NEW YORK (CBSNewYork) – A new study on heart stents produced sobering and possibly life-altering results.

It says that stents may not be needed in some cases.

As CBS2’s Dr. Max Gomez reports, the key is why you’re putting in a stent.

They’re used to open up clogged arteries in the heart. When a patient is having a heart attack, stents are clearly life savers. But many stents are put in for chest pain, called angina. Those are now being called into question.

“I felt this constriction come right across. I’m not sure if that’s the right word, but it came right across my chest and it was really tight,” heart attack patient Truman Beatty said.

That heart attack led to six stents being placed in several of Beatty’s heart arteries. The metal scaffolds open the artery and then keep it open.

But a large portion of stents are put in for another reason – to increase blood flow to the heart muscle and ease the painful chest cramps called angina. The new study in the journal The Lancet suggests that stents for what’s called ‘stable angina’ fail to ease chest pain.

“Stent alone for single blockage of 70, 80 or 90 percent is not enough. We need to do additional tests,” said Dr. Samin Sharma, the director of interventional cardiology at the Mount Sinai Health System.

Sharma explained that in the British study half the 200 volunteers actually had a sham procedure – a cardiac catheterizations without a stent. But neither they nor the doctors evaluating them knew who got a stent and who didn’t. Six weeks later, both groups of patients had equivalent pain scores and exercise tolerance. So did they need the stent?

“Benefit of the stent may come later — it could be six months, nine months, or one year,” Sharma said.

In other words, the placebo effect of thinking you got a stent may have helped for a while, but not long term.

Sharma said additional sophisticated blood flow tests in heart arteries could determine which angina patients would benefit from a stent.

Again, the study does not mean that all stents are bad. Some definitely save lives during a heart attack.

But if you have what’s called ‘stable angina,’ then you should ask your doctor about having heart artery blood flow tests to help tell if a stent will ease your chest pain.