Histological Features of Symptomatic Carotid Plaques in Relation to Age and Smoking

Assessment of Carotid Plaque Enhancement on Contrast-Enhanced Ultrasound as a Predictor for Severe Coronary Artery Disease

Background and Aim  Contrast-enhanced ultrasound (CEUS) can reliably identify vulnerable plaques. As atherosclerosis is a systemic disease, we evaluated whether contrast enhancement of carotid plaque (CECP) can predict severe coronary artery disease (CAD) by comparing CECP in patients who have had acute coronary syndromes (ACS) recently with asymptomatic individuals. Settings and Design  This case-control study was done at a tertiary care center during 2022. Materials and Methods  Fourteen participants were recruited in each group, after screening in-patients for carotid plaques and inclusion and exclusion criteria. Those who had history of ACS were enrolled as cases, while those who did not were enrolled as controls. All these patients underwent grayscale, Doppler, and CEUS examination for characterization of the carotid plaque. For cases, findings on CEUS were also compared with the severity of CAD on catheter coronary angiography. Statistical Analysis  Diagnostic parameters including sensitivity, specificity, and diagnostic accuracy were calculated and proportions were compared by using Fisher's exact test. Results  Eight out of 28 patients showed CECP. CECP and CAD were positively associated with p -Value of 0.033. Eighty-three percent patients with triple vessel disease and 50% patients with double vessel disease on coronary angiography showed CECP. Sensitivity and specificity of CECP for prediction of CAD were 50 and 92.9%, respectively. Conclusion  CECP on CEUS can predict CAD and is a more reliable indicator of severe CAD than plaque characteristics on grayscale and Doppler imaging; making it useful for screening of patients at risk of having CAD.

B-mode ultrasound characteristics of carotid plaques in symptomatic and asymptomatic patients with low-grade stenosis

Carotid plaque features assessed using B-mode ultrasound can be useful for the prediction of cerebrovascular symptoms. Therefore, the aim of this retrospective study was to determine the ability of ultrasound B-mode imaging to differentiate between carotid plaques causing less than 50% stenosis in symptomatic and asymptomatic patients. A dataset of 1,593 patients with carotid disease who underwent carotid ultrasound between 2016 and 2021 was evaluated retrospectively between January and April of 2022. A total of 107 carotid plaques from 35 symptomatic and 52 asymptomatic patients causing low-grade stenosis on B-mode images were included in the analysis. Chi-square, independent t-test and Mann-Whitney U test were used to compare the variables. There was a significant association between hypertension and the presence of cerebrovascular symptoms (p = 0.01). Predominantly hypoechoic and hyperechoic carotid plaque were significantly associated with the presence and absence of cerebrovascular symptoms, respectively (predominantly hypoechoic: p = 0.01; predominantly hyperechoic: p = 0.02). Surface irregularity was significantly associated with the presence of cerebrovascular symptoms (p = 0.02). There is was a significant difference in the carotid plaque length and area between the symptomatic and asymptomatic patients (plaque length: symptomatic median 9 mm, interquartile range [IQR] 6 mm; asymptomatic median 6 mm, IQR 4.5 mm, p = 0.01; plaque area: symptomatic median 24 mm, IQR 30 mm; asymptomatic median 14 mm, IQR 17 mm, p = 0.01); however, this difference was not significant for plaque thickness (p = 0.55), or common carotid artery intima-media thickness (p = 0.7). Our findings indicate that hypertension patients with predominantly hypoechoic carotid plaques and plaques with an irregular surface are associated with the presence of cerebrovascular symptoms. In addition, the carotid plaques in symptomatic patients were longer and larger compared to asymptomatic patients.

Exploring Gender Disparities in the Prevalence and Clinical Characteristics of Atherosclerotic Cranial Stenosis

Background Atherosclerotic cranial stenosis (ACS) is a significant contributor to vascular events, including ischemic strokes. While early clinical studies suggested a divergence in the distribution of intracranial and extracranial stenosis between genders, recent evidence has highlighted the complexity of these disparities. Therefore, this study aims to investigate gender differences in the prevalence and clinical characteristics of atherosclerotic cranial stenosis in patients admitted with stroke. Methods This cross-sectional study was conducted at a tertiary care hospital located in the Southern Region of Saudi Arabia between June 2022 and December 2022. It included patients of all age groups who had been diagnosed with an ischemic stroke during the study period. Data were collected from electronic health records and medical archives, and data analysis was performed using Statistical Package for the Social Sciences (SPSS version 26, IBM Inc., Chicago, IL, USA). Results In our study, 201 stroke patients were analyzed, with 161 (80.09%) identified as having atherosclerotic stenosis. Of these, 57.8% were male, and 42.2% were female. Gender disparities were evident, with higher stenosis prevalence in males (46.27% vs. 33.83% in females). Significant gender differences were observed in dyslipidemia (p = 0.013), metabolic syndrome (p = 0.019), and smoking habits (p < 0.001). Males exhibited higher rates of extracranial stenosis (p = 0.012) and combined stenosis (p = 0.009) compared to females; however, females exhibited higher rates of intracranial stenosis (p = 0.013). Further analyses revealed significant associations in dyslipidemia (adjusted odd ratio (AOR): 0.245, p = 0.004), metabolic syndrome (AOR: 5.159, p = 0.006), obesity (AOR: 8.085, p = 0.016), smoking habits (AOR: 0.002, p < 0.001), and intracranial stenosis (AOR: 5.667, p = 0.005) within the female cohort. Conversely, age, hypertension, diabetes mellitus, ischemic heart disease, and extracranial stenosis did not show statistically significant associations in females (p > 0.05). Conclusion We observed a substantial presence of atherosclerotic cranial stenosis, with males showing higher rates, and identified significant gender-related variations in dyslipidemia, metabolic syndrome, and smoking habits as important factors. This highlights the necessity of tailoring ACS assessment and treatment by considering gender-specific risk factors and clinical characteristics for improved patient care and stroke management.

MR Angiography of Extracranial Carotid Disease

Magnetic resonance angiography sequences, such as time-of-flight and contrast-enhanced angiography, provide clear depiction of vessel lumen, traditionally used to evaluate carotid pathologic conditions such as stenosis, dissection, and occlusion; however, atherosclerotic plaques with a similar degree of stenosis may vary tremendously from a histopathological standpoint. MR vessel wall imaging is a promising noninvasive method to evaluate the content of the vessel wall at high spatial resolution. This is particularly interesting in the case of atherosclerosis as vessel wall imaging can identify higher risk, vulnerable plaques as well as has potential applications in the evaluation of other carotid pathologic conditions.

Fluid structure interaction analysis to stratify the behavior of different atheromatous carotid plaques

BACKGROUND

In asymptomatic carotid stenosis (ACS), different plaque types, i.e. lipidic (LP), fibrous (FP), and calcific (CP), could have different hemodynamic and structural behaviors.

METHODS

Different carotid plaques, reconstructed from medical imaging of ACS >70%, were analyzed by computing fluid structure interaction (FSI), modeling the spatial distribution of wall shear stresses (WSS), plaque displacements (D), von Mises stresses (VMS), and absorbed elastic energy (AEE) together with their maximum-in-space values at the systole (WSS<inf>syst</inf>, D<inf>syst</inf>, VMS<inf>syst</inf> and AEE<inf>syst</inf>).

RESULTS

WSS resulted significantly higher in CP, whereas D and VMS showed the highest values for LP. Regarding AEE<inf>syst</inf> stored by the plaques, LP absorbed in average 2320 J/m³, FP 408 J/m³ (470%) and CP 99 J/m³ (2240%), (P<0.01, P<0.01, and P<0.01, respectively).

CONCLUSIONS

Depending upon their nature, plaques store different deformations and inner distributions of forces, thus potentially influencing their vulnerability.

Arterial Spin-Labeling Parameters and Their Associations with Risk Factors, Cerebral Small-Vessel Disease, and Etiologic Subtypes of Cognitive Impairment and Dementia

BACKGROUND AND PURPOSE

Cerebral small-vessel disease may alter cerebral blood flow (CBF) leading to brain changes and, hence, cognitive impairment and dementia. CBF and the spatial coefficient of variation can be measured quantitatively by arterial spin-labeling. We aimed to investigate the associations of demographics, vascular risk factors, location, and severity of cerebral small-vessel disease as well as the etiologic subtypes of cognitive impairment and dementia with CBF and the spatial coefficient of variation.

MATERIALS AND METHODS

Three hundred ninety patients with a diagnosis of no cognitive impairment, cognitive impairment no dementia, vascular cognitive impairment no dementia, Alzheimer disease, and vascular dementia were recruited from the memory clinic. Cerebral microbleeds and lacunes were categorized into strictly lobar, strictly deep, and mixed-location and enlarged perivascular spaces into the centrum semiovale and basal ganglia. Total and region-specific white matter hyperintensity volumes were segmented using FreeSurfer. CBF (n = 333) and the spatial coefficient of variation (n = 390) were analyzed with ExploreASL from 2D-EPI pseudocontinuous arterial spin-labeling images in white matter (WM) and gray matter (GM). To analyze the effect of demographic and vascular risk factors as well as the location and severity of cerebral small-vessel disease markers on arterial spin-labeling parameters, we constructed linear regression models, whereas logistic regression models were used to determine the association between arterial spin-labeling parameters and cognitive impairment no dementia, vascular cognitive impairment no dementia, Alzheimer disease, and vascular dementia.

