March 26, 2007 -- Doctors hoping to minimize chest pains associated with heart disease and perhaps even prevent heart attacks have long treated patients with stents, hollow tubes surgically implanted into blocked artery to prop them open.
Now a landmark study shows that while stents may improve blood flow, using them along with conventional drug therapies is no more effective at preventing heart attacks and other cardiac events than drug therapy alone. The findings, announced today at the American College of Cardiology conference, could have profound effects for patients and device manufacturers, since a staggering 800,000 Americans receive stents each year.
The Clinical Outcome Utilizing Revascularization and Aggressive Drug Evaluation, or COURAGE, study looked at more than 2,200 patients in the United States and Canada with a blocked artery and chronic chest pain and found that those treated with the traditional mélange of drugs -- high doses of statins, blood-pressure lowering medications and aspirin -- fared just as well as those who also received stents.
There was no statistical difference in how long patients lived or whether they suffered a heart attack, and the procedure only moderately improved angina, chest pains associated with defective heart muscle. And the relief wasn't permanent: After five years, there was no difference in symptoms between patients who received a stent in addition to medication and those treated with medication alone.
"It does not relieve risk of heart attack and it is only marginally better at relieving angina, so why should you go on stenting?" said Steve Nissen, president of the American College of Cardiology. "We should reserve it for those that just don't do well on medical therapy or if they have symptoms that are interfering with lifestyle," he added.
He said that, in fact, there is no reason to think stents would prevent heart attack. "What happens when you put a stent in is you're attacking one narrowing in the artery, but it's not the narrowing that's going to cause the next heart attack," he explained. "It's the plaque developing everywhere else that's going to cause the next heart attack and that's what the medicines treat."
Still, some clinicians say the news isn't really all that noteworthy since stents are normally implanted to relieve symptoms, not prolong life. "From my standpoint, it validates what was known since the inception of angioplasty -- that it relieves symptoms," says William O'Neill, executive dean for clinical affairs at the Miller School of Medicine at the University of Miami. Still, he predicts the study will decrease the number of stents implanted because many doctors will interpret the results to show they are overused.
Lead author Dr. William Boden, chief of cardiology at Buffalo General Hospital, also predicts the number of surgeries will decline as a result of the findings, but said it will be for good reason. Many cardiologists were doing angioplasties simply because they didn't want to deny patients what could be a beneficial therapy, he said. The results show they should try medication first, he argued. "I think the results will be profound in terms of how it changes the practice of cardiology in medicine."
News of Study Jolts Stent Makers' Stocks
Heart patients and cardiologists aren't the only ones affected by the announcement. The medical device manufacturer Boston Scientific makes almost a third of its revenue on stents and saw its shares drop by 10 percent in the last month as investors got wind of the coming news. The other major stent manufacturer is Johnson & Johnson, whose shares were down about 5 percent in the last month.
In fact, the study, which was funded by the U.S. Department of Veterans Affairs, set off something of a firestorm in the cardiology community, with doctors who perform angioplasty defending their specialty and the benefits of stenting, which is now a $6 billion industry.
In a dramatic turn, at a Boston Scientific event last night, Dr. Martin B. Leon, a Columbia University cardiologist who performs the surgery, railed against the study, which he said was "rigged to fail," according to a Wall Street Journal report.
He discussed the results of the study before they were scheduled to be released on Tuesday, prompting the conference to issue a statement saying it was disappointed results were released early and that it will be "considering strong sanctions against the individual or individuals involved."
Whatever rifts the study might cause in the scientific community, Boden says patients hearing the news should remember medical decisions are made on an individual basis and advised them to have a conversation with their doctor about the severity of their symptoms. Since the research shows there is no harm in waiting to perform the procedure, he predicts many patients will decide to try drug therapies for several months before considering more aggressive options.
Moreover, the American Heart Association guidelines already state that patients should first be treated with medications before undergoing stenting or other medical procedures such as bypass surgery -- which has been shown to be clinically effective -- are tried.