Sept. 14, 2007 -- There is good news and bad news about the safety of the new generation of drug-coated stents used to prop open blocked coronary arteries.
Survival among patients treated with the drug-covered stents was no different than that among patients who got traditional, bare-metal stents in an analysis of studies involving more than 18,000 heart patients.
Earlier research suggesting a survival advantage in patients who got the older stents led to a steep decline in sales of the newer, drug-coated versions over the past year.
But the new analysis also found a significantly higher risk of heart attacks among patients treated with stents coated with the drug paclitaxel than among those who got stents coated with the drug sirolimus or traditional bare-metal stents.
And patients who got the paclitaxel-coated stents were more likely than those treated with other stents to develop blood clots at the stent site a month or more after implantation.
Analysis researcher Peter Juni, MD, of Switzerland’s University of Bern, tells WebMD that the findings suggest a clear advantage for the sirolimus stent over the paclitaxel stent.
“It is reasonable to assume, based on the combined findings from these randomized, controlled trials, that if a drug-eluting stent is needed, the sirolimus-eluting stent is the better choice,” he says.
Stent Maker Challenges Finding
The findings were challenged Thursday by an official with the company that markets the paclitaxel-coated stent.
In a written statement sent to WebMD, Donald Baim, MD, of Boston Scientific Corp. called the analysis “fundamentally flawed.”
Specifically, Baim complained that the studies included in the analysis were too diverse to allow for meaningful comparisons among the different stents.
“The methodology is flawed and so are the conclusions, which are out of line with virtually all prior studies and the experience of millions of real-world patients,” writes Baim.
Juni rejected the criticism, saying that every effort was made to develop an analysis model that accounted for these differences.
The analysis included 38 studies following a total of 18,023 patients treated with either drug-coated or bare-metal stents for up to four years.
Mortality rates proved to be the same among all patients.
Patients who got the drug-coated stents needed fewer repeat procedures to open a reblocked coronary artery, known as revascularization, compared with those who got bare-metal stents. Revascularization rates were slightly lower for the siromilus stents vs. the paclitaxel stents.
And the risk of stents getting clogged (a complication associated with stents) occurring more than a month after implantation was more than twice as high among patients treated with paclitaxel-coated stents vs. bare-metal stents, and 85% higher than among sirolimus-stent treated patients.
Findings ‘Suggestive, Not Conclusive’
The researchers conclude that "sirolimus-eluting stents seem to be clinically better than bare-metal and paclitaxel-eluting stents."
The findings are published in the Sept. 15 issue of the journal Lancet.
University of Texas Health Science Center cardiologist Steven R. Bailey, MD, says the conclusion may be overstating the evidence, given that the studies including in the analysis were so diverse.
Bailey is chief of the division of cardiology at the University of Texas Health Science Center at San Antonio, and he is also a spokesman for the Society for Cardiovascular Angiography and Intervention.
He termed the analysis "suggestive, but not necessarily conclusive" evidence that one drug-coated stent is better than the other.
He tells WebMD that decisions about which stent patients should get, or whether they should get stents at all, are more complex than clinicians once thought.