Common carotid intima-media features determine distal disease phenotype and vulnerability in asymptomatic patients

Objectives: There is a growing awareness of the importance of carotid plaque features evaluation in stroke prediction. Carotid intima-media thickness (IMT) and recently its echogenicity were used for stroke prediction, although their clinical relevance was not well determined. The aim of this study was to assess the relationship between common carotid artery (CCA) ultrasound markers of atherosclerosis and distal, bifurcation and internal carotid artery (ICA), plaque features.

Methods: We analyzed 137 carotid arteries in 87 asymptomatic patients with known carotid disease (mean age 69 ± 6 year, 34.5% females). Intima media thickness (IMT) and its gray scale median (IM-GSM) were measured at the CCA. Plaque textural features including gray scale median (GSM), juxtaluminal black area (JBA-mm(2)) without a visible cap, and plaque coarseness, at bifurcation and ICA were also determined. CCA measurements were correlated with those of the distal plaques.

Results: An increased IMT in CCA correlated with plaque irregularities in the bifurcation and ICA (r=0.53, p<0.001), while IM-GSM was closely related to plaque echogenicity (GSM) (r=0.76, p<0.001), and other textural plaque features. Both, IMT and IM-GSM correlated weakly with stenosis severity (r=0.27, p=0.001 and r=-0.18, p=0.026) respectively.

Conclusion: In asymptomatic patients, measurements of CCA reflect distal, bifurcation and ICA disease, with IMT reflecting plaque irregularities and IM-GSM as markers of textural plaque abnormalities. Integrating measurements of both IMT and IM-GSM in a model could be used as a better marker of disease vulnerability over and above each measure individually.