Randomized Trial of the Yukon Nonpolymer-Based Rapamycin-Coated Stent and the Polymer-Based Paclitaxel-Eluting Stent in Patients With Coronary Artery Disease - ISAR-TEST

Description:

The goal of the trial was to evaluate treatment with a polymer-free, sirolimus coated stent compared with treatment with the polymer-based paclitaxel-eluting TAXUS stent among patients with de novo coronary lesions.

Hypothesis:

Treatment with the polymer-free, sirolimus coated stent will be noninferior with respect to in-stent late lumen loss compared with treatment with the polymer-based paclitaxel-eluting TAXUS stent.

Study Design

Study Design:

Patients Enrolled: 450
Mean Follow Up: Nine months
Mean Patient Age: Mean age 67 years

Patient Populations:

Angina pectoris and/or a positive stress test with de novo stenosis ≥50% in a native vessel

Exclusions:

Acute MI, left main lesion, or in-stent restenosis

Primary Endpoints:

In-stent late lumen loss, evaluated for noninferiority (0.13 mm margin)

Secondary Endpoints:

Angiographic restenosis and target lesion revascularization

Drug/Procedures Used:

Patients were randomized to the polymer-free, sirolimus coated stent (n=225) or the polymer-based paclitaxel-eluting TAXUS stent (n=225). The polymer-free stent was coated using a machine in the catheterization laboratory prior to percutaneous coronary intervention. Patients underwent angiographic follow-up at 6-8 months.

Principal Findings:

Baseline characteristics were well-balanced between groups, with 43% of patients presenting with unstable angina. Mean ejection fraction was 55%. Lesion length was 12.8 mm, with an average of 1.16 stents used in the polymer-free sirolimus coated stent group and 1.08 used in the paclitaxel-eluting stent group (p<0.01).

Thrombotic stent occlusion at nine months occurred in 0.4% of the polymer-free sirolimus coated stent group and 0.9% of the paclitaxel-eluting stent group (p=NS). The primary endpoint of in-stent late lumen loss met the criteria for noninferiority, with a late loss of 0.48 mm in each group and a difference between groups of 0.002 mm (95% confidence interval 0-0.10 mm). In-segment late loss also did not differ by groups (0.34 mm for the polymer-free sirolimus coated stent group vs. 0.24 mm in the paclitaxel-eluting stent group). Angiographic restenosis occurred in 14.2% and 15.5%, respectively (p=0.73), and target lesion revascularization in 9.3% each. There was no difference in death or myocardial infarction (MI) by nine months (4.4% vs. 4.0%, p=NS).

Interpretation:

Among patients with de novo coronary lesions, use of a polymer-free, sirolimus coated stent was shown to be noninferior with respect to in-stent late lumen loss at angiographic follow-up compared with the polymer-based paclitaxel-eluting TAXUS stent.

Polymer coating allows for timed and sustained release of the drug from the stent. However, during deployment of the stent, complications can occasionally occur in which the polymer coating becomes web-like and pulls away from the stent, resulting in bare stent areas and exposed polymers. Additionally, there is concern that late stent thrombosis may be associated with presence of a polymer.

The present study demonstrates the comparable angiographic efficacy of use of a nonpolymer-based sirolimus coated stent with that of a polymer-based, paclitaxel-eluting stent. However, the trial size was relatively small and larger studies would be needed to establish comparable clinical efficacy. Additionally, given the two different drug coatings (sirolimus on the nonpolymer stent and paclitaxel on the polymer coated stent), it is unknown if the results were driven only by the presence or absence of polymer or if the results were attributable to the different drugs used on the stent.

References:

Mehilli J, et al. Randomized Trial of a Nonpolymer-Based Rapamycin-Eluting Stent Versus a Polymer-Based Paclitaxel-Eluting Stent for the Reduction of Late Lumen Loss. Circulation. 2006;113:273-279.

Presented by Dr. Adnan Kastrati at TCT 2005, Washington, DC.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Chronic Angina

Keywords: Myocardial Infarction, Follow-Up Studies, Coronary Restenosis, Sirolimus, Constriction, Pathologic, Angioplasty, Balloon, Coronary, Stents, Paclitaxel, Thrombosis, Polymers, Catheterization, Confidence Intervals, Exercise Test


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