Kent Peterson, senior editor, has also produced award-winning work in television and radio.

If a blocked artery causes a heart attack, opening the artery with a stent could save your life. But if the blockage only causes chest pain, a landmark study suggests a stent may not be worthwhile in many cases.

The new findings contradict what most heart doctors have long believed. This could lead to major changes in how chest pain is treated.

How stents help

A stent is a tiny mesh tube that is inserted into a narrowed or blocked artery. Once in place, it expands to hold the artery open and restore greater blood flow. Besides helping people who have heart attacks, stents are often given to people with angina—chest pain.

The most common kind of angina is called stable angina. Pain is felt during strenuous activities when the heart muscle can’t get as much blood as it needs. Unstable angina is unpredictable. Severe pain can occur anytime, whether the heart is working hard or not. Unstable angina can be a warning sign of an imminent heart attack.

Experts agree that stents benefit people who have unstable angina or a heart attack. But they have long debated whether stents help people with stable angina avoid heart problems and death.

Some estimates say more than 500,000 stents are implanted in the United States every year. Most are given to people with stable angina. The new study set out to determine whether that’s a good idea.

The trial

Two hundred volunteers with stable angina were recruited for the study. For six weeks, they were treated with heart medications. Then half of them had a stent surgically placed into a partially blocked artery. The other half had a similar procedure, but it was a sham—no stent was inserted.

To prevent bias, both test subjects and researchers monitoring the results didn’t know who got a stent and who didn’t.

In the following weeks, both groups improved equally. They reported less chest pain and did better on treadmill tests.

“Surprisingly, even though the stents improved blood supply, they didn’t provide more relief of symptoms compared to drug treatments, at least in this patient group,” said Dr. Rasha Al-Lamee, lead author of the study from the National Heart & Lung Institute at Imperial College London, in a news release.

The apparent benefits of the fake treatment stunned many cardiologists. The findings could mean that the placebo effect—feeling better because you believe you received a worthwhile treatment—made a difference. Or perhaps people with stable angina don’t need a stent because drug treatments work well enough.

The study’s shortcomings

Though the findings were groundbreaking, some doctors are quick to point out that the study had significant drawbacks. Among them:

• Researchers assessed the results just six weeks after the procedures were performed. The study can’t say whether the possible benefits of the sham procedure would last longer than that.
• Only people who had a single blocked coronary artery were studied. The results might be different in people who have more than one blocked or narrowed artery.

Experts say additional research is needed to confirm the findings and answer these questions.

What to do

Like many other surgical procedures, placing a stent has certain risks—even death. That’s why there is keen interest in finding other equally effective ways to treat narrowed or blocked arteries. For now, there isn’t enough evidence to say that people with stable angina should never get stents.

If you are diagnosed with any form of angina, discuss the risks and benefits of stents with your doctor. If you think you may have symptoms of unstable angina (chest pain regardless of exertion), seek emergency care immediately.

Have you received a stent? Add a comment to tell our community whether it helped you and if any complications developed.