Patients must be given clearer information before they undergo a common operation for heart disease, a London cardiologist has said.
People with stable angina should be told angioplasty would not reduce death risk or heart attack, but may relieve symptoms, said Dr Aseem Malhotra.
This should be clear on patient consent forms, he wrote in a medical journal.
The British Cardiovascular Intervention Society said there was no evidence of inappropriate treatment in the UK.
Angioplasty helps ensure a blood supply to the heart, using a tube called a stent to open up a narrowed artery.
For people who have had a heart attack it can be a lifesaver.
It may also be provided for patients before their condition becomes unstable, to relieve symptoms of chest pain.
People with angina suffer pain caused by restricted blood supply to the heart.
If there is an obvious trigger, such as exercise, it is called "stable" angina.
They may be offered angioplasty if medication does not ease their symptoms.
In a commentary in the Journal of the American Medical Association Internal Medicine, Dr Malhotra, a consultant cardiologist, said these patients - more than 30,000 in the UK each year - were rarely told the operation would not help prevent heart attacks or prolong life.
"The elephant in the room is that randomised studies have not demonstrated outcomes benefit for stenting stable coronary artery disease in addition to optimal medical therapy despite its widespread use," he said.
Dr Malhotra cited one study in the US that found 88% of patients having angioplasty thought it would prevent a heart attack.
He believes the figure in the UK would be similar.
He is concerned the system of "payment by activity" for hospitals in England may incentivise these procedures, and there may also be some unnecessary treatment carried out by the private sector.
Dr Malhotra argues this issue should be mandatory in securing consent, to reduce any harm that may be caused by the operations, and to curb unnecessary costs.
"It is imperative to provide patients with all the information before subjecting them to a procedure that still carries a 1% risk of heart attack, stroke or death," he said.
A spokesman for the British Cardiovascular Intervention Society said there was no evidence in the UK that patients has been treated inappropriately.
He said changing the consent form was not the best way of ensuring patients understood their treatment.
But Prof Terence Stephenson, chairman of the Academy of Medical Royal Colleges, backed the call.
"This is an example of a legitimate debate of appropriate or inappropriate use of clinical procedures or interventions," he said.
"This is an issue of increasing importance to the medical profession.
"It is primarily about providing appropriate good quality care but is particularly important when resources are limited."
The academy will publish a report on waste in the NHS after the summer.