Stents not more beneficial than medications in stable coronary artery disease: Study

By Dr. Ananya Mandal, MDFeb 28 2012

The placement of a stent to repair a narrowed artery in the heart has become routine worldwide. A new analysis of earlier clinical trials shows that inserting a stent has no benefit over standard medical care in treating stable coronary artery disease.

Stable coronary artery disease is the type of heart ailment that causes angina, or chest pain, after physical exercise or emotional stress but generally not at other times. The review of studies excluded studies of the emergency use of stents for heart attacks. Stent implantation involves a procedure called percutaneous coronary intervention, or P.C.I., in which a surgeon inserts a mesh tube made of metal into an artery that has become narrowed by accumulated plaque. The tube, threaded through an artery in the leg or arm, expands to hold the artery open at the point where blood flow is restricted. The stents may also be coated with medicine that helps to keep the artery open. The cost of the procedure varies from about $30,000 to $50,000, and more than one million are performed every year in the United States.

According to Dr. David L. Brown, an author of the analysis, the risk for death is about one in a thousand, and complications can include stroke, heart attack, bleeding, kidney damage and serious allergic reactions. The review showed no raised risk of such events.

For this meta analysis the researchers included eight randomized trials comparing P.C.I. with standard medical care. Combining data from all the studies, the researchers found that prescribing beta blockers, ACE inhibitors, statins and daily aspirin — now standard for treatment of stable coronary artery disease — was just as effective as stent implantation for prevention of chest pain, heart attack, the need for a future P.C.I. and death.

The review, published in The Archives of Internal Medicine, included only prospective randomized trials that compared P.C.I. and medical therapy with medical therapy alone. There were 7,229 patients in all, half randomized to P.C.I. and half to medicine alone. More than 70 percent of the surgical patients received stents, and the studies followed patients for an average of more than four years.

Death rates were 8.9 percent with P.C.I. and 9.1 percent with medical treatment. Rates for nonfatal heart attacks were 8.9 percent for those who got stents and 8.1 percent for those on medicine alone. P.C.I. was eventually performed on 30.7 percent of patients who got only medicine, but a second P.C.I. was required for 21.4 percent of those who got stents. None of these differences was statistically significant.

Angina is often the symptom that convinces doctors and patients that medical therapy is not enough and that a stent is required. But in this analysis, 29 percent of people who had P.C.I. still had angina, compared with 33 percent of those on medicine, an insignificant difference.

More than half of patients with stable coronary artery disease are now implanted with stents without even trying drug treatment, Dr. Brown said. The reason, he believes, is financial. “In many hospitals, the cardiac service line generates 40 percent of the total hospital revenue, so there’s incredible pressure to do more procedures,” he said. “When you put in a stent, everyone is happy — the hospital is making more money, the doctor is making more money — everybody is happier except the health care system as a whole, which is paying more money for no better results.”

Dr. Allan Schwartz, chief of cardiology at Columbia, who was not involved in the study, said that the analysis reinforced what was already known — that treatment with medicine first is usually the best approach. “I agree with the conclusions,” he said, “but they shouldn’t be oversimplified. Cardiac disease is complicated, and there are lot of factors that go into assessing who should and shouldn’t be treated with stenting.” Sometimes a stent is indicated even in patients with stable coronary artery disease, he said — for example, when the medicine doesn’t work or has intolerable side effects.

Dr. Harlan Krumholz, a cardiologist and professor of medicine at Yale who was not involved in the study, said that the findings hold a lesson for doctors treating heart patients. “When people are making decisions, it’s important to disclose to them that this procedure — outside of an emergency — is not known to be lifesaving or to prevent heart attacks,” he said. “The vast majority of people who have this procedure have the expectation that it will help them live longer. That belief is out of alignment with the evidence.”

The authors conclude that their study “suggests that up to 76% of patients with stable CAD can avoid PCI altogether if treated with optimal medical therapy, resulting in a lifetime savings of approximately $9450 per patient in health care costs.”

In an accompanying editorial, William Boden writes that “the inescapable fact is that it is increasingly harder to justify use of PCI solely for angina relief in such patients — especially as an initial approach to management, and if medical therapy has not been first instituted (or if efforts to optimize pharmacologic treatment in those treated initially medically are not undertaken).”

Archives editor Rita Redberg places the study in the journal’s “Less Is More” category and writes that, despite the evidence, “fewer than half of Americans with stable CAD who undergo stent placement have received medical therapy first.”