About 20 years ago, doctors first used a stent—an inflatable tube, usually metal or plastic—to reopen blocked blood vessels around the heart. Since, it’s become a standard of care for relieving heart-related chest pain. But new research suggests stents may be more placebo than panacea.
Researchers at Imperial College London conducted a study on 200 patients who had one severely blocked artery to the heart, which starves the heart of oxygen and causes chest pain, especially when someone with the condition tries to exert themselves. For six weeks, the research team gave the participants statins and blood pressure medication, and then each patient underwent a routine procedure to insert a stent into the affected arteries.
Except only about half of the patients actually got a stent.
The other half underwent a dummy procedure, in which doctors went through the motions of putting a stent in, but didn’t actually do it. Both groups were then given the standard aftercare for stent procedures, including taking blood thinners.
Six weeks later, they all got on a treadmill and ran for a while to see if the chest pain they were used to experiencing during exercise had decreased. It turned out that there was no statistical difference between the exercise-related chest pain of those who got the stents and those who did not. The results, published in the Lancet on Nov. 2, suggest the common procedure may not actually be any better than drugs control chest pain.
The study posits that perhaps stents don’t do much in these cases because new arteries become blocked all the time, the New York Times reports (paywall). A stent might clear one blocked artery, but the pain, potentially caused by any number of constricted arteries, could continue.
In real-world settings, doctors start off by treating patients with constricted heart arteries with statins and meds to lower blood pressure. If these drugs are enough to alleviate symptoms, doctors will leave it at that. But if chest pain is so severe it limits a person’s activities, or the arteries are dangerously blocked, doctors next insert a stent to try to open up those vessels.
These guidelines are based on a history of patients reporting feeling better after getting a stent put in. But it’s hard to separate out physical changes from the possibility that patients, having undergone an intervention, feel better as a result of the placebo effect alone. They think they should feel better, so, for reasons scientists still don’t totally understand, they do.
The placebo effect isn’t always a bad thing; in this case, both groups of patients improved. But it does suggest that maybe inserting stents—which can be risky procedures simply because they work close to the heart—isn’t a good solution for everyone with chest pain because of clogged arteries. Especially when it seems drugs work just fine.
There are still some cases where stents will be necessary. For example, not all patients can tolerate statins or blood-thinning medication. In addition, the patients in this study all had only one restricted artery; sicker patients with multiple constricted arteries may feel better if a stent can open one up. And stents still can be useful for treating other heart conditions, like repairing ruptured arteries.