Differences in the CT findings between vulnerable plaque and culprit lesions in acute coronary syndrome.

BACKGROUND

The CT finding of "vulnerable plaque" is widely regarded as similar to that of a culprit lesion in an acute coronary syndrome (ACS). However, this hypothesis may not be accurate, since "vulnerable plaques" may substantially change their morphology when they rupture to cause an ACS.

METHODS

We retrospectively evaluated coronary CT angiography data sets of 25 patients with ACS who had vulnerable (n = 10) or culprit plaques (n = 15). We analyzed CT features including positive remodeling (PR), low attenuation plaque (LAP), the napkin ring sign (NRS), degree of stenosis (normal, <50%, 50-99%, 100%), and myocardial hypoperfusion in the left ventricle.

RESULTS

There was no difference in the prevalence of PR, NRS, or LAP between vulnerable and culprit plaques. In contrast, a majority (80%, 8/10) of vulnerable plaques were associated with <50% luminal stenosis while total occlusion was identified in 47% (7/15) of culprit plaques (p = .037). In all patients with occlusion, myocardial hypoperfusion was demonstrated in the corresponding arterial territory on CT.

CONCLUSION

CT features of vulnerable and culprit plaques differ in cases with thrombotic occlusion reflecting dynamic plaque changes related to the episode of ACS.