Early vascular responses after everolimus-eluting stent implantation assessed by serial observations of intracoronary optical coherence tomography.

A recent OCT study revealed that the lack of stent strut endothelial coverage is associated with late stent thrombosis after drug-eluting stent implantation. However, the sequential changes of stent strut endothelial coverage in the extremely early period have never been reported. Serial OCTs were performed in 35 patients with 35 EES (everolimus-eluting stent)-treated de novo lesions at 0, 2, 4, and 12 weeks after EES implantation. Serial changes in quantitative parameters of the neointima (neointimal thickness, stent strut coverage, and apposition of each strut) were analyzed. Mean neointimal thickness significantly increased from 35.9 to 51.8 and 108.2 μm at 2, 4, and 12 weeks, respectively (p < 0.001 for all), and the percentage of uncovered stent struts significantly decreased from 74.7 to 19.5% and 0.4% (p < 0.001, respectively). There was no stent malapposition at 4 weeks compared with immediate post-intervention (0 vs. 5.4 %, p = 0.031). This OCT study demonstrates that neointimal coverage of stent struts progresses to about 80 % and malapposition of stent struts completely disappears at 4 weeks after EES implantation. In addition, neointimal coverage of stent struts was almost complete within 12 weeks.