Study: Coronary stents not likely to relieve chest pain
Having a stent placed in a coronary vessel to relieve chest pain may be of no benefit for some heart patients despite the procedure being one of the most common in cardiac care, doctors reported in a new study.
The British research concluded that some heart patients are better off with medications alone because the devices offer no appreciable improvement.
But a heart specialist at Northwell Health in Manhasset said while interesting, the British findings should not be used to change the current standard of care.
Stents are tiny mesh-like tubes that are widely used to prop open arteries blocked with plaque, especially among patients having a heart attack. For these people, stents are lifesaving devices and reams of studies have demonstrated their effectiveness.
The minuscule scaffolds, however, also are inserted in patients who have chest pain during exertion, such as walking a short distance or exercising on a treadmill. This condition is called angina. These patients may have narrowed arteries with or without blockages of plaque.
“The most important reason we give patients a stent is to unblock an artery when they are having a heart attack,” Dr. Rasha Al-Lamee of Imperial College in London said in a statement.
“However, we also place stents into patients who are getting pain only on exertion caused by narrowed, but not blocked arteries. It’s this second group that we studied,” said Al-Lamee, who led the investigation.
More than 500,000 people worldwide have received stents to relieve heart attacks and chest pain. Insertion of the devices can cost anywhere from $12,000 to more than $35,000.
The new research, reported in the online edition of The Lancet, involved 200 patients with stable angina. Interventional cardiologists inserted a stent in 105 of the patients and also prescribed potent anti-clotting medication.
Ninety-five patients underwent what’s called a “sham” procedure. They were wheeled into the cardiac catheterization laboratory and a catheter was threaded through an artery, but they did not receive a stent.
Doctors nevertheless found a powerful placebo effect among patients who thought they had received a stent but instead received only medication and the sham procedure.
Even the patients who got the stents didn’t fare better than those in the placebo group, according to the new research. Six weeks after treatment, people in both groups said they felt better, and both groups saw improved performance 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 Al-Lamee, an interventional cardiologist, a doctor who specializes in stenting and other procedures where a catheter is threaded through an artery.
Dr. Cindy Grines, an interventional cardiologist at Northwell’s Sandra Atlas Bass Heart Hospital, said the study is not large enough to make a difference in the treatment of heart patients.
“First, it was an extremely small study with only six weeks of follow-up,” Grines said in an email.
“Cardiology guidelines will not change based on a single small trial,” she said.
Moreover, Grines added, it took three-and-a-half years and five large British hospitals to enroll only 200 patients, which suggests the doctors’ strategy was applied to only a small fraction of patients.
The lengthy time to conduct the research on such a small population, she added, suggests “selection bias,” which means researchers may have structured the study to obtain a desired outcome.
Stable angina, the condition under study in the research is relatively common, especially in older adults. People who have the problem report chest pain during simple exercise because of restricted blood flow to the heart.
A Lancet editorial by two American cardiologists stated that medical guidelines should be changed because of the British research. One of the authors of the editorial, Dr. David Brown of Washington University in St. Louis, is a former heart specialist at Stony Brook University.
Grines, nevertheless, is steadfast in her position that the study is not strong enough to influence medical practice.
“Although this trial is thought provoking, it is applicable to a very small number of patients with stable, low-risk coronary disease who are willing to take multiple medications with very close medical observation,” Grines said.