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Coronary Stents for Restenosis of the Arteries
Coronary stents have become the standard of care for propping open coronary arteries that have been cleared of plaque through coronary angioplasty. Clinical research has shown that stents save lives, reduce pain and complications for patients, and offer cost-effective therapy. Recent innovations in stent therapy - such as drug-coated tests and use of various clot-inhibiting drugs in conjunction with stents - have brought additional benefits.
Major Breakthrough: First introduced in the mid-1990s, stents were the first major breakthrough in controlling re-narrowing of arteries following angioplasty. Dr. Stephen Ellis, head of the Cleveland Clinic's catheterization labs, calls stents "the gold standard." They are now used in 70-90 percent of angioplasty procedures. Some 400,000 stent placements occurred in 1998, most in patients older than 65. Roughly 45 percent were in patients aged 45-64, the primary income-producing years.
Better Health: Widespread clinical data show that stents reduce the post-angioplasty narrowing that can bring chest pain, additional surgery, disability, and death. For those patients whose arteries refuse to stay open, however, physicians and researchers are developing new techniques.
- Stents with "Clot-Stoppers": In conjunction with stents, many physicians are beginning to use specially engineered drugs to reduce the tendency of blood molecules to bind to one another after a stent procedure. This, in turn, reduces the likelihood that arteries will once again become clogged and, thus, the threat of future heart attacks. Clinical studies at the Cleveland Clinic have found that this approach enhanced outcomes, including reduced deaths and reduced complications.
- Following completion of a major study in 1998 measuring the effect of using such drugs with stents, the Chairman of the Cleveland Clinic Cardiology Department said, "If we extrapolate findings from [this study] to the more than 500,000 stenting and angioplasty procedures that will be done across the world in 1998, we see a reduction of 2,500 deaths, 40,000 myocardial infarctions, and 6,500 revascularization procedures per year."
- A study begun in June, 1999, was halted early because of overwhelming evidence of the benefit of this therapy to patients. It found that within 48 hours of patients receiving the therapy, the incidence of death, heart attacks, and emergency room care dropped almost 40 percent.
- Stents with "Nets": Technically called "capture devices," these devices are like tiny screens or "fishnets" that are used during the surgery to catch tissue debris that breaks loose from the vessel wall during the angioplasty or stent procedure. By preventing this material from flowing downstream and entering other vessels, the devices reduce the risk of further heart attacks or complications.
- On October 19, 2000, The Wall Street Journal reported on the results of the first large-scale clinical trial of this kind of device: "… it reduced by half the number of heart attacks suffered by a group of patients who were particularly prone to complications caused by downstream debris." The physician who conducted the study told the paper that the combination of stents with the collection device represented "progressive leverage" against heart disease and improved "the durability of the outcome for patients."
- Stents that Deliver Drugs: A new generation of stents is now being developed that will release drugs that reduce or prevent the development of scar tissue, which can later re-block an opened artery.
- Two small studies reported in The Wall Street Journal in January 2001 found that the drug-coated stents stopped all restenosis (the process in which scar tissue re-clogs the opened arteries). "We're not talking about some kind of reduction of restenosis," said the physician who ran one of the studies. "We're talking about the radical abolition of what we se normally. There is basically no tissue visible in the stent."
Cost-Effectiveness: Studies have shown that stents are cost-effective. A study published in the Journal of the American College of Cardiology in 1999 reported that "coronary stenting provides equivalent or better one-year patient outcomes without increasing cumulative health costs." Another study, published in the American Heart Journal last year found that when stents were used on a "provisional" basis (that is, only when the angioplasty results were suboptimal), they offered lower projected costs over a 4-year period than either bypass surgery or angioplasty. The study also reported that when stents were used in all cases, as opposed to only those with suboptimal angioplasty results, the 4-year costs of stents were only somewhat higher.
Costs of Heart Disease: The American Heart Association reports that coronary heart disease costs the US more than $100 billion per year, $47 billion of which is due to lost productivity resulting from mortality and morbidity.
- Coronary heart disease is the primary reason for premature, permanent disability in the US labor force, according to the heart association. It accounts for 19 percent of disability allowances under Social Security.
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