Background/Purpose: Increased cardiovascular (CV) risk in gout relates to crystal-driven inflammation. Monosodium urate (MSU) crystals are found in ~25% of patients with asymptomatic hyperuricemia (AH) by ultrasound (US) [1,2]. Whether AH patients with crystal deposits depict an increased CV risk has not been assessed so far. We aimed to assess the association between the deposit of MSU crystals in AH and the severity and extension of the coronary atherosclerotic disease (CAD).

Methods: Cross-sectional study, approved by the local ethics committee. Consecutive patients with AH (serum uric acid [SUA] >7.0 mg/dL) admitted due to an acute coronary event were selected. Those with current urate lowering treatment (ULT) were excluded. US of both knees and 1^stMTP joints was performed to detect signs of MSU crystals deposition: doble contour sign, snow storm sign, tophus or joint effusion. When present, US-guided arthrocentesis was performed to confirm MSU crystals by polarised light microscopy. US and microscopy findings were later reviewed by a blinded rheumatologist. CAD was assessed through the severity of coronary artery calcification (absent, mild, moderate or severe) and the total of significant coronary lesions (>50% of the diameter) at coronariography by a blinded cardiologist. Traditional CV risk factors were also collected. Association between coronariographic features and crystal identification was analysed by logistic regression for binary variables and lineal regression for continous variables.

Results: Fifty-one patients were enrolled, median (p25-75) age 73 years (59-81), 76.5% males. Median SUA at admission was 7.6 mg/dL (7.08-8.6). Moderate-to-severe calcification was present in 21 (41.2%) patients, and the median number of significant coronary lessions was 3.0 (2-5). US found lesions in 49 (96.0%) patients: joint effusion in 94.1%, tophi in 9.8%, doble contour sign in 9.8% and snow storm sign in 3.9%. Arthrocentesis was performed in 48 patients. MSU crystals were identified in 11 patients (21.6% of total). No significant differences between groups were found in traditional CV risk factors or SUA levels. The presence of moderate to severe coronary calcification significantly differed between groups and strongly associate to the detection of MSU crystals [Table]. The number of significant lesions did not associate to MSU crystals identification, though a trend tomards more lesions in MSU+ patients was noted.

Conclusion: Our study found a more severe coronary calcification in those AH patients with deposits of MSU crystals. These patients might benefit from ULT aiming to reduce their CV risk, but this should be addressed in future studies.

References: [1] Arthritis Res Ther; 13:R4. [2] Ann Rheum Dis; 71:157.

Table.

	MSU+ patients (n= 11)	MSU- patients (n=40)	p-value	Association analysis
Moderate-severe coronary calcification (n,%)	8 (72.7%)	13 (32.5%)	0.016	OR 9.406+ (95%CI 1.459, 60.637)
Significant coronary lesions (median, p25-75)	4.0 (3.0-5.0)	3.0 (1.3-4.0)	0.137	β 0.693 (95%CI -0.596, 1.982) R2 0.003

MSU: monosodium urate; OR: odds ratio; CI: confidence interval. ⁺ Model adjusted for age, gender, hypertension, diabetes, dyslipemia, smoking, glomerular filtration rate and serum uric acid at admission.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/asymptomatic-deposit-of-monosodium-urate-crystals-associates-to-a-more-severe-coronary-calcification-in-hyperuricemic-patients-with-acute-coronary-syndrome/