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CAROTID PLAQUE IN THE PRESENCE OF NORMAL COMMON CAROTID ARTERY INTIMAL MEDIAL THICKNESS

CAROTID PLAQUE IN THE PRESENCE OF NORMAL COMMON CAROTID ARTERY INTIMAL MEDIAL THICKNESS

 



Author Block DW Armstrong, D Brouillard, M Matangi
Kingston, Ontario


BACKGROUND: Much has been made about the measurement of IMT in the distal common carotid artery (CCA) and its ability to predict patients at increased risk for future cardiovascular events. It has been our impression that there are many patients with carotid plaque either in the carotid bulb, the internal carotid artery (ICA) or the external carotid artery (ECA) who have a normal CCA IMT. The purpose of our investigation was to assess the prevalence of a normal CCA IMT in patients with carotid plaque.
METHODS: CAROTIDfile, the carotid duplex imaging module of CARDIOfile our cardiology database and reporting system was searched for all patients with an ICA stenosis of 1-39% or greater. Carotid stenoses were defined using established ICAVL imaging and velocity criteria. Carotid disease could be bilateral or unilateral. We then looked at the CCA IMT values for these patients. A normal CCA IMT was deemed to be present when both the R) and L) CCA IMT were <1.00mm.
RESULTS: See Table 1.
CONCLUSION: In patients with carotid plaque in the ICA, ECA or carotid bulb, 38.5% have normal CCA IMT in both common carotid arteries. It is clear that by focusing only on CCA IMT one misses the bigger picture, which is clear evidence of atherosclerosis, indicating increased cardiovascular risk. We believe there should be a paradigm shift away from CCA IMT towards carotid plaque.

Table 1. *The normal on one side are abnormal by ICAVL on the other.
Total. 2291 Percentage
Bilateral plaque. 1708 74.6
Unilateral plaque 583 25.4
IMT ≤ 1.00mm in both CCA 883 38.5
ICAVL stenosis R) carotid L) carotid
Normal* 296 287
1-39% 1396 1342
40-59% 461 509
60-79% 87 92
>80% 51 61