NEW ORLEANS, March 26 — Many heart patients routinely implanted with stents to open arteries gain no lasting benefit compared to those treated with drugs alone, researchers are reporting today.
The researchers said that patients who received stents to prop open coronary blood vessels in addition to being treated with statins and other heart drugs during a five-year clinical trial had better blood flow to their heart than those treated only with drugs. But they did not live longer or have fewer heart attacks.
That finding confirmed the results of smaller trials. In this study, however, researchers also found that the one previously unquestioned advantage of stenting — better relief from the chest pain, shortness of breath and other symptoms from arteries that are clogged — disappeared over time even though the implants were highly successful at improving blood flow.
By the end of five years, more than 7 out of 10 patients in both groups were free of angina pains, the common symptom of restricted blood flow to the heart muscle, according to the researchers, who disclosed their results at the scientific meeting here of the American College of Cardiology.
Dr. Steven Nissen, the current president of the cardiology group, called the study a “blockbuster.”
The findings raised new questions about the value of angioplasty and stenting, which has been used in 6 million patients around the world since the mid-1990’s and is especially popular in the United States. Close to 1 million Americans annually are now getting stents implanted following angioplasty, a procedure that creates pathways through severe blockages in coronary arteries by inflating tiny balloons inside them. Angioplasty and stenting generally cost between $25,000 and $50,000.
Stents were developed to combat the tendency of many vessels to quickly close again after angioplasty, in which a tiny balloon is inserted to open the artery. The latest drug-coated stents, which cost about $2,200 apiece and are especially effective at preserving the channel created by angioplasty, generate nearly $3 billion in sales in the United States alone for Boston Scientific and Johnson & Johnson, the two companies that dominate the market.
Shares in the two companies’ stock began falling even before the official announcement of the results.
Sales of the drug-coated stents have been falling since last spring because studies showed that potentially deadly clots form in a small percentage of patients long after they are implanted. The number affected is thought to be only a handful out of every thousand patients, but no one knows how long the risk continues.
Those who get drug-coated stents are now told by most doctors to take anti-clotting drugs indefinitely. Doctors have switched other patients to older bare metal stents that do not appear to have the late-clotting risk.
The disadvantage of the bare metal stents is that they reclog twice as often, which exposes patients to the risks of more repeat procedures.
The clinical study released today raises new questions about the effectiveness of stenting, at least in the type of patients studied in the trial, which was named COURAGE (for Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation).
Studies have shown that angioplasty and stenting can save lives when used during heart attacks. The procedure is also recommended for many patients who have poor blood flow to the heart during periods of exercise or stress that is not relieved by rest or drugs.
But hundreds of thousands of Americans who undergo the procedure each year fall into the group studied in the clinical trial that is not believed to be in immediate danger of a heart attack even though accumulating plaque has narrowed coronary arteries by 70 percent or more.
Since 2002, practice guidelines from the American Heart Association and the American College of Cardiology have called for using angioplasty and stenting — or bypass surgery, an even more invasive alternative — only after extensive efforts to treat the symptoms of such patients with drugs. But they have been increasingly ignored, cardiologists say, by patients and doctors choosing the more immediate and initially reliable relief provided by stenting.
Doctors at the meeting here said the new data should encourage more doctors to follow the practice guidelines, but they were not certain that would happen.
Examples of how the results might be questioned emerged even before the data itself. Dr. David Kandzari, chief medical officer for Cordis, Johnson & Johnson’s stent subsidiary, noted that the more than 2,200 patients in the trial came largely from Veterans Administration hospitals in the United States and Canada — groups that get many medicines for free and are therefore more likely to take them as prescribed. Moreover, compliance with drug prescriptions is more common in clinical trials than in everyday life.
Other shortcomings might be that 85 percent of the patients were male and 86 percent of them were white.
The trial enrolled patients from 1999 to 2004. Nearly all of the patients stented received the older bare metal versions, because drug-coated stents did not enter the American market until 2003. Some studies suggest that death and heart attack rates are similar for the two types of stent, but newer drug-coated products from companies like Medtronic and Abbott Laboratories may change that. For the most part, both groups in the trial had the same drug therapy. Close to 95 percent took aspirin, about 90 percent took cholesterol-lowering statins like Lipitor, 85 percent took beta-blockers and two-thirds took ACE inhibitors.
The drug therapy group was slightly more likely to have taken calcium-channel blockers and pain-killing nitrates.
