Drug-eluting stents: Cost-effectiveness vs. quality of life, longevity

Based on research done by David Cohen, MD, the overall economic burden of clinical restenosis at a rate of 13.8%—multiplied by $19,000—averages $2,550 in costs per patient.

While drug-eluting stents are cost effective, they need to be evaluated for their ability to save lives and improve the quality of life as well, according to William Weintraub, MD, chief of cardiology at the Christiana Care Health System in Wilmington, Del.

Drug-eluting stents probably don’t save lives, but they don’t cost lives either, Weintraub said at the Cardiovascular Revascularization Therapies (CRT) 2008 meeting in Washington, D.C., last week.

In order to establish the value of drug-eluting stents (DES), Weintraub examined the aspect of restenosis. He cautioned, however, that limitations exist to evaluate the true burden of restenosis because clinical trials are highly selective.

He based his presentation on the research of David Cohen, MD, director of cardiovascular research at Saint Luke’s Mid America Heart Institute in Kansas City and formerly the director of the economics and quality of life research group at the Harvard Clinical Research Institute.

Weintraub estimated that the mean one-year follow-up cost per patient with restenosis is $23,808 compared to $4,087 per patient without restenosis. Most of the cost is attributed to repeat revascularization.

Repeat revascularization does not occur in every patient. The difference in cost between the two populations, divided by the number of patients who actually undergo a prior repeat revascularization, provides a sense of the increased costs that could be reasonably associated with DES, which he estimated at $19,000.

Based on this method, the overall economic burden of clinical restenosis at a rate of 13.8%—multiplied by $19,000—averages $2,550 in costs per patient.

“If we had a therapy that does nothing else but prevent restenosis, we could spend that [$2,550] as a cost minimization,” Weintraub said.

Compared to bare-metal stents, do drug-eluting stents save lives? The overall results are very similar, according to Weintraub.

In large meta-analysis conducted 15 years ago, Emory University researchers found no statistical difference in mortality after six years related to restenosis in more than 3,000 patients who underwent angiographic restudy after successful percutaneous transluminal coronary angioplasty.

The impact of restenosis on quality-adjusted life years (QALY) and cost-effectiveness still needs to be considered. Weintraub does not quite agree with Cohen’s QALY statistics because—when associated with restenosis—they are largely transient and depend on several factors, he said.

Restenosis can be predicted by lesion length, vessel diameter, and the presence or absence of diabetes. For patients with longer lesions, smaller vessels, and diabetes, the restenosis rate in the pre-DES era was 34%. In the absence of diabetes with short lesions and large vessels, it was 64% in the pre-DES era.

“This plays directly to the issue of cost-effectiveness analysis, because therapy is going to be more cost-effective if the rate of restenosis is higher, assuming that the relative benefit is the same,” Weintraub said.

The presentation also referenced the SIRIUS trial, which compared the one-year medical care costs of the sirolimus-eluting stent (Cordis’ Cypher) to a control group. The results found that $1,650 per repeat revascularization was avoided, which Weintraub said will relate very strongly to the cost of the individual DES.

He cautioned the audience about Cohen’s conclusion that $27,000 per QALY was gained, because he said one has to consider the cost of QALY gained as more exploratory.

In a separate trial that compared paclitaxel-eluting stent (Boston Scientific’s Taxus) to a control group, in which the costs fell to $760 per repeat revascularization avoided, the relative costs of DES compared to controls favored DES.

“The net result of all this is that there has been a shift in our pattern of revascularization toward more PCI as DES have taken hold. There was more PCI in 2004 than in 2001, less CABG, which has economic implications,” Weintraub said.

Overall, the cost of revascularization has fallen in the past few years, but the cost-effectiveness of DES must first follow a demonstration of clinical effectiveness.

“In chronic stable coronary disease, DES appear to be cost effective, but this will be sensitive to the cost of the stents,” Weintraub said.

He also said that drug-eluting stents will become less expensive as more stents enter the market and as companies become better at manufacturing them.