RESULTS

Increasing age, male sex, hypertension, hyperlipidemia, history of heart disease, and smoking were associated with lower CBF and a higher spatial coefficient of variation. Higher numbers of lacunes and cerebral microbleeds were associated with lower CBF and a higher spatial coefficient of variation. Location-specific analysis showed mixed-location lacunes and cerebral microbleeds were associated with lower CBF. Higher total, anterior, and posterior white matter hyperintensity volumes were associated with a higher spatial coefficient of variation. No association was observed between enlarged perivascular spaces and arterial spin-labeling parameters. A higher spatial coefficient of variation was associated with the diagnosis of vascular cognitive impairment no dementia, Alzheimer's disease, and vascular dementia.

CONCLUSIONS

Reduced CBF and an increased spatial coefficient of variation were associated with cerebral small-vessel disease, and more specifically lacunes, whereas cerebral microbleeds and white matter hyperintensities were associated with WM-CBF and GM spatial coefficient of variation. The spatial coefficient of variation was associated with cognitive impairment and dementia, suggesting that hypoperfusion might be the key underlying mechanism for vascular brain damage.

Alterungsbedingte Gefäßveränderungen am Beispiel der Arteria carotis

Einer der Hauptrisikofaktoren für das Vorliegen einer Karotisstenose und des karotisbedingten Schlaganfalls ist das Lebensalter. Ziel dieses Übersichtsartikels ist die Darstellung des aktuellen Wissensstands über altersbedingte Veränderungen der Gefäße am Beispiel der Karotisstenose.

Die Gefäßalterung (vaskuläre Seneszenz) als Abnahme struktureller und funktioneller Eigenschaften der Gefäßwand spielt sich auf verschiedenen Ebenen ab. Auf multizellulärer Ebene kommt es mit zunehmendem Alter hauptsächlich aufgrund von atherosklerotischen Veränderungen der Gefäßwand zu einer Zunahme von Gefäßvolumen und -durchmesser sowie der Intima-Media-Dicke. Auf zellulärer und extrazellulärer Ebene kommt es zur Abnahme von Elastinfasern, glatten Muskelzellen und der Gesamtzellularität sowie zur Zunahme der Lipid‑, Cholesterin- und Kalziumphosphatablagerungen und der Neovaskularisierung. Ursachen der Gefäßalterung auf molekularer Ebene sind insbesondere oxidativer Stress, chronische Entzündungsreaktion, mitochondriale Dysfunktion, epigenetische Veränderungen, Dysregulation der Expression nicht kodierender RNAs (ncRNAs) und die Zunahme der Seneszenz. Der altersbedingte Verlust der Heilungs- und Reparaturfähigkeit des Gewebes macht die Plaques vulnerabler und im Falle der A. carotis anfälliger für ischämische Schlaganfälle.

Zunehmende Erkenntnisse über den Einfluss des Alterns auf die Epigenetik und der ncRNAs in atherosklerotischen Plaques kann zukünftig das individuelle Risiko von Patienten genauer quantifizieren und zur Entwicklung zielgerichteter Therapiestrategien beitragen. Weitere Studien sind auf diesem Gebiet jedoch notwendig, um das gesamte Ausmaß der Gefäßalterung und den damit einhergehenden Erkrankungen zu verstehen, damit diesen dann gezielt entgegenwirkt werden kann.

Association Between 18-FDG Positron Emission Tomography and MRI Biomarkers of Plaque Vulnerability in Patients With Symptomatic Carotid Stenosis

Purpose: Pathologic studies suggest that unstable plaque morphology and inflammation are associated with cerebrovascular events. ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) is a validated technique for non-invasive imaging of inflammation-related plaque metabolism, and MRI can identify morphologic features of plaque instability. The aim of this study was to investigate the association of selected imaging characteristics of plaque vulnerability measured with MRI and PET in patients with symptomatic carotid stenosis.

Methods: Patients from the BIOVASC study were selected based on the following inclusion criteria: (1) age ≥ 50 years; (2) recent (<30 days) ischaemic stroke (modified Rankin scale ≤3) or motor/speech/vision TIA; (3) ipsilateral internal carotid artery stenosis (≥5 0% lumen-narrowing); (4) carotid PET/CTA and MRI completed. Semi-automated plaque analysis of MRI images was performed to quantify morphologic features of plaque instability. PET images were co-registered with CTA and inflammation-related metabolism expressed as maximum standardised uptake value (SUV_max).

Results: Twenty-five patients met inclusion criteria (72% men, mean age 65 years). MRI-measured plaque volume was greater in men (1,708–1,286 mm³, p = 0.03), patients who qualified with stroke (1,856–1,440 mm³, p = 0.05), and non-statin users (1,325–1,797 mm³, p = 0.03). SUV_max was associated with MRI-measured plaque lipid-rich necrotic core (LRNC) in the corresponding axial slice (r_s = 0.64, p < 0.001) and was inversely associated with whole-plaque fibrous cap thickness (r_s = −0.4, p = 0.02) and calcium volume (r_s = −0.4, p = 0.03).

Conclusion: This study demonstrated novel correlations of non-invasive imaging biomarkers of inflammation-related plaque metabolism with morphological MRI markers of plaque instability. If replicated, our findings may support the application of combined MRI and PET to detect vulnerable plaque in future clinical practise and randomised trials.

Association of Smoking With Postprocedural Complications Following Open and Endovascular Interventions for Intermittent Claudication

Importance

Smoking is a key modifiable risk factor in the development and progression of peripheral artery disease, which often manifests as intermittent claudication (IC). Smoking cessation is a first-line therapy for IC, yet a minority of patients quit smoking prior to elective revascularization.

Objective

To assess if preprocedural smoking is associated with an increased risk of early postprocedural complications following elective open and endovascular revascularization.

Design, Setting, and Participants

This retrospective cohort study used nearest-neighbor (1:1) propensity score matching of 2011 to 2019 data from the Veterans Affairs Surgical Quality Improvement Program, including all cases with a primary diagnosis of IC and excluding emergent cases, primary procedures that were not lower extremity revascularization, and patients with chronic limb-threatening ischemia within 30 days of the intervention. All data were abstracted June 18, 2020, and analyzed from July 26, 2020, to June 30, 2021.

Exposures

Preprocedural cigarette smoking.

Main Outcomes and Measures

Any and organ system-specific (ie, wound, respiratory, thrombosis, kidney, cardiac, sepsis, and neurological) 30-day complications and mortality, overall and in prespecified subgroups.

Results

Of 14 350 included cases of revascularization, 14 090 patients (98.2%) were male, and the mean (SD) age was 65.7 (7.0) years. A total of 7820 patients (54.5%) were smoking within the preprocedural year. There were a total of 4417 endovascular revascularizations (30.8%), 4319 hybrid revascularizations (30.1%), and 5614 open revascularizations (39.1%). A total of 1594 patients (11.1%) had complications, and 57 (0.4%) died. Among 7710 propensity score-matched cases (including 3855 smokers and 3855 nonsmokers), 484 smokers (12.6%) and 34 nonsmokers (8.9%) experienced complications, an absolute risk difference (ARD) of 3.68% (95% CI, 2.31-5.06; P < .001). Compared with nonsmokers, any complication was higher for smokers following endovascular revascularization (26 [4.3%] vs 52 [2.1%]; ARD, 2.19%; 95% CI, 0.77-3.60; P = .003), hybrid revascularization (204 [17.3%] vs 163 [14.1%]; ARD, 3.18%; 95% CI, 0.23-6.13; P = .04), and open revascularization (228 [15.4%] vs 153 [10.3%]; ARD, 5.18%; 95% CI, 2.78-7.58; P < .001). Compared with nonsmokers, respiratory complications were higher for smokers following endovascular revascularization (20 [1.7%] vs 6 [0.5%]; ARD, 1.17%; 95% CI, 0.35-2.00; P = .009), hybrid revascularization (33 [2.8%] vs 10 [0.9%]; ARD, 1.93%; 95% CI, 0.85-3.02; P = .001), and open revascularization (32 [2.2%] vs 19 [1.3%]; ARD, 0.89%; 95% CI, 0-1.80; P = .06). Wound complications and graft failure were higher for smokers compared with nonsmokers following open interventions (wound complications: 146 [9.9%] vs 87 [5.8%]; ARD, 4.05%; 95% CI, 2.12-5.99; P < .001; graft failure: 33 [2.2%] vs 11 [0.7%]; ARD, 1.50%; 95% CI, 0.63-2.37; P = .001). In a sensitivity analysis, compared with active smokers (n = 5173; smoking within 2 weeks before the procedure), the risk of any complication was decreased by 65% for never smokers (n = 1197; adjusted odds ratio, 0.45; 95% CI, 0.34-0.59) and 29% for former smokers (n = 4755; cessation more than 1 year before the procedure; adjusted odds ratio, 0.71; 95% CI, 0.61-0.83; P = .001 for interaction).

