Cardiovascular monosodium urate (MSU) deposits can be detected by dual-energy computed tomography (DECT) significantly more often in patients with gout than in healthy controls, according to study results published in JAMA Cardiology.
Investigators conducted a prospective study of 106 patients seen at a rheumatology clinic between January 2017 and November 2018. Patients with gout were evaluated according to the American Rheumatism Association classification criteria. Healthy controls were defined as individuals with no prior history or current evidence of gout attacks, or inflammatory rheumatic diseases. All study participants were aged >35 years and underwent DECT to assess MSU deposits in the aorta and coronary arteries. Researchers also calculated coronary calcium score. In addition, they examined cadavers, using DECT to identify any cardiovascular MSU deposits, and DECT positivity was verified with a polarizing microscope. Frequency of MSU deposits was compared between the patient and control group using a 2-tailed t test. The positive predictive value of DECT for MSU deposits was calculated using results from the cadaver tests.
The final study cohort comprised 59 patients with gout (mean age, 59±5.7 years [age range, 47-89 years]) and 47 healthy controls (mean age, 70±10.4 years [age range, 44-86 years]). Most patients in the gout (78.0%) and control (59.6%) groups were men. Six cadavers were also analyzed, with a mean age at death of 76±17 years (age range, 56-95 years).
Compared with the control group, patients with gout experienced significantly higher frequencies of cardiovascular (χ2 =17.68; P <.001) and coronary (χ2 =8.97; P =.003) MSU deposits. MSU deposits were detected in 51 (86.4%) patients with gout, among whom 10 (16.9%) had aorta deposits, 19 (32.2%) had coronary artery deposits, and 22 (37.3%) had both aorta and coronary deposits. However, just 7 (14.9%) healthy controls demonstrated cardiovascular MSU deposits: 2 (4.3%) with aortic deposits, 2 (4.3%) with coronary artery deposits, and 3 (6.4%) with both aortic and coronary artery deposits.
In addition, coronary calcium score was significantly higher among patients with gout (900 Agatston units [AU]; 95% CI, 589-1211 AU) compared with healthy controls (263 AU; 95% CI, 76-451 AU; P =.001). Patients with MSU deposits had significantly higher coronary calcium scores (950 AU; 95% CI, 639-1261 AU) compared with those without MSU deposits (217 AU; 95% CI, 37-397AU; P <.001). Gout attacks were also more common among patients with MSU (χ2 =35.96; P <.001). From the 6 cadavers, 8 biopsy specimens were collected and determined to be MSU-positive with DECT; 7 cadaver specimens were histologically proven to be present by polarizing microscopy. It was indicated that DECT had a positive predictive value for MSU deposits of 87.5%.
Overall, MSU deposits observed with DECT were more frequent in patients with gout compared with healthy controls. Gout and MSU deposits were also associated with higher coronary calcium score. These data indicate the utility and feasibility of DECT-detected cardiovascular MSU deposits. Further study is required to analyze the relationship between gout and coronary heart disease.
Klauser AS, Halpern EJ, Strobl S, et al. Dual-energy computed tomography detection of cardiovascular monosodium urate deposits in patients with gout [published online September 11, 2019]. JAMA Cardiol. doi:10.1001/jamacardio.2019.3201