Morphological Characteristics of In-stent Restenosis with Different Degrees of Area Stenosis: An Optical Coherence Tomography Study

Purpose: The morphological characteristics of in-stent restenosis (ISR) in relation to varying degrees of area stenosis have not been comprehensively examined. This study aimed to explore the tissue characteristics of patients experiencing ISR with different degrees of area stenosis through the utilization of optical coherence tomography (OCT). Methods In total, 230 patients with ISR who underwent OCT were divided into the following three groups: area stenosis (AS) < 70% (n = 26); 70%-80% (n = 119) and AS ≥ 80% (n = 85). Results Among the 230 patients, the clinical presentation as stable angina was 61.5% in AS < 70%, followed by 47.2% in 70% < AS ≤ 80%, and 31.8% in AS ≥ 80% ( P  = 0.010). The OCT findings showed that heterogeneous neointima, ISNA, LRP, neointima rupture, TCFA-like pattern, macrophage infiltration, red and white thrombus was more common with AS increased. Ordinal logistic regression analysis showed that higher AS was associated with previous dyslipidaemia (odds ratio [OR], 6.706, 95% confidence interval ([CI], 1.764–25.483; P  = 0.005) and neointima rupture (odds ratio [OR], 4.472, 95% confidence interval ([CI], 1.228–16.281; P  = 0.023). Conclusions Patients with higher degrees of area stenosis in the context of ISR exhibited a greater number of discernible morphological characteristics as identified through OCT analysis. Furthermore, previous dyslipidemia and neointima rupture was highly associated with and the progression of ISR lesions.