Conclusions and Relevance

In this cohort study, more than half of patients with IC were smoking prior to elective revascularization, and complication risks were higher across all modalities of revascularization. These findings stress the importance of smoking cessation to optimize revascularization outcomes.

A Computational Fluid-Structure Interaction Study for Carotids With Different Atherosclerotic Plaques

Atherosclerosis is a systemic disease that leads to accumulation of deposits, known as atherosclerotic plaques, within the walls of the carotids. In particular, three types of plaque can be distinguished: soft, fibrous, and calcific. Most of the computational studies who investigated the interplay between the plaque and the blood flow on patient-specific geometries used nonstandard medical images to directly delineate and segment the plaque and its components. However, these techniques are not so widely available in the clinical practice. In this context, the aim of our work was twofold: (i) to propose a new geometric tool that allowed to reconstruct a plausible plaque in the carotids from standard images and (ii) to perform three-dimensional (3D) fluid-structure interaction (FSI) simulations where we compared some fluid-dynamic and structural quantities among 15 patients characterized by different typologies of plaque. Our results highlighted that both the morphology and the mechanical properties of different plaque components play a crucial role in determining the vulnerability of the plaque.

Correlation Between Calcification Characteristics of Carotid Atherosclerotic Plaque and Plaque Vulnerability

Purpose

To investigate the relationship between calcification characteristics of carotid atherosclerotic plaque and lipid rich necrotic core (LRNC) and intraplaque hemorrhage (IPH).

Methods

Patients with severe carotid stenosis undergoing carotid endarterectomy (CEA) were selected. Ultrasound and CT angiography (CTA) were performed to evaluate the calcification characteristics of the plaque before the surgery.

Results

A total of 142 patients were included and 142 pathological specimens of postoperative plaque were obtained accordingly. There were 78 plaques (54.9%) with LRNC and 41 (28.9%) with IPH. The plaque with LRNC had higher calcification rate (93.6%) compared with the plaque with IPH (87.8%). LRNC was often found in multiple calcification (P = 0.003) and mixed type calcification (P = 0.001). Multiple calcification was more likely to combine with IPH (P = 0.008), while simple basal calcification was not likely to combine IPH (P = 0.002). Smaller granular calcification was more likely to be associated with IPH (P < 0.05). In multivariate regression analysis of IPH and calcification characteristics, simple basal calcification was still a protective factor for IPH (OR, 0.25; 95% CI, 0.09–0.66; P = 0.005), while multiple calcification was closely related to the occurrence of IPH (OR, 3.58; 95% CI, 1.49–8.61; P = 0.004).

Conclusion

Calcification characteristics of carotid atherosclerotic plaques are closely related to the vulnerability of plaques, especially multiple calcification and mixed type calcification.

Red and White Thrombus Characteristics in Patients Undergoing Carotid Endarterectomy

OBJECTIVE

The study aimed to compare the characteristics of red and white thrombi in patients undergoing carotid endarterectomy.

MATERIAL AND METHODS

The study was conducted in 81 patients with ischemic stroke who underwent carotid endarterectomy for carotid artery stenosis. Carotid plaques were graded by two pathologists. Thrombus materials were divided into two groups: white and red. The parameters of assessment were plaque rupture, lipid core, fibrous cap thickness, inflammation, intraplaque hemorrhage, calcification, necrotic core, and neovascularization. Normally distributed data were evaluated using Mann-Whitney U and Chi-squared tests.

RESULTS

The ratio of white and red thrombus was 19.8% and 80.2%, respectively. Lipid core, plaque rupture, necrotic core, neovascularization, intraplaque hemorrhage, obstruction, and inflammation were observed more in red thrombus, which were statistically significant. Calcification and fibrous cap thickness were not statistically significant in the two groups. Moreover, intimal smooth muscle cells were present in all thrombus types.

CONCLUSION

In our study, we found that red thrombi had more unstable characteristics than white thrombi. Thus, the risk for ischemic cerebrovascular events is more in red thrombi. However, this finding cannot be generalized due to the small number of patients in this study. Therefore, studies involving more patients are needed.

The carotid plaque as paradigmatic case of site-specific acceleration of aging process: The microRNAs and the inflammaging contribution

Atherosclerosis is considered a chronic inflammatory disease of arteries associated with the aging process. Many risk factors have been identified and they are mainly related to life-styles, gene-environment interactions and socioeconomic status. Carotid and coronary artery diseases are the two major atherosclerotic conditions, being the primary cause of stroke and heart attack, respectively. Nevertheless, carotid plaque assumes particular aspects not only for the specific molecular mechanisms, but also for the types of atheroma which may be associated with a better or a worst prognosis. The identification of circulating blood biomarkers able to distinguish carotid plaque types (stable or vulnerable) is a crucial step for the improvement of adequate therapeutic approaches avoiding or delaying endarterectomy in the oldest old individuals (> 80 years), a population predicted to growth in the next years. The review highlights the most recent knowledge on carotid plaque molecular mechanisms, focusing on microRNAs (miRs), as a site-specific accelerated aging within the conceptual framework of Geroscience for new affordable therapies.

The Role of Vascular Aging in Atherosclerotic Plaque Development and Vulnerability

BACKGROUND

The ongoing demographical shift is leading to an unprecedented aging of the population. As a consequence, the prevalence of age-related diseases, such as atherosclerosis and its thrombotic complications is set to increase in the near future. Endothelial dysfunction and vascular stiffening characterize arterial aging and set the stage for the development of cardiovascular diseases. Atherosclerotic plaques evolve over time, the extent to which these changes might affect their stability and predispose to sudden complications remains to be determined. Recent advances in imaging technology will allow for longitudinal prospective studies following the progression of plaque burden aimed at better characterizing changes over time associated with plaque stability or rupture. Oxidative stress and inflammation, firmly established driving forces of age-related CV dysfunction, also play an important role in atherosclerotic plaque destabilization and rupture. Several genes involved in lifespan determination are known regulator of redox cellular balance and pre-clinical evidence underlines their pathophysiological roles in age-related cardiovascular dysfunction and atherosclerosis.

OBJECTIVE

The aim of this narrative review is to examine the impact of aging on arterial function and atherosclerotic plaque development. Furthermore, we report how molecular mechanisms of vascular aging might regulate age-related plaque modifications and how this may help to identify novel therapeutic targets to attenuate the increased risk of CV disease in elderly people.

Presentation and outcomes of carotid endarterectomy in active smokers

OBJECTIVE

Smoking is a significant modifiable risk factor in the pathogenesis of carotid artery disease and has been shown to be a predictor of worse outcomes after vascular surgery. However, the effect of active smoking on outcomes of patients undergoing carotid endarterectomy is unknown. This study analyzed the outcomes of carotid endarterectomy by smoking status in a large national database.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program targeted carotid endarterectomy files (2011-2017) were reviewed. Patients were stratified according to smoking status, and outcomes were compared using propensity score matching (1:1) based on preoperative characteristics.

RESULTS

During the study period, 26,293 patients underwent carotid endarterectomy, with 19,282 (73.34%) nonsmokers and 7011 (26.66%) smokers. Smokers were more likely to be younger, to have chronic obstructive pulmonary disease, to have a symptomatic presentation, and to have higher anatomic risk (P < .05). Smokers were also more likely to have emergent surgery, to have general anesthesia, and to be reintubated (P < .05). After propensity matching, 5354 nonsmokers were matched with 5354 smokers who underwent carotid endarterectomy. Smokers were at significantly higher risk for death, with an odds ratio of 1.93 (confidence interval, 1.18-3.13).

CONCLUSIONS

Smokers are at increased risk for death after carotid endarterectomy compared with matched counterparts. Smoking should be considered an important risk factor for worse outcomes, and patients should be strongly counseled on the importance of smoking cessation before undergoing carotid endarterectomy.

Patient risk factors associated with embolic stroke volumes after revascularization

OBJECTIVE

Previous research has shown that subclinical, microembolic infarcts result in long-term cognitive changes. Whereas both carotid endarterectomy (CEA) and carotid artery stenting (CAS) have potential for microembolic events, CAS has been shown to have a larger volume of infarct. We have previously shown that large-volume infarction is associated with long-term memory deterioration. The purpose of this study was to identify independent risk factors that trend toward higher embolic volumes in both procedures.

METHODS

A total of 162 patients who underwent carotid revascularization procedures were prospectively recruited at two separate institutions. Preoperative and postoperative brain magnetic resonance images were compared to identify procedure-related microinfarcts. A novel semiautomated approach was used to define volumes of infarcts for each patient. Patient-related factors including comorbidities, symptomatic status, and medications were analyzed. Tweedie regression analysis was used to identify risk factors associated with procedure-related infarct volume. Variables with an unadjusted P value of ≤ .05 were included in the multivariate analysis.

