Medication-releasing Stent Reduces Risk Of Artery Re-narrowing Following Angioplasty

Drug-eluting stents have revolutionized the treatment ofatherosclerotic coronary artery disease, according to backgroundinformation in the article. These stents (which release medications,such as sirolimus and paclitaxel) have been shown to safely reduceclinical and angiographic restenosis (narrowing again of the arteryafter treatment) compared with bare metal stents. Enrollment in thetrials for these stents, however, was restricted to relatively simplestenoses (vessel diameter of 2.5-3.75 mm with lesion length 30 mm orless). More than 55 percent of lesions currently treated with thesebioactive devices may fall outside this range. The efficacy ofdrug-eluting stents has not been established for small vessels (inwhich the utility of stents as a class is still uncertain), largevessels (in which outcomes with bare metal stents are favorable), or inlong lesions requiring multiple stents.

Gregg W. Stone, M.D., of Columbia University Medical Center andCardiovascular Research Foundation, New York, and colleagues conducteda study (the TAXUS V trial) to investigate the safety and efficacy of apaclitaxel-eluting stent in a patient population with more complexcoronary lesions than previously studied. The trial, conducted fromFebruary 2003 to March 2004 at 66 academic and community-basedinstitutions, included 1,156 patients who underwent stent implantationin a single coronary artery stenosis (vessel diameter, 2.25-4.0 mm;lesion length, 10-46 mm), including 664 patients (57.4 percent) withcomplex or previously unstudied lesions (requiring 2.25-mm, 4.0-mm,and/or multiple stents) and had 9-month clinical and angiographicfollow-up. Patients were randomly assigned to receive 1 or more baremetal stents (n = 579) or identical-appearing paclitaxel-eluting stents(n = 577).

The average reference vessel diameter was 2.69 mm, thereference lesion length was 17.2 mm. An average of 1.38 stents (totalaverage length, 28.4 mm) were implanted per lesion. Stents of 2.25 mmand 4.0 mm in diameter were used in 18 percent and 17 percent oflesions, respectively; multiple stents were used in 33 percent oflesions.

"Compared with bare metal stents, implantation ofpaclitaxel-eluting stents reduced the 9-month rate of target lesionrevascularization from 15.7 percent to 8.6 percent and target vesselrevascularization from 17.3 percent to 12.1 percent. Among patientsreceiving the paclitaxel-eluting stent compared with a bare metalstent, the rate of in-stent restenosis was reduced with from 31.9percent to 13.7 percent and analysis segment angiographic restenosiswas reduced from 33.9 percent to 18.9 percent," the authors write.

"By multivariate analysis, randomization to thepaclitaxel-eluting stent was an independent predictor of freedom from9-month target lesion revascularization [2.2 times more likely], targetvessel revascularization [1.7 times more likely], and restenosis [2.9times more likely]. These benefits were achieved with comparable safetyin both groups, with similar rates of cardiac death, myocardialinfarction, and stent thrombosis at 1 and 9 months."

Angiographic restenosis was also reduced among patientsreceiving 2.25-mm stents (49.4 percent vs. 31.2 percent), 4.0-mm stents(14.4 percent vs. 3.5 percent), and multiple stents (57.8 percent vs.27.2 percent).

"In conclusion, the TAXUS V trial investigated the use ofpaclitaxel-eluting stents in a patient population with more complexlesions than had been previously studied. Angiographic restenosis andtarget vessel revascularization were significantly reduced in theentire cohort, as well as in those patients with complex disease," theauthors write.

(JAMA. 2005; 294:1215-1223. Available pre-embargo to the media at www.jamamedia.org)

Editor's Note: This study was sponsored and funded by BostonScientific Corp., Natick, Mass. For the financial disclosures of theauthors, please see the JAMA article.

Editorial: Paclitaxel-Eluting Stents in Complex Lesions

In an accompanying editorial, Antonio Colombo, M.D., and JohnCosgrave, M.D., of the Columbus and San Raffaele Hospitals, Milan,Italy, comment on the study by Stone et al.

"It is becoming increasingly clear that drug-eluting stentshave not abolished the restenotic process, and especially in high-risklesions, target vessel revascularization rates exceed 10 percent. Thissuggests that while the two most studied stents are a vast improvementover the bare metal stent, there is still room for further progress.Perhaps thinner strut stents or drug combinations may hold the key todecrease restenosis even further. Finally, there is the huge challengeof reducing myocardial infarction and death following percutaneouscoronary intervention and stent placement. The next step is to movefrom the complex lesion to the complex patient," the authors write.

(JAMA. 2005; 294:1268-1270. Available pre-embargo to the media at www.jamamedia.org.)