Medical Device Daily Associate

Data from two recently released studies appears to offer more evidence of the benefits of Cordis' (Miami Lakes, Florida) Cypher drug-eluting stent (DES) in the clinical setting.

Results from a prospective, randomized clinical trial of small coronary vessels seem to suggest that the Cypher outperformed competitor Boston Scientific's (Natick, Massachusetts) Taxus Express stent, which utilizes the drug paclitaxel, in three key endpoints that are utilized to assess efficacy: late lumen loss (primary endpoint), restenosis and target lesion revascularization (secondary endpoint).

The ISAR-SMART trial results appear in the February issue of the European Heart Journal.

At 12 months' follow-up, patients treated with the Cypher stent demonstrated significantly better results than those patients treated with the Taxus device: in-stent late lumen loss in the Taxus stent group was 0.56 +/-0.59, compared to the Cypher patient group 0.25 +/- 0.55.

Angiographic binary restenosis (greater than or equal to 50% diameter stenosis) was found in 19% of the lesions in the Taxus stent group and 11.4% of the lesions in the Cypher stent group.

Additionally, target lesion revascularization was conducted in 14.7% of the lesions treated with the Taxus vs. 6.6% of the lesions treated with the Cypher.

ISAR-SMART investigator and study author Adnan Kastrati, MD, of Deutsches Herzzentrum (Munich, Germany), said that "based on the results of this study, one would conclude that the Taxus stent is associated with greater late lumen loss and is less effective in reducing restenosis in small coronary vessels than the Cypher stent."

Cordis noted that small vessel diameter has been identified as an important predictor of restenosis after treatment with a coronary stent.

The 360 patients in the study were randomly selected for treatment with either drug-eluting stent and had challenging blockages in vessels with an average diameter size of less than 2.80 mm.

The company said that the Cypher also has demonstrated positive results in other small-vessel studies such as SES SMART, a randomized, multi-center prospective trial and SVELTE, a multi-center historical controlled study that assessed efficacy in treating small coronary vessels.

"The ISAR-SMART trial is one of nine randomized, controlled clinical trials that have demonstrated a statistically significant benefit of the Cypher stent vs. the Taxus stent and is another addition to the outstanding body of clinical evidence," said Dennis Donohoe, MD, worldwide vice president of clinical and regulatory affairs at Cordis.

The company also said that findings of another study found that Cypher may reduce restenosis and the occurrence of major adverse cardiac events in patients with complex coronary artery lesions without increasing the risk of blood clots (thrombosis).

In the other trial, six-month results of the Stenting of Coronary Arteries in Non-Stress/Benestent Disease (SCANDSTENT) study were published recently in the Jan. 17 issue of the Journal of the American College of Cardiology.

The SCANDSTENT study is the only randomized study examining the Cypher against bare-metal stents that includes complex patients, defined as patients with blockages longer than 15 mm, side-branch lesions, ostial lesions, and lesions angled at greater than 45 degrees.

"In the first six months after receiving a Cypher stent, we saw significant clinical and angiographic improvement in these challenging patient cases," said lead investigator Henning Kelbaek, MD, chief physician at Rigshospitalet (Copenhagen, Denmark). "Longer-term follow-up and studies of drug-eluting stents in thrombotic lesions are needed, but if these positive outcomes continue there will be few situations in which use of a bare metal stent will be considered favorable," he said.

Kelbaek and his colleagues randomized 322 patients with angina pectoris, unstable angina and complex lesions to treatment with either a Cypher stent or a bare-metal stent.

Investigators found that at six months the Cypher outperformed the bare-metal stent. When comparing the Cypher stent group with the bare-metal stent group, researchers found improvements in the narrowest vessel size (minimal lumen diameter; 1.63 mm vs. 2.48 mm), significant reductions in narrowing of the vessel (diameter stenosis; 19.3% vs. 43.8%), a dramatic reduction in narrowing of the vessel on multiple occasions (>50% stenosis in main branch; 2% vs. 31.9%) and significantly lower rates of target lesion revascularization (TVR; 2.4% vs. 29.6%).

The study also documented low angiographic and clinical restenosis rates with the Cypher compared with a pooled analysis of other Cypher stent vs. bare-metal stent studies, including RAVEL, SIRIUS, DIABETES and SES-SMART studies.

The Cypher was found to reduce angiographic restenosis by 80% and TVR by 75% compared to the bare metal stent group in the pooled analysis. In the SCANDSTENT trial, angiographic restenosis was reduced by 94% and TVR by 92%.

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