RESULTS

There were 80 CAS and 82 CEA procedures performed and analyzed for the data set; 81% of CAS patients had procedure-related new infarcts with a mean volume of 388.15 ± 927.90 mm³ compared with 30% of CEA patients with a mean volume of 74.80 ± 225.52 mm³. In the CAS cohort, increasing age (adjusted coefficient ± standard error, 0.06 ± 0.02; P < .01) and obesity (1.14 ± 0.35; P < .01) were positively correlated with infarct volume, whereas antiplatelet use (-1.11 ± 0.33; P < .001) was negatively correlated with infarct volume. For the CEA group, diabetes (adjusted coefficient ± standard error, 1.69 ± 0.65; P < .01) was identified as the only risk factor positively correlated with infarct volume, whereas increasing age (-0.10 ± 0.05; P = .03) was negatively correlated with infarct volume.

CONCLUSIONS

Risk factors for CAS- or CEA-related infarct volumes are identified in our study. Although the result warrants further validation, this study showed that advanced age, obesity, and diabetes independently predicted volume of microinfarcts related to CAS and CEA. These data provide valuable information for patient factor-based risk stratification and preoperative consultation for each procedure.

Immediate and Delayed Procedural Stroke or Death in Stenting Versus Endarterectomy for Symptomatic Carotid Stenosis

Background and Purpose- Stenting for symptomatic carotid stenosis (carotid artery stenting [CAS]) carries a higher risk of procedural stroke or death than carotid endarterectomy (CEA). It is unclear whether this extra risk is present both on the day of procedure and within 1 to 30 days thereafter and whether clinical risk factors differ between these periods. Methods- We analyzed the risk of stroke or death occurring on the day of procedure (immediate procedural events) and within 1 to 30 days thereafter (delayed procedural events) in 4597 individual patients with symptomatic carotid stenosis who underwent CAS (n=2326) or CEA (n=2271) in 4 randomized trials. Results- Compared with CEA, patients treated with CAS were at greater risk for immediate procedural events (110 versus 42; 4.7% versus 1.9%; odds ratio, 2.6; 95% CI, 1.9-3.8) but not for delayed procedural events (59 versus 46; 2.5% versus 2.0%; odds ratio, 1.3; 95% CI, 0.9-1.9; interaction P=0.006). In patients treated with CAS, age increased the risk for both immediate and delayed events while qualifying event severity only increased the risk of delayed events. In patients treated with CEA, we found no risk factors for immediate events while a higher level of disability at baseline and known history of hypertension were associated with delayed procedural events. Conclusions- The increased procedural stroke or death risk associated with CAS compared with CEA was caused by an excess of events occurring on the day of procedure. This finding demonstrates the need to enhance the procedural safety of CAS by technical improvements of the procedure and increased operator skill. Higher age increased the risk for both immediate and delayed procedural events in CAS, mechanisms of which remain to be elucidated. Clinical Trial Registration- URL: https://clinicaltrials.gov . Unique identifier: NCT00190398. URL: http://www.isrctn.com . Unique identifier: ISRCTN57874028. URL: http://www.isrctn.com . Unique identifier: ISRCTN25337470. URL: https://clinicaltrials.gov . Unique identifier: NCT00004732.

Effect of cigarette smoking on carotid artery atherosclerosis: a community-based cohort study

Cigarette smoking is closely associated with the development of cardiovascular diseases. However, the relationship between cigarette smoking and subclinical atherosclerosis has not been fully studied. We sought to clarify the association between cigarette smoking and carotid intima-media thickness (cIMT) in a general Japanese population. Among 1,209 participants who received a medical check-up with cardiovascular examination at our institution, 450 participants (37.2%) were smokers (including both past and current smokers). We evaluated cIMT as a marker of subclinical atherosclerosis. The value of cIMT and rate of carotid plaque defined as IMT ≥ 1.1 mm did not differ between smokers and never smokers. However, the rate of carotid high-risk atheroma, defined as carotid artery atheroma including hypoechoic dominant and ulceration, was significantly higher among smokers than never smokers (30.4%, vs 23.6%, p = 0.009). Even after adjustment for covariates, cigarette smoking was independently associated with high-risk atheroma formation (odds ratio 1.384, 95% CI 1.019-1.880; p = 0.038). The value of cIMT and the rate of high-risk atheroma were significantly higher in smokers than never smokers in the subgroup of participants aged ≥ 60 years, whereas the rate of high-risk atheroma only was higher in smokers than never smokers in the subgroup of participants aged < 60 years. In conclusion, the development of high-risk carotid artery atheroma may precede the thickening of cIMT in cigarette smokers, which suggests the novel insight for the pathological mechanism underlying cardiovascular events and cigarette smoking.

Quantitative assessment of carotid plaque morphology (geometry and tissue composition) using computed tomography angiography

OBJECTIVE

Quantification of carotid plaque morphology (geometry and tissue composition) may help stratify risk for future stroke and assess plaque progression or regression in response to medical risk factor modification. We assessed the feasibility and reliability of morphologic measurements of carotid plaques using computed tomography angiography (CTA) and determined the minimum detectable change in plaque features by this approach.

METHODS

CTA images of both carotid arteries in 50 patients were analyzed by two observers using a semiautomatic image analysis program, yielding 93 observations per user (seven arteries were excluded because of prior stenting). One observer repeated the analyses 4 weeks later. Measurements included total plaque volume; percentage stenosis (by diameter and area); and tissue composition for calcium, lipid-rich necrotic core (LRNC), and intraplaque hemorrhage (IPH). Reliability of measurements was assessed by intraclass and interclass correlation and Bland-Altman plots. Dice similarity coefficient (DSC) and modified Hausdorff distance (MHD) assessed reliability of geometric shape measurements. We additionally computed the minimum amount of change in these features detectable by our approach.

RESULTS

The cohort was 51% male (mean age, 70.1 years), and 56% had a prior stroke. The mean (± standard deviation) plaque volume was 837.3 ± 431.3 mm³, stenosis diameter was 44.5% ± 25.6%, and stenosis area was 58.1% ± 29.0%. These measurements showed high reliability. Intraclass correlation coefficients for plaque volume, percentage stenosis by diameter, and percentage stenosis by area were 0.96, 0.87, and 0.83, respectively; interclass correlation coefficients were 0.88, 0.84, and 0.78. Intraclass correlations for tissue composition were 0.99, 0.96, and 0.86 (calcium, LRNC, and IPH, respectively), and interclass correlations were 0.99, 0.92, and 0.92. Shape measurements showed high intraobserver (DSC, 0.95 ± 0.04; MHD, 0.16 ± 0.10 mm) and interobserver (DSC, 0.94 ± 0.05; MHD, 0.19 ± 0.12 mm) luminal agreement. This approach can detect a change of at least 3.9% in total plaque volume, 1.2 mm³ in calcium, 4.3 mm³ in LRNC, and 8.6 mm³ in IPH with the same observer repeating measurements and 9.9% in plaque volume, 1.9 mm³ in calcium, 7.9 mm³ in LRNC, and 6.8 mm³ in IPH for two different observers.

CONCLUSIONS

Carotid plaque geometry (total volume, diameter stenosis, and area stenosis) and tissue composition (calcium, LRNC, and IPH) are measured reliably from clinical CTA images using a semiautomatic image analysis program. The minimum change in plaque volume detectable is ∼4% if the same observer makes both measurements and ∼10% for different observers. Small changes in plaque composition can also be detected reliably. This approach can facilitate longitudinal studies for identifying high-risk plaque features and for quantifying plaque progression or regression after treatment.

Biobanking: Objectives, Requirements, and Future Challenges-Experiences from the Munich Vascular Biobank

Collecting biological tissue samples in a biobank grants a unique opportunity to validate diagnostic and therapeutic strategies for translational and clinical research. In the present work, we provide our long-standing experience in establishing and maintaining a biobank of vascular tissue samples, including the evaluation of tissue quality, especially in formalin-fixed paraffin-embedded specimens (FFPE). Our Munich Vascular Biobank includes, thus far, vascular biomaterial from patients with high-grade carotid artery stenosis (n = 1567), peripheral arterial disease (n = 703), and abdominal aortic aneurysm (n = 481) from our Department of Vascular and Endovascular Surgery (January 2004–December 2018). Vascular tissue samples are continuously processed and characterized to assess tissue morphology, histological quality, cellular composition, inflammation, calcification, neovascularization, and the content of elastin and collagen fibers. Atherosclerotic plaques are further classified in accordance with the American Heart Association (AHA), and plaque stability is determined. In order to assess the quality of RNA from FFPE tissue samples over time (2009–2018), RNA integrity number (RIN) and the extent of RNA fragmentation were evaluated. Expression analysis was performed with two housekeeping genes—glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB)—using TaqMan-based quantitative reverse-transcription polymerase chain reaction (qRT)-PCR. FFPE biospecimens demonstrated unaltered RNA stability over time for up to 10 years. Furthermore, we provide a protocol for processing tissue samples in our Munich Vascular Biobank. In this work, we demonstrate that biobanking is an important tool not only for scientific research but also for clinical usage and personalized medicine.

