The influence of serum uric acid on coronary atherosclerosis plaque phenotypes by computed tomography angiography: The missing link?

Background and aims: The interaction of serum uric acid (SUA) with atherogenesis is incompletely understood. Aim of our study was to investigate the association of SUA levels with coronary plaque composition including high-risk-plaque (HRP) features by coronary computed tomography angiography (CTA) and for the prediction of major adverse cardiac events (MACE).

Methods and results: 1242 patients (age 66.17 ± 11.03; 56 % males) referred to coronary CTA were included. SUA>6.5 mg/dl was defined as hyperuricemia. CTA-image analysis included: Coronary stenosis severity (CADRADS), plaque burden (SIS/G-score weighted for non-calcifying plaque), plaques types (1 = calcifying; 2 = mixed (predominantly calcifying); 3 = mixed (predominantly noncalcifying), 4 = noncalcifying."High-risk-plaque"(HRP)-features were quantified: Low-attenuation plaque (LAP) density, Spotty calcification, Napkin-Ring Sign (NRS), Remodeling Index. Coronary Artery Calcium Score (CAC) was measured. Primary outcome was MACE. HRP-features were more prevalent in patients with hyperuricemia (p = 0.005, p = 0.0002, p = 0.0004). SUA level was associated with LAP<30HU (HR:1.23; p = 0.04). Plaque burden and CAC-score were higher in the hyperuricemia group (G-score:p = 0.022 and CAC:p = 0.027). After a mean follow-up of mean 8,32 years, MACE rate was 2.9 %. There was no difference in the MACE rate between subjects with elevated SUA and normals (HR 1.221:95%CI:0.817-2.563; p = 0.597). Low-attenuation-plaque density/LAP<30HU was the strongest prognosticator for MACE (p = 0.033 and p = 0.013); stenosis severity, plaque types and G-score were also predictive, but not SUA, CAC and the other conventional cardiovascular risk factors (except smoking).

Conclusion: SUA is associated with HRP-features and coronary plaque burden. Low attenuation plaque is the strongest predictor of MACE, but not SUA level and other major CVRF. CTA imaging biomarkers may improve CV-risk stratification in patients with hyperuricemia.