Symptomatic Carotid Atherosclerosis Research Articles

Cartilage Oligomeric Matrix Protein Associates With a Vulnerable Plaque Phenotype in Human Atherosclerotic Plaques.

Background and Purpose- Extracellular matrix proteins are important in atherosclerotic disease by influencing plaque stability and cellular behavior but also by regulating inflammation. COMP (cartilage oligomeric matrix protein) is present in healthy human arteries and expressed by smooth muscle cells. A recent study showed that transplantation of COMP-deficient bone marrow to apoE-/- mice increased atherosclerotic plaque formation, indicating a role for COMP also in bone marrow-derived cells. Despite the evidence of a role for COMP in murine atherosclerosis, knowledge is lacking about the role of COMP in human atherosclerotic disease. Methods- In the present study, we investigated if COMP was associated with a stable or a vulnerable human atherosclerotic plaque phenotype by analyzing 211 carotid plaques for COMP expression using immunohistochemistry. Results- Plaque area that stained positive for COMP was significantly larger in atherosclerotic plaques associated with symptoms (n=110) compared with asymptomatic plaques (n=101; 9.7% [4.7-14.3] versus 5.6% [2.8-9.8]; P=0.0002). COMP was positively associated with plaque lipids (r=0.32; P=0.000002) and CD68 cells (r=0.15; P=0.036) but was negatively associated with collagen (r=-0.16; P=0.024), elastin (r=-0.14; P=0.041), and smooth muscle cells (r=-0.25; P=0.0002). COMP was positively associated with CD163 (r=0.37; P=0.00000006), a scavenger receptor for hemoglobin/haptoglobin and a marker of Mhem macrophages, and with intraplaque hemorrhage, measured as glycophorin A staining (r=0.28; P=0.00006). Conclusions- The present study shows that COMP is associated to symptomatic carotid atherosclerosis, CD163-expressing cells, and a vulnerable atherosclerotic plaque phenotype in humans.

Abstract 42: CAS versus CEA Treatment Differences in Long-Term Outcomes and Post-Procedural Durability: the Carotid Stenosis Trialist Collaboration (CSTC)

Introduction: A 3.4% (95% CI: 2.1% to 4.7%) higher peri-procedural stroke and death risk has been previously documented for those treated with carotid artery stenting (CAS) relative to those treated with carotid endarterectomy (CEA). However, the CAS versus CEA treatment differences in long-term outcomes and the post-procedure durability have not been described. Methods: Data from the 4 largest CAS-versus-CEA randomized trials for treatment of symptomatic carotid atherosclerosis (EVA-3S, SPACE, ICSS, and CREST) were pooled, and treatment differences assessed for the outcome of any stroke or death during a 120-day peri-procedural period, plus ipsilateral stroke afterward. Results: Long-term follow-up was analysed for 4754 patients. Median length of follow-up across the studies ranged from 2.0 to 6.9 years, with 88 peri-procedural and 55 post-procedural events among those CEA-treated, and 169 and 64 for those CAS-treated. After the peri-procedural period, the annual rates of stroke following CAS was 0.6% (95% CI: 0.5 to 0.8) and following CEA 0.6% (95% CI: 0.5 to 0.8), resulting in non-significant durability differences of less than 1% over the period extending up to 9 years (see Table). The previously-documented 3.4% higher peri-procedural event rate in the CAS group contributed to a significant 3.1% (95% CI: 1.6% to 4.7%) treatment difference at 1-year, and the aforementioned similar durability implied that this significant difference remained relatively constant over the period extending up to 9 years (see table). Conclusions: The post-procedure durability of CAS and CEA were similar, both with event rates below 1%. The similarity of post-procedure events rates implies that the previously-documented higher peri-procedural in the CAS group is “carried forward” with a higher risk of outcomes extending to 9-years.

Analysis of 18F-Fluorodeoxyglucose and 18F-Fluoride Positron Emission Tomography in Korean Stroke Patients with Carotid Atherosclerosis.

