Evaluation in 3 Months Duration of Neointimal Coverage After Zotarolimus-Eluting Stent Implantation by Optical Coherence Tomography

We performed this study to investigate the vascular response in early period after zotarolimus-eluting stent (ZES) (Endeavor Sprint, Medtronic CardioVascular, Minneapolis, Minnesota) implantation. The ZES has different characteristics, with biocompatible polymer and rapid drug-elution, compared with the first-generation drug-eluting stents (DES). The ENDEAVOR OCT (Evaluation in 3 Months Duration of Neointimal Coverage after Zotarolimus-Eluting Stent Implantation by Optical Coherence Tomography) trial is a prospective, single-center study evaluating vascular healing patterns with optical coherence tomography (OCT) at 3 months after stent implantation. A total of 31 ZES in 30 patients underwent serial OCT at immediate post-intervention and 3 months. Neointimal growth and malapposition were analyzed at each stent strut of cross-sectional OCT images with 0.5-mm intervals. The incidence of malapposition at post-intervention and 3 months was 6.0% and 0.2%, respectively. However, late acquired malapposition was not detected at 3 months. Of 31 stents, 27 stents (87.1%) were covered completely with neointima, but the remaining 4 stents had 2 (0.8%), 4 (0.9%), 4 (1.2%), and 6 (1.4%) uncovered struts. Overall mean percentage of covered stent struts was 99.9 ± 0.4%. This finding was consistent among groups with acute coronary syndrome and stable angina pectoris (99.9 ± 0.3% vs. 99.9 ± 0.4%, p = 0.92). Intracoronary thrombus was documented in 1 stent (3.2%) among 31 stents. Most of the stent struts were covered with neointima, and late acquired malapposition was not found at 3 months after ZES implantation. Therefore, the current study demonstrated that ZES might have a favorable in vivo vascular response at 3 months after stent implantation. (Evaluation of Zotarolimus Eluting Stent at 3 Months Using Optical Coherence Tomography [ENDEAVOR OCT]; NCT00815139)