Carotid atherosclerotic plaque stenosis: the stabilizing role of statins

Gray-Scale Median in Patients with Symptomatic and Asymptomatic Carotid Atherosclerosis-Risk Factors and Diagnostic Potential

BACKGROUND

The identification of clinical factors affecting the gray-scale median (GSM) and determination of GSM diagnostic utility for differentiating between symptomatic and asymptomatic internal carotid artery (ICA) stenosis.

METHODS

This study included 45 patients with asymptomatic and 40 patients with symptomatic ICA stenosis undergoing carotid endarterectomy (CEA). Echolucency of carotid plaque was determined using computerized techniques for the GSM analysis. Study groups were compared in terms of clinical risk factors, coexisting comorbidities, and used pharmacotherapy.

RESULTS

Mean GSM values in the symptomatic group were significantly lower than in the asymptomatic group (p < 0.001). Both in the univariate as well as in the multiple regression analysis, GSM was significantly correlated with D-dimers and fasting plasma glucose levels and tended to correlate with β-adrenoceptor antagonist use in the symptomatic group. In asymptomatic patients, GSM was associated with the presence of grade 2 and grade 3 hypertension, and tended to correlate with the use of metformin, sulfonylureas, and statin. Independent factors for GSM in this group remained as grade 3 hypertension and statin's therapy. The receiver operating characteristic (ROC) analysis revealed that GSM differentiated symptomatic from asymptomatic ICA stenosis with sensitivity and specificity of 73% and 80%, respectively.

CONCLUSION

The completely diverse clinical parameters may affect GSM in symptomatic and asymptomatic patients undergoing CEA, whose clinical characteristics were similar in terms of most of the compared parameters. GSM may be a clinically useful parameter for differentiating between symptomatic and asymptomatic ICA stenosis.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Relationship of pharmacotherapy and the incidence of embolic complications of carotid reconstructive surgery

Aim. To evaluate the relationship between lipid-lowering and antiplatelet therapy and the incidence of cerebral microembolism and related complications in open and endovascular revascularization of the carotid arteries (CA).

Material and methods. This single-center study involved patients with internal CA stenosis. The patients were divided into 2 groups depending on the surgery type performed: carotid endarterectomy (CEA)  — 163 patients; CA stenting (CAS)  — 71 patients. All patients underwent intraoperative transcranial Doppler monitoring to register cerebral embolism during CAS and CE.

Results. In CAS, microembolism episodes were observed in 66,2% vs 22,1% of patients in the CEA group (p=0,04), the largest number of which was recorded during catheterization of the internal CA and embolic filter installation (p=0,000). There were no significant differences between the groups in terms of the stroke incidence. In 8 patients in the CAS group and 1 patient in the CEA group, a transient ischemic attack was observed within 30 days after surgery (p=4x10-4 ). Intraoperative embolism was a predictor of a neurological event in the early postoperative period (odds ratio (OR), 33,08; 95% confidence interval (CI): 3,49-56,37 (p6 months before surgery reduces the likelihood of embolism by 4 times (OR 0,25; 95% CI: 0,11-0,58 (p=0,001), while lipid-lowering and antiplatelet therapy combination — by 12,5 times (OR, 0,08; 95% CI: 0,01-0,40 (p=0,001)).

Conclusion. Preoperative antiplatelet and statin therapy reduces the likelihood of embolism during the CA revascularization procedure.

Exploration of Crucial Mediators for Carotid Atherosclerosis Pathogenesis Through Integration of Microbiome, Metabolome, and Transcriptome

Background

Carotid atherosclerosis (CAS) is an important cause of stroke. Although interactions between the gut microbiome and metabolome have been widely investigated with respect to the pathogenesis of cardiovascular diseases, information regarding CAS remains limited.

Materials and Methods

We utilized 16S ribosomal DNA sequencing and untargeted metabolomics to investigate the alterations in the gut microbiota and plasma metabolites of 32 CAS patients and 32 healthy controls. The compositions of the gut microbiota differed significantly between the two groups, and a total of 11 differentially enriched genera were identified. In the metabolomic analysis, 11 and 12 significantly changed metabolites were screened in positive (POS) and negative (NEG) modes, respectively. α-N-Phenylacetyl-L-glutamine was an upregulated metabolite in CAS patients detected in both POS and NEG modes and had the highest | log₂(fold change)| in POS mode. In addition, transcriptomic analysis was performed using the GSE43292 dataset.

