[OCT analysis of in-stent neointima over 5 years post-DES implantation]

Objective: To investigate the characteristics of neointimal hyperplasia (NIH) in patients with in-stent restenosis (ISR) over 5 years post-drug-eluting stent (DES) implantation based on optical coherence tomography (OCT). Methods: In this cross-sectional study, patients with DES-ISR who underwent OCT examination at PLA General Hospital between March 2010 and March 2022 were retrospectively included. All patients were divided into≤5 years DES-ISR group and>5 years DES-ISR group according to the time interval after DES implantation. Quantitative and qualitative analyses were conducted on OCT images to compare the clinical data and lesion characteristics of two patient groups. Furthermore, the independent clinical predictive factors of in-stent neoatherosclerosis (ISNA) were analyzed by multivariable logistic regression. Results: A total of 230 DES-ISR patients with 249 lesions were included, with an age of (63.1±10.4) years and 188 males (81.7%). The median interval after DES implantation was 6 (2, 9) years. There were 117 patients (122 ISR lesions) in the≤5 years DES-ISR group, and 113 patients (127 ISR lesions) in the>5 years DES-ISR group. Compared with≤5 years DES-ISR,>5 years DES-ISR showed more heterogeneous patterns (65.4% (83/127) vs. 48.4% (59/122), P=0.007), diffuse patterns (46.5% (59/127) vs. 31.2% (38/122), P=0.013), macrophage accumulations (44.1% (56/127) vs. 31.2% (38/122), P=0.035) in NIH and higher prevalence of ISNA (83.5% (106/127) vs. 72.1% (88/122), P=0.031). According to multivariable logistic regression, the independent predictive factor for ISNA was female (OR=0.44, 95%CI 0.21-0.90, P=0.026). Female (OR=0.48, 95%CI 0.23-0.99, P=0.046) and low-density lipoprotein cholesterol level (OR=1.62, 95%CI 1.01-2.59, P=0.046) were independent predictive factors, respectively, for lipid ISNA. Calcified ISNA was independently associated with time interval of post-DES implantation (OR=1.18, 95%CI 1.07-1.29, P=0.001). Conclusion: DES-ISR patients with a time interval of>5 years after stent implantation have a higher prevalence of ISNA and more complex lesions. Gender, the level of low-density lipoprotein cholesterol, and the time interval post-DES implantation are independently correlated with ISNA, lipid ISNA, and calcified ISNA.