Introduction: Coronary artery calcium (CAC) scores have been found to be highly predictive of future major adverse cardiovascular events among patients with no prior history of coronary artery disease. Ultrasound-derived Carotid intima-media thickness (CIMT) does not directly measure any specific coronary artery characteristic, but purportedly does represent over-all atherosclerotic burden. However, how CIMT correlates with the direct coronary artery measures of CAC and CT Coronary Angiography (CTCA)-derived coronary artery plaque compositional characteristics, especially among asymptomatic diabetic patients, is unknown.
Methods: A total of 182 asymptomatic diabetic patients who were enrolled in the FACTOR-64 trial and randomized to receive a baseline CAC score and CTCA, and also underwent bilateral carotid ultrasonography, were included in this study. CAC scores, CCTA quantitative coronary plaque compositional characteristics, and CIMT measurements were obtained using semi-automated. Left and right CIMT results were averaged and compared to stratified CAC scores and CTCA results and analyzed for significance by ANOVA.
Results: The mean age of the studied cohort was 61.8 years and 54% were male. The mean duration of diabetes was 10.4 years. Table 1 shows the average CIMT measurements stratified by CAC and CTCA. As previously reported, CAC scores correlated most with the presence of calcified plaque. No significant differences in average CIMT were identified based on stratifications of either CAC or any coronary plaque compositional characteristic.
Conclusions: In asymptomatic diabetic patients, CIMT does not correlate with CAC or coronary plaque compositional characteristics. This data offers additional evidence that CIMT has little utility as a surrogate marker for coronary artery disease in patients with diabetes.