ObjectiveThe objective of this study was to analyze uptake patterns and intensity of 18F-fluorodeoxyglucose (FDG) and 18F-sodium fluoride (NaF) radioligands in carotid atheroma among stroke patients according to carotid atheroma characteristics.MethodsBetween September 2015 and January 2017, consecutive acute stroke or transient ischemic attack patients with 50% or more proximal internal carotid artery stenosis on brain computed tomography angiography were prospectively enrolled. All patients received FDG and NaF positron emission tomography (PET) evaluation when their neurological status was stabilized. Uptake values of FDG and NaF were compared by target to blood ratio (TBR) according to the calcification burden, atheroma volume and the presence of a necrotic core of carotid atheroma.ResultsA total of 18 patients with 36 carotid arteries were finally enrolled, with 10 patients diagnosed as acute cerebral infarction due to symptomatic carotid stenosis. FDG uptake at symptomatic carotid arteries was significantly more increased than that at asymptomatic arteries (TBR: 1.17±0.23 vs. 1.01±0.15, Mann-Whitney U-test, p=0.02), but NaF uptake was not different (TBR: 1.38±0.49 vs. 1.51±0.40, p=0.40). In terms of calcification degree, NaF uptake increased as calcification burden increased (none, 1.28±0.36; spotty, 1.29±0.29; linear, 1.74±0.44; analysis of variance, p=0.02).ConclusionCarotid evaluation by FDG is superior to NaF PET in the detection of symptomatic carotid atherosclerosis among stroke patients. NaF PET uptake reflects the overall calcification burden.

IP127. Risk Factors for Major Adverse Clinical Events After Carotid Endarterectomy Based on Patient Age and Symptoms

Carotid endarterectomy (CEA) is a well-established surgical procedure in the treatment of symptomatic and asymptomatic carotid atherosclerosis. We reviewed the American College of Surgeons National Surgical Quality Improvement Program database to assess which factors contribute to major adverse clinical events (MACEs) in the 30-day postoperative period. The American College of Surgeons National Surgical Quality Improvement Program database was queried among all participating institutions for CEAs performed in 2011 to 2015. Patients’ demographic data, comorbid conditions, preprocedure medication use, and operative variables were analyzed using multivariate logistic regression analysis to determine predictors of postoperative MACEs. There were 17,888 patients who underwent CEA analyzed; the patients were grouped by age (<75 and ≥75 years old) and whether they presented symptomatically (SYM) or asymptomatically (AS) before the procedure. For AS patients <75 years, the rate of stroke, myocardial infarction (MI), death, and MACEs was 1.8%, 1.6%, 0.4%, and 3.6%, respectively; for patients ≥75 years, rates were 1.7%, 2.3%, 0.7%, and 4.3%. The rate of MI was significantly higher in older patients (P = .0133). The odds of postoperative stroke was 73% higher (P < .0011) in diabetics, 57% higher (P = .0109) with American Society of Anesthesiologists (ASA) score 4 or 5, and 34% higher with operative time >2.5 hours (P = .0189). SYM patients ≥75 years had 1.1 times higher risk of postoperative stroke if they had insulin-dependent diabetes (P = .0148). Reintubation and reoperation were associated with increased risk of postoperative stroke in both age groups, whether SYM or AS (P < .0001), as well as postoperative MI (P < .0001). AS patients <75 years had higher likelihood of postoperative MI if they had history of congestive heart failure (P = .0257) and operative time >2.5 hours (P = .0033). SYM patients ≥75 years had 46% higher likelihood of postoperative MI if operative time >2.5 hours (P = .0023). Mortality was higher in AS patients <75 years with ASA score 4 or 5 (P = .0006) and those ≥75 years (P = .0072) and in patients who were reintubated (P < .0001). In SYM patients <75 years, the rate of stroke, MI, death, and MACEs was 4.8%, 1.4%, 0.9%, and 6.3%, respectively. In those ≥75 years, rates were 4.9%, 2.6%, 1.6%, and 7.8%. Older patients had higher rates of MI and MACEs (P = .001 and P= .0103). SYM patients <75 years had higher mortality if they had chronic obstructive pulmonary disease (P = .0002) and diabetes (P = .0062). SYM patients of all ages had higher mortality with postoperative stroke or MI (P < 0.0001). Patients 75 years or older are at increased risk of postoperative MI after CEA regardless of symptomatic status. Diabetes, increased operative time, and ASA score 4 or 5 were associated with higher MACE rates among all age groups.

