The correlation between carotid artery atherosclerosis and clinical ischemic heart disease in lupus patients

The extent of subclinical atherosclerosis can be assessed by ultrasound measurement of carotid intima-media thickness (cIMT) and total plaque area (TPA). We aimed to investigate the correlation between measures of atherosclerosis as documented on imaging studies of the carotid vasculature and clinical coronary artery disease (CAD) in systemic lupus erythematosus (SLE).

The study patients were recruited from the University of Toronto prospective cohort of SLE patients. Patients who had a history of CAD were compared to those without CAD. TPA and cIMT were measured using high-resolution optimized ultrasound systems. Logistic regression models were used to investigate the strength of association between ultrasound measures of atherosclerosis and CAD. The strength of association as expressed by odds ratio (OR) was compared between TPA and cIMT.

A total of 103 SLE patients were analyzed (27 patients with a history of CAD). Carotid IMT correlated only moderately with TPA (r = 0.43, p < 0.001). Both measures were significantly associated with the presence of CAD. However, TPA showed a stronger association than cIMT (OR 9.55 vs. 2.02, respectively). TPA was also more strongly associated with dyslipidemia and hypertension compared to cIMT.

In SLE patients, cIMT correlates only moderately with TPA, suggesting that they measure different phenotypes of atherosclerosis. Carotid TPA correlated better than cIMT with cardiovascular risk factors and CAD, suggesting that it may serve as a better tool for the investigation of atherosclerosis in SLE.