Thin calcification (< 2 mm) can highly predict intraplaque hemorrhage in carotid plaque: the clinical significance of calcification types

Study on the correlation between carotid plaque calcification types and acute ischemic stroke

Introduction

Computed tomography angiography (CTA) was used to explore the correlation between the calcification types of carotid plaques and ipsilateral acute ischemic stroke. This could provide new insights into the clinical evaluation and treatment of ischemic stroke.

Methods

This study obtained information on patients undergoing head and neck CTA examinations at the First People's Hospital of Lianyungang between September 2022 and August 2023 to investigate the clinical differences in baseline data between the acute ischemic stroke and control groups. Patients meeting the inclusion and exclusion criteria were classified into 1 to 6 groups according to their plaque calcification characteristics. The correlation between calcified plaque type and ipsilateral acute ischemic anterior circulation stroke was analyzed using paired sample chi-square and Spearman correlation tests.

Results

Based on the inclusion and exclusion criteria, this study included 589 patients with plaques at the bifurcation of the carotid arteries. In both the acute ischemic stroke and control groups, sex, smoking, alcohol consumption, systolic blood pressure, blood sugar, cholesterol, high-density lipoprotein, and homocysteine levels were statistically significant (p < 0.05). During the Spearman correlation analysis between calcification type and acute stroke (1,178 carotid arteries), different calcification types of plaques were linked with ipsilateral acute anterior circulation stroke with statistically significant differences (p < 0.001). Finally, the chi-squared test of the paired samples showed that the grade of plaque calcification is often higher on the side of acute infarction than on the side without acute infarction, and the difference is statistically significant (p < 0.001).

Discussion

Carotid plaque calcification is associated with acute ischemic stroke. Our findings provide novel insights into the study of calcification in carotid atherosclerotic plaques and additional radiological evidence to clinically assess the risk of ischemic stroke.

Association between Pericarotid Fat Density and Positive Remodeling in Patients with Carotid Artery Stenosis

Background/Objectives: The underlying mechanism of the potential involvement of inflammatory crosstalk between pericarotid fat and vascular layers in atherosclerosis pathogenesis is unclear. We investigated the association between pericarotid fat density and positive remodeling and inflammatory markers in carotid stenosis. We hypothesized that pericarotid fat density might serve as a marker of plaque inflammation in a clinical setting. Methods: We evaluated the stenosis degree and pericarotid fat density in 258 patients with carotid plaques. Plaque composition was examined, and the correlation between pericarotid fat density and expansive remodeling was investigated. Pearson's product-moment correlation coefficient was used to examine the relationship between pericarotid fat density and the expansive remodeling ratio. We also evaluated the relationship of pericarotid fat density with plaque composition, degree of stenosis, and macrophage and microvessel counts by. The subgroup analysis compared these factors between symptomatic mild carotid stenosis. Results: The pericarotid fat density was -63.0 ± 11.1 HU. The carotid fat densities were -56.8 ± 10.4 HU in symptomatic and -69.2 ± 11.4 HU in asymptomatic lesions. The pericarotid fat density values in intraplaque hemorrhage, lipid-rich necrotic core, and fibrous plaque were -51.6 ± 10.4, -59.4 ± 12.8, and -74.2 ± 8.4 HU, respectively. Therefore, the expansive remodeling ratio was 1.64 ± 0.4. Carotid fat density and expansive remodeling ratio were correlated. Immunohistochemistry showed high macrophage and microvessel levels (143.5 ± 61.3/field and 121.2 ± 27.7/field, respectively). In symptomatic mild carotid stenosis, pericarotid fat density was correlated with other inflammatory factors. The pericarotid fat density and expansive remodeling ratio (2.08 ± 0.21) were high in mild stenosis (-50.1 ± 8.4 HU). Conclusions: Pericarotid fat and intraplaque components were well correlated. Carotid fat density may be a marker of plaque inflammation in carotid plaques.

Clinical Significance of Carotid Endarterectomy and Carotid Artery Stenting in Older Patients Over 80

As the average life expectancy increases, neurosurgeons are likely to encounter patients aged 80 years and above with carotid stenosis; however, whether old age affects clinical post-treatment outcomes of carotid endarterectomy (CEA) or carotid artery stenting (CAS) remains inconclusive. Thus, this study aimed to evaluate the outcomes following CEA or CAS in patients aged 80 years and above. This study included older over 80 years (n = 34) and younger patients (<80 years; n = 222) who underwent CEA or CAS between 2012 and 2022. All of them were followed up for a mean of 55 months. All-cause mortality, the incidence of vascular events, ability to perform daily activities, and nursing home admission rates were assessed. During follow-up periods, 34 patients (13.3%) died due to coronary artery disease, malignancy, and pneumonia, and the incidence was significantly higher in the elderly group than in the younger group (P = 0.03; HR, 3.01; 95% CI, 1.53-5.56). The incidence of vascular events did not differ between the older group (29.5%) and the younger group (26.9%, P = 0.58); however, the incidence was significantly higher in patients with high-intensity plaques than in those without that (P = 0.008; HR, 2.83, 95%CI, 1.27-4.87). The decline in the ability to perform daily activities and increased nursing home admission rates were high in elderly patients (P < 0.01). Although the mortality rate was higher in the elderly group, subsequent vascular events were comparable to that in the younger group. The results suggest that CEA and CAS are safe and useful treatments for carotid stenosis in older patients, especially to prevent ipsilateral ischemic stroke.

Thin Calcification Predicts Lipid Component in Carotid Plaque-Relationship Between Lipid Distribution and Thin Calcification

BACKGROUND

Accurately evaluating plaque characteristics is essential because lesions with lipid-rich plaque put patients at risk of thromboembolic complications from carotid artery stenting. Near-infrared spectroscopy (NIRS) is a diagnostic imaging modality that identifies lipid components from the near-infrared absorption pattern but does not reveal the distribution of calcification. The purpose of this study was to investigate the calcification characteristics of unstable carotid plaques, focusing on relationships between the calcification characteristics revealed by computed tomography angiography and the lipid core distribution derived from NIRS.

METHODS

Participants in this retrospective analysis comprised 35 patients (29 men, 6 women; mean age, 76.0 years; range, 52-89 years) who underwent carotid artery stenting in our institute between January 2021 and December 2022. We evaluated the thickness and length of carotid calcifications at the minimal lumen level from preoperative computed tomography angiography and analyzed the relationship with maximum lipid core burden index (max-LCBI) from NIRS.

RESULTS

Strong negative linear correlations were observed between the thickness of calcification and max-LCBI at Area (any segment in a target lesion) (r = -0.795, P < 0.001), max-LCBI at minimal lumen area (r = -0.795, P < 0.001) and lipid core burden index (LCBI) at lesion (rate of LCBI in entire plaque lesion) (r = -0.788, P < 0.001), respectively. Significant negative linear correlations were observed between distribution of calcification length and max-LCBI at area (r = -0.429, P = 0.01), max-LCBI at minimal lumen area (r = -0.373, P = 0.027), and LCBI at lesion (r = -0.443, P = 0.008).

CONCLUSIONS

Thin and ubiquitous carotid calcification was associated with LCBI values derived from NIRS indicative of carotid lipid plaque distribution, implying the possibility of predicting lesion instability.