Results

A total of 132 differentially expressed genes (DEGs) were screened. Among the upregulated DEGs in CAS patients, FABP4 exhibited the highest | log₂(fold change)|. Furthermore, FABP4 was positively associated with Acidaminococcus and had the highest Spearman’s correlation coefficient and the most significant p-value among the microbiota–DEG pairs.

Conclusion

In this study, we investigated the potential “microbiota–metabolite–gene” regulatory axis that may act on CAS, and our results may help to establish a theoretical basis for further specialized study of this disease.

Do Carotid Plaque Ulcers Heal? Potential Detection of Carotid Artery Plaque Healing by Carotid Ultrasound Imaging

OBJECTIVES

Carotid plaque ulcers confer an increased risk for stroke/ transient ischemic attacks in both symptomatic and asymptomatic carotid artery stenosis. Little is known about the healing rates of ulcers or the development of new ulcers. Carotid Duplex studies are noninvasive and easily repeatable tests to monitor progression of carotid stenosis and plaque morphology. Our aim was to determine the prevalence and healing rates of ultrasound-detected carotid plaque ulcers.

METHODS

We retrospectively reviewed 5837 carotid Duplex studies performed in an outpatient ultrasound laboratory affiliated with the neurological department of an academic center. A total of 3215 patients underwent a first carotid ultrasound Duplex study, and 2622 follow-up studies were done. Carotid ulcer was defined as a 2 mm deep surface indentation in a carotid plaque with a well-defined back wall, as determined by multimodal ultrasound imaging techniques.

RESULTS

The prevalence of carotid plaque ulcers among the 3215 patients with a first ultrasound study was 3% (82/3215). The mean follow-up was 42 ± 30 months, and the median number of follow-up studies was 6. Among patients with ulcers, follow-up studies were available in 65/82 patients. During the follow-up period, 28/65 (43%) ulcers healed. Among all 2622 follow-up studies, 45 patients developed a new ulcer.

CONCLUSIONS

Duplex-detected carotid plaque ulcer prevalence is low. The carotid ulcers healed in approximately half of patients during follow-up. Factors associated with ulcer healing and development remain poorly understood.

Statin use and mortality in atrial fibrillation: A systematic review and meta-analysis of 100,287 patients

Statins are effective for reducing cardiovascular disease in patients at risk or with cardiovascular disease. The benefit of statin therapy on adverse cardiovascular outcomes in patients with non-valvular atrial fibrillation (AF) is not clear. We performed a systematic review and meta-analysis of studies retrieved from MEDLINE via PubMed and Cochrane (CENTRAL) database of studies investigating the efficacy of statins in AF patients. The principal endpoint was all-cause mortality. Other endpoints were cardiovascular mortality, ischemic stroke, composite endpoints and any bleeding. We included 14 studies (2 post-hoc analysis of randomized clinical trials, 8 prospective and 4 retrospective) with 100,287 AF patients, of whom 23,228 were on statins. The pooled hazard ratio (HR) for all-cause mortality was 0.59 (95 % Confidence Interval [CI] 0.54-0.65). This association was consistent by aging, sex and prevalent cardiovascular or cerebrovascular disease. and the beneficial effect was evident already after 12 months of therapy. The absolute risk reduction for all-cause mortality in patients treated with statins was 10 % (95 % CI 9-10). The pooled HR for statins against cardiovascular mortality was 0.75 (95 % CI 0.58-0.96). No association was found with other secondary endpoints. Regarding bleeding events, the pooled HR for statin use was 0.60 (95 % CI 0.48-0.76). Our meta-analysis shows that in AF patients, statin therapy was associated with a reduction in all-cause and cardiovascular mortality are reduced by 41 % and 25 %, respectively. Randomized clinical trials in AF patients are necessary, as well as clarity on AF-specific LDL cholesterol targets.

Is it possible to prevent cerebral embolization by improving the design and technology of carotid stent implantation?

INTRODUCTION

The prevention of atherosclerotic plaque fragmentation during carotid artery stenting is a fundamental problem in decreasing the risk of disability of patients. The goal of this review is to clarify whether the stent design can have a decisive impact on the rate of intraoperative and postoperative complications.

AREAS COVERED

Different designs of the carotid stents are briefed and the advantages and disadvantages of different stent designs are discussed as well as the results of their clinical use. Various solutions are presented to reduce cerebral embolism during carotid artery stenting.

