Impaired kidney function is associated with intraplaque hemorrhage in patients undergoing carotid endarterectomy

Clinical risk scores for stroke correlate with molecular signatures of vulnerability in symptomatic carotid patients

Unstable carotid stenosis is an important cause of ischemic stroke, yet the basis of disease pathophysiology remains largely unknown. We hypothesized that integrated analyses of symptomatic carotid stenosis patients at increased stroke risk stratified by clinical scores, CAR and ABCD2, with transcriptomic and clinical data could improve identification of molecular pathways and targets for instability. We show that high CAR score reflects plaque instability processes related to intra-plaque hemorrhage, angiogenesis, inflammation, and foam cell differentiation, whereas ABCD2 associates with neutrophil-mediated immunity, foam cell differentiation, cholesterol transport, and coagulation. Repressed processes in plaques from high-risk patients were ossification, chondrocyte differentiation, SMC migration, and ECM organization. ABCB5 gene was found as the top upregulated in high-risk patient’s plaques, localized to macrophages in areas with neovascularization and intra-plaque hemorrhage. The link between ABCB5 and intra-plaque hemorrhage suggests its key role for plaque instability that warrants further exploration.

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We integrated stroke risk in carotid stenosis patients with plaque transcriptomics

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High CAR and ABCD2 scores reflect plaque instability processes and hemorrhage

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ABCB5 is upregulated in high-risk plaques, macrophages, and around neovessels

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CAR and ABCD2 capture vulnerable plaque features and improve risk stratification

The TAXINOMISIS Project: A multidisciplinary approach for the development of a new risk stratification model for patients with asymptomatic carotid artery stenosis

INTRODUCTION

Asymptomatic carotid artery stenosis (ACAS) may cause future stroke and therefore patients with ACAS require best medical treatment. Patients at high risk for stroke may opt for additional revascularization (either surgery or stenting) but the future stroke risk should outweigh the risk for peri/post-operative stroke/death. Current risk stratification for patients with ACAS is largely based on outdated randomized-controlled trials that lack the integration of improved medical therapies and risk factor control. Furthermore, recent circulating and imaging biomarkers for stroke have never been included in a risk stratification model. The TAXINOMISIS Project aims to develop a new risk stratification model for cerebrovascular complications in patients with ACAS and this will be tested through a prospective observational multicentre clinical trial performed in six major European vascular surgery centres.

METHODS AND ANALYSIS

The risk stratification model will compromise clinical, circulating, plaque and imaging biomarkers. The prospective multicentre observational study will include 300 patients with 50%-99% ACAS. The primary endpoint is the three-year incidence of cerebrovascular complications. Biomarkers will be retrieved from plasma samples, brain MRI, carotid MRA and duplex ultrasound. The TAXINOMISIS Project will serve as a platform for the development of new computer tools that assess plaque progression based on radiology images and a lab-on-chip with genetic variants that could predict medication response in individual patients.

CONCLUSION

Results from the TAXINOMISIS study could potentially improve future risk stratification in patients with ACAS to assist personalized evidence-based treatment decision-making.

Expression of Cyclophilin A in Coronary Artery Plaque with Intraplaque Hemorrhage Is More Frequent in Deceased Patients Who Had Impaired Kidney Function

Patients with impaired kidney function have a high frequency of intraplaque hemorrhage (IPH) in their coronary arteries. Levels of cyclophilin A (CyPA), an indirect matrix metalloproteinase inducer, are increased in deceased patients who had impaired kidney function. In this study, we have examined the relationship between IPH and CyPA.We examined 47 samples of coronary plaque from 27 cadavers with coronary stenosis. These sections, all with > 50% coronary stenosis, were stained with an antibody against CyPA and the expression of CyPA was semi-quantified. Cadavers and plaques were classified into one of two groups depending on the presence or absence of IPH. IPH was defined as the presence of red blood cells stained with hematoxylin and eosin (HE) indicative of overt acute hemorrhage.In an individual analysis, estimation of glomerular filtration rate (eGFR) in the IPH group was significantly lower than that in the non-IPH group (P = 0.002). In a histological analysis, the percentage of stained area of CyPA in the IPH group was significantly higher than that in the non-IPH group (P < 0.0001).IPH was associated with a significantly higher expression of CyPA in this study. In addition, patients with IPH in their coronary arteries had significantly impaired kidney function.

Carotid Plaque Morphology is Similar in Patients with Reduced and Normal Renal Function

BACKGROUND

Chronic Kidney Disease (CKD) is associated with an increased risk for cardiovascular events such as stroke. However, it is still unclear if decreased kidney function is associated with a vulnerable atherosclerotic plaque phenotype. To explore if renal function was associated with carotid plaque vulnerability we analyzed carotid plaques obtained at surgery from the Carotid Plaque Imaging Project (CPIP).

