Two‐week interval optical coherence tomography: Imaging evidence on neointimal coverage completion after implantation of the endeavor zotarolimus‐eluting stent

Abstract

To obtain imaging evidence by 2-week optical coherence tomography (OCT) on the completion of neointimal coverage (NIC; the percentage of stent strut coverage and thickness of the formed neointima) completion after implantation of the Endeavor zotarolimus-eluting stent (E-ZES). Despite the fact that NIC is a cardinal process in the pathomechanism of late stent thrombosis, little imaging information is available on morphological changes thereof on a short-time interval basis. 27 Japanese patients with stable angina pectoris and de novo native coronary artery lesions were enrolled, and 27 lesions (30 implantations) were examined. OCT was performed at weeks 2, 4, 6, 8, and 10 after E-ZES implantation. NIC was examined using cross-sectional OCT images obtained at the 1.0-mm intervals. In total, 621 cross-sectional OCT images, which depicted 7,747 stent struts, were analyzed. The mean percentages of stent strut coverage at weeks 2, 4, 6, 8, and 10 after E-ZES implantation were 12.3, 70.4, 67.9, 86.0, and 99.2%, respectively; a marked increase was found between weeks 2 and 4. The mean thicknesses of the formed neointima were 40.2, 52.1, 48.1, 86.5, and 146.2 μm at respective weeks, with the high-signal and thick neointima (146 µm) at week 10. An intracoronary thrombus was detected in only one stent at week 4. The full circumferential coverage of the vessel wall by the high-signal neointima was found at as early as week 10 after E-ZES implantation, imparting a surrogate index for vascular healing by NIC.