EXPERT OPINION

There is no conclusive evidence for the benefits of closed cell and hybrid stents. The stent design cannot completely resolve the problem of cerebral embolism. Most of the events of cerebral microembolism occur at the stages of stent delivery rather than protrusion of an atherosclerotic plaque in the long-term follow-up. Most likely, minimization of the risks for periprocedural and postprocedural strokes requires not only the new solutions in stent design as well as the corresponding delivery systems and brain embolic protection systems, but also the new strategies of preprocedural drug stabilization of the atherosclerotic plaque in the carotid artery. Abbreviations: CAS, carotid artery stenting; CE, carotid endarterectomy; DW-MRI, diffusion-weighted magnetic resonance imaging; ECA, external carotid artery; ICA, internal carotid artery; IVUS, intravascular ultrasound examination; OCT, optical coherence tomography.

MicroRNAs as sentinels and protagonists of carotid artery thromboembolism

Stroke is the leading cause of serious disability in the world and a large number of ischemic strokes are due to thromboembolism from unstable carotid artery atherosclerotic plaque. As it is difficult to predict plaque rupture and surgical treatment of asymptomatic disease carries a risk of stroke, carotid disease continues to present major challenges with regard to clinical decision-making and revascularization. There is therefore an imminent need to better understand the molecular mechanisms governing plaque instability and rupture, as this would allow for the development of biomarkers to identify at-risk asymptomatic carotid plaque prior to disease progression and stroke. Further, it would aid in creation of therapeutics to stabilize carotid plaque. MicroRNAs (miRNAs) have been implicated as key protagonists in various stages of atherosclerotic plaque initiation, development and rupture. Notably, they appear to play a crucial role in carotid artery thromboembolism. As the molecular pathways governing the role of miRNAs are being uncovered, we are learning that their involvement is complex, tissue- and stage-specific, and highly selective. Notably, miRNAs can be packaged and secreted in extracellular vesicles (EVs), where they participate in cell-cell communication. The measurement of EV-encapsulated miRNAs in the circulation may inform disease mechanisms occurring in the plaque itself, and therefore may serve as sentinels of unstable plaque as well as therapeutic targets.

Lower body mass index is not of more benefit for diabetic complications

AIMS/INTRODUCTION

To investigate the relationship between different body mass index (BMI) levels and vascular complications in type 2 diabetes mellitus patients.

MATERIALS AND METHODS

Data were collected from 3,224 individuals with type 2 diabetes mellitus (male/female: 1,635/1,589; age 61.31 ± 11.45 years), using a retrospective case study design. The association of BMI quintiles and diabetes mellitus vascular complications was assessed using multiple logistic regression models adjusting for age, sex, diabetes duration, smoking status, drinking and other confounders, using those with the lowest quintile of BMI as the reference group.

RESULTS

With increasing BMI, the detection rate of diabetic peripheral neuropathy and peripheral arterial disease initially decreased and then it increased, whereas the detection rate of diabetic kidney disease and carotid atherosclerotic plaques showed an upward trend; however, diabetic retinopathy was irregular. The odds ratios of diabetic peripheral neuropathy decreased as BMI increased from the 21st percentile to the 80th percentile initially, and increased when BMI was in >80th percentile. The same result was shown in peripheral arterial disease. BMI >80th percentile showed a 1.426-fold risk of diabetic kidney disease and a 1.336 -fold risk of carotid atherosclerotic plaque.

CONCLUSIONS

In patients with type 2 diabetes mellitus, the relationship between different BMIs and vascular complications varies. A U-shaped relationship was observed between BMI and diabetic peripheral neuropathy, as well as BMI and peripheral arterial disease. BMI is positively correlated with diabetic kidney disease and carotid atherosclerotic plaque; however, it is not correlated with diabetic retinopathy.

The Association Between SYNTAX Score II and Carotid Artery Disease Severity in Patients Who Underwent Coronary Artery Bypass Grafting

The SYNTAX score (SS) and SS II, which include additional clinical parameters, are widely used today for deciding revascularization following coronary angiography. We investigated the association between the presence and severity of carotid artery disease (CrAD) using the SS and SS II in 287 patients who underwent coronary artery bypass grafting. We based this investigation on the known association between coronary artery disease and CrAD. A significant association was observed between the groups with and without CrAD in terms of SS II values (28.4 ± 9.6 vs 21.4 ± 7.7, respectively; P < .001). A significant difference was also observed when stenosis was classified according to severity as <50%, 50% to 70%, and >70% ( P < .001). The results indicated a positive correlation between the presence and severity of CrAD as SS II increased ( r = 0.187, P = .005). According to the results of multivariate logistic regression analysis, the SS II was an independent predictor of CrAD.

