Introduction : Gout is associated with higher cardiovascular risk and increases with disease severity. It is not clear if the monosodium urate (MSU) crystal burden is associated with traditional cardiovascular risk factors. The objective of this study was to explore the relationship between the extent of MSU deposition assessed with ultrasonography (US) and dual-energy CT (DECT) and cardiovascular risk.
Methods : Gout patients naive of urate lowering therapy were included in this cross-sectional study to undergo DECT scans for the assessment of total MSU volume deposition of the knees and feet, and US to evaluate the number of joints with the double contour (DC) sign among the femoro-patellar, talo-crural and first metatarsophalangeal joints. Participants were screened for traditional cardiovascular risk factors and levels of the ACC/AHA 10 year-risk for heart disease or stroke was calculated. The primary endpoint was the Spearman correlation coefficient ρ between DECT MSU volume and cardiovascular risk.
Results : A total of 50 patients predominantly male (46/50) aged 62.6 years (±14.1) were included. Participants had gout duration of 9.5 years (±11.8), had experienced 4.1 flares (± 6.3) over the past year, had serum urate (SU) levels of 8.1mg/dL (±2.3), and 35/50 had at least one US tophus of 1.5 cm3 (±1.8). The volume of MSU deposits with DECT was 3.9cm3 (± 11.2) for the feet and 2cm3 (± 4.4) for the knees. Overall, 28 patients presented with the metabolic syndrome. Correlations between DECT volumes of MSU deposits of the knees, feet, and knees + feet were poor with ρ respectively of 0.23, 0.03 and 0.21. The was no correlation between the number of joints with the DC sign and cardiovascular risk (ρ of 0) and the correlation was poor with SU levels (ρ=0.09). Patients with the metabolic syndrome had similar DECT volume of MSU deposits than those without (p=0,29).
Conclusion : This study suggests that the association of gout with traditional cardiovascular risk factors is not related to the extent of the monosodium urate crystal burden.