.

He said: “Patients often have this treatment believing it will save them from a heart attack or prolong their life. But there is no convincing scientific evidence that this is true.

“Cardiologists who stent patients with stable angina are frequently not giving this information to patients.”

Patients with stable angina experience chest pain, caused by restricted blood flow, brought on by a trigger, such as exercise or stress. Dr Malhotra cited a US study that found nine in ten patients with stable angina wrongly believed that angioplasty would cut their chance of a heart attack.

The operation is also used as an emergency procedure to help maintain blood flow in patients who have suffered a heart attack. About 60,000 patients a year receive angioplasty in these circumstances.

Dr Malhotra emphasised there was good evidence to show it helped save the lives of such patients. He also said angioplasty could help reduce the frequency and severity of chest pain in those with stable angina. But he said patients with stable angina should be given all the information before making a decision on surgery. And he said they should be told that leading a healthy lifestyle and taking drugs such as statins could cut the chance of a heart attack.

“Doctors should give them all the information before subjecting them to treatment,” he added.

His comments were backed up by NHS England’s heart disease tsar, Professor Huon Gray.

He said: “There is no evidence that coronary angioplasty reduces risk of heart attack or death in patients with uncomplicated stable angina, and it is important that doctors are clear with their patients about this.”