Morphology and histology of silent and symptom-causing atherosclerotic carotid plaques - Rationale and design of the Helsinki Carotid Endarterectomy Study 2 (the HeCES2)

INTRODUCTION

Every fifth ischemic stroke is caused by thromboembolism originating from an atherosclerotic carotid artery plaque. While prevention is the most cost-effective stroke therapy, antiplatelet and cholesterol-lowering drugs have a ceiling effect in their efficacy. Therefore, discovery of novel pathophysiologic targets are needed to improve the primary and secondary prevention of stroke. This article provides a detailed study design and protocol of HeCES2, an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis.

MATERIALS AND METHODS

Recruitment and carotid endarterectomies of the study patients with carotid atherosclerosis were performed from October 2012 to September 2015. After brain and carotid artery imaging, endarterectomised carotid plaques (CPs) and blood samples were collected from 500 patients for detailed biochemical and molecular analyses. Findings to date: We developed a morphological grading for macroscopic characteristics within CPs. The dominant macroscopic CP characteristics were: smoothness 62%, ulceration 61%, intraplaque hemorrhage 60%, atheromatous gruel 59%, luminal coral-type calcification 34%, abundant (44%) and moderate (39%) intramural calcification, and symptom-causing "hot spot" area 53%. Future plans: By combining clinically oriented and basic biomedical research, this large-scale study attempts to untangle the pathophysiological perplexities of human carotid atherosclerosis. Key Messages This article is a rationale and design of the HeCES2 study that is an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis. The HeCES2 study strives to develop diagnostic algorithms including radiologic imaging to identify carotid atherosclerosis patients who warrant surgical treatment. In addition, the study aims at finding out new tools for clinical risk stratification as well as novel molecular targets for drug development.

Effects of probucol on atherosclerotic plaque and soluble thrombomodulin in patients with coronary heart disease

This study explored the effects of probucol on atherosclerotic plaques and soluble thrombomodulin in patients with coronary heart disease (CHD). Five hundred and eighty-three patients with CHD who were admitted to Jining First People's Hospital from February 2013 to February 2014. A total of 300 of them received conventional treatment, and were assigned to the control group, while the remaining 283 patients were treated with probucol in addition to the conventional treatment, and were assigned to the observation group. A retrospective analysis was performed on the total cholesterol levels, atherosclerotic plaque sizes, and soluble thrombomodulin levels. Probucol was administered at a dose of 500 mg twice a day for a period of 16 weeks. The total cholesterol level decreased gradually over time during the treatment. After 8 weeks of treatment, the total cholesterol level in the observation group was lower than that in the control group (P<0.05). After 8 weeks of treatment, the atherosclerotic plaque area in the observation group decreased compared with that before treatment (P<0.05). After 8 and 16 weeks of treatment, the plaque area in the observation group was smaller than that in the control group (P<0.05). The soluble thrombomodulin level at any time-point after treatment was lower than that before treatment in both groups (P<0.05). At the same time-point, the level in the observation group was lower than that in the control group (P<0.05). The total cholesterol and soluble thrombomodulin levels were positively correlated with the atherosclerotic plaque area (r=0.841, P=0.001; r=0.725, P=0.008). When patients with CHD were treated with probucol in addition to the conventional treatment, a reduction of the atherosclerotic plaque area, as well as a decrease of both the total cholesterol and soluble thrombomodulin levels, was observed. Overall, patients with CHD experienced improved symptoms following treatment with probucol.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Ultrasonographical Features Associated with Progression of Atherosclerosis in Patients with Moderate Internal Carotid Artery Stenosis

