摘要： Introduction: Coronary artery bypass grafting (CABG) is a method of choice in treatment of diffuse coronary artery disease (CAD), although it has some limitations such as late saphenous vein graft (SVG) patency loss, which occurs in one fifth of all conduits at 5 years. Since atherosclerosis in SVG has diffuse characteristics, it appears that significantly and non-significantly stenosed lesions may have an equal impact on worse prognosis. Aim: To assess non-significant lesions of SVG by the use of optical coherence tomography (OCT) and investigate the clinical and laboratory findings with the potential impact on plaque composition. Material and methods: Twenty-nine patients with 43 non-significant lesions were enrolled in the study. All variables were assessed using uni- and multivariable logistic regression analysis with each plaque morphology as a dependent variable. Odds ratio (OR) and 95% confidence interval (CI) were computed. Results: Plaque rupture (PRT) was independently associated with age (OR = 1.49, 95% CI: 1.09–2.04, p = 0.015) and lower rates of high-density lipoproteins (HDL) cholesterol (OR = 0.67, 95% CI: 0.49–0.92, p = 0.016). Intimal tearing or rupture (ITR) was related to reduced GFR (OR = 0.52, 95% CI: 0.38–0.72, p = 0.0004). Lipid-rich plaque (LRP) was associated with raised platelet count (PLT) (OR = 1.51, 95% CI: 1.16–1.96, p = 0.004) and increased frequency of smoking (OR = 1.45, 95% CI: 1.12–1.89, p = 0.007). Conclusions: Atherosclerosis of SVG is not restricted to significantly stenosed lesions. Plaque composition is independently associated with different types of clinical and laboratory findings, mostly recognized as risk factors of CAD.