Since their introduction in 1986, stents — those tiny wire mesh tubes that prop open clogged arteries — have been thought to offer big rewards for millions of people with heart disease.

Incorporating simple physics with medical ingenuity, stents are used to keep arteries open after angioplasty, a procedure in which a balloon-tipped catheter is carefully threaded to an arterial trouble spot close to the heart. There, the balloon inflates to prop open a plaque-laden blockage. The balloon is then deflated and removed, while the stent surrounding it remains in place to keep that section of artery from reclosing.

This go-to treatment is proven to save lives when done during a heart attack. Stents are viewed as a safer, less expensive alternative to open heart surgery, in which blood vessels taken from elsewhere in the body are used to route blood flow around clogged arteries. (Actually, the price gap is closing, with both procedures now averaging about $30,000 for patients getting multiple stents, according to Frank Smart, MD, chairman of the Department of Cardiovascular Medicine at Atlantic Health in New Jersey.)

But about 1 million Americans undergo nonemergency stenting each year — usually for a condition known as stable angina, the chest pain and shortness of breath that results from the heart not getting enough blood. When stents are used in these situations, the risks and benefits are not as clear, as some recent research has shown.

This raises new questions for heart disease patients and their physicians: To stent or not to stent?

  • Research suggests caution is necessary. After stents became a common treatment for both heart attacks and heart disease, it was discovered that in up to 40 percent of patients that the artery would reclog at the site of the procedure, a process known as restenosis. (This reclogging also occurred with balloon angioplasty, in which a balloon was used to reopen an artery, but no stent was used.) Early this decade, drug-eluting stents — devices that slowly release a medication designed to prevent restenosis at the site of the stent — were introduced. Within a few years, these newer stents were used in a majority of angioplasty procedures. But the results of several studies raised new questions about this practice.
  • A warning to physicians. In December 2006, the Food and Drug Administration (FDA) convened a meeting to review research suggesting a link between drug-eluting stents and rare blood clots. Afterward, a group representing 3,700 cardiologists worldwide issued a warning recommending drug-coated stents be prescribed with care. The American Heart Association, American College of Cardiology, American College of Surgeons and other groups issued a joint advisory recommending that patients who get drug-coated stents continue anti-platelet therapy — with aspirin, Plavix and other drugs — for at least a year after the procedure ... and possibly indefinitely. Sometimes this drug therapy — which can cost about $120 a month — is "prematurely discontinued within the first year," raising risks of poor outcomes, noted the advisory committee.

 

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A question of effectiveness
Researchers in a large clinical trial known as COURAGE tracked nearly 2,300 patients with substantial but stable blockages (the disease state for which stenting is most commonly done in the United States) for an average of five years. They found that drug therapy alone — high doses of cholesterol-lowering statins, aspirin and other heart drugs — was just as effective in providing long-term symptom relief as a combination of those drugs and stent implantation. Stents, which cost many thousands of dollars more than the drugs alone, provided no added benefit in preventing heart attacks or death. The only benefit of stenting: an initial improvement in blood flow and pain relief, which disappeared over time. The study included mostly patients with bare metal stents.

"Two treatments are not always better than one," explained COURAGE study lead William Boden, MD, of the University of Buffalo in New York. "These findings, along with data from recent studies of more than 5,000 patients combined, show that [stent-employed angioplasty] has no impact on reducing major cardiovascular events."

His study — the first large, long-term head-to-head comparison of stent vs. no-stent treatment in patients with clogged arteries but in no immediate danger of cardiac death —was hailed by some. Steven Nissen, MD, of the Cleveland Clinic, said the findings should make patients feel secure about relying on drugs alone as a "very safe, reasonable and cost-effective strategy" for initially treating coronary artery disease that's not being controlled with diet, exercise and other lifestyle measures.

The results of the COURAGE study suggest new consideration for medication as an initial intervention for another reason: Drugs can help ease arterial plaque buildup throughout the body, whereas stents help only in areas where they are placed.

The results also make clear the importance of making strict lifestyle changes — either as a first step or along with medication — to significantly improve heart health. Members of both the stent and medication groups adhered well to a lifestyle regimen that was recommended as part of the study treatment. This included moderate to intense exercise at least five days a week, eating a healthful diet, maintaining or losing weight, not smoking, and preventing or controlling diabetes, high blood pressure and other risks factors for heart disease.