Expensive drug-coated stents — used to prop open clogged coronary arteries — are not worth using in many patients, Swiss researchers said on Friday.
The devices can, however, be cost-effective in a subset of heart patients who have particularly narrow vessels.
Their findings from an 18-month study of 826 patients paint a less favorable value-for-money picture than previous research and will stoke fresh controversy over when to use drug stents.
It comes just days before a key review of the cost-effectiveness of the devices by Britain's National Institute of Health and Clinical Excellence (NICE).
NICE alarmed manufacturers in August with an initial proposal that drug stents were not worth using on the state health service. The watchdog's appraisal committee will meet to draw up its final draft recommendations on November 6, though the decision will not be made public for several weeks.
Stents are a multibillion-dollar business for companies like Boston Scientific and Johnson & Johnson, who make the two drug-eluting stents assessed in the Swiss study.
The devices are designed to prevent arteries re-narrowing as often happens with bare metal stents, but their use has dropped recently because of fears that deadly blood clots can form inside the devices in rare cases.
"If used in all patients, drug-eluting stents are not good value for money, even if prices were substantially reduced," Matthias Pfisterer, of Basel's University Hospital, and colleagues wrote in the Lancet journal.
Higher treatment costs
Only in high-risk patients with small vessels measuring less than 3 millimeters or bypass-graft stenting, which represented about a third of the study sample, were drug-eluting stents truly cost-effective.
"Thus, targeted stent use could be the preferred strategy today. Lower prices of drug-eluting stents alone are unlikely to result in such stents being cost effective in all patients, even if the problems of late stent thrombosis are solved with new generations of drug-eluting stents," the researchers concluded.
The Swiss team calculated that overall long-term treatment costs were higher with drug stents, at an average 11,808 euros ($17,020), compared to 10,450 for bare metal ones.
Rates of major adverse cardiac events or death were no different between the two groups.
The cost calculations were made on the basis of 2004 Swiss stent prices, when J&J's Cypher drug stent cost an average 2,275 euros, Boston's Taxus 1,935 and bare metal devices 1,260.
Since 2004 prices have fallen but the cost of bare stents has decreased more than for drug-coated ones, so the discrepancy between the two types has widened, the researchers added.