Detection of symptomatic carotid atherosclerosis from 18F-fluorodeoxyglucose and 18F-sodium fluoride positron emission tomography after stroke: A prospective study

Detection of symptomatic carotid atherosclerosis from 18F-fluorodeoxyglucose and 18F-sodium fluoride positron emission tomography after stroke: A prospective study

Symptomatic carotid atherosclerosis detection by positron emission tomography imaging

Symptomatic carotid atherosclerosis detection by positron emission tomography imaging

NGAL and MMP-9/NGAL as biomarkers of plaque vulnerability and targets of statins in patients with carotid atherosclerosis.

Neutrophil gelatinase associated lipocalin (NGAL) is expressed in atherosclerotic lesions and was recently implicated in the pathogenesis of cardiovascular pathologies. Statins are known to exert stabilizing effects on atherosclerotic plaque. The aims of our study were (1) to investigate the association of serum NGAL and metalloproteinase (MMP)-9/NGAL complex with the vulnerability of the atherosclerotic plaque, and (2) to reveal the effects of statin treatment on circulating NGAL and MMP-9/NGAL levels in patients with carotid artery stenosis. We examined the levels of NGAL and MMP-9/NGAL in blood samples from 136 patients with carotid artery stenosis by specific enzyme-linked immunosorbent assays. Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of American Heart Association [AHA]), displayed the highest levels of NGAL (both p<0.0001) and MMP-9/NGAL complex (p=0.0004 and p=0.004, respectively). Moreover, patients with symptomatic carotid atherosclerosis had significantly higher NGAL levels compared to asymptomatic patients (p=0.0007). The statin-treated group (n=108) demonstrated lower NGAL (73.9 vs. 128.0 μg/L, p<0.0001) and MMP-9/NGAL (28.9 vs. 40.6 μg/L, p=0.046) as compared to the non-statin group (n=28). Furthermore, in multivariate regression analysis NGAL, but not MMP-9/NGAL levels, were independently associated with symptomatic carotid artery stenosis. In addition, statin treatment was independently associated with lower NGAL levels. Circulating NGAL and MMP-9/NGAL are associated with plaque vulnerability in patients with carotid artery stenosis. Statin treatment could contribute to plaque stabilization by reducing circulating NGAL and MMP-9/NGAL levels.

Carotid intraplaque hemorrhage on vessel wall MRI does not correlate with TCD emboli monitoring in patients with recently symptomatic carotid atherosclerosis.

Background Carotid intraplaque hemorrhage (IPH) seen on vessel wall MRI is associated with an increased risk of stroke or transient ischemic attack, as are microembolic signals (MES) detected by transcranial Doppler (TCD). We sought to examine the association between IPH and MES in acute stroke patients with symptomatic carotid atherosclerosis. Methods Through a retrospective chart review, we included patients from 2011 to 2013 with acute ischemic stroke due to carotid atherosclerosis of varying stenosis who had both 3D volumetric MRI of the neck and TCD emboli monitoring. Results Twenty-four patients met the inclusion criteria. Mean time from stroke to MRI was 1.4 ± 1.9 days and to TCD was 2.6 ± 2.4 days. MES was seen in 10 patients (42%) and IPH was present in seven patients (29%), but we did not find a relationship between MES and IPH ( p = 0.64). Conclusion In patients with recent acute ischemic stroke attributed to carotid atherosclerosis, we did not detect an association between the presence of IPH and MES. While this small study may be underpowered, an alternate explanation is that MES and IPH reflect vulnerable carotid atherosclerosis through different mechanisms. This untested concept warrants prospective study in a larger cohort.

