Explaining the results, Rasha Al-Lamee, a lead author of the study and a researcher at the National Heart and Lung Institute at Imperial College London, said that stents don't appear to bring any greater pain relief than medications.
"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," Al-Lamee said in a statement.
As previously mentioned, heart stents are routinely inserted by doctors to treat blocked arteries, which is often a lifesaving procedure. And they are also regularly used to relieve chest pain.
But despite their popularity, one in 50 stent recipients has serious complications, including heart attacks, strokes, bleeding or even death.
Conservative estimates suggest that more than 500,000 heart patients receive stents every year for pain relief, according to researchers. Others estimates are significantly higher. In the United States, hospitals insert these devices at costs ranging from $11,000 to $41,000.
Considering the serious risks and high costs, the study's results suggest that cardiologists should think twice about prescribing heart stents simply to treat chest pain, and when the situation is not necessarily life threatening.
To conduct the study, researchers at the Imperial College London – led by cardiologist Dr. Justin E. Davies – worked with 200 patients who all had a profoundly blocked coronary artery as well as chest pain severe enough to reduce physical activity.
For six weeks, all of these recruited patients were treated with drugs to reduce the risk of heart attack – such as aspirin, a blood pressure drug and a statin. They were also given medications that open blood vessels or slow the heart rate, relieving chest pain.
Following these initial weeks of treatment, each patient underwent a real or fake procedure to insert a heart stent. The surgery was conducted on every person, but a stent was only inserted in half of the individuals, while nothing was left in the others.
Patients receiving the "sham procedure" were then studied and compared to those who had actually received a stent. Neither the researchers nor the patients were aware of who had a stent inserted and who did not. Both groups also took strong medications to prevent blood clots.
Although the stents worked properly for those who had received them, greatly improving blood flow through blocked arteries, both groups of patients had less chest pain and performed better on treadmill tests six weeks after the surgery. Whether or not a patient had a stent, their condition appeared to improve about the same.
Some specialists have already decided to change their recommendations to patients based on the study.
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"It's a very humbling study for someone who puts in stents," Brahmajee K. Nallamothu, an interventional cardiologist at the University of Michigan, told The New York Times.
After reviewing the research, Nallamothu immediately advised a patient scheduled to receive a stent against the procedure.
"I took him off the table," he said.
Others are taking a more cautious approach to the results.
"We don't know if the conclusions apply to people with more severe disease," David Maron, a cardiologist at Stanford University, told The New York Times. "And we don't know if the conclusions apply for a longer period of observation."
Maron commended the study however, saying it was "very well conducted." Yet he also said the research left some unanswered questions.
Some are also suggesting a potential placebo effect could have affected the results. Neal Dickert, Jr., a cardiologist and ethicist at Emory University, pointed out that such effects can be "surprisingly powerful."
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However, Redberg is confident that the results have wide-ranging implications.
"This is a great example of a device that got on the market without ever having a high-quality trial behind it," she said, according to Vox. "For 40 years, we have been doing this procedure without any evidence that it's better than a sham procedure."
Heart stents became popular in the 1990s, as they are less invasive than bypass surgery. Heart disease remains the lead cause of death in the U.S., with 790,000 Americans having heart attacks annually. Heart stents have become a normal and widely accepted treatment.
Yet, despite the results, even the study's leader hesitated to say that heart patients should opt out of inserting a stent. Davies explained that "some don't want drugs or can't take them," leaving the stent as a valid option.
Nonetheless, the study is forcing cardiovascular experts to reexamine the readily accepted treatment.
"This should make us take a step back and ask questions about what we are accomplishing for this procedure," Yale cardiologist Harlan Krumholz told Vox.