New-generation stents show promise
At $2,400, NIR should do the job better
With U.S. Food and Drug Administration approval expected as early as the first quarter of this year, cardiologists will be able to get their first crack at one of the new second-generation stents that have already proven successful in Europe. A recent study by researchers at Beth Israel-Deaconess Medical Center in Boston found that the new intravascular rigid-flex (NIR) stent provides excellent results.1
When this and other new stents are introduced to the U.S. market, costs should come down as well. Stents for an average case now cost about $2,400 a large chunk out of the hospital’s DRG reimbursement of $10,000. The purchases of the devices is Beth Israel’s No. 1 expense including all other hospital services, says Donald S. Baim, MD, professor of medicine at Harvard University Medical School in Cambridge, MA, and chief of the interventional cardiology section at Beth Israel. In Europe, where several second-generation stents are already used, prices have been cut in half.
"Each operator in each cath lab is going to have to make a judgment on which stent to use based on a combination of performance and price," Baim says. "When the price competition kicks in, it should bring the tremendous burden on hospitals under control. This competition to fuel the development of better technology and to bring prices down is a breath of fresh air."
"Stents only work if you can get them where you have to go," Baim continues. "The new stents are much more deliverable than the first generation. Using them means cases will go faster and easier."
The NIR stent addresses the major problems encountered when using first-generation devices except for one: The physician cannot see the stent well enough to ensure if a second is needed, the two stents could touch without overlapping and without leaving a gap, Baim says. A development project is in place to enhance the NIR’s visibility and to further improve deliverability and access to side branches.
What will happen to the old stents?
If the newer stents are so much better, will the older ones still be around? Yes, says Baim. "The problems are ones that we’ve been working around and living with for a decade. We know which cases are going to be straightforward. If an older stent costs me half as much as some high-tech second generation model, then maybe in the interest of the cath lab budget, I would use the first-generation stent in some cases.
"But if it’s a difficult case or if there were no price penalty, I would use one of the newer stents every time. The older ones aren’t worse in terms of outcomes, but delivering the new ones is easier."
Some 60% of all interventional cardiology cases now involve the use of a stent, and that’s good news for patients who generally continue to do well with the devices even five years after implant, according to recent research. But the first generation of small cylindrical scaffolds used to prop open narrowed arteries have their drawbacks, as new technologies often do. They’re rigid, hard to deliver, and expensive. And their flaws make it impossible to use them on some patients.
Baim led a randomized trial of 847 patients at 41 sites comparing the NIR stent (9 mm, 6 mm, or 32 mm) to the more traditional 15-mm Palmaz-Schatz stent. The Palmaz-Schatz has had more than 90% of the U.S. market share since its approval in 1994.
The NIR stent did just as well as the Palmaz-Schatz in the study presented at the 70th Scientific Sessions of the American Heart Association in November. Quantitative coronary angiography and 30-day major adverse clinical events are being tabulated, but only one death and no emergent coronary artery bypass graft surgery have occurred thus far.
Based on clinical experiences with the NIR stent during the trial, cardiologists expect the NIR stent to be a major player in interventional cardiology, Baim says. Progressive refinements are planned, and it has been successful in the European market.
European experience has been good
The Beth Israel study confirms the findings of European researchers.2 In a multicenter international registry of 255 patients, the NIR stent was deployed successfully 98% of the time, even though many of the patients had complex, difficult-to-treat lesions. The percent diameter stenosis was reduced from 61% before the intervention to 17% afterward.
Roger Laham, MD, a physician at Beth Israel, says the European experience was a start, and the U.S. study now lays the groundwork for FDA approval of the device. "This is a very positive study that shows the NIR stent offers a lot compared to the first-generation stents. This will increase the confidence level of U.S. operators. The NIR expands our abilities in arteries we couldn’t reach with the Palmaz-Schatz."
The new device solves most of the problems of the earlier devices. Although stenting is beneficial in a lot of cases, some patients haven’t been eligible because the first-generation devices just couldn’t be delivered. If the lesion is located distally in the artery, or if the proximal vessel is extremely tortuous or stiff from calcium, the first-generation stent would almost predictably fail, Baim says.
References
1. Baim DS. Acute and 30-day clinical results of the NIRVANA Trial. Abstract #3314.96 . Circulation 1997; Suppl 1:1-594.
2. Almagor Y, Feld Y, Kiemeneij F, et al. First international new intravascular rigid-flex endovascular stent study (FINESS): Clinical and angiographic results after elective and urgent stent implantation. J Amer Coll Cardio 1997; 30:847-854.
Suggested reading
Krumholz HM, Cohen DJ, Williams C. Health after coronary stenting or balloon angioplasty: results from the stent restenosis study. Am Heart J 1997; 134:337-345.
Patients who underwent stenting had less angiographic restenosis and a tendency for fewer ischemic events, compared with those receiving conventional balloon angioplasty. At one-year follow-up, however, there were few differences in the health-related quality-of-life.
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