Comparative Study of Protein Expression Levels of Five Plaque Biomarkers and Relation with Carotid Plaque Type Classification in Patients after Carotid Endarterectomy

Atherosclerosis is an inflammatory process resulting in local plaque deposition in the vessel wall of arteries with symptoms to various areas of vascular tree. Identification of patients with progressive advanced atherosclerotic disease is mainly based on the known characteristics of the vulnerable or recently ruptured plaque. Molecular and cellular features associated with the vulnerable plaque are considered potential diagnostic markers for plaque rupture and thrombosis. Here, protein expression levels of the metalloproteases MMP-1, MMP-9, osteopontin (OPN), and cytokines TNFα and IL-6 in tissue extracts of carotid plaques in patients after endarterectomy were estimated by Western immunoblotting, after SDS-PAGE analysis and evaluated based on the ultrasonographic plaque morphology. The gender and age effect was also examined. MMP-1, MMP-9, and IL-6 were expressed in higher levels compared to OPN and TNFa as well as in symptomatic (with type II and III carotid plaque classification) than asymptomatic (type IV) patients with differences considered statistically significant (P values <0.05). A significant positive correlation between MMP-1 and IL-6 (with Pearson correlation coefficient 0.748) is also notable. The data give further insight into the possible role of specific biomarker and enhance the need for further studies in order to clarify the proper one(s) for detection of the vulnerable plaque and help identify patients at risk for cardiovascular events.

Ideal cardiovascular health associated with fatty liver: Results from a multi-ethnic survey

BACKGROUND AND AIMS

Little is known about the role of liver enzymes as predictors of non-liver-related morbidity and mortality. The ideal cardiovascular health (CVH) score proposed by the American Heart Association (AHA) can be used to predict mortality and morbidity. We investigated the association of the CVH score with liver enzymes and the risk of non-alcoholic fatty liver disease (NAFLD) among US adults.

METHODS

By using the National Health and Nutrition Examination Survey database (cross-sectional), the CVH score was calculated as meeting ideal levels of the following components: 4 behaviors (smoking, body mass index, physical activity and diet adherence) and 3 factors (total cholesterol, blood pressure and fasting glucose).

RESULTS

Individuals with a higher CVH score ("better CVH") had a more favorable profile of liver biomarkers. Adjusted (for age, gender, race, poverty to income ratio, education, marital status and alcohol intake) linear regression indicated significant and negative associations between liver biomarkers and CVH score: (β = -0.069, p < 0.001) for alanine aminotransferase, (β = -0.095, p < 0.001), aspartate aminotransferase, (β = -0.067, p < 0.001), alkaline phosphatase and (β = -0.125, p < 0.001) and fatty liver index. In the logistic regression, with the same confounders, individuals with a higher CVH score had 12% less likelihood of NAFLD compared with those with a lower score. Furthermore, each CVH metric separately was inversely linked to the risk of NAFLD.

CONCLUSIONS

For the first time among US adults, our findings shed light on the role CVH on liver biomarkers.

Echolucency-based phenotype in carotid atherosclerosis disease for risk stratification of diabetes patients

AIM

The study investigated the association of carotid ultrasound echolucent plaque-based biomarker with HbA1c, measured as age-adjusted grayscale median (AAGSM) as a function of chronological age, total plaque area, and conventional grayscale median (GSM_conv).

METHODS

Two stages were developed: (a) automated measurement of carotid parameters such as total plaque area (TPA); (b) computing the AAGSM as a function of GSM_conv, age, and TPA. Intra-operator (novice and experienced) analysis was conducted.

RESULTS

IRB approved, 204 patients' left/right CCA (408 images) ultrasound scans were collected: mean age: 69 ± 11 years; mean HbA1c: 6.12 ± 1.47%. A moderate inverse correlation was observed between AAGSM and HbA1c (CC of -0.13, P = 0.01), compared to GSM (CC of -0.06, P = 0.24). The RCCA and LCCA showed CC of -0.18, P < 0.01 and -0.08; P < 0.24. Female and males showed CC of -0.29, P < 0.01 and -0.10, P = 0.09. Using the threshold for AAGSM and HbA1c as: low-risk (AAGSM > 100; HbA1c < 5.7%), moderate-risk (40 < AAGSM < 100; 5.7% < HbA1c < 6.5%) and high-risk (AAGSM < 40; HbA1c > 6.5%), the area under the curve showed a better performance of AAGSM over GSM_conv. A paired t-test between operators and expert (P < 0.0001); inter-operator CC of 0.85 (P < 0.0001).

CONCLUSIONS

Echolucent plaque in patients with diabetes can be more accurately characterized for risk stratification using AAGSM compared to GSM_conv.

Carotid Artery Wall Imaging: Perspective and Guidelines from the ASNR Vessel Wall Imaging Study Group and Expert Consensus Recommendations of the American Society of Neuroradiology

Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease.

Ideal cardiovascular health predicts lower risk of abnormal liver enzymes levels in the Chilean National Health Survey (2009-2010)

High levels of gamma glutamyltransferase (gamma-GT) and alanine aminotransferase (ALT), as well as fatty liver index (FLI) has been associated with higher cardiovascular disease risk factors in adults. The aim of this study was to examine the relationship between gamma-GT, ALT, and fatty liver index FLI levels across a gradient number of ideal cardiovascular health metrics in a representative sample of adults from the Chilean National Health Survey 2009-2010. Data from 1,023 men and 1,449 women (≥ 15 years) from the Chilean Health Survey 2009-2010 were analyzed. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet adherence) and three factors (total cholesterol, blood pressure and fasting glucose). Adults were grouped into three categories according to their number of ideal cardiovascular health metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). Blood levels of gamma-GT and ALT were measured and the FLI was calculated. A higher number of ideal cardiovascular health index metric was associated with lower gamma-GT, ALT and FLI (p from trend analysis <0.001). Also, adults meeting at least 3-4 metrics were predicted less likely to have prevalence of abnormal levels of gamma-GT and FLI (p<0.001) compared to adults who met only 0-2 metrics. These findings reinforce the usefulness of the ideal cardiovascular health metrics proposed by the American Heart Association as a tool to identify target subjects and promote cardiovascular health in South-American adults.

Exposure to Cigarette Smoke and the Morphology of Atherosclerotic Plaques in the Extracranial Arteries Assessed by Computed Tomography Angiography in Patients with Essential Hypertension

The aim of the study was to determine the relationship between exposure to cigarette smoke and the morphology of atherosclerotic plaques in the extracranial arteries assessed by computed tomography angiography in patients with hypertension. The study included 61 hypertensive patients: 17 active smokers (group A), 18 non-smokers, declaring environmental exposure to tobacco smoke (group B), and 26 non-smokers, not declaring exposure to cigarette smoke (group C). The number of segments with plaques was significantly higher in group A compared to groups B and C. The number of segments with non-calcified and mixed plaques was significantly higher in group A and group B than in group C. A positive correlation between cigarette-years and the number of segments with atherosclerotic plaques was noted. In summary, both active smoking and environmental exposure to tobacco smoke appear to increase the number of segments of the extracranial arteries with non-calcified and mixed atherosclerotic plaques.

Evaluation of cerebral blood flow change after cigarette smoking using quantitative MRA

BACKGROUND AND OBJECTIVE

Changes in cerebral blood flow (CBF) immediately after cigarette smoking (CS) are still unclear. Our purpose was to evaluate the hemodynamic changes in each intracranial vessel after CS by using quantitative magnetic resonance angiography (MRA).

MATERIAL AND METHODS

Fifteen healthy male smokers less than 45 years old with more than 3 pack-year smoking history were enrolled in this study. The hemodynamic change in the vessels, represented by cerebral flow rate (CFR, ml/s) and flow velocity (FV, cm/s), was quantitatively measured in eleven vascular segments of the brain using phase-contrast MRA. Two sets of data at each vessel before and after CS were statistically analyzed by paired t-test. Three of 15 participants, as a control group, followed all the procedures but did not smoke.

RESULTS

Total CFR of the distal intracranial vessels (anterior, middle, and posterior cerebral arteries; ACA, MCA, and PCA) was significantly reduced after CS by 7.3% (847 vs. 785 ml/s, p = 0.024). Such flow changes were statistically more significant in the anterior circulation (ACA and MCA) compared to the posterior circulation (PCA). All distal intracranial vessels did not have significant FV change while peak systolic velocity and mean velocity dropped 7.4 and 4.3% and pulsatility index decreased 10.9% in the internal carotid artery. Regarding cross-sectional areas, all distal intracranial vessels showed diminished, and only MCA had a statistical significance (9.9 vs. 9.3 mm2, p = 0.016).

CONCLUSIONS

There was a significant decrease of CFR after CS especially in the anterior circulation of twelve young male smokers. Considering the changes of FV and cross-sectional area all together, it can be suggested that cerebrovascular impedance increased after CS especially at the main trunk level of the distal intracranial vessels (ACA, MCA, and PCA).

Pathological Quantification of Carotid Artery Plaque Instability in Patients Undergoing Carotid Endarterectomy

BACKGROUND

Unstable atherosclerotic carotid plaques cause cerebral thromboemboli and ischemic events. However, this instability has not been pathologically quantified, so we sought to quantify it in patients undergoing carotid endarterectomy (CEA).Methods and Results:Carotid plaques were collected during CEA from 67 symptomatic and 15 asymptomatic patients between May 2015 and August 2016. The specimens were stained with hematoxylin-eosin and elastica-Masson. Immunohistochemistry was performed using an endothelial-specific antibody to CD31, CD34 and PDGFRβ. The histopathological characteristics of the plaques were studied. By multiple-variable logistic regression analysis, plaque instability correlated with the presence of plaque rupture [odds ratio (OR), 9.75; P=0.013], minimum fibrous cap thickness (OR per 10 μm 0.70; P=0.025), presence of microcalcifications in the fibrous cap (OR 7.82; P=0.022) and intraplaque microvessels (OR 1.91; P=0.043). Receiver-operating characteristics analyses showed that these factors combined into a single score diagnosed symptomatic carotid plaques in patients with carotid artery stenosis with a high level of accuracy (area under the curve 0.92; 95% confidence interval 0.85-0.99 vs. asymptomatic).

