Subclinical carotid atherosclerosis in patients with traditional cardiovascular risk factors

Purpose: Carotid atherosclerosis is a marker of cardiovascular disease burden and is associated with cardiovascular morbidity and mortality however its correlation with the traditional cardiovascular risk factors is sometimes doubted. Our aim was to study the relationship between the extent of carotid artery atherosclerosis and cardiovascular risk factors and assess the prevalence of subclinical atherosclerosis in asymptomatic middle-aged subjects. Methods: This cross-sectional study included 123 patients (mean age 56,4±7,1 years, 45% female) with no evidence of coronary artery disease and with ≥1 traditional cardiovascular risk factor. For each participant 10-year cardiovascular risk was estimated using SCORE (Systemic Coronary Risk Evaluation) chart. In cigarette smokers number of pack-years was calculated. The extent of subclinical atherosclerosis was evaluated through carotid artery ultrasound imaging by assessing carotid intima-media thickness (CIMT) and presence of atherosclerotic plaque. Results: CIMT was the highest in the carotid bifurcation (1,29±0,46 mm in men and 1,27±0,46 mm in women). The mean values of CIMT in the common carotid artery (CCA) were 0,82±0,15 mm in men and 0,79±0,13 mm in women, in the internal carotid artery - 0,88±0,42 mm and 0,77±0,27 mm, respectively. Carotid plaque was present in total of 48 (39%) participants (in 46% of males and in 31% of females). A logical relationship was observed between common carotid intima-media thickness (CCIMT) and risk category, calculated by SCORE chart. CCIMT was 0,93±0,14 mm in high-risk group, 0,82±0,13 mm in intermediate-risk group and 0,71±0,09 mm in low-risk group, p<0,0001. The differences for the occurrence of the carotid plaque in low (13%), intermediate (43%) and high (78%) risk groups were also significant (p<0,0001). Robust regression analysis was performed to evaluate the association between cardiovascular risk factors and carotid atherosclerosis. The analysis demonstrated that among the risk factors, age and smoking had a strongest influence on CCIMT. A one year increase in age resulted in 0,008 mm increase of CCIMT (95% CI: 0,006-0,011; p<0,0001), while the increase of smoking by 1 pack-year resulted in 0,004 mm increase of CCIMT (95% CI: 0,002-0,006; p<0,0001). Conclusions: In asymptomatic patients, the extent of subclinical atherosclerosis correlates with the total cardiovascular risk calculated by SCORE chart, while age and smoking are the strongest determinants of CCIMT. Atherosclerotic plaque is present in total of 39% of asymptomatic middle-aged subjects, and its prevalence in women is 31%.