Pathological Quantification of Carotid Artery Plaque Instability in Patients Undergoing Carotid Endarterectomy

Circ J. 2017 Dec 25;82(1):258-266. doi: 10.1253/circj.CJ-17-0204. Epub 2017 Jul 29.


Background: Unstable atherosclerotic carotid plaques cause cerebral thromboemboli and ischemic events. However, this instability has not been pathologically quantified, so we sought to quantify it in patients undergoing carotid endarterectomy (CEA).Methods and Results:Carotid plaques were collected during CEA from 67 symptomatic and 15 asymptomatic patients between May 2015 and August 2016. The specimens were stained with hematoxylin-eosin and elastica-Masson. Immunohistochemistry was performed using an endothelial-specific antibody to CD31, CD34 and PDGFRβ. The histopathological characteristics of the plaques were studied. By multiple-variable logistic regression analysis, plaque instability correlated with the presence of plaque rupture [odds ratio (OR), 9.75; P=0.013], minimum fibrous cap thickness (OR per 10 μm 0.70; P=0.025), presence of microcalcifications in the fibrous cap (OR 7.82; P=0.022) and intraplaque microvessels (OR 1.91; P=0.043). Receiver-operating characteristics analyses showed that these factors combined into a single score diagnosed symptomatic carotid plaques in patients with carotid artery stenosis with a high level of accuracy (area under the curve 0.92; 95% confidence interval 0.85-0.99 vs. asymptomatic).

Conclusions: This analysis of carotid plaque instability strongly suggested that the diagnostic scoring of carotid plaque instability improves the understanding and treatment of carotid artery disease in patients undergoing CEA.

Keywords: Carotid artery disease; Carotid endarterectomy; Unstable plaque.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carotid Artery Diseases / surgery
  • Carotid Stenosis
  • Endarterectomy, Carotid / adverse effects*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Odds Ratio
  • Plaque, Atherosclerotic / complications
  • Plaque, Atherosclerotic / diagnosis*
  • Risk Assessment / methods*
  • Risk Factors
  • Rupture, Spontaneous
  • Severity of Illness Index*