Neointimal coverage of zotarolimus-eluting stent at 1, 2, and 3 months’ follow-up: an optical coherence tomography study

Incomplete neointimal coverage and malapposed struts after stenting are associated with increased risk of stent thrombosis. We aimed to evaluate neointimal coverage early after Resolute zotarolimus-eluting stent (R-ZES) implantation using optical coherence tomography (OCT). A total of 20 patients with de novo native coronary lesions with R-ZES were enrolled. Among these patients, 20 stented lesions in 19 patients were evaluated at 1, 2, and 3 months after R-ZES implantation. The strut apposition and neointimal coverage were evaluated by OCT. Neointimal hyperplasia (NIH) thickness and percentage of covered struts and the proportion of incompletely apposed struts were measured at 1-mm intervals. The mean percentages of covered stent struts were over 85 % within 3 months (88.4 ± 6.3 % at 1 month, 95.5 ± 5.5 % at 2 months, 93.6 ± 3.5 % at 3 months). The percentages of incompletely apposed struts were not significantly different among the groups (4.4 ± 4.2 % at 1 month, 1.9 ± 1.9 % at 2 months, 3.1 ± 2.2 % at 3 months, p = 0.51). Mean NIH thickness (38.9 ± 8.1 μm at 1 month, 70.6 ± 18.8 μm at 2 months, 54.1 ± 5.9 at 3 months, p = 0.0016) was thickest in the 2 months group. Most of all OCT findings within 2 months demonstrated neointimal coverage with low signal intensity. The neointimal coverage of ZES-R was over 85 % within 3 months. These data may support shorter requirement of dual antiplatelet therapy duration with R-ZES.