Reproducibility of histological assessment of carotid plaque: implications for studies of carotid imaging.

BACKGROUND

Thromboembolism from carotid plaque is an important cause of stroke. Identification of unstable plaque would therefore be clinically useful. Unfortunately, studies of carotid plaque imaging have shown poor agreement with histology. However, this may be due to inconsistent methods and the variability of assessments of carotid plaque histology, rather than inadequate imaging.

METHODS

We assessed the reproducibility of histological assessment in 60 plaques, and section-to-section variability along the length of 26 plaques.

RESULTS

Kappa values ranged from 0.35 to 0.89 and from 0.44 to 0.68, respectively, for intra- and inter-observer reproducibility. There was considerable section-to-section variability within plaques.

CONCLUSIONS

The accuracy of imaging of carotid plaque morphology will be underestimated unless variability in the histology assessment is taken into account.