Abstract
Abstract
Hyperuricaemia and gout predict cardiovascular events, yet whether urate acts within coronary plaque is unknown, and lowering serum urate has not reduced risk. Here, we show that non-contrast, ECG-gated dual-energy computed tomography identifies urate within coronary plaque and separates it from calcium, which single-energy CT cannot. Among 116 patients (348 vessels), coronary urate occurred in 35.3% of patients and 17.5% of vessels and was the only independent predictor of high-risk plaque (odds ratio 4.91; 95% confidence interval 1.43-16.82); the calcium score was not. Urate-positive patients were normouricaemic, indicating local deposition. In an independent cohort of 92 patients, photon-counting CT, using a different spectral mechanism, corroborated the finding from the routine calcium-scoring scan. Cross-polarised micro-optical coherence tomography confirmed needle-shaped, negatively birefringent monosodium urate crystals, and histopathology localised xanthine oxidase to CD68⁺/CD163-low macrophages at the necrotic-core periphery, rising with plaque progression. Coronary urate is an imageable marker of crystal-driven inflammation and plaque vulnerability.