Newer-Generation DES: Promising Two-Year Results vs Taxus For Xience V and Noborifrom Heartwire — a professional news service of WebMD

May 14, 2008 (Barcelona, Spain) - Longer-term results for the so-called "next-generation" drug-eluting stents (DES) are trickling in, offering the hope that newer polymers, drugs, or stent designs represent a true improvement over first-generation DES. Two-year results for the Xience V stent in the SPIRIT III study and for the Nobori stent in the NOBORI I and II trials suggest that the newer stents may be superior to the Taxus stent.

Two-year follow-up for both trials was presented here at the EuroPCR 2008 meeting.

Presenting the two-year results for SPIRT III, Dr Gregg Stone (Columbia University, New York, NY) showed that the gap separating MACE and target-vessel-failure (TVF) rates in patients treated with the everolimus-eluting Xience V stent vs the paclitaxel-eluting Taxus stent has continued to widen between 12 and 24 months, favoring the Xience everolimus-eluting stent. One-year results for the study, recently published in the Journal of the American Medical Association [1], suggested that the newer device was statistically superior to the Taxus for MACE, but for TVF (any cardiac events in the treated vessel) showed only a trend in favor of the Xience V. But at two years, the difference between the groups was statistically significant, Stone reported Tuesday. MACE rates were reduced by 45%, while TVF was reduced by 32%. Rates of target lesion revascularization (TLR) and stent thrombosis were also numerically lower for the Xience V stent.

Two-Year Clinical Results for SPIRIT III

Further probing of the MACE end point showed that while death and cardiac death rates were not significantly different between the two groups, MI rates showed a strong trend in favor of the Xience V, and all-cause death/MI events combined just reached statistical significance, again favoring the Xience V. The trial was not, however, powered to demonstrate a difference in clinical events, Stone clarified.

Intriguingly, an analysis of stent-thrombosis rates for both stents, based on timing of dual antiplatelet therapy discontinuation, suggested that there were fewer stent thrombosis "episodes" after six months in Xience V–treated patients who had discontinued their meds than in Taxus-treated patients who had stopped dual antiplatelet therapy. The observation "is potentially important and deserves further study," Stone commented.

Available in Europe since early 2006, the Xience V stent received the thumbs-up from an FDA advisory panel last year but has not yet been granted marketing approval in the US.

Nobori Results

Dr Bernard Chevalier (Centre Cardiologique du Nord, Saint-Denis, France) presented late results for the phase 1 and 2 NOBORI study of Terumo's stent by the same name. The Nobori stent uses the S-stent platform, a biodegradable polymer, and Biolimus A9; the device received CE Mark approval in Europe earlier this year. In the phase 1 study, the Nobori was compared with the Taxus Express stent, while in phase 2, the comparator stent was the Taxus Liberté; two-year data were available only for the 85 Nobori-treated patients/35 Taxus-treated patients in the phase 1 study.

According to Chevalier, the NOBORI I trial met its clinical end point of noninferiority in terms of in-stent late loss in both phase 1 and 2 of the study, with most angiographic results at nine months showing statistical superiority of the Nobori stent. Although the numbers of patients and events at two years were too small to be statistically meaningful, the rates of TLR and TVF were numerically lower in the Nobori-treated patients. Of note, there were no stent thromboses out to two years for the Nobori stent, despite the fact that only 25% of patients remained on dual antiplatelet therapy at this time.

Two-Year Clinical Results for NOBORI

Discussing the results following their presentation, Dr Evelyn Regar (Erasmus Medical Center, Rotterdam, the Netherlands) suggested that the next-generation DES seem to be, albeit at an early stage, superior to their predecessors. "The new-generation DES, Nobori and Xience V, showed sustained efficacy and safety results over two-year follow-up and proved superior in their respective primary trial end points," she said. While the trend favoring reduced stent thrombosis for the newer stents in both trials is "reassuring," Regar reminded the audience that none of the trials to date have been powered to address the question of stent thrombosis.

Stone disclosed receiving research support from Abbott and Boston Scientific. Chevalier disclosed consulting for Abbott, Medtronic, and Terumo and receiving research grants from Boston Scientific and Cordis.

1. Stone GW, Midei M, Newman W, et al. Comparison of an everolimus-eluting stent and a paclitaxel-eluting stent in patients with coronary artery disease: A randomized trial. JAMA 2008; 299:1903-1913. Abstract

The complete contents of Heartwire , a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.

Heartwire from Medscape © 2008  Medscape

Cite this: Shelley Wood. Newer-Generation DES: Promising Two-Year Results vs Taxus For Xience V and Noborifrom Heartwire — a professional news service of WebMD - Medscape - May 14, 2008.