Coronary calcification in SLE: comparison with the Multi-Ethnic Study of Atherosclerosis

Objective. Accelerated atherosclerosis is a major cause of morbidity and death in SLE. The purpose of this study was to determine whether the prevalence and extent of coronary artery calcium (CAC) is higher in female SLE patients compared with a non-SLE sample from the Multi-Ethnic Study of Atherosclerosis (MESA). Methods. CAC was measured in 80 female SLE patients and 241 female MESA controls from the Baltimore Field Centre, ages 45 64 years, without evidence of clinical cardiovascular disease. Binary regression was used to estimate the ratio of CAC prevalence in SLE vs MESA controls, controlling for demographic and cardiovascular risk factors. To compare the groups with respect to the quantity of CAC among those with non-zero Agatston scores, we used linear models in which the outcome was a logtransformed Agatston score. Results. The prevalence of CAC was substantially higher in SLE. The differences were most pronounced and statistically significant in those aged 45 54 years (58% vs 20%, P< 0.0001), but were still observed among those aged 55 65 years (57% vs 36%, P = 0.069). After controlling for age, ethnicity, education, income, diabetes mellitus, hypertension, hyperlipidaemia, high-density lipoprotein levels, smoking, education and BMI, SLE patients still had a significantly higher prevalence of CAC than controls. Among those with CAC, the mean log Agatston score did not differ significantly between SLE and MESA participants. Conclusion. Women with SLE have a higher prevalence of CAC than comparable women without SLE, even after adjusting for traditional cardiovascular risk factors, especially among those aged 45 54 years.