CONCLUSIONS

This analysis of carotid plaque instability strongly suggested that the diagnostic scoring of carotid plaque instability improves the understanding and treatment of carotid artery disease in patients undergoing CEA.

Arterial ageing: from endothelial dysfunction to vascular calcification

Complex structural and functional changes occur in the arterial system with advancing age. The aged artery is characterized by changes in microRNA expression patterns, autophagy, smooth muscle cell migration and proliferation, and arterial calcification with progressively increased mechanical vessel rigidity and stiffness. With age the vascular smooth muscle cells modify their phenotype from contractile to 'synthetic' determining the development of intimal thickening as early as the second decade of life as an adaptive response to forces acting on the arterial wall. The increased permeability observed in intimal thickening could represent the substrate on which low-level atherosclerotic stimuli can promote the development of advanced atherosclerotic lesions. In elderly patients the atherosclerotic plaques tend to be larger with increased vascular stenosis. In these plaques there is a progressive accumulation of both lipids and collagen and a decrease of inflammation. Similarly the plaques from elderly patients show more calcification as compared with those from younger patients. The coronary artery calcium score is a well-established marker of adverse cardiovascular outcomes. The presence of diffuse calcification in a severely stenotic segment probably induces changes in mechanical properties and shear stress of the arterial wall favouring the rupture of a vulnerable lesion in a less stenotic adjacent segment. Oxidative stress and inflammation appear to be the two primary pathological mechanisms of ageing-related endothelial dysfunction even in the absence of clinical disease. Arterial ageing is no longer considered an inexorable process. Only a better understanding of the link between ageing and vascular dysfunction can lead to significant advances in both preventative and therapeutic treatments with the aim that in the future vascular ageing may be halted or even reversed.

Unstable carotid artery plaque: new insights and controversies in diagnostics and treatment

Cardiovascular disease is estimated to be the leading cause of death, globally causing 14 million deaths each year. Stroke remains a massive public health problem and there is an increasing need for better strategies for the prevention and treatment of this disease. At least 20% of ischemic strokes are thromboembolic in nature, caused by a thromboembolism from an atherosclerotic plaque at the carotid bifurcation or the internal carotid artery. Current clinical guidelines for both primary and secondary prevention of stroke in patients with carotid stenosis caused by atherosclerotic plaques remain reliant on general patient characteristics (traditional risk factors for stroke) and static measures of the degree of artery stenosis. Patients with similar traditional risk factors, however, have been found to have different risk of stroke, and it has in recent years become increasingly clear that the degree of artery stenosis alone is not the best estimation of stroke risk. There is a need for new methods for the assessment of stroke risk to improve risk prediction for the individual patient. This review aims to give an overview of new methods available for the identification of carotid plaque instability and the assessment of stroke risk.

Age-associated changes in human carotid atherosclerotic plaques

Little is known about changes in carotid plaque morphology during aging and the possible impact on cardiovascular events. Only few studies addressed so far age-related modifications within atherosclerotic lesions. Therefore, in this work we endeavored to summarize the current knowledge about changing of plaque composition in elderly. The data from hitherto existing studies confirm that atherosclerotic plaques undergo distinct alternations with advanced age. However, the results are often ambiguous and the changes do not seem to be as disastrous as expected. Interestingly, none of the studies could definitely evidence increased plaque vulnerability with advanced age. Nevertheless, based on the previous work showing decrease in elastin fibers, fibroatheroma, SMCs, overall cellularity and increase in the area of lipid core, hemorrhage, and calcification, the plaque morphology appears to transform toward unstable plaques. Otherwise, even if inflammatory cells often accumulate in plaques of younger patients, their amount is reduced in the older age and so far no clear association has been observed between thin fibrous cap and aging. Thus, the accurate contribution of age-related changes in plaque morphology to cardiovascular events has yet to be elucidated. KEY MESSAGES Composition of carotid atherosclerotic lesions changes during aging. These alternations are however, just moderate and depend upon additional variables, such as life style, accompanying disease, genetics, and other factors that have yet to be determined. Based on the current data, the age-associated plaque morphology seems to transform toward vulnerable plaques. However, the changes do not seem to be as disastrous as expected.

Relationship between dyslipidemia and carotid plaques in a high-stroke-risk population in Shandong Province, China

INTRODUCTION

The precise associations between stroke and carotid plaques and dyslipidemia are unclear. This population-based study aimed to examine the relationship between carotid plaques and dyslipidemia in a high-stroke-risk population.

METHODS

Ultrasonography of left and right carotid arteries was conducted in 22,222 participants in a second screening survey of individuals with high stroke risk. Subjects were divided into two groups according to the presence or absence of carotid plaques. Blood TC (total cholesterol), TG (total triglycerides), and LDL-C (low-density lipoprotein cholesterol) levels were recorded.

RESULTS

Multivariate logistic regression analysis, controlled for gender, age, education, geographic region, smoking, exercise, and overweight (Model 2), identified TG as a predictor of carotid-plaque risk (odds ratio [OR] = 1.109, 95% confidence interval [CI]: 1.038-1.185, P = 0.002), and the association between carotid plaques and LDL-C (OR = 0.967, 95%CI: 0.949-0.994, P = 0.019) was less significant, whereas there was no association between carotid plaques and TC (OR = 1.002, 95%CI: 0.932-1.007, P = 0.958). After additional adjustment for hypertension, diabetes, and atrial fibrillation (Model 3), TG remained a risk factor for carotid plaques (OR = 1.086, 95%CI: 1.016-1.161, P = 0.015), but no associations were observed between carotid plaques and LDL-C (OR = 0.972, 95%CI: 0.910-1.038, P = 0.394) or TC (OR = 1.003, 95%CI: 0.933-1.079, P = 0.928). Only the association between TG and carotid plaques (OR = 1.084, 95%CI: 1.014-1.159, P = 0.017) was independent of all covariates (covariates in Model 3 plus history of stroke or transient ischemic attack, and stroke family history) in Model 4.

CONCLUSION

These findings indicate that TG was an independent risk factor for carotid plaques in high-risk population for stroke, whereas LDL-C and TC were not associated with the appearance of carotid plaques independently.

SASH1, a new potential link between smoking and atherosclerosis

OBJECTIVE

We have previously reported that SASH1 expression is increased in circulating human monocytes from smokers and was positively correlated with the number of carotid atherosclerotic plaques. The aim of this study was to further validate the link between smoking, SASH1 and atherosclerosis within the vascular wall and to assess the impact of SASH1 expression on endothelial cell functions.

METHOD

Human carotids with atherosclerotic plaques were obtained from 58 patients (45 of them with known smoking status: smoker, non-smoker, ex-smokers), and were processed for gene expression analyses and immunostaining. To investigate its function, SASH1 was silenced in human aortic endothelial cells (HAECs) using two different siRNA and subcellular localization of SASH1 was determined by immunostaining and subcellular fractionation. Subsequently the transcriptomic analyses and functional experiments (wound healing, WST-1 proliferation or Matrigel assays) were performed to characterize SASH1 function.

RESULTS

SASH1 was expressed in human vascular cells (HAECs, smooth muscle cells) and in monocytes/macrophages. Its tissue expression was significantly higher in the atherosclerotic carotids of smokers compared to non-smokers (p < 0.01). In HAECs, SASH1 was expressed mostly in the cytoplasm and SASH1 knockdown resulted in an increased cell migration, proliferation and angiogenesis. Transcriptomic and pathway analyses showed that SASH1 silencing results in a decreased CYP1A1 expression possibly through the inhibition of TP53 activity.

CONCLUSION

We showed that SASH1 expression is increased in atherosclerotic carotids in smokers and its silencing affects endothelial angiogenic functions; therefore we provide a potential link between smoking and atherosclerosis through SASH1 expression.

Symptomatic carotid atherosclerotic disease: correlations between plaque composition and ipsilateral stroke risk

BACKGROUND AND PURPOSE

For symptomatic patients with carotid artery stenosis, the risk benefit for surgical intervention may vary among patient groups. Various modalities of plaque imaging have been promoted as potential tools for additional risk stratification, particularly in patients with moderate stenosis. However, it remains uncertain to what extent carotid plaque components predict risk of future ipsilateral ischemic stroke.

METHODS

In 2 large atherosclerotic carotid plaque biobank studies, we related histological characteristics of 1640 carotid plaques with a validated risk model for the prediction of individual 1- and 5-year stroke risk.

