Implication of Earlier Carotid Atherosclerosis for Stroke and Its Subtypes

Yoji Nagai, MD, PhD, Kazuo Kitagawa, MD, PhD, Masayasu Matsumoto, MD, PhD

Disclosures

Prev Cardiol. 2003;6(2) 

In This Article

Carotid Atherosclerosis as a Reflector of Systemic Atherosclerosis

As an indicator of earlier carotid atherosclerosis, common carotid artery (CCA) wall thickness is often evaluated by measuring its intima-media thickness (IMT). Studies have shown associations of increased CCA IMT with traditional and relatively new cardiovascular risk factors.[6,7,8,9,10,11,12,13,14] Also, increased IMT has been reported in patients with end-organ damage such as left ventricular hypertrophy,[15] cerebral white matter lesions,[16] and albuminuria,[17] as well as in those with a history of cardiovascular events. Moreover, increased IMT is strongly associated with the presence of atheroma elsewhere in the carotid arteries,[18] the coronary arteries,[19] and the abdominal aorta.[20] On the basis of these findings, CCA IMT appears to reflect systemic atherosclerosis.

CCA IMT has been often evaluated as a surrogate end point for cardiovascular diseases; however, CCA is less prone to atherosclerosis than the carotid bifurcation, and whether a slight increase in IMT represents focal atherosclerosis is controversial.[21,22] Under such conditions, Ebrahim et al.[23] have shown that focal carotid plaques are more strongly associated with cardiovascular risk than is a diffuse increase in IMT.[23] For the quantification of such plaques, Handa et al.[24] used a scoring system, which is currently known as the "plaque score" (PS). PS is defined as the sum of all plaque heights in bilateral carotid arteries. Because PS increases in parallel with the height and number of atheromas, it may allow for the quantification of later stages of carotid atherosclerosis. PS has been associated with cardiovascular risk factors and diseases,[24,25,26,27] suggesting its potential utility as a reflection of systemic atherosclerosis. Nonetheless, partly due to the lack of large prospective studies, its advantage over IMT measurements is not currently known.

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