Semiautomated carotid artery plaque composition: are intraplaque CT imaging features associated with cardiovascular risk factors?

Background: Little remains known about the connection between cardiovascular (CV) risk factors and carotid plaque morphologies. This study set out to assess for any such associations.

Materials and methods: A retrospective review was completed of consecutive patients that had CTA neck imaging prior to CEA. Body mass index (BMI), tobacco and/or alcohol use, and history of diabetes and/or hypertension were collected from patients' medical records. Lab values were dichotomized based on values: total cholesterol < 200 or ≥ 200; low-density lipoprotein (LDL) < 130 or ≥ 130, high-density lipoprotein < 35 or ≥ 35, and triglycerides < 200 or ≥ 200. A semiautomated analysis of CTA images computed maximum stenosis, intraplaque volumes of intraplaque hemorrhage, lipid-rich necrotic core (LRNC), and matrix, and intraplaque volume and proportional plaque makeup of calcifications of each carotid plaque.

Results: Of 87 included patients, 54 (62.1%) were male. Mean age was 70.1 years old. Both diabetes and hypertension were associated with greater intraplaque calcification volume (p = 0.0009 and p = 0.01, respectively), and greater proportion of calcification within a plaque (p = 0.004 and p = 0.01, respectively). Higher BMI was associated with greater intraplaque volume of LRNC (p=0.02) and matrix (0.0007). Elevated total cholesterol was associated with both larger intraplaque calcification volume (p = 0.04) and greater proportion of calcification within a plaque (p = 0.01); elevated LDL was associated with greater intraplaque calcification volume (p = 0.005).

Conclusion: Multiple CV risk factors are associated with morphological differences in carotid artery plaques. Dysregulation of both total cholesterol and LDL and higher BMI are associated with higher volumes of intraplaque LRNC, a marker of plaque vulnerability.