Lower Expression of Genes Involved in Protection against Oxidative Stress in Symptomatic Carotid Atherosclerosis

Oxidative stress is increased in atherosclerosis, manifested both in blood and tissue (atherosclerotic plaque). We aim at describing the expression of a number of genes related to oxidative stress response in carotid atherosclerotic plaques and their relation to symptomatic state. We have studied the messenger RNA expression levels for genes related to oxidative stress in a population of 44 patients undergoing carotid endarterectomy, according to the presence (24 patients) or absence (20 patients) of symptoms. Samples were homogenized, RNA was extracted, and gene expression was measured by quantitative reverse transcription polymerase chain reaction arrays. Data showed a decrease in expression of oxidative stress protective genes in symptomatic patients and increased expression of pro-oxidant genes. Asymptomatic patients maintain higher levels of expression of protective genes in the tissue. This study establishes a close relationship between symptoms and levels of expression of genes that protect against oxidative stress. We propose the existence of a mechanism that silences these genes, causing a more severe atherosclerotic disease state.

Blood Pressure Lowering Treatment in Patients with Carotid Artery Stenosis.

Stroke is the second most common cause of death and the most common cause of disability worldwide. Up to 30% of ischaemic strokes are caused by carotid atherosclerosis, usually due to thromboemboli from an atherosclerotic plaque at the carotid bifurcation. High blood pressure is an important risk factor for atherosclerosis, the development of unstable carotid plaques, and ischaemic strokes. Differentiation between asymptomatic and symptomatic carotid atherosclerosis is critical to treatment management because of the difference in natural history. Intensive medical treatment including blood pressure lowering medication reduces the risk of both primary and secondary vascular events in patients at risk. This review summarises recent data on blood pressure management in patients with carotid artery stenosis.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) is Associated with Symptomatic Carotid Atherosclerosis and Drives Pro-inflammatory State In Vitro

Neutrophil gelatinase-associated lipocalin (NGAL), a protein found in activated neutrophils, is expressed in kidney tubule cells in response to noxious stimuli, and is thus recognized as a marker of acute kidney injury. Recent studies have suggested that NGAL could also have pathophysiological importance in cardiovascular diseases. The aim of the present study was to examine NGAL expression in human carotid endarterectomy tissues ex vivo as well as the effects of NGAL in the main cell types involved in atherogenesis, namely in human macrophages, endothelial cells, and smooth muscle cells in vitro. NGAL protein was analyzed in human endarterectomy samples from patients with asymptomatic and symptomatic carotid stenosis by immunofluorescence, and NGAL mRNA expression was detected using RealTime-PCR. Human monocyte derived macrophages (MDM), human coronary artery smooth muscle cells (HCASMC), and human umbilical vein endothelial cells (HUVEC) were treated with recombinant human (rh) NGAL at different concentrations. Interleukin (IL)-6, IL-8, and monocyte chemo-attractant protein-1 (MCP-1) were determined by specific enzyme linked immunosorbent assays (ELISAs) in culture supernatants of such treated cells. Expression of NGAL protein was demonstrated by macrophages, smooth muscle cells, and endothelial cells in human carotid atherosclerotic tissue. NGAL mRNA expression was detected at a higher rate in atherosclerotic tissue of patients with symptomatic carotid stenosis (in 70%; n = 19) compared with asymptomatic patients (in 37%; n = 20, P < .001). Treatment of MDM, HCASMC, and HUVEC with rhNGAL led to a significant (P < .05) and concentration dependent increase of pro-inflammatory cytokines IL-6, IL-8, and MCP-1 in all cell types analyzed. By induction of pro-inflammatory mediators in human macrophages, smooth muscle cells and endothelial cells, NGAL, which is predominantly expressed in atherosclerotic plaques of symptomatic patients, could be involved in creating the local and systemic pro-inflammatory environment characteristic for atherosclerosis.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) is Associated with Symptomatic Carotid Atherosclerosis and Drives Pro-inflammatory State In Vitro

