Abstract 2564: No Late and no Very Late Stent Thrombosis with a Drug-Eluting Stent of the Second Generation: 2 Years Results from the Randomized NOBORI-I Trial

Abstract

Background: Late (after 30 days to 1 year) and very late (after 1 year) stent thrombosis is a continuous concern for drug-eluting stents (DES) of the first generation. These stents are characterized by their durable polymer and a ,,360 degree“ elution of the antiproliferative drug not only into the vessel wall, but also into the blood stream. Therefore, the second generation Nobori stent was developed with a biodegradable polymer and a drug elution restricted only to the vessel wall (abluminal coating). The drug, Biolimus A9, is a potent antiproliferative and antiinflammatory Limus derivative. Methods: The NOBORI-I trial was a prospective randomized study designed to compare the Nobori stent with the Taxus stent (2:1) in pats with single de-novo native coronary lesions, a vessel diameter of 2.5–3.5 mm and a lesion length below 25 mm. Predilatation was required. The primary endpoint was in-stent late lumen loss (LL) at 9 months. The study was designed as a noninferiority trial. 363 pats were enrolled in 29 sites in Europe, Asia and Australia. Clopidogrel (in addition to ASA) was recommended for at least 6 months. Results: With an in-stent LL of 0.12 mm in the Nobori and 0.33 mm in the Taxus group (p <0.001) the primary endpoint was reached, with a significant result also for superiority. The results for late and very late stent thrombosis are depicted in the table . Dual antiplatelet therapy was present at one year in 52% of the pats in the Nobori and in 55% of the pats in the Taxus group. After 2 years, it was maintained in 25% of the Nobori and in 20% of the Taxus pats. Conclusions: As compared to a DES of the first generation with a durable polymer and circumferential drug release, the second generation Nobori stent with its biodegradable polymer and a drug-elution restricted to the vessel wall seems to be safer. Due to the limited power of this study regarding safety, higher number of patients are needed to corrobarate these promising findings.