Objectives: Certain neointimal patterns including neoatherosclerosis (NA) are known to be associated with poor clinical outcome. The prevalence and time course of different neointimal patterns have not been studied systematically. The aim of this study was to investigate the serial changes in neointimal pattern after drug-eluting stent implantation.
Patients and methods: A total of 132 patients with 207 drug-eluting stents, who underwent two follow-up optical coherence tomography studies at 6 and 12 months, were included. Neointimal patterns were categorized as homogeneous, heterogeneous, layered, or NA using optical coherence tomography. Quantitative and qualitative analyses of neointima were carried out.
Results: Both at 6 and at 12 months, the homogenous neointima was the predominant type (>75%), followed by the layered and the heterogeneous pattern. At 12 months, progression to NA was observed in 0.6% of the patients in the homogeneous group, in 5.6% of the patients in the heterogeneous group, and in 3.9% of the patients in the layered group. Regression to the homogeneous pattern was observed in 5.6% of the patients in the heterogeneous group and 11.5% of the patients in the layered group.
Conclusion: The homogenous neointima is the predominant pattern both at 6 and at 12 months. The neointimal pattern changed between 6 and 12 months in 10.6% of stents. Further studies are needed to understand the mechanisms of these neointimal changes and their clinical significance.