RESULTS

No significant heterogeneity between the studies was found. Predicted 5-year stroke risk (top versus bottom quartile) was related to plaque thrombus (odds ratio, 1.42; 95% confidence interval, 1.11-1.89; P=0.02), fibrous content (0.65; 0.49-0.87; P=0.004), macrophage infiltration (1.41; 1.05-1.90; P=0.02), high microvessel density (1.49; 1.05-2.11; P=0.03), and overall plaque instability (1.40; 1.05-1.87; P=0.02). This association was not observed for cap thickness, calcification, intraplaque hemorrhage, or lymphocyte infiltration. Plaques removed within 30 days of most recent symptomatic event were most strongly correlated with predicted stroke risk.

CONCLUSIONS

Features of the vulnerable carotid plaque, including plaque thrombus, low fibrous content, macrophage infiltration, and microvessel density, correlate with predicted stroke risk. This study provides a basis for plaque imaging studies focused on stroke risk stratification.

A Study Design to Evaluate Association between Smoking and Intracranial Atherosclerotic Stenosis

Purpose

Smoking is a well known risk factor for stroke. The cerebral arteries may be uniquely susceptible to the atherosclerotic effects of smoking, such that it has a different risk profile for stroke compared with other atherosclerosis risk factors. It remains uncertain whether smoking is associated specifically with intracranial (IC) or extracranial (EC) atherosclerotic cerebrovascular disease. The aim of this study design will be to evaluate the association between smoking and severe IC stenosis, adjusting for other atherosclerosis risk factors, particularly age distribution.

Study design

This is a retrospective cohort study design. Participants are patients (n=1714) with severe atherosclerotic stenosis undergoing cerebral catheter angiography because of stroke or transient ischaemic attack. All atherosclerotic steno-occlusive lesions are described in terms of location (anterior versus posterior circulation, IC versus EC, or intradural versus extradural). The atherosclerotic or stroke risk factors for analysis include age, gender, smoking history, number of lesions (single versus multiple), cardiac disease, diabetes mellitus, hypertension, family history, dyslipidemia, history of previous stroke, alcohol intake, metabolic syndrome and body mass index. Statistical analysis includes univariate analysis followed by multivariate logistic regression. The relationship between IC atherosclerotic stenosis and smoking will be assessed. Differences in risk factor distribution is analysed according to age at intervals of 10 years. Significant risk factors associated with IC atherosclerotic stenosis will also be assessed by multivariate logistic regression analysis.

Summary

This is an analytical study design that intends to measure the association between IC or EC atherosclerotic stenosis and smoking and other risk factors. We anticipate that it will have the power to detect any relationship between smoking and IC atherosclerotic lesions especially in younger patients.

Systematic study of the effects of lowering low-density lipoprotein-cholesterol on regression of coronary atherosclerotic plaques using intravascular ultrasound

BACKGROUND

Conflicting results currently exist on the effects of LDL-C levels and statins therapy on coronary atherosclerotic plaque, and the target level of LDL-C resulting in the regression of the coronary atherosclerotic plaques has not been settled.

METHODS

PubMed, EMBASE, and Cochrane databases were searched from Jan. 2000 to Jan. 2014 for randomized controlled or blinded end-points trials assessing the effects of LDL-C lowering therapy on regression of coronary atherosclerotic plaque (CAP) in patients with coronary heart disease by intravascular ultrasound. Data concerning the study design, patient characteristics, and outcomes were extracted. The significance of plaques regression was assessed by computing standardized mean difference (SMD) of the volume of CAP between the baseline and follow-up. SMD were calculated using fixed or random effects models.

RESULTS

Twenty trials including 5910 patients with coronary heart disease were identified. Mean lowering LDL-C by 45.4% and to level 66.8 mg/dL in the group of patients with baseline mean LDL-C 123.7 mg/dL, mean lowering LDL-C by 48.8% and to level 60.6 mg/dL in the group of patients with baseline mean LDL-C 120 mg/dL, and mean lowering LDL-C by 40.4% and to level 77.8 mg/dL in the group of patients with baseline mean LDL-C 132.4 mg/dL could significantly reduce the volume of CAP at follow up (SMD -0.108 mm3, 95% CI -0.176 ~ -0.040, p = 0.002; SMD -0.156 mm3, 95% CI -0.235 ~ -0.078, p = 0.000; SMD -0.123 mm3, 95% CI -0.199 ~ -0.048, p = 0.001; respectively). LDL-C lowering by rosuvastatin (mean 33 mg daily) and atorvastatin (mean 60 mg daily) could significantly decrease the volumes of CAP at follow up (SMD -0.162 mm3, 95% CI: -0.234 ~ -0.081, p = 0.000; SMD -0.101, 95% CI: -0.184 ~ -0.019, p = 0.016; respectively). The mean duration of follow up was from 17 ~ 21 months.

CONCLUSIONS

Intensive lowering LDL-C (rosuvastatin mean 33 mg daily and atorvastatin mean 60 mg daily) with >17 months of duration could lead to the regression of CAP, LDL-C level should be reduced by >40% or to a target level <78 mg/dL for regressing CAP.

Time-dependent changes in atherosclerotic plaque composition in patients undergoing carotid surgery

BACKGROUND

Time-dependent trends in the incidence of cardiovascular disease have been reported in high-income countries. Because atherosclerosis underlies the majority of cardiovascular diseases, we investigated temporal changes in the composition of atherosclerotic plaques removed from patients undergoing carotid endarterectomy.

METHODS AND RESULTS

The Athero-Express study is an ongoing, longitudinal, vascular biobank study that includes the collection of atherosclerotic plaques of patients undergoing primary carotid endarterectomy in the province of Utrecht from 2002 to 2011. Histopathologic features of plaques of 1583 patients were analyzed in intervals of 2 years. The analysis included quantification of collagen, calcifications, lipid cores, plaque thrombosis, macrophages, smooth muscle cells, and microvessels. Large atheroma, plaque thrombosis, macrophages, and calcifications were less frequently observed over time, with adjusted odds ratios of 0.72 (95% confidence interval, 0.650-0.789), 0.62 (95% confidence interval, 0.569-0.679), 0.87 (95% confidence interval, 0.800-0.940), and 0.75 (95% confidence interval, 0.692-0.816) per 2-year increase in time, respectively. These changes in plaque characteristics were consistently observed in patient subgroups presenting with stroke, transient ischemic attack, ocular symptoms, and asymptomatic patients. Concomitantly, risk factor management and secondary prevention strategies among vascular patients scheduled for carotid endarterectomy significantly improved over the past decade.

CONCLUSIONS

In conclusion, over the past decade, atherosclerotic plaques harvested during carotid endarterectomy show a time-dependent change in plaque composition characterized by a decrease in features currently believed to be causal for plaque instability. This appears to go hand in hand with improvements in risk factor management.

Carotid plaque hemorrhage on magnetic resonance imaging strongly predicts recurrent ischemia and stroke

Objective

There is a recognized need to improve selection of patients with carotid artery stenosis for carotid endarterectomy (CEA). We assessed the value of magnetic resonance imaging (MRI)-defined carotid plaque hemorrhage (MRIPH) to predict recurrent ipsilateral cerebral ischemic events, and stroke in symptomatic carotid stenosis.

Methods

One hundred seventy-nine symptomatic patients with ≥50% stenosis were prospectively recruited, underwent carotid MRI, and were clinically followed up until CEA, death, or ischemic event. MRIPH was diagnosed if the plaque signal intensity was >150% that of the adjacent muscle. Event-free survival analysis was done using Kaplan–Meier plots and Cox regression models controlling for known vascular risk factors. We also undertook a meta-analysis of reported data on MRIPH and recurrent events.

Results

One hundred fourteen patients (63.7%) showed MRIPH, suffering 92% (57 of 62) of all recurrent ipsilateral events and all but 1 (25 of 26) future strokes. Patients without MRIPH had an estimated annual absolute stroke risk of only 0.6%. Cox multivariate regression analysis proved MRIPH as a strong predictor of recurrent ischemic events (hazard ratio [HR] = 12.0, 95% confidence interval [CI] = 4.8–30.1, p < 0.001) and stroke alone (HR = 35.0, 95% CI = 4.7–261.6, p = 0.001). Meta-analysis of published data confirmed this association between MRIPH and recurrent cerebral ischemic events in symptomatic carotid artery stenosis (odds ratio = 12.2, 95% CI = 5.5–27.1, p < 0.00001).

Interpretation

MRIPH independently and strongly predicts recurrent ipsilateral ischemic events, and stroke alone, in symptomatic ≥50% carotid artery stenosis. The very low stroke risk in patients without MRIPH puts into question current risk–benefit assessment for CEA in this subgroup. ANN NEUROL 2013;73:774–784

Carotid plaque characterization by virtual histology intravascular ultrasound related to the timing of carotid intervention

PURPOSE

To determine the incidence of vulnerable plaques characterized by virtual histology intravascular ultrasound (VH IVUS) in patients with severe internal carotid artery (ICA) stenosis and its relationship to the timing of protected carotid artery stenting (CAS).

