Subclinical atherosclerosis in patients with rheumatoid arthritis by utilizing carotid intima-media thickness as a surrogate marker

BACKGROUND & OBJECTIVES: Patients with rheumatoid arthritis (RA) are more prone for accelerated atherosclerosis and Asian Indians as an ethnic group are predisposed to a high risk of premature atherosclerosis. However, sparse data are available regarding the burden of atherosclerosis among asymptomatic adult patients with RA in south India. We studied the burden of asymptomatic atherosclerosis in adult south Indian patients with RA at Tirupati, Andhra Pradesh, India, utilizing carotid intima-media thickness (CIMT) as a surrogate marker. METHODS: Ultrasound examination of the carotids and CIMT measurement (mm) were carried out in 32 patients with RA, 32 age- and gender-matched normal controls, and 32 patients with atherosclerosis and angiographically proven coronary artery disease. The CIMT values in patients with CAD and normal controls were used to derive the appropriate cut-off value of CIMT for defining atherosclerosis that would be applicable for the ethnic population studied. RESULTS: Patients with RA had a higher mean CIMT (mm) compared with normal control subjects (0.598 ± 0.131 vs 0.501 ± 0.081; P = 0.001). Carotid plaque was found more frequently among the cases compared with normal controls [5/32 (15.6%) vs 0/32 (0%), P=0.020]. Using this cut-off value derived by the receiver operator characteristic curve method (≥ 0.57 mm; sensitivity 84.4; specificity 90.6%) and the 75(th) percentile value among normal controls (≥ 0.55 mm) as surrogate markers, the presence of subclinical atherosclerosis was significantly more among asymptomatic patients with RA compared with normal controls [(59.3 vs 12.5%; P<0.001) and (62.5 vs 25%; P<0.001) respectively]. INTERPRETATION & CONCLUSIONS: Based on the present findings CIMT appears to be a useful surrogate marker for detecting subclinical atherosclerosis in adult Indian patients with RA.