Aims: We sought to investigate subclinical neoatherosclerotic changes and the healing response to sirolimus-eluting stents (SES) to clarify the clinical safety and the neointimal pathology of SES more than 10 years after implantation.
Methods and results: We investigated a total of 180 SES without stent failure in 103 patients who underwent optical coherence tomography (OCT) examination of stented vessels more than five years after implantation. We assessed the presence or absence of neoatherosclerosis and the healing process using OCT and compared the results between stents at five to 10 years after implantation (Group A, 114 stents with 19,873 struts) and stents more than 10 years after implantation (Group B, 66 stents with 10,937 struts). The median stent age of the whole cohort was 9.4 (7.8–10.9) years. In the OCT analysis, Group B was associated with higher frequencies of neoatherosclerosis than Group A. However, the prevalence of uncovered stents and stent malapposition was not significantly different between the two groups.
Conclusions: SES of more than 10 years of age are associated with a higher frequency of OCT-defined neoatherosclerosis than SES of five to 10 years of age, indicating continuous development of neoatherosclerosis beyond 10 years after implantation.