Monosodium urate burden assessed with dual-energy computed tomography predicts the risk of flares in gout: a 12-month observational study : MSU burden and risk of gout flare.

BACKGROUND: Predicting the risk of flares in patients with gout is a challenge and the link between urate burden and the risk of gout flare is unclear. The objective of this study was to determine if the extent of monosodium urate (MSU) burden measured with dual-energy computed tomography (DECT) and ultrasonography (US) is predictive of the risk of gout flares. METHODS: This prospective observational study recruited patients with gout to undergo MSU burden assessment with DECT (volume of deposits) and US (double contour sign) scans of the knees and feet. Patients attended follow-up visits at 3, 6 and 12 months. Patients having presented with at least one flare at 6 months were compared to those who did not flare. Odds ratios (ORs) (95% confidence interval) for the risk of flare were calculated. RESULTS: Overall, 64/78 patients included attended at least one follow-up visit. In bivariate analysis, the number of joints with the double contour sign was not associated with the risk of flare (p = 0.67). Multivariate analysis retained a unique variable: DECT MSU volume of the feet. For each 1 cm3 increase in DECT MSU volume in foot deposits, the risk of flare increased 2.03-fold during the first 6 months after initial assessment (OR 2.03 (1.15-4.38)). The threshold volume best discriminating patients with and without flare was 0.81 cm3 (specificity 61%, sensitivity 77%). CONCLUSIONS: This is the first study showing that the extent of MSU burden measured with DECT but not US is predictive of the risk of flares.

The lack of association between the burden of monosodium urate crystals assessed with dual-energy computed tomography or ultrasonography with cardiovascular risk in the commonly high-risk gout patient.

BACKGROUND: Gout is associated with higher cardiovascular risk that increases with disease severity. The objective of this study was to explore the relationship between the extent of monosodium urate (MSU) crystal deposition, assessed with ultrasonography (US) and dual-energy computed tomography (DECT), and cardiovascular risk. METHODS: Gout patients were included in this cross-sectional study to undergo DECT scans for the assessment of total MSU volume deposition in the knees and feet, and US to evaluate the number of joints with the double contour (DC) sign. Participants were screened for traditional cardiovascular risk factors, and levels of the American College of Cardiology (ACC)/American Heart Association (AHA) 10-year risk for heart disease or stroke were calculated. The primary endpoint was the Spearman correlation coefficient ρ between DECT MSU volume and cardiovascular risk. RESULTS: A total of 42 patients were included; they were predominantly male (40/42) and aged 63.0 ± 13.2 years. Overall, 28/42 patients presented with the metabolic syndrome and the average 10-year coronary event or stroke risk according to the ACC/AHA (n = 33) was 21 ± 15%. Correlations between DECT volumes of MSU deposits in the knees, feet, and knees + feet and cardiovascular risk according to the ACC/AHA were very poor, with ρ = 0.18, -0.01, and 0.13, respectively. The was no correlation between the number of joints with the DC sign and cardiovascular risk (ρ = -0.07). DECT MSU deposit volume was similar in patients with and without metabolic syndrome (p = 0.29). CONCLUSIONS: The extent of MSU burden does not increase the estimated risk of cardiovascular events in gout patients.

Ultrasonography and dual-energy computed tomography provide different quantification of urate burden in gout: results from a cross-sectional study.

BACKGROUND: Ultrasonography (US) and dual-energy computed tomography (DECT) can assess urate burden in gout. The objective of this study was to compare the quantification of urate deposition provided by US to the one provided by DECT. METHODS: Patients with a diagnosis of gout were prospectively recruited to undergo quantification of urate deposition using US and DECT. US examination for tophi and the double contour (DC) sign was performed on the knees and feet and corresponding DECT scans provided volumes of tophi and of overall urate deposition. The primary endpoint was the intra-class correlation coefficient (ICC) of the volume of the index tophus measured by US and DECT and its 95% confidence interval (CI 95%). RESULTS: Of the 64 patients included, 34 presented with at least one tophus on US. DECT inter-reader agreement for urate deposition was perfect with an ICC of 1 (1-1) and good for the measurement of the index tophus with an ICC of 0.69 (0.47-0.83). The ICC for the measurement of the index tophus between the two techniques was poor with a value of 0.45 (0.1-0.71). The average ratio between the index tophi volume as assessed by DECT and US was 0.65. The number of DC-positive joints did not correlate with DECT volume of overall deposits (Spearman correlation coefficient of 0.23). CONCLUSIONS: DECT measurements of tophi give smaller volumes to the same tophi measured with US, and US signs of urate deposition in joints do not correlate with overall DECT volumes of extra-articular deposition.

Bone metastases revealing primary tumors. Comparison of two series separated by 30 years.

OBJECTIVE: To compare two series of patients admitted to a rheumatology department for bone metastases 30 years apart and to obtain a pragmatic estimation of the percentage of bone metastases revealing cancer. METHODS: The recent series was composed of 132 patients seen between 1989 and 1996 and the earlier series of 50 patients admitted between 1958 and 1967. All patients were admitted to the same rheumatology department for bone metastases from a diagnosed or undiagnosed primary. Both series were studied retrospectively. The rate of occurrence of each cancer diagnosis was determined in the patients with and without known primaries. RESULTS: Among the patients with metastatic disease as the first manifestation of cancer, the percentage with lung cancer increased from the early to the recent series, particularly among women, whereas the percentages with prostate and breast cancer decreased. The primary remained unknown in 27% and 38% of patients in the early and recent series, respectively. CONCLUSION: Despite the introduction of new investigations, our ability to identify primaries responsible for bone metastases does not seem to have improved. However, our data should be interpreted with caution since recruitment probably differed between the two series.