Race-ethnic variation in carotid bifurcation geometry

Area of Science:

• Vascular anatomy
• Atherosclerosis research
• Race-ethnic health disparities

Background:

• Arterial geometry and local blood flow disturbances are implicated in atherogenesis.
• Carotid bifurcation hemodynamics are influenced by the relative sizes of the common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA).
• Carotid bifurcation atherosclerosis prevalence varies by race-ethnic group, being lower in African Americans despite a higher vascular risk factor profile.

Purpose of the Study:

• To investigate potential race-ethnic differences in carotid bifurcation anatomy.
• To determine if anatomical variations contribute to observed disparities in carotid atherosclerosis.

Main Methods:

• Measurements of CCA, carotid bulb, ICA, and ECA diameters were taken from cerebral angiograms.
• Calculated ratios included bulb/CCA, ICA/CCA, ECA/CCA, ECA/ICA, and total cross-sectional outflow/inflow ratio.
• Analysis included 272 bifurcations from African American, white, and Caribbean Hispanic patients.

Main Results:

• African Americans demonstrated a significantly lower ICA/CCA ratio (P < .001) and ICA/ECA ratio (P < .0001).
• African Americans showed a significantly higher ECA/CCA ratio (P < .0001) compared to white and Hispanic groups.
• The study population comprised 103 white, 87 Hispanic, and 82 African American patients, with a mean age of 59.8 years.

Conclusions:

• Significant race-ethnic differences exist in the relative dimensions of the CCA, ICA, and ECA.
• African Americans possess a proportionally smaller ICA and a larger ECA compared to white and Caribbean Hispanic individuals.
• These anatomical variations may play a role in the differential prevalence of carotid atherosclerosis among racial and ethnic groups.