METHODS

Patients were enrolled through the CPIP cohort. The indication for surgery was plaques with stenosis >70%, associated with ipsilateral symptoms or plaques with stenosis >80% not associated with symptoms. Transversal sections from the most stenotic plaque region were analyzed for connective tissue, calcium, lipids, macrophages, intraplaque hemorrhage, and smooth muscle cells. Homogenates were analyzed for collagen and elastin.

RESULTS

Carotid endarterectomy specimens from 379 patients were obtained. The median GFR was 73 ml/min/1.73 m2. Plaque characteristics showed no significant association with eGFR, neither when eGFR was divided in CKD groups nor when eGFR was handled as a continuous variable and adjusting for other known risk factors (ie, age, diabetes, hypertension, and smoking).

CONCLUSIONS

The higher risk of cardiovascular disease such as stroke in CKD is not associated with increased plaque vulnerability and other factors have to be sought.

eGFR and deep white matter hyperintensity as predictors of cognitive decline long after carotid endarterectomy

Chronic kidney disease and white matter hyperintensity (WMH) are associated with cognitive decline. The aim of this study was to assess the correlations between estimated glomerular filtration rate (eGFR) or WMH and cognitive function in patients who have undergone carotid endarterectomy (CEA). Cognitive functions were investigated using the Neurobehavioral Cognitive Status Examination (Cognistat) in 83 patients who had undergone CEA. The eGFR at 5 years prior to examination was significantly associated with severe cognitive impairment (odds ratio, 0.89 per 1-mL/min/1.73 m² increase, 95% confidence interval 0.82–0.97, p = 0.0004). Receiver operating characteristic analysis revealed that a cutoff eGFR of 46.8 mL/min/1.73 m² at 5 years prior to examination offered the most reliable predictor of severe cognitive impairment (sensitivity 88.9%, specificity 76.5%, area under the curve 0.848). The eGFR at 5 years prior to examination showed a significant linear association with total Cognistat score (r² = 0.11035, p = 0.0032) compared to eGFR at 3 years prior to examination (r² = 0.06455, p = 0.0230) or at examination (r² = 0.0210, p = 0.0210). Spearman’s correlation coefficient revealed that orientation, comprehension, repetition, construction, memory, and similarity correlated with eGFR at 5 years prior to examination. Conversely, Fazekas grade for deep WMH at examination was associated with total Cognistat score (p = 0.0016), unlike that at 3 years (p = 0.0100) or 5 years prior to examination (p = 0.0172). While eGFR correlates with future cognitive function, deep WMH associates with present cognitive function in patients who have undergone CEA.

Magnetic Resonance Imaging Identified Brain Ischaemia in Symptomatic Patients Undergoing Carotid Endarterectomy Is Related to Histologically Apparent Intraplaque Haemorrhage

OBJECTIVE

Intraplaque haemorrhage (IPH) has been independently associated with a higher risk of future ipsilateral stroke in patients with carotid artery stenosis. Evaluation of plaque characteristics may contribute to risk assessment of recurrent (silent) cerebrovascular events in order to prioritise patients for timing of treatment. It is unknown if patients showing histologically apparent IPH also have increased risk of silent ischaemic brain lesions in the waiting period between index event and revascularisation.

METHODS

A retrospective analysis was performed based on prospectively collected data of patients included simultaneously in the magnetic resonance imaging (MRI) substudy of the International Carotid Stenting Study and Athero-Express biobank. Patients randomised for carotid endarterectomy (CEA) underwent surgery between 2003 and 2008. Brain MRI was performed one to seven days prior to CEA. Plaques were histologically examined for presence of IPH. The primary outcome parameter was presence of silent ipsilateral brain ischaemia on magnetic resonance diffusion weighted imaging (MR-DWI) appearing hypo or isointense on apparent diffusion coefficient.

RESULTS

Fifty-three patients with symptomatic carotid stenosis meeting the study criteria were identified, of which 13 showed one or more recent ipsilateral DWI lesion on pre-operative scan. The median time between latest ipsilateral neurological event and revascularisation was 45 days (range 6-200) in DWI negative patients vs. 34 days (range 6-74, p = .16) in DWI positive patients. IPH was present in 24/40 (60.0%) DWI negative patients vs. 12/13 (92.3%) DWI positive patients (OR 8.00; 95% CI 0.95-67.7, p = .06). Multivariable logistic regression analysis correcting for age and type of index event revealed that IPH was independently associated with DWI lesions in the waiting period till surgery (OR 10.8; 95% CI 1.17-99.9, p = .04).

CONCLUSION

Symptomatic patients with ipsilateral carotid stenosis and silent brain ischaemia on pre-operative MR-DWI, more often showed pathological evidence of IPH compared with those without ischaemic lesions. This identifies carotid IPH as a marker for patients at risk of silent brain ischaemia and possibly for future stroke and other arterial disease complications. Such patients may be more likely to benefit from CEA than those without evidence of ipsilateral carotid IPH.