Carotid artery stenosis (CAS) is a leading cause of ischemic stroke. Plaque stabilization is a major management approach. Information about the ultrasonographical and clinical features associated with the progression of moderate internal carotid artery (ICA) stenosis (50-69%) could assist with prognostication and risk factor modifications. We evaluated 287 patients with moderate ICA stenosis (50-69%) and subsequently evaluated them at follow-up points at 12, 24, and 36 months. Patients were divided into three groups according to the degree of ICA stenosis: progression (70-99%, n = 48), stable (50-69%, n = 210), and regression (< 50%, n = 29). Responsible plaque thickness (RPT) across groups during follow-up was compared using a repeated measure ANOVA test. An ordinal regression was subsequently applied to identify risk factors for atherosclerosis progression. Male (P = 0.04), hypoechoic plaque (P < 0.01), smoking (P = 0.02), plaque ulceration (P = 0.05), and contralateral severe CAS or occlusions (P = 0.04) on ultrasound was more frequent in the progression group vs. other two groups. The ordinal regression revealed that only hypoechoic plaque (OR, 7.03; 95% CI, 3.34-14.81; P < 0.01) and contralateral ICA severe stenosis or occlusion (OR, 2.86; 95% CI, 1.41-5.80; P < 0.01) were independently associated with stenosis progression, while statin use was inversely associated with stenosis progression (OR, 0.26; 95% CI, 0.13-0.54; P < 0.01). Of note, symptomatic vs. asymptomatic moderate CAS at baseline was not associated with progression. For patients with moderate CAS, hypoechoic plaque, contralateral severe stenosis or occlusion on ultrasonography, and statin use are independently related to stenosis progression. Statin use may delay the progression of carotid stenosis.

The Anti-Inflammatory Effects of Statins on Coronary Artery Disease: An Updated Review of the Literature

Background:

Statins have long been used for the protection against coronary artery disease (CAD). Their beneficial effect apart from cholesterol reduction lies in their pleiotropic properties. Emerging evidence from laboratory studies and clinical trials as well have pointed out the pivotal role of inflammation on the initiation and exacerbation of atherosclerosis; a major cause of CAD. Inflam-mation markers such as high sensitivity C-reactive protein and adhesion molecules are shown to in-crease in CAD patients and are used as prognostic tools. It is well known that statins can actually re-duce the circulating levels of these agents slowing therefore the inflammatory process; interestingly not all types have the same outcome.

Conclusion:

The anti-inflammatory effect of statins on the formation of atherosclerotic plaque and the function of endothelial cells is thus of particular importance as these agents can actually ameliorate CAD prognosis

Lack of Association between Statin Use and Angiographic and Clinical Outcomes after Pipeline Embolization for Intracranial Aneurysms

BACKGROUND AND PURPOSE

Use of statin medications has been demonstrated to improve clinical and angiographic outcomes in patients receiving endovascular stent placement for coronary, peripheral, carotid, and intracranial stenoses. We studied the impact of statin use on long-term angiographic and clinical outcomes after flow-diverter treatment of intracranial aneurysms.

MATERIALS AND METHODS

We performed a post hoc analysis from pooled patient-level datasets from 3 Pipeline Embolization Device studies: the International Retrospective Study of the Pipeline Embolization Device, the Pipeline for Uncoilable or Failed Aneurysms Study, and the Aneurysm Study of Pipeline in an Observational Registry. We analyzed data comparing 2 subgroups: 1) patients on statin medication, and 2) patients not on statin medication at the time of the procedure and follow-up. Angiographic and clinical outcomes were compared by using the χ² test, Fisher exact test, or Wilcoxon rank sum test.

RESULTS

We studied 1092 patients with 1221 aneurysms. At baseline, 226 patients were on statin medications and 866 patients were not on statin medications. The mean length of clinical and angiographic follow-up was 22.1 ± 15.1 months and 28.3 ± 23.7 months, respectively. There were no differences observed in angiographic outcomes at any time point between groups. Rates of complete occlusion were 82.8% (24/29) versus 86.4% (70/81) at 1-year (P = .759) and 93.3% (14/15) versus 95.7% (45/47) at 5-year (P = 1.000) follow-up for statin-versus-nonstatin-use groups, respectively. There were no differences in any complication rates between groups, including major morbidity and neurologic mortality (7.5% versus 7.1%, P = .77).

CONCLUSIONS

Our study found no association between statin use and angiographic or clinical outcomes among patients treated with the Pipeline Embolization Device.

Pleiotropic effects of statins in the perioperative setting

Statins belong to a specific group of drugs that have been described for their ability to control hyperlipidemia as well as for other pleiotropic effects such as improving vascular endothelial function, inhibition of oxidative stress pathways, and anti-inflammatory actions. Accumulating clinical evidence strongly suggests that statins also have a beneficial effect on perioperative morbidity and mortality. Therefore, this review aims to present all recent and pooled data on statin treatment in the perioperative setting as well as to highlight considerations regarding their indications and therapeutic application.

