Correlation Between the Intima-Media Thickness of the Proximal and Distal Common Carotids

BACKGROUND: Increased IMT (intima-media thickness) in carotids is used as an early atherosclerosis marker and to evaluate the risk of cardiovascular problems. Ultrasound is used in the evaluation because it is accessible and low cost. Measurements for different carotid regions are described. OBJECTIVE: To compare the proximal and distal region IMTs for the bilateral common carotid and guide its use in clinical practice. METHODS: The IMT was measured in the proximal and distal common carotid arteries of 798 individuals (35-74 years old) of both genders using high-resolution ultrasound. Pearson's correlation coefficient was used to establish associations. The analyses were initially performed for the entire sample as well as subgroups with IMT <0.90 mm (49% of the sample) and ≥0.90 mm for at least one measurement site. The statistical significance was p < 0.05. RESULTS: The correlations investigated were significant. In the group with an IMT <0.90 mm, the correlations were between 0.44 and 0.62. In the subgroup with an IMT ≥0.90 mm, the correlations were significantly reduced to between 0.20 and 0.40. CONCLUSION: The data suggest that the IMT is more uniform along the carotid during early development and tends develop focally as it progresses. Therefore, in clinical evaluations of patients, the common carotid length should be investigated bilaterally to better use the available software and discern the IMT.