Taxus-V: Marked decrease in restenosis in complex lesion cohort

Multiple stent group had significant increase in periprocedural major adverse event rate.

ORLANDO — The slow-release, polymer-based paclitaxel-eluting stent was found safe and effective in a highly complex patient and lesion cohort in the Taxus-V trial, reported here.

“We already knew what the Taxus stent [paclitaxel-eluting, Boston Scientific] could do from the Taxus-IV trial,” said principal investigator Gregg W. Stone, MD. “In Taxus-V we went to smaller vessels, much longer lesions — so long that they required overlapping stents — and to larger vessels.

“The Taxus stent was effective in reducing angiographic restenosis, late loss, target lesion revascularization, and did so safely. There were no cardiac deaths or other deaths at 30 days and no increase in stent thrombosis,” said Stone, vice chairman of the Cardiovascular Research Foundation and interventional cardiologist at New York-Presbyterian Hospital/Columbia University Medical Center.

When looking at the rate of target vessel revascularization, the trial was positive, Stone said, but “it is notable that we had more late loss and a higher angiographic restenosis rate than in the prior Taxus-IV trial, and the Taxus-IV trial had a higher rate than the Taxus-III trial.

“So what we’ve learned is that as you expose more and more complex lesions to drug-eluting stents, they certainly work but they are not perfect. As we treat very complex patients we will have patients that come back with restenosis; we still need more effective and safer drug-eluting stents.”

Drug-eluting vs. bare metal

Taxus-V was a randomized, controlled and blinded trial that included 1,156 patients with CAD. There were no significant differences in baseline characteristics between the drug-eluting stent and bare metal stent groups. In the bare metal or control group, 29.9% of patients had diabetes; 31.7% had diabetes in the Taxus group.

The percentage of patients with type B₂/lesions was 79.9% in the control group and 75.4% in the Taxus group (see chart).

CARDIOLOGY TODAY

The rate of major adverse cardiac events at 30 days was 3.6% in the control group and 5.1% in the Taxus group (P=.25). At nine months, the rate was 21.2% for patients treated with the bare metal stent and 15% for patients treated with the paclitaxel-eluting stent (P=.008).

The nine-month rate of target vessel revascularization was 15.7% in the control group and 8.6% in the Taxus group (P=.0003); target lesion revascularization at nine months was 17.3% in the bare metal stent group and 12.1% in the drug-eluting stent group (P=.018).

Subgroup analyses

The 2.25 mm stent subgroup included 95 patients who received a bare metal stent and 108 who received the drug-eluting stent. At nine months, the target lesion revascularization rate favored the drug-eluting group: 21.5% in the bare metal group and 10.4% in the Taxus group (P=.03).

Within the 4.0 mm stent subgroup (103 control, 99 drug-eluting), the nine-month target lesion revascularization rate was 5% for controls and 0% for drug-eluting (P=.06).

Multiple stents

The 379 patients receiving multiple stents represented the most complicated subgroup, Stone said. This was “truly a complex lesion cohort, the worst we’ve studied so far,” with more than a third of patients having diabetes and about 75% having type C lesions. The stent length within this subgroup was about 44 mm for patients receiving either type of stent.

While there was a marked decrease in clinical and angiographic restensosis with the slow-release Taxus stent, the 30-day rate of major adverse cardiac events for patients in the bare metal stent group was 3.3% and 8.3% for patients in the Taxus group (P=.047), with an increase in non-Q-wave MI. Stone said this was due to greater myonecrosis from transient side branch narrowing with decreased flow.

In commenting on the results following Stone’s presentation, Sheldon Goldberg, MD, said that he had “been hedging [his] bets for a long time because the Taxus stent is a complex endeavor,” including the stent design, the drug and the polymer.

“This study is striking,” Goldberg said, “with a very acceptable rate of stent thrombosis in the complex high-risk population, but the increased risk of non-Q-wave MI in the overlapping stent group needs further delineation.” Goldberg is professor of medicine at Drexel University College of Medicine.– by Kathy Holliman

For more information:

• Stone GW, Ellis SG, Cannon L, et al. Outcomes of the polymer-based, paclitaxel-eluting Taxus stent in complex lesions: principal clinical and angiographic results from the Taxus-V pivotal randomized trial. Late-breaking trial presented at the American College of Cardiology Scientific Session 2005. March 6-9, 2005. Orlando.