Cell-Based Models for Development of Antiatherosclerotic Therapies

The leading cause of death worldwide is cardiovascular disease. Among the conditions related to the term, the most prominent one is the development of atherosclerotic plaques in the walls of arteries. The situation gets even worse with the fact that the plaque development may stay asymptomatic for a prolonged period of time. When it manifests as a cardiovascular disorder, it is already too late: the unfortunate individual is prescribed with a plethora of synthetic drugs, which are of debatable efficacy in the prevention of atherosclerotic lesions and safety. Cell models could be useful for the purpose of screening substances potentially effective against atherosclerosis progression and effective in reduction of already present plaques. In this overview, we present studies making use of in vitro and ex vivo models of atherosclerosis development that can prove valuable for clinical applications.

Oxidized Low-Density Lipoprotein (OxLDL)-Treated Dendritic Cells Promote Activation of T Cells in Human Atherosclerotic Plaque and Blood, Which Is Repressed by Statins: microRNA let-7c Is Integral to the Effect

Background

Activated T cells and dendritic cells (DCs) are colocalized in atherosclerotic plaques in association with plaque rupture. Oxidized low‐density lipoprotein (oxLDL) promotes immune activation and inflammation. We studied the effects of statins (atorvastatin and simvastatin) on human DC maturation and T‐cell activation.

Methods and Results

Human peripheral blood monocytes were differentiated to DCs and stimulated with oxLDL. T cells were isolated from carotid endarterectomy specimens from patients undergoing carotid endarterectomy or from healthy individuals. Naïve T cells were cocultured with pretreated DCs. The effects of statin were studied. OxLDL induced DC maturation and T‐cell activation. OxLDL induced atherogenic heat shock proteins (HSP) 60 and 90 and decreased potentially atheroprotective heat shock protein 27, effects restored by atorvastatin. T cells exposed to oxLDL‐treated DCs produced interferon‐γ and interleukin (IL)‐17. Atorvastatin and simvastatin suppressed the DC maturation showing lower expression of CD80, CD83, and CD86, and limited their production of tumor necrosis factor‐α, IL‐1β and IL‐6, and increased transforming growth factor‐β and IL‐10 secretion. Statin‐treated DCs inhibited Th1 and/or Th17 polarization by downregulation of transcriptional factors T‐bet and RORγt expression, and induced T regulatory cells with IL‐10 production. OxLDL‐induced miRNA let7c and phosphorylation of Akt and ERK were repressed by statins. Let‐7c had a pivotal role in mediating effect of oxLDL. Experiments on T cells derived from carotid atherosclerotic plaques or healthy individuals showed similar results.

Conclusions

Statins repress human DC maturation induced by oxLDL, limit T‐cell activation, and repress an atherogenic heat shock protein profile and promote induction of T regulatory cells. MicroRNA let‐7c is integral to the effects.

Anti-Atherosclerotic Effects of a Phytoestrogen-Rich Herbal Preparation in Postmenopausal Women

The risk of cardiovascular disease and atherosclerosis progression is significantly increased after menopause, probably due to the decrease of estrogen levels. The use of hormone replacement therapy (HRT) for prevention of cardiovascular disease in older postmenopausal failed to meet expectations. Phytoestrogens may induce some improvements in climacteric symptoms, but their effect on the progression of atherosclerosis remains unclear. The reduction of cholesterol accumulation at the cellular level should lead to inhibition of the atherosclerotic process in the arterial wall. The inhibition of intracellular lipid deposition with isoflavonoids was suggested as the effective way for the prevention of plaque formation in the arterial wall. The aim of this double-blind, placebo-controlled clinical study was to investigate the effect of an isoflavonoid-rich herbal preparation on atherosclerosis progression in postmenopausal women free of overt cardiovascular disease. One hundred fifty-seven healthy postmenopausal women (age 65 ± 6) were randomized to a 500 mg isoflavonoid-rich herbal preparation containing tannins from grape seeds, green tea leaves, hop cone powder, and garlic powder, or placebo. Conventional cardiovascular risk factors and intima-media thickness of common carotid arteries (cIMT) were evaluated at the baseline and after 12 months of treatment. After 12-months follow-up, total cholesterol decreased by 6.3% in isoflavonoid-rich herbal preparation recipients (p = 0.011) and by 5.2% in placebo recipients (p = 0.020); low density lipoprotein (LDL) cholesterol decreased by 7.6% in isoflavonoid-rich herbal preparation recipients (p = 0.040) and by 5.2% in placebo recipients (non-significant, NS); high density lipoprotein (HDL) cholesterol decreased by 3.4% in isoflavonoid-rich herbal preparation recipients (NS) and by 4.5% in placebo recipients (p = 0.038); triglycerides decreased by 6.0% in isoflavonoid-rich herbal preparation recipients (NS) and by 7.1% in placebo recipients (NS). The differences between lipid changes in the isoflavonoid-rich herbal preparation and placebo recipients did not reach statistical significance (p > 0.05). Nevertheless, the mean cIMT progression was significantly lower in isoflavonoid-rich herbal preparation recipients as compared to the placebo group (6 μm, or <1%, versus 100 μm, or 13%; p < 0.001 for the difference). The growth of existing atherosclerotic plaques in isoflavonoid-rich herbal preparation recipients was inhibited by 1.5-fold (27% versus 41% in the placebo group). The obtained results demonstrate that the use of isoflavonoid-rich herbal preparation in postmenopausal women may suppress the formation of new atherosclerotic lesions and reduce the progression of existing ones, thus promising new drug for anti-atherosclerotic therapy. Nevertheless, further studies are required to confirm these findings.

