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

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). 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). 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.