TAXUS V - TAXUS V

Description:

The goal of the TAXUS V trial was to evaluate the efficacy of the slow-rate release polymer-based paclitaxel-eluting stent compared with bare stent in patients with single complex coronary lesions.

Hypothesis:

Treatment with the slow-rate release polymer-based paclitaxel-eluting stent will be associated with a reduction in target vessel revascularization (TVR) compared with bare stent.

Study Design

Study Design:

Patients Enrolled: 1,156
Mean Follow Up: One year
Mean Patient Age: Mean age 63 years
Female: 31

Patient Populations:

Nonemergent stent implantation of single lesions visually estimated to be ≥10 mm and ≤46 mm in length, with reference vessel diameter ≥2.25 mm and ≤4.0 mm

Primary Endpoints:

TVR at nine months

Drug/Procedures Used:

Patients undergoing nonemergent stent implantation of a single lesion were randomized in a double-blind manner to either paclitaxel-eluting stent (n=577) or bare metal stent (n=579). Stents were available in diameter of 2.25-4.0 mm and in lengths of 8-32 mm. Patients were followed for one year. Angiographic follow-up was performed at nine months. Patients will be followed clinically for five years.

Concomitant Medications:

Aspirin indefinitely and clopidogrel for at least six months

Principal Findings:

Baseline characteristics were well matched between the treatment groups, with 31% diabetics and 31% female. Multiple stents were used in 33% of patients, and the mean stent length was 28 mm.

The primary endpoint of TVR at nine months was lower in the paclitaxel-eluting stent group compared with the bare metal stent group (12.1% vs. 17.3%, p=0.018), driven by a reduction in target lesion revascularization (TLR) (8.6% vs. 15.7%, p=0.0003), with no difference in non-TLR (4.8% vs. 4.2%, p=0.67).

As a result of the reduction in TVR, the overall major adverse cardiac event (MACE) rate was also lower in the paclitaxel-eluting stent group (15.0% vs. 21.2%, p=0.008). There was no difference in the other components of the MACE endpoint, including cardiac death (0.5% vs. 0.9%), Q-wave myocardial infarction (MI) (0.5% vs. 0.2%), or non-Q-wave MI (4.8% vs. 4.4%). Stent thrombosis occurred in 0.7% of patients in each group.

At angiographic follow-up, in-stent late lumen loss was lower in the paclitaxel-eluting stent group compared with the bare metal stent group (0.49 mm vs. 0.90 mm, p<0.0001), as was in-stent binary restenosis (13.7% vs. 31.9%, p<0.0001). In the subgroup of patients who underwent intravascular ultrasound, in-stent net volume obstruction was lower in the paclitaxel-eluting stent group (13.1% vs. 31.8%, p<0.001).

In a subgroup analysis of patients who were treated with multiple stents (n=379; n=326 with stent overlap), the rate of 30-day MI was significantly higher in the paclitaxel-eluting stent group (8.3% vs. 3.3%, p=0.047). The presenter suggested this was due to an increase in side branch TIMI flow reduction, which was more frequent in the paclitaxel-eluting stent group (42.6% vs. 30.6%, p=0.03).

Interpretation:

Among patients undergoing nonemergent stent implantation of a single, complex lesion, treatment with the slow-release paclitaxel-eluting stent was associated with a reduction in the primary endpoint of TVR compared with treatment with a bare metal stent.

Data from TAXUS V are consistent with the earlier TAXUS studies, which also showed a reduction in TVR associated with paclitaxel-eluting stent use over bare metal stents. However, prior trials were conducted in patients with less complex lesions. The present study extends these findings to include more complex lesions. However, the increase in 30-day MI in the multiple stent group warrants further monitoring.

References:

Stone GW, et al. Comparison of a Polymer-Based Paclitaxel-Eluting Stent With a Bare Metal Stent in Patients With Complex Coronary Artery Disease. JAMA. 2005;294:1215-1223.

Presented by Dr. Gregg W. Stone at the March 2005 ACC Annual Scientific Session, Orlando, FL.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease

Keywords: Paclitaxel, Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Metals, Thrombosis, Drug-Eluting Stents, Polymers, Diabetes Mellitus


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