ATLANTA -- Up to $162 million could be saved annually if cardiologists implant artery tubes called stents into a more select group of patients, according to a new cost analysis performed by Duke University Medical Center cardiologists.
The researchers said the cost savings could be achieved without compromising the quality of patient care.
Stents are tiny metal tubes implanted in the artery immediately after an angioplasty to help prevent the artery from renarrowing, a process known as restenosis. In an angioplasty procedure, a tiny balloon is inflated at the site of an arterial blockage, cracking and displacing the plaque and restoring blood flow to the heart.
As the popularity of stenting has grown, many cardiologists now automatically implant a stent, even when an excellent result is achieved with the balloon alone. Stents are used in more than 500,000 procedures in the United States every year.
"We have shown that there is a group of patients whose arteries are very unlikely to renarrow after angioplasty and who get stent-like results without needing the stent," said cardiologist Dr. Warren Cantor, who led the analysis. "The amount of potential health care savings range from $114 million to $162 million."
Cantor prepared the results of his analysis for presentation Wednesday at the annual scientific sessions of the American Heart Association. The study was supported by the Royal College of Physicians and Surgeons of Canada.
Previous studies by the same Duke team found that approximately one in 12 patients may not need stents because their vessels are very unlikely to renarrow after balloon angioplasty. The researchers determined this after an analysis that showed that those patients least likely to have renarrowing of the artery had "stent-like" results (less than 30 percent residual narrowing) immediately after balloon inflations. They also had three common characteristics: they were men, their vessels had shorter atherosclerotic lesions, and the location of the lesion involved was not at the top of the left anterior descending artery (LAD), the artery that supplies blood to the front of the heart.
In their analysis, the researchers pooled the results of seven different angioplasty trials and an angioplasty registry totaling 5,143 patients. They then compared what the costs would be of pursuing each of the following three treatment strategies:
- Every patient receives a stent.
- All patients receive a stent except those who have "stent-like" results after balloon angioplasty alone
- All patients receive a stent except those with "stent-like" results who are male, have short lesions and no lesions located in the proximal LAD artery.
"Based on the combination criteria, about 8 percent of the patients wouldn't need a stent, at a savings of $114 million per year," Cantor said. "If the decision to stent was based solely on how the vessel looked immediately after angioplasty, 18 percent of patients wouldn't require stenting, at a savings of $162 million."
The benchmark for clinical success of these procedures is whether or not the treated vessels renarrow and the patient needs another artery-opening procedure, whether it be angioplasty or coronary artery bypass surgery. In this analysis, the combination group had a 14 percent revascularization rate six months after the procedure, similar to that seen with stent insertion.
"We were pleased to find that relatively simple criteria could identify patients at very low-risk for requiring repeat revascularization after treatment with balloon angioplasty alone," Cantor said. "Although only a small proportion of patients are in this very low-risk group, the potential cost savings are substantial."
Before the advent of stents, up to one-third of all patients who received an angioplasty needed another angioplasty or a bypass operation after six months due to restenosis. Since the introduction of stents in the United States, less than 10 years ago, the restenosis rate has been nearly cut in half.
While stents have markedly reduced the rate of restenosis, Cantor said stents have their own drawbacks. When restenosis does occur within a stent, it is more difficult to treat. Also, there is a slight (1 percent) risk of clot formation in the stent, which could lead to myocardial infarction. Joining Cantor in the analysis were Dr. Michael Sketch, Dr. Eric Peterson, Dr. Robert Califf, Dr. Magnus Ohman, Patricia Cowper and Anne Hellkamp.