METHODS

The study included 141 patients (119 men; mean age 66.9 ± 9 years) with severe ICA stenosis undergoing CAS with cerebral protection. Patients were classified in 3 groups: 39 symptomatic early CAS (<14 days from clinical symptoms); 58 symptomatic delayed CAS (range 15-180 days), and 44 asymptomatic CAS. Culprit plaque component was evaluated by VH IVUS. A vulnerable plaque was defined by a thin-cap fibroatheroma and/or calcified thin-cap fibroatheroma.

RESULTS

The composite disabling stroke/mortality was 2.1%. The incidence of vulnerable plaques was significantly higher in the symptomatic early CAS group (25/39, 64.1%) than in the symptomatic delayed CAS group (26/58, 44.8%; p=0.048) or the asymptomatic CAS group (14/44, 31.8%; p=0.003). Symptomatic patients showed a significantly higher incidence of vulnerable plaques (52.6%) than asymptomatic patients (31.8%, p=0.022). There were no significant differences between the symptomatic delayed and asymptomatic groups (p=0.129). By clinical subgroup, a vulnerable plaque was observed in 29 (52.7%) of the patients with 55 transient ischemic attacks, 22 (52.4%) of the 42 minor stroke patients, and 14 (31.8%) of the 44 asymptomatic patients (p=0.152).

CONCLUSION

The incidence of vulnerable plaques was significantly higher in symptomatic patients, increasing as the intravascular study was performed closer to the index ischemic episode.

Historical perspective of carotid artery stenting in Japan: analysis of 8,092 cases in The Japanese CAS survey

BACKGROUND AND PURPOSE

We conducted a large retrospective survey of the clinical results of carotid artery stenting (CAS) for about 10 years performed by neurointerventionists at 43 Japanese institutions. Hence, the historical perspective of CAS in Japan was demonstrated.

METHODS

Cases were stratified into three separate periods based on the approval status of devices: the first period, in which off-label CAS was performed using balloon protection; the second period, using a limited number of approved devices under filter protection; the third period, using appropriate protection selected from several different options based on the preoperative evaluation (tailored CAS). Clinical results were retrospectively evaluated. Then 30-day results of each period were examined. The major adverse event (MAE) was defined as stroke, myocardial infarction or death.

RESULTS

Between January 2001 and December 2010, a total of 8,092 cases were registered, including 4,072, 1,526 and 2,494 in the first, second and third period, respectively. In the first period, 92 % of CAS was performed under balloon protection. In contrast, 91 % was done under filter protection in the second period. In the third period, various protection methods were used, including balloon (31 %), filter (50 %) and proximal protection (18 %). The rate of MAE at 30 days was 6.1 %, 10.2 % and 3.5 % in the first, second and third periods, respectively, and 6.3 % in all periods combined. The rate of MAE in the third period was significantly lower than that in the first and second periods.

CONCLUSIONS

The historical paradigm of CAS in Japan was demonstrated. Due to the improvement of devices, increasing experience and appropriate selection of protection, CAS is continuing to evolve into a safer and more efficacious method of stroke prevention.

Plaque characteristics of asymptomatic carotid stenosis and risk of stroke

BACKGROUND

The optimal treatment of asymptomatic carotid stenosis (ACS) is controversial. To optimize the risk-benefit ratio of carotid artery revascularization, it is crucial to identify ACS patients who are at increased stroke risk. Recent data suggest that plaque vulnerability depends on its composition. Therefore, we assessed plaque composition in ACS to determine predictors for ipsilateral cerebrovascular events.

METHODS

62 patients with 65 ACS ≥50% underwent 3-T MRI of the carotid bifurcation (TOF, special dark-blood weighted noncontrast and contrast-enhanced T(1) and T(2) images) and of the brain. The different plaque components (lipid core, intraplaque hemorrhage, calcification and the status of the fibrous cap) were assessed. Furthermore, the plaque volume and the volume of clinically silent cortical and subcortical infarcts in the territory of the stenosed carotid artery as seen on FLAIR images were determined by using a semi-automated software. Carotid stenosis was considered asymptomatic if there had not been any clinically apparent ischemic events in the corresponding vascular territory within the previous 6 months. During follow-up, information on the occurrence of cerebrovascular events, medical treatment and sonographic changes of the stenosis was collected.

RESULTS

At baseline, 24 ACS (37%) were classified as high grade. A lipid-rich necrotic core was the dominant plaque component in 16 ACS (25%). The plaque volume was higher in ACS with a lipid-rich necrotic core as dominant plaque component (p = 0.002) and in patients with prior stroke/TIA (p = 0.010). After a median follow-up of 18.9 months (interquartile range 3.5-30.1) there were 2 ipsilateral strokes and 3 ipsilateral TIAs. The average annual event rate was 7.7%. A lipid-rich necrotic core (HR 7.21; 95% CI 1.12-46.28; p = 0.037), sonographic progression of the stenosis (HR 7.00; 95% CI 1.13-41.34; p = 0.036), history of stroke (HR 11.03; 95% CI 1.23-99.36; p = 0.032), and the volume of clinically asymptomatic ischemic brain lesions (HR 1.14/cm(3); 95% CI 1.03-1.25; p = 0.008) predicted cerebrovascular events. Patients on statin therapy at follow-up were at lower risk of events (HR 0.17; 95% CI 0.03-1.00; p = 0.05).

CONCLUSIONS

In addition to medical history and sonographic findings, a lipid-rich necrotic core within the plaque turned out as a predictor of cerebrovascular events. Therefore, MR imaging of carotid plaques deserves further attention and might be helpful to improve risk stratification of asymptomatic carotid disease. The identified predictors could be combined in a risk model and tested in larger prospective studies.

Fatty liver index, gamma-glutamyltransferase, and early carotid plaques

An association between fatty liver and carotid atherosclerosis has been established; however, it is not clear whether this relationship is a consequence of shared conventional risk factors or whether it is determined by specific circulating factors originating from liver or adipose tissue. To identify the factors possibly linking fatty liver and atherosclerosis, we assessed, in 1,012 subjects free of confounding diseases (e.g., hypertension, diabetes, cardiovascular diseases, and dyslipidemia) and metabolic syndrome, the relationship between the presence of early plaques at carotid bifurcation and fatty liver index (FLI; a validated surrogate marker of fatty liver), as well as the associations between carotid plaque presence and established atherosclerotic risk factors, family history of cardiovascular disease (FH-CVD) or diabetes, insulin sensitivity, serum liver enzymes, adipokines, fatty free acids, and high-sensitivity C-reactive protein (hsCRP). A total of 55 of 1,012 subjects (5.4%) had small plaque at carotid bifurcation. Subjects with plaque were older and had higher prevalence of FLI ≥60 and FH-CVD, higher blood pressure, plasma low-density lipoprotein cholesterol, glucose, gamma-glutamyltransferase (GGT), and hsCRP, as compared to subjects without plaques (P < 0.05). In a logistic regression model, adjusted for sex, liver transaminase, and alcohol consumption, the independent predictors of plaque presence were age (P < 0.0005), FLI ≥60 (P < 0.0005), and current smoking (P < 0.05). When FLI in the model was replaced by variables used in its equation (e.g., body mass index, waist circumference, plasma triglycerides, and GGT), the independent determinants of plaque presence were age (P < 0.001), GGT (P = 0.001), and current smoking (P < 0.05).

CONCLUSIONS

Our cross-sectional study suggests that subjects with FLI ≥60 are at higher risk of atherosclerotic lesions, independently of established risk factors, and that serum GGT may represent a link between fatty liver and the development of early atherosclerosis.

Predictors of new atherosclerotic carotid plaque development in patients with rheumatoid arthritis: a longitudinal study

Introduction

Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality attributed to both classical risk factors and chronic inflammation. We assessed longitudinally the factors associated with new carotid plaques in nondiabetic RA patients and apparently healthy individuals.

Methods

In our present prospective observational study, carotid plaques were identified by ultrasonography at baseline and follow-up end, separated by an average of 3.6 ± 0.2 years, in 64 patients (mean age 59.2 ± 12.0 and disease duration at baseline 7.8 ± 6.2 years, 83% women, clinical and laboratory evaluation every 3 to 6 months). In a substudy, 35 of the patients were matched 1:1 for traditional cardiovascular risk factors with 'healthy' controls and were studied in parallel.

Results

New atherosclerotic plaques formed in 30% of patients (first plaque in 9%) who were significantly older than the remaining patients. Tobacco use, blood pressure, body mass index, average cumulative low-density lipoprotein, high-sensitivity C-reactive protein, erythrocyte sedimentation rate level, RA stage, functional class, disease duration and treatment modalities during follow-up did not differ significantly between subgroups after application of the Bonferroni correction. RA was in clinical remission, on average, for approximately 70% of the follow-up time and was not different between subgroups. Multivariate analysis including all the above parameters revealed that age (P = 0.006), smoking (P = 0.009) and duration of low-dose corticosteroid use (P = 0.016) associated independently with new plaque formation. RA patients displayed similar numbers of newly formed carotid plaques to the tightly matched for traditional cardiovascular risk factors 'healthy' controls, although more patients than controls had carotid plaques at baseline.

Conclusions

Formation of new atherosclerotic plaques in this small cohort of patients with well-controlled RA depended mainly on traditional cardiovascular risk factors and corticosteroid use, whereas an adverse effect of residual systemic inflammation was not readily detectable.