NEJM: Xience stents best Taxus Express at one year for TLF
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“Previous studies have established the superiority of coronary everolimus-eluting stents over paclitaxel-eluting stents with respect to angiographic findings,” the authors wrote. “However, these trials were not powered for superiority in clinical endpoints.”
To address this, Gregg W. Stone, MD, from Columbia University Medical Center and New York Presbyterian Hospital in New York City, and colleagues randomly assigned 3,687 patients at 66 U.S. sites to receive either everolimus-eluting or paclitaxel-eluting stents during the SPIRIT IV clinical trial.
The trial took place between Aug. 10, 2006, and July 30, 2008, and participants were 18 years or older and diagnosed with angina or inducible ischemia and up to three untreated native coronary artery lesions—32.2 percent had diabetes mellitus.
During the trial, 2,458 patients were assigned to receive the Xience stent (Abbott Vascular) and 1,229 patients were assigned to receive the Taxus Express stent (Boston Scientific). Patients did not undergo angiography during the trial.
Researchers used TLF (cardiac death, target-vessel MI or ischemia-driven target-lesion revascularization) at one year as the primary endpoint.
Study results showed that patients in the everolimus arm saw a 38 percent decline in TLF and a 45 percent reduction for secondary endpoints of ischemia-driven target-lesion revascularization.
Target-lesion failure occurred at rates of 4.2 and 6.8 percent for the everolimus and paclitaxel arms, respectively.
Rates for ischemia-driven target-lesion revascularization at one year were 2.5 and 4.6 percent for the everolimus and paclitaxel arms, respectively.
Additionally, the researchers found that the everolimus-eluting stent group had overall lower rates of stent thrombosis, MI and target-vessel MI at one year; however mortality rates did not significantly differ between the two groups.
Cardiac events were reported more frequently in the paclitaxel patient arm compared with the everolimus arm, 9.9 versus 7.9 percent, respectively.
The trial also evaluated twelve patient subgroups with both paclitaxel and everolimus stents and found that patients implanted with everolimus-eluting stents had overall lower rates of TLF.
In the subgroup of patients with diabetes, rates of TLF were similar for the everolimus and paclitaxel arms, 6.4 and 6.9 percent, respectively.
“The simultaneous reduction of stent thrombosis, MI and target-lesion revascularization with everolimus-eluting stents suggests that, with drug-eluting stents, it is possible to achieve minimal late loss, resulting in increased clinical efficacy without sacrificing safety,” the authors concluded.
In an accompanied editorial, Drs. Richard A. Lang and L. David Hillis of the University of Texas Health Science Center in San Antonio, asked, “Should we abandon paclitaxel-eluting stents in favor of second-generation everolimus-eluting stents on the basis of the results of the study by Stone et al?”
While Lang and Hillis said that second-generation drug-eluting stents were designed to have better deployment, safety and efficacy rates, it is still unclear why the second-generation devices perform better than the first-generation devices.
The authors said the differences could be attributed to their antiproliferative agents, polymer layers or stent frame.
“The antiproliferative drug (everolimus) may result in less neointimal proliferation and retenosis than those that occur with older drug-eluting stents,” the authors wrote.
Additionally, everolimus-eluting stents are $300 more expensive than paclitaxel-eluting stents, the authors wrote. Because 20 to 30 percent of patients undergoing PCI are diabetic, Lang and Hillis said that a cost-effective analysis would be beneficial to evaluate whether the 1 to 2 percentage point reduction of MI risk would “warrant its [paclitaxel-eluting stents] routine use.”
The authors concluded that “further studies are needed to determine whether second-generation stents are superior in reducing the incidence of stent thrombosis and MI when antiplatelet therapy that is more effective than clopidogrel—that is, prasugrel—is administered.”