Neutrophil gelatinase-associated lipocalin (NGAL), a protein found in activated neutrophils, is expressed in kidney tubule cells in response to noxious stimuli, and is thus recognized as a marker of acute kidney injury. Recent studies have suggested that NGAL could also have pathophysiological importance in cardiovascular diseases. The aim of the present study was to examine NGAL expression in human carotid endarterectomy tissues exvivo as well as the effects of NGAL in the main cell types involved in atherogenesis, namely in human macrophages, endothelial cells, and smooth muscle cells invitro. NGAL protein was analyzed in human endarterectomy samples from patients with asymptomatic and symptomatic carotid stenosis by immunofluorescence, and NGAL mRNA expression was detected using RealTime-PCR. Human monocyte derived macrophages (MDM), human coronary artery smooth muscle cells (HCASMC), and human umbilical vein endothelial cells (HUVEC) were treated with recombinant human (rh) NGAL at different concentrations. Interleukin (IL)-6, IL-8, and monocyte chemo-attractant protein-1 (MCP-1) were determined by specific enzyme linked immunosorbent assays (ELISAs) in culture supernatants of such treated cells. Expression of NGAL protein was demonstrated by macrophages, smooth muscle cells, and endothelial cells in human carotid atherosclerotic tissue. NGAL mRNA expression was detected at a higher rate in atherosclerotic tissue of patients with symptomatic carotid stenosis (in 70%; n=19) compared with asymptomatic patients (in 37%; n=20, p<.001). Treatment of MDM, HCASMC, and HUVEC with rhNGAL led to a significant (p<0.05) and concentration dependent increase of pro-inflammatory cytokines IL-6, IL-8, and MCP-1 in all cell types analyzed. By induction of pro-inflammatory mediators in human macrophages, smooth muscle cells and endothelial cells, NGAL, which is predominantly expressed in atherosclerotic plaques of symptomatic patients, could be involved in creating the local and systemic pro-inflammatory environment characteristic for atherosclerosis.

Intracranial versus Extracranial Symptomatic Carotid Atherosclerosis in Chinese Patients: Risk Factors, Stroke Mechanisms, and Long-Term Prognosis

This study aims to investigate the clinical-radiological features and stroke mechanisms of symptomatic intracranial internal carotid artery (IICA) atherosclerosis and prognoses of patients with IICA atherosclosis, and compare these data with those from patients with symptomatic extranial carotid artery (EICA) atherosclerosis. We prospectively recruited 155 patients with symptomatic IICA or EICA atherosclerosis (stenosis ≥50% or occlusion) from 1968 Chinese patients with a first-ever ischemic stroke or transient ischemic attack. The patients were followed up for stroke recurrence, cardiovascular events, and death. There were 80 and 75 patients in the IICA and EICA groups, respectively. Multivariate logistic regression analyses showed that the patients in the IICA group were associated with hypertension (odds ratio [OR], 5.980; 95% confidence interval [CI], 1.790-19.976) and asymptomatic intracranial atherosclerosis (OR, 2.564; 95% CI, 1.222-5.377), while the patients in the EICA group were associated with smoking (OR, 2.397; 95% CI, 1.150-4.998) and contralateral EICA disease (OR, 4.742; 95% CI, 1.455-15.455). Hemodynamic stroke alone was more common in the IICA group; artery-to-artery embolism was identified more often in the EICA group (P <.05). The cumulative incidences of ipsilateral stroke recurrence, stroke recurrence and cardiovascular events, and death at 5 years were 43.5%, 52.4%, and 27.3%, respectively, in the patients of the IICA group, which did not differ from those of the EICA group. IICA atherosclerosis as well as EICA atherosclerosis is an important cause of stroke in Chinese patients. Patients with symptomatic IICA atherosclerosis had unique clinical-radiological features and stroke mechanisms compared with those with symptomatic EICA atherosclerosis; their long-term prognosis was poor.

