Relevance of Carotid Intima-Media Thickness and Plaque Morphology in the Risk Assessment of Patients with Acute Ischemic Cerebral Infarcts: A Case-Control Study of Large Series from a Single Center

Abstract

Background: Carotid atherosclerosis is not only a marker of systemic atherosclerosis but also a predictor of ischemic stroke. The purpose of this study is to correlate the relationship between atherosclerotic risk factors, plaque categories, percentage of stenosis, stroke subtypes, and carotid intima-media thickness (CIMT) in patients with acute ischemic stroke.

Methods: This case-control study was conducted over 4 years from December 2014 to December 2018. A total of 500 cases diagnosed with acute cerebral infarct using computed tomography or magnetic resonance imaging were included in the study. Two hundred and fifty healthy controls were studied for the presence of atherosclerotic risk factors and carotid artery IMT by B-mode Doppler ultrasonography. The IMT value thus calculated was 0.79 mm and such a value would include >95% of the controls. Carotid plaques were detected from both sides of IMT measurement of the carotid system.

Results: A total of 500 cases of acute infarct and 250 healthy controls were included in this case-control study. CIMT was abnormal in 348 cases with 192 males and 156 females with a mean value of 0.912 ± 0.124 against 0.794 ± 0.132; P < 0.001 controls. Mean CIMT (averaged right and left) varied directly according to the increasing plaque stenosis ranging from 0.70 mm to 0.96 mm in males and 0.68 mm to 0.94 mm in females ranging from no plaque to cases with ≥50% stenosis (P < 0.001 across stenosis categories). On multivariate analysis, CIMT (>0.79) remained associated as compared to other variables (PR [Probability] 5.33, 95% confidence interval: 1.398-22.784; P = 0.012). Mean right CIMT of patients with lacunar infarction, cardioembolism, and large artery stroke was 0.886 ± 0.230, 0.919 ± 0.171, and 0.938 ± 0.169 mm, respectively (P = 0.032). Mean left CIMT of patients with lacunar infarction, cardioembolism, and large artery stroke was 0.884 ± 0.195, 0.916 ± 0.144, and 0.930 ± 0.137 mm, respectively (P = 0.034).

Conclusion: CIMT measurements are independent markers of acute ischemic cerebral infarcts. In the current study, CIMT was found to be higher among acute ischemic stroke patients who were the elderly, smoker, hypertensive, diabetic, and hypercholesterolemic than that of nonsmoker, normotensive, nondiabetic, and normocholesterolemic controls.

Keywords: Acute ischemic cerebral infarct; carotid intima-media thickness; common carotid artery; plaque category; stenosis; stroke subtypes.

Figure 1

Defining plaque morphology. (a) Focal plaque at the far wall of the carotid bulb with calcification and acoustic shadowing. (b) Focal smooth homogenous plaque (arrow) located on the far wall of the proximal common carotid artery. (c) Moderate-to-large amount of heterogeneous multiple plaques (arrows) with focal calcification and irregular surface, in mid common carotid artery