Background: Everolimus-eluting stents (EES) have shown favorable clinical outcomes. However, there have been no studies evaluating early vascular response after EES implantation. We designed a prospective study to compare the neointimal response between zotarolimus-eluting stents (ZES) and EES at 3 and 12 months using serial optical coherence tomography examinations.
Methods and results: Sixty patients who underwent 3-month and 12-month follow-up optical coherence tomography (36 EES, 24 ZES) were included. Neointimal coverage and malapposition were evaluated using a strut-based analysis at both 3 and 12 months. Neointimal hyperplasia area and thrombus were assessed. ZES showed a higher incidence of covered struts (81.5 vs. 77.1%, P<0.0001) and lower incidence of malapposed struts (1.4 vs. 2.3%, P=0.001) than EES at 3 months. However, at 12 months, EES showed a slightly higher incidence of covered struts (96.4 vs. 93.6%, P<0.0001) and a lower incidence of malapposed struts (0.9 vs. 1.1%, P=0.03) than ZES. Neointimal hyperplasia area was greater in the ZES group than in the EES group at both 3 and 12 months (0.77 vs. 0.49 mm, P=0.03 and 1.50 vs. 0.97 mm, P=0.01, respectively). No significant difference in the incidence of thrombus was observed at both 3 and 12 months.
Conclusion: ZES showed rapid neointimal healing compared with EES at 3 months. However, at 12 months, EES had a slightly better vascular healing profile than ZES.