Abstract T MP30: Biomarkers for the Evaluation of Vulnerability in Carotid Atherosclerotic Plaques

Background and Purpose: Several biomarkers, such as the soluble CD40 ligand (sCD40L), Matrix metalloproteinase-9 (MMP-9), Interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF), have been known as biomarkers associated with plaque vulnerability in coronary arteries. However, their clinical utility in carotid atherosclerosis remains unknown. The aim of this study was to assess the availability of these biomarkers for the assessment of plaque vulnerability in the patients with carotid artery stenosis. Methods: Between May 2013 and June 2014, the patients with carotid atherosclerotic plaques were enrolled in this study. These patients were divided into two groups (symptomatic and asymptomatic group). The baseline clinical data included age, gender, smoking habit, and the grade of carotid stenosis. Serum levels of biomarkers (MMP-9, IL-6, VEGF and plasma levels of sCD40L) were measured. We also collected the data of biochemical examination (serum total cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, blood sugar and C-reactive protein). Results: We enrolled 35 consecutive patients (23 in symptomatic and 12 in asymptomatic group) with the carotid artery stenosis (NASCET 53.9 % vs. 47.8 %, p=0.59). There was no significant difference between the two groups in baseline clinical data and biochemical values. Plasma sCD40L level was significantly higher in symptomatic group than in asymptomatic group (1720 vs. 958 pg/ml, respectively, p&lt;0.01). No other biomarkers were correlated significantly in the two groups [serum MMP-9 (171 vs. 149 ng/ml, respectively, p=0.27), IL-6 (3.7 vs. 2.7 pg/ml, p=0.24), and VEGF (56 vs. 46 pg/ml, p =0.48)]. Conclusions: We found that the patients with symptomatic carotid atherosclerosis had higher levels of plasma sCD40L, and it may be useful to evaluate the vulnerability of carotid atherosclerotic plaques.

Carotid inflammation on 18F-fluorodeoxyglucose positron emission tomography associates with recurrent ischemic lesions

BackgroundInflammation plays an important role in the development of ischemic stroke. We hypothesized that inflammation of carotid atherosclerosis, as measured by 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET), associates with the early recurrent ischemic lesions (ERILs). MethodsThis prospective study included patients with symptomatic carotid atherosclerosis. ERILs were defined as newly developed ischemic lesions in the territory of symptomatic internal carotid artery stenosis, as detected by follow-up diffusion-weighted imaging (DWI). The patients with and without ERILs were compared in terms of risk factors, inflammatory markers, and FDG uptake on PET. ResultsOf the 21 patients, 8 had ERILs (38.1%). Compared to the patients without ERILs, those with ERILs had higher FDG uptake (maximum standardized uptake value, 3.07±0.79 vs. 2.17±0.68, p=0.013) and were more likely to have irregular carotid plaques (100% vs. 38.5%, p=0.007). Inflammatory markers were not different between the two groups, and also did not correlate with FDG uptake. ConclusionsIncreased carotid plaque inflammation, as measured by FDG uptake on PET, may be a useful marker for identifying patients with symptomatic carotid atherosclerosis who are at risk of recurrence.

Impact of risk scoring on decision-making in symptomatic moderate carotid atherosclerosis

Benefit from carotid endarterectomy (CEA) in symptomatic moderate (50-69 per cent) carotid stenosis remains marginal. The Fourth National Clinical Guideline for Stroke recommends use of the risk score from the European Carotid Surgery Trial (ECST) to aid decision-making in symptomatic carotid disease. It is not known whether clinicians are, in fact, influenced by it. Using the ECST risk prediction model, three scenarios of patients with a low (less than 10 per cent), moderate (20-25 per cent) and high (40-45 per cent) 5-year risk of stroke were devised and validated. Invitations to complete an online survey were sent by e-mail to vascular surgeons and stroke physicians, with responses gathered. The questionnaire was then repeated with the addition of the ECST risk score. Two hundred and one completed surveys were analysed (21·5 per cent response rate): 107 by stroke physicians and 94 by vascular surgeons. The high-risk scenario after the introduction of the ECST risk score showed an increased use of CEA (66·7 versus 80·1 per cent; P = 0·009). The low-risk scenario after risk score analysis demonstrated a swing towards best medical therapy (23·4 versus 57·2 per cent; P < 0·001). CEA was preferred in the moderate-risk scenario and this was not altered significantly by introduction of the risk score (71·6 versus 75·6 per cent; P = 0·609). Vascular surgeons exhibited a preference towards CEA compared with stroke physicians in both low- and moderate-risk scenarios (P < 0·001 and P = 0·003 respectively). The addition of a risk score appeared to influence clinicians in their decision-making towards CEA in high-risk patients and towards best medical therapy in low-risk patients.

