Crystal deposition measured with dual-energy computed tomography: association with mortality and cardiovascular risks in gout.

OBJECTIVES: To determine whether the volume of monosodium urate (MSU) crystal deposition measured with dual-energy CT (DECT) is predictive of short-term mortality and development of cardiovascular comorbidities and diabetes mellitus. METHODS: Patients with a diagnosis of gout having had baseline DECT scans of their knees and feet to measure the volume of MSU crystal deposition were included to undergo a follow-up visit. Risk factors for mortality and a composite variable (onset of any cardio-metabolic event) were examined using multivariable Cox models. RESULTS: A total of 128 patients aged 66.1 (14.0) years with gout durations of 11.4 (10.4) years were included; most were naïve of urate lowering therapy (61.7%), with a follow-up visit at 24 (12, 36) months. Baseline serum urate (SU) level was 7.44 (2.29) mg/dl and DECT volume of MSU crystals was 0.2 (0, 0.9) cm3. A total of 14 patients died during follow-up, 6/14 from a cardiovascular cause, and 17 patients presented a new cardio-metabolic comorbidity. Factors associated with mortality risk were baseline DECT volume of MSU crystals [hazard ratio (HR) 1.02, 95% CI: 1.002, 1.03] and baseline SU level (HR 1.04, 95% CI: 1.003, 1.06). DECT volume of MSU crystals was the only factor associated with the onset of cardio-metabolic comorbidities with a HR of 1.014 (95% CI: 1.001, 1.03). CONCLUSIONS: Volume of MSU crystals measured with DECT is a biomarker for the risk of developing new cardio-metabolic diseases and for all-cause mortality.

Characteristics Of Difficult-To-Treat Psoriatic Arthritis: A Comparative Analysis.

OBJECTIVE: The EULAR task force recently published the difficult-to-treat rheumatoid arthritis (D2T RA) criteria, however, a definition of D2T patients in psoriatic arthritis (PsA) is still lacking. To date, we have little data concerning D2T PsA, especially in real-world. One of the limitations of the D2T RA EULAR definition is the absence of a temporal criterion. The primary endpoint of this work was to study the characteristics of D2T PsA patients using the EULAR definition. The second objective was to study a sub-group of patients with a predefined more stringent definition including a temporal criterion. METHODS: A retrospective study was performed in a tertiary center. D2T PsA was defined as failure of ≥ 2 b/tsDMARDs with different mechanism of action. Very D2T PsA was defined as failure of ≥ 2 b/tsDMARDs in less than 2 years of follow-up. D2T and Very D2T PsA patients were compared to nD2T PsA patients using statistical tests. RESULTS: 150 PsA patients were included (from 2004 to 2015): 49 D2T PsA and 101 nD2T PsA. D2T PsA was associated with a higher prevalence of axial involvement (p=0.030), axial and/or peripheral structural damage (p=0.007) at baseline and more bDMARDs discontinuation due to poor dermatological control (p=0.005). There was no significant difference regarding comorbidities such as obesity, smoking status, fibromyalgia or depression. In multivariate analysis, peripheral structural damage at baseline was found to be a predictive factor for D2T PsA with an OR of 2.57 (1.16 to 5.69; p=0.020). 17 PsA (11.3%) patients were categorized as Very D2T PsA. When compared to nD2T group, proportion of obesity was higher (p=0.015) and axial involvement was more prevalent in the Very D2T group (p=0.020). CONCLUSION: D2T PsA patients had a higher prevalence of axial involvement, peripheral structural damage and therapeutic discontinuation due to poor dermatological control whereas Very D2T PsA patients were more likely obese with axial involvement. Very D2T PsA represent a minim proportion among patients when applying a more stringent definition. Pending the PsA D2T definition by the European and American societies, this study highlights some characteristics that may help practitioners better identify D2T patients.

Prediction of renal and cardiometabolic outcomes in gout during urate-lowering therapy by sonography.

OBJECTIVES: To assess whether the extent of monosodium urate (MSU) crystal deposition estimated by ultrasound could predict renal and cardiometabolic events during urate-lowering therapy (ULT). METHODS: A prospective study on gout patients from two referral centers initiating ULT who underwent baseline ultrasound and were followed for 1 year. Ultrasound scans assessed six joints for double-contour (DC) signs and tophi. A five-point change (mL/min/1.73 m2 ) in the glomerular filtration rate at month 12 (M12) was considered significant. Outcomes of interest were renal function degraded versus improved and a composite cardiometabolic outcome (new hypertension, diabetes, atherosclerotic disease, and cardiovascular death). Homogeneity analyses and Cox regression models were performed. RESULTS: One hundred sixty patients were recruited. At baseline, 81.1% of patients (n = 129) showed sonographic tophi with a mean number of 1.4 joints (±1.3) with a DC sign. At M12, 18 patients (11.3%) were lost to follow-up. The serum urate (SU) target (<6.0 mg/dL) was reached in 86 patients (69.9%). Regarding renal function, 15.9% of patients showed improvement, while in 31.0% it degraded. Fourteen new cardiometabolic events occurred in 12 patients. Neither the DC sign nor tophi showed any significant impact on the outcomes of interest. Baseline SU level was higher in those with renal improvement but not with renal decline, while achieving the SU target protected against new cardiometabolic events (HR = 0.2; 95% CI: 0.05-0.81). CONCLUSIONS: Sonographic MSU crystal burden was unhelpful in predicting renal and cardiometabolic events during the first year of ULT. Reaching the SU target prevented cardiometabolic events, while its benefit in preserving/improving renal function is unclear.