Previous research has linked raised serum uric acid levels to increased coronary lipid plaque. Xanthine oxidoreductase (XOR) is a purine metabolism rate-limiting enzyme that is thought to play an essential role in coronary atherosclerosis. However, the link between coronary lipid plaque and XOR remains unknown. Patients with stable coronary artery disease who had elective percutaneous coronary intervention using near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) guidance were included in the study.Based on a prior publication, they were categorised into three groups: high, normal, and low plasma XOR activity. The researchers looked at quantitative coronary angiography and grayscale IVUS. The primary endpoint was NIRS-IVUS assessment of coronary lipid plaques in a nontarget artery with lipid core burden index (LCBI) and maximum LCBI in 4 mm (maxLCBI4mm). Out of 68 patients, 11, 31, and 26 were classed as having low, normal, or high XOR activity. Among the three groups, the high XOR activity group had the longest lesion length, the smallest mini- mum lumen diameter, and the highest percentage of diameter stenosis in a nontarget artery.Grayscale IVUS analysis revealed that the high XOR activity group had a lower lumen area than the rest. In a nontarget vessel, LCBI (102.1 ± 56.5 versus 65.6 ± 48.5 vs 55.6 ± 37.8, p = 0.04) and maxLCBI4mm (474.4 ± 171.6 vs 347.4 ± 181.6, 294.0 ± 155.9, p = 0.04) were considerably greater in the high XOR group than in the low and normal groups. In patients with stable coronary artery disease, higher XOR activity was related to coronary lipid-rich plaque in a nontarget vessel.