Usefulness of Contrast-Enhanced Ultrasound for Detection of Carotid Plaque Ulceration in Patients With Symptomatic Carotid Atherosclerosis

Previous data have indicated that carotid plaque ulceration is a strong predictor of cerebrovascular events. Standard ultrasound and color Doppler ultrasound (CDUS) scans have poor diagnostic accuracy for the detection of carotid plaque ulceration. The aim of the present prospective study was to assess the value of contrast-enhanced ultrasound (CEUS) scans for the detection of carotid plaque ulceration. The Institutional Ethics Committee approved the study protocol, and all patients provided informed consent. The patients hadsymptomatic stenosis of the internal carotid artery and underwent carotid computedtomographic angiography as part of their clinical evaluation. All patients underwent a CDUS examination in conjunction with CEUS. Carotid plaque ulceration wasdefined as the presence of ≥1 disruptions in the plaque-lumen border ≥1× 1 mm. Carotid computed tomographic angiography was used as reference technique. The study population consisted of 20 patients (mean age 64 ± 9 years, 80% men), and 39 carotid arteries were included in the present analysis. Computed tomographic angiography demonstrated that the plaque surface was smooth in 15 (38%), irregular in 7 (18%) and ulcerated in 17 (44%) carotid arteries. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CDUS for the detection of ulceration was29%, 73%, 54%, 46%, and 57%, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CEUS for the detection of ulceration was 88%, 59%, 72%, 63%, and 87%, respectively. CEUS had superior sensitivity and diagnostic accuracy for the assessment of carotid plaque ulceration compared with CDUS. CEUS improved theintrareader and inter-reader variability for the assessment of carotid plaque ulcerationcompared with CDUS. In conclusion, CEUS could be an additional method for the detection of carotid plaque ulceration. The role of CDUS for the assessment ofcarotidplaque ulceration seems limited.

Increased expression of heparanase in symptomatic carotid atherosclerosis

ObjectiveProliferation of smooth muscle cells (SMCs) can stabilize atherosclerotic lesions but the molecular mechanisms that regulate this process in humans are largely unknown. We have previously shown that heparan sulfate proteoglycans (HSPGs), such as perlecan, regulate SMC growth in animal models by modulating heparin-binding mitogens. Since perlecan is expressed at low levels in human atherosclerosis, we speculated that the effect of heparan sulfate (HS) in human disease was rather influenced by HS degradation and investigated the expression of heparanase (HPSE) in human carotid endarterectomies. Methods and resultsGene expression analysis from 127 endarterectomies in the BiKE database revealed increased expression of HPSE in carotid plaques compared with normal arteries, and a further elevation in symptomatic lesions. Increased HPSE protein expression in symptomatic plaque tissue was verified by tissue microarrays. HPSE mRNA levels correlated positively with expression of inflammatory markers IL-18, RANTES and IL-1β, and also T-cell co-stimulatory molecules, such as B7.2, CD28, LFA-1 and 4-1BB. Previously reported single nucleotide polymorphisms within HPSE were associated with differential mRNA expression in plaques. Immunohistochemistry revealed that inflammatory cells were major producers of HPSE in plaque tissue. HPSE immunoreactivity was also observed in SMCs adjacent to the necrotic core and was co-localized to deposits of fibrin. ConclusionsThis study demonstrates increased expression of HPSE in human atherosclerosis associated with inflammation, coagulation and plaque instability. Since HS can regulate SMC proliferation and influence plaque stability, the findings suggest that HPSE degradation of HS take part in the regulation of SMC function in human atherosclerosis.

