Compared to bare metal stents, placement of stents that release the medication paclitaxel reduces the risk of the artery re-narrowing nine months following angioplasty for patients with complex coronary artery lesions, according to an article in the September 14 issue of JAMA.
Drug-eluting stents have revolutionized the treatment of atherosclerotic coronary artery disease, according to background information in the article. These stents (which release medications, such as sirolimus and paclitaxel) have been shown to safely reduce clinical and angiographic restenosis (narrowing again of the artery after treatment) compared with bare metal stents. Enrollment in the trials for these stents, however, was restricted to relatively simple stenoses (vessel diameter of 2.5-3.75 mm with lesion length 30 mm or less). More than 55 percent of lesions currently treated with these bioactive devices may fall outside this range. The efficacy of drug-eluting stents has not been established for small vessels (in which the utility of stents as a class is still uncertain), large vessels (in which outcomes with bare metal stents are favorable), or in long lesions requiring multiple stents.
Gregg W. Stone, M.D., of Columbia University Medical Center and Cardiovascular Research Foundation, New York, and colleagues conducted a study (the TAXUS V trial) to investigate the safety and efficacy of a paclitaxel-eluting stent in a patient population with more complex coronary lesions than previously studied. The trial, conducted from February 2003 to March 2004 at 66 academic and community-based institutions, included 1,156 patients who underwent stent implantation in a single coronary artery stenosis (vessel diameter, 2.25-4.0 mm; lesion length, 10-46 mm), including 664 patients (57.4 percent) with complex or previously unstudied lesions (requiring 2.25-mm, 4.0-mm, and/or multiple stents) and had 9-month clinical and angiographic follow-up. Patients were randomly assigned to receive 1 or more bare metal stents (n = 579) or identical-appearing paclitaxel-eluting stents (n = 577).
The average reference vessel diameter was 2.69 mm, the reference lesion length was 17.2 mm. An average of 1.38 stents (total average length, 28.4 mm) were implanted per lesion. Stents of 2.25 mm and 4.0 mm in diameter were used in 18 percent and 17 percent of lesions, respectively; multiple stents were used in 33 percent of lesions.
"Compared with bare metal stents, implantation of paclitaxel-eluting stents reduced the 9-month rate of target lesion revascularization from 15.7 percent to 8.6 percent and target vessel revascularization from 17.3 percent to 12.1 percent. Among patients receiving the paclitaxel-eluting stent compared with a bare metal stent, the rate of in-stent restenosis was reduced with from 31.9 percent to 13.7 percent and analysis segment angiographic restenosis was reduced from 33.9 percent to 18.9 percent," the authors write.
"By multivariate analysis, randomization to the paclitaxel-eluting stent was an independent predictor of freedom from 9-month target lesion revascularization [2.2 times more likely], target vessel revascularization [1.7 times more likely], and restenosis [2.9 times more likely]. These benefits were achieved with comparable safety in both groups, with similar rates of cardiac death, myocardial infarction, and stent thrombosis at 1 and 9 months."
Angiographic restenosis was also reduced among patients receiving 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 of paclitaxel-eluting stents in a patient population with more complex lesions than had been previously studied. Angiographic restenosis and target vessel revascularization were significantly reduced in the entire cohort, as well as in those patients with complex disease," the authors 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 Boston Scientific Corp., Natick, Mass. For the financial disclosures of the authors, please see the JAMA article.
Editorial: Paclitaxel-Eluting Stents in Complex Lesions
In an accompanying editorial, Antonio Colombo, M.D., and John Cosgrave, 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 stents have not abolished the restenotic process, and especially in high-risk lesions, target vessel revascularization rates exceed 10 percent. This suggests that while the two most studied stents are a vast improvement over the bare metal stent, there is still room for further progress. Perhaps thinner strut stents or drug combinations may hold the key to decrease restenosis even further. Finally, there is the huge challenge of reducing myocardial infarction and death following percutaneous coronary intervention and stent placement. The next step is to move from 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.)
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