Association between serum uric acid and high-risk plaques assessed by coronary CT angiography.

Objectives: To investigate the association between serum uric acid (UA) and high-risk plaques (HRPs) assessed by coronary CT angiography (CCTA).

Methods: In this retrospective study, we included outpatients who underwent CCTA. HRP was defined as ≥any 2 of the following features: positive remodelling, low-attenuation plaque (LAP), napkin ring sign and spotty calcification. Plaque volume, Agatston score, vessel stenosis, segment stenosis score (SSS) and segment involvement score (SIS) were also determined by CCTA. Logistic regression analysis was used to assess the relationship between serum UA and the risk of HRP. Receiver operating characteristic (ROC) curve analysis was performed to assess model's accuracy and discrimination. Subgroup analysis based on sex (male/female), diabetes mellitus (yes/no), smoking status (yes/no), alcohol use (yes/no), obstructive coronary artery disease (CAD) (yes/no), Agatston score (<300 or ≥300) was performed.

Results: 1411 subjects were included in the final analysis, with a mean age of 64.26±9.92 years and a median serum UA value of 425 µmol/L (IQR 296-622). A total of 344 cases of HRPs were identified. Multivariable logistic regression showed that serum UA (OR 2.96 per SD increment, 95% CI 1.85~4.76, p<0.001) was associated with higher risk of HRP after adjustment of sex, diabetes mellitus, smoking, obstructive CAD, age, Agatston score, total plaque volume, LAP volume, SSS and SIS. ROC analysis showed that area under curve of the model was 0.86 (95% CI 0.83 to 0.88, p<0.001). In subgroup analysis, no effect modification was found (all p>0.05).

Conclusion: Serum UA is an independent risk factor for high-risk coronary artery plaques on CCTA. Measuring serum UA might provide improvement of discrimination and reclassification for CAD when added to clinical characteristics.