Asymmetric Dimethylarginine Limits the Efficacy of Simvastatin Activating Endothelial Nitric Oxide Synthase

Background

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), is considered a risk factor for the pathogenesis of cardiovascular diseases. Simvastatin, a lipid‐lowering drug with other pleiotropic effects, has been widely used for treatment of cardiovascular diseases. However, little is known about the effect and underlying molecular mechanisms of ADMA on the effectiveness of simvastatin in the vascular system.

Methods and Results

We conducted a prospective cohort study to enroll 648 consecutive patients with coronary artery disease for a follow‐up period of 8 years. In patients with plasma ADMA level ≥0.49 μmol/L (a cut‐off value from receiver operating characteristic curve), statin treatment had no significant effect on cardiovascular events. We also conducted randomized, controlled studies using in vitro and in vivo models. In endothelial cells, treatment with ADMA (≥0.5 μmol/L) impaired simvastatin‐induced nitric oxide (NO) production, endothelial NO synthase (eNOS) phosphorylation, and angiogenesis. In parallel, ADMA markedly increased the activity of NADPH oxidase (NOX) and production of reactive oxygen species (ROS). The detrimental effects of ADMA on simvastatin‐induced NO production and angiogenesis were abolished by the antioxidant, N‐acetylcysteine, NOX inhibitor, or apocynin or overexpression of dimethylarginine dimethylaminohydrolase 2 (DDAH‐2). Moreover, in vivo, ADMA administration reduced Matrigel plug angiogenesis in wild‐type mice and decreased simvastatin‐induced eNOS phosphorylation in aortas of apolipoprotein E–deficient mice, but not endothelial DDAH‐2‐overexpressed aortas.

Conclusions

We conclude that ADMA may trigger NOX‐ROS signaling, which leads to restricting the simvastatin‐conferred protection of eNOS activation, NO production, and angiogenesis as well as the clinical outcome of cardiovascular events.

Exploring the effects of the atherosclerosis progression and the choice of affected arteries in the design of experiments with Apolipoprotein E-deficient mice

The objective of this study is to explore the longitudinal progression of atherosclerosis and the correlation between methods to measure the lesion in apolipoprotein E-deficient mice. Atherosclerosis progression was assessed by measurements of foam cell-rich depositions in their proximal aortas, and/or in surgically excised arteries, to assess the histological luminal narrowing. A longitudinal study was performed by comparing the values for carotid, aorta, and femoral and iliac arteries using common histological techniques. There were no significant differences in progression between different arteries, but correlation with the classical measurement of atherosclerosis in the aortic root was poor. Each laboratory requires specific standardization. Carotid arteries were sensitive to atherosclerosis in these mice, and progression was exponential. In conclusion, morphometric data show the importance of the choice of the duration of treatment, the appropriate controls, and the age at which to begin the experiments.

Relationship between pre-stroke cardiovascular medication use and stroke severity

INTRODUCTION

Stroke is a major health problem with important morbidity and mortality. Various risk factors and cardiovascular medication groups are known to have an influence on stroke incidence, but less is known about the relation between medication use and stroke severity.

AIM

To determine if relationships exist between the pre-stroke cardiovascular medication use and stroke severity.

