Favorable neointimal coverage in everolimus-eluting stent at 9 months after stent implantation: comparison with sirolimus-eluting stent using optical coherence tomography

Recent studies reported favorable angiographic and clinical outcomes after everolimus-eluting stent (EES) implantation. However, there were no studies to assess vascular responses after EES implantation using optical coherence tomography (OCT). Therefore, the OCT findings in EES were investigated and compared with those in sirolimus-eluting stent (SES). Follow-up OCT studies were performed in 110 lesions (40 EES and 70 SES) of 104 patients at 9 months after stent implantation. The strut apposition, neointimal hyperplasia (NIH) thickness and stent coverage on each stent struts were evaluated. The mean NIH thickness was significantly greater in EES-treated lesions than in SES-treated lesions (115 ± 52 μm vs. 89 ± 58 μm, P = 0.001, respectively). The percentage of uncovered strut was significantly smaller in EES-treated lesions than in SES-treated lesions (4.4 ± 4.7% vs. 10.5 ± 12.7%, P = 0.016, respectively). There was no significant difference in the percentage of malapposed strut between the two groups (0.4 ± 0.8% in EES vs. 1.7 ±  4.5% in SES, P = 0.344). The incidence of intracoronary thrombus was significantly lower in EES-treated lesions than in SES-treated lesions (5.0% vs. 34.3%, P < 0.001, respectively). EES showed a significantly lower incidence of uncovered stent struts and intracoronary thrombus than SES in 9-month follow-up OCT examination. Compared to SES, EES might have more favorable vascular responses after stent implantation.