Biomarker Discovery in Serum from Patients with Carotid Atherosclerosis

Background: Blood-based biomarkers of atherosclerosis have been used to identify patients at high risk for developing stroke. We hypothesized that patients with carotid artery disease would have a distinctive proteomic signature in blood as compared to a healthy control population without carotid artery disease. In order to discover protein biomarkers associated with increased atherosclerotic risk, we used two different strategies to identify biomarkers from patients with clinically defined atherosclerosis who were undergoing endarterectomy for atherosclerotic carotid artery disease. These patients were compared with healthy matched controls. Methods: Serum was obtained from patients undergoing endarterectomy (EA; n = 38) and compared to a group of age-matched healthy controls (n = 40). Serum was fractionated using anion exchange chromatography and three different surface-enhanced laser desorption/ionization (SELDI) chip surfaces and then evaluated with mass spectrometry (MS) and two-dimensional difference gel electrophoresis (2D-DIGE). Results: A random forest (RF) analysis of the SELDI-MS protein peak data distinguished these two groups with 69.2% sensitivity and 73.2% specificity. Four unique SELDI peaks (4.2, 4.4, 16.7 and 28 kDa, all p< 0.01) showed the greatest influence in the RF model. The EA patients with a history of prior clinical atherosclerotic plaque rupture manifested as either stroke or transient ischemic attack (symptomatic; n = 16) were compared to patients with carotid atherosclerosis but no clinical evidence of plaque rupture (asymptomatic; n = 22). Analysis of the SELDI spectra did not separate these two patient subgroups. A subgroup analysis using 2D-DIGE images obtained from albumin-depleted serum comparing symptomatic (n = 10) to asymptomatic EA patients (n = 10) found 4 proteins that were differentially expressed (p < 0.01) in the symptomatic patients. These proteins were identified as α₁-antitrypsin, haptoglobin and vitamin D binding protein that were downregulated and α₂-glycoprotein precursor that was upregulated in the symptomatic EA group. Conclusions: SELDI-MS data analysis of fractionated serum suggests that a distinct protein signature exists in patients with carotid atherosclerosis compared to age-matched healthy controls. Identification of 4 proteins in a subset of patients with symptomatic and asymptomatic carotid atherosclerosis suggests that these and other protein biomarkers may assist in identifying high-risk patients with carotid atherosclerosis.

Osteoprotegerin: A Biomarker With Many Faces

Osteoprotegerin (OPG), a member of the tumor necrosis factor receptor superfamily, is a soluble decoy receptor for the osteoclast differentiation factor receptor-activator of nuclear factor κB ligand (RANKL) that inhibits interaction between RANKL and its membrane-bound receptor RANK (Figure).1 The RANKL/OPG/RANK axis has been shown to regulate bone remodeling2,3 and was more recently found to be involved in carcinogenesis as well as central thermoregulation.4,5 This system has also been linked to the development of atherosclerosis and plaque destabilization.6,7 RANKL exhibits several properties with relevance to atherogenesis, such as promotion of inflammatory responses in T cells and dendritic cells, induction of chemotactic properties in monocytes, induction of matrix metalloproteinase (MMP) activity in vascular smooth muscle cells (SMC), and RANKL has also been found to have prothrombotic properties.2,8 In observational studies, elevated circulating OPG levels have been associated with prevalence and severity of coronary artery disease, cerebrovascular disease, and peripheral vascular disease.2,8 Circulating OPG levels are increased in patients with acute coronary syndrome,9 and enhanced expression has been found within symptomatic carotid plaques.10 Elevated OPG levels have also been associated with the degree of coronary calcification in the general population as a marker of coronary atherosclerosis.11 OPG has been reported to predict survival in patients with heart failure after acute myocardial infarction,12 to predict heart failure hospitalization and mortality in patients with acute coronary syndrome,9 and to be associated with long-term mortality in patients with ischemic stroke.13 There are also a few …