Patients who sign up for common procedures to clean out blocked arteries in the heart often believe they are cutting their risk of heart attack and death, when in fact they aren’t.

That’s the conclusion of a new survey from a large Massachusetts hospital that shows doctors fail to make clear the real benefits - or lack thereof - of a treatment that may cost as much as $17,000 and has significant, though rare, side effects.

During the procedure, called percutaneous coronary intervention or PCI, patients often receive stents (small metal mesh tubes) to help keep the artery open.

PCI is done in more than one million Americans every year, a rate many doctors say is unnecessarily high. When used to remove a blood clot after a heart attack, the procedure reduces the odds that a patient will suffer another attack in the future.

But in those with stable chest pain due to narrowed arteries in the heart - the population surveyed in the new study - clinical trials show the only benefit is to ease the pain.

“I think doctors do a great job of explaining the procedure itself,” Dr. Michael Rothberg, who led the survey, told Reuters Health via e-mail.

“What they don’t say (or the patients don’t understand) is that improving the blood flow will not prevent a heart attack or make the patient live any longer.”

Dr. Rothberg, of Baystate Medical Center in Springfield, Massachusetts, and colleagues surveyed 153 patients with stable chest pain, also known as angina.

The patients had all signed up for a test known as coronary angiography, in which cardiologists guide a thin plastic tube (a catheter) to the heart via an artery to look for signs of cholesterol plaques. These plaques narrow the arteries and limit blood supply to the heart, which can cause chest pain and other symptoms during physical activity.

If there is substantial narrowing, the doctor may then choose to do a PCI. This is done by inflating a balloon at the end of the plastic tube, which breaks up the cholesterol buildup. Then the doctors place a stent to prop open the artery.

Nearly all the patients in the survey said they understood why their doctor might perform a PCI, and more than half felt they were part of the decision making.

However, more than eight in 10 thought the procedure would cut their risk of suffering a fatal heart attack. Most of their doctors, on the other hand, indicated they knew that not to be the case.

“The informed consent process failed,” said Dr. Alicia Fernandez, of the University of California, San Francisco, who wrote an editorial about the findings.

“Patients often undergo invasive procedures without a clear understanding of expected benefits. This is distressing, particularly when non-invasive options may be just as good.”

Such treatment options include cholesterol-lowering statins, which reduce the risk of recurrent heart attacks, aspirin to keep the blood from clotting and blood pressure medicine.

Of the 53 patients who ended up getting a stent, less than half said their activity beforehand was limited by their angina.

The researchers also presented a series of hypothetical patient scenarios to the cardiologists at Baystate. While seven in 10 doctors believed PCI would only help with symptoms, 43 percent still said they would do PCI anyway.

“There is widespread agreement that PCI is used in many patients where there is no reasonable expectation of patient benefit,” said Dr. Rita Redberg, a cardiologist at the University of California, San Francisco, who was not involved in the research.

She said her own research agreed with the new findings, showing that doctors would do PCIs even when they didn’t expect to see a benefit.

“There is a great enthusiasm for PCI among cardiologists that exceeds the evidence to support its benefit,” Redberg told Reuters Health in an e-mail.

In rare cases, the procedure can lead to stroke, emergency bypass surgery and death. While such complications only occur in between one in 100 and one in 1000 patients, they do happen given the high number of procedures, Redberg said.

So why do doctors continue to do these expensive procedures, when the benefit may not outweigh the risks?

“On an intellectual level, cardiologists do understand the data from randomized trials,” said Dr. William Boden, medical director of cardiovascular services at Kaleida Health in Buffalo, New York.

But clinical evidence alone won’t change clinical practice, added Boden, who led one of the first studies to show that PCI is no better than drug therapy for stable angina.

“There are no financial disincentives to avoiding PCI,” he said in an e-mail. “On the contrary, in a fee-for-service model, physicians are paid for doing procedures.”

He said there should be a “time-out” between the diagnostic test of the heart and a potential intervention.

“It would be like hitting the ‘pause button,’” he said. “That way, the patient could confer with his/her private or referring physician, weigh the pros and cons of each therapeutic choice, or give a trial of medical therapy a good chance to work before proceeding straight-away to urgent PCI.”

Rothberg said Baystate was now involved in a government-funded study to improve the informed consent process for PCI. Until better decision aids are made available, he advised patients to ask more questions of their doctors.

“Patients often overestimate how much benefit they will get from something, especially if a doctor recommends it,” he said. “Ask ‘what are the alternatives’ and ‘what will happen if I wait or do nothing?’”

SOURCE:  Annals of Internal Medicine, September 7, 2010.