METHODS

A retrospective study was conducted on a database with anonymized data of 1974 patients with a suspected stroke, admitted to the Universitair Ziekenhuis (UZ) Brussel. Stroke severity was quantified using the National Institute of Health Stroke Scale (NIHSS). Cardiovascular medication groups were first included in a multivariable linear regression model. Second, to obtain clinically interpretable results, all variables that were retained in the final linear regression model were introduced in a cumulative odds ordinal logistic regression model with proportional odds.

RESULTS

Angiotensin II receptor blockers (ARBs), statins, and antiarrhythmics were significantly associated with stroke severity at the 10 % α level in a multivariable linear regression model, suggesting a possible effect of these medication groups on stroke severity. Only pre-stroke statin use showed a significant relationship with the NIHSS score in the ordinal logistic regression model with an adjusted odds ratio of 0.740 (95 % CI 0.580-0.944; p = 0.015).

CONCLUSION

Pre-stroke use of statins is significantly associated with lower stroke severity. No significant relationship was detected between pre-stroke use of other medication groups and stroke severity, defined by the NIHSS score.

Impact of Cognitive Dysfunction on Survival in Patients With and Without Statin Use Following Carotid Endarterectomy

BACKGROUND:

Early cognitive dysfunction (eCD) is a subtle form of neurological injury observed in ∼25% of carotid endarterectomy (CEA) patients. Statin use is associated with a lower incidence of eCD in asymptomatic patients having CEA.

OBJECTIVE:

To determine whether eCD status is associated with worse long-term survival in patients taking and not taking statins.

METHODS:

This is a post hoc analysis of a prospective observational study of 585 CEA patients. Patients were evaluated with a battery of neuropsychometric tests before and after surgery. Survival was compared for patients with and without eCD stratifying by statin use. At enrollment, 366 patients were on statins and 219 were not. Survival was assessed by using Kaplan-Meier methods and multivariable Cox proportional hazards models.

RESULTS:

Age ≥75 years (P = .003), diabetes mellitus (P &lt; .001), cardiac disease (P = .02), and statin use (P = .014) are significantly associated with survival univariately (P &lt; .05) by use of the log-rank test. By Cox proportional hazards model, eCD status and survival adjusting for univariate factors within statin and nonstatin use groups suggested a significant effect by association of eCD on survival within patients not taking statin (hazard ratio, 1.61; 95% confidence interval, 1.09–2.40; P = .018), and no significant effect of eCD on survival within patients taking statin (hazard ratio, 0.98; 95% confidence interval, 0.59–1.66; P = .95).

CONCLUSION:

eCD is associated with shorter survival in patients not taking statins. This finding validates eCD as an important neurological outcome and suggests that eCD is a surrogate measure for overall health, comorbidity, and vulnerability to neurological insult.

microRNAs in Cerebrovascular Disease

Cardiovascular diseases are major causes of morbidity and mortality in developed countries. Cerebrovascular diseases, especially stroke, represent major burden of disability and economy impact. Major advances in primary and secondary prevention and therapy are needed in order to tackle this public health problem. Our better understanding of pathophysiology is essential in order to develop novel diagnostic and therapeutic tools and strategies. microRNAs are a family of important post-transcriptional regulators of gene expression and their involvement in the pathophysiology of cerebrovascular diseases has already been reported. Moreover, microRNAs may represent above-mentioned potential diagnostic and therapeutic tools in clinical practice. Within this chapter, we briefly describe basic epidemiology, aetiology and clinical manifestation of following cerebrovascular diseases: extracranial carotid atherosclerosis, acute stroke, intracranial aneurysms and cerebral arterio-venous malformations. Further, in each chapter, the current knowledge about the involvement of specific microRNAs and their potential use in clinical practice will be summarized. More specifically, within the subchapter "miRNAs in carotid atherosclerosis", general information about miRNA involvement in atherosclerosis will be described (miR-126, miR-17-92, miR-155 and others) with special emphasis put on miRNAs affecting carotid plaque progression and stability (e.g. miR-145, miR-146 or miR-217). In the subchapter "miRNAs in acute stroke", we will provide insight into recent knowledge from animal and human studies concerning miRNA profiling in acute stroke and their expression dynamics in brain tissue and extracellular fluids (roles of, e.g. let-7 family, miR-21, miR-29 family, miR-124, miR-145, miR-181 family, miR-210 and miR-223). Subchapters dealing with "miRNAs and AV malformations" and "miRNAs and intracranial aneurysms" will focus on miR-21, miR-26, miR-29 family and miR-143/145.