Low levels of high-density lipoprotein cholesterol are associated with echolucent carotid artery plaques: the tromsø study

Determinants of Carotid Wall Echolucency in a Cohort of European High Cardiovascular Risk Subjects: A Cross-Sectional Analysis of IMPROVE Baseline Data

Echolucency, a measure of plaque instability associated with increased cardiovascular risk, can be assessed in both the carotid plaque and the plaque-free common carotid intima-media (IM) complex as a gray-scale median (plaque-GSM and IM-GSM, respectively). The impact of specific vascular risk factors on these two phenotypes remains uncertain, including the nature and extent of their influence. This study aims to seek the determinants of plaque-GSM and IM-GSM. Plaque-GSM and IM-GSM were measured in subjects from the IMPROVE study cohort (aged 54-79, 46% men) recruited in five European countries. Plaque-GSM was measured in subjects who had at least one IMTmax ≥ 1.5 mm (n = 2138), whereas IM-GSM was measured in all subjects included in the study (n = 3188). Multiple regression with internal cross-validation was used to find independent predictors of plaque-GSM and IM-GSM. Plaque-GSM determinants were plaque-size (IMTmax), and diastolic blood pressure. IM-GSM determinants were the thickness of plaque-free common carotid intima-media complex (PF CC-IMTmean), height, systolic blood pressure, waist/hip ratio, treatment with fibrates, mean corpuscular volume, treatment with alpha-2 inhibitors (sartans), educational level, and creatinine. Latitude, and pack-yearscode were determinants of both plaque-GSM and IM-GSM. The overall models explain 12.0% of plaque-GSM variability and 19.7% of IM-GSM variability. A significant correlation (r = 0.51) was found between plaque-GSM and IM-GSM. Our results indicate that IM-GSM is a weighty risk marker alternative to plaque-GSM, offering the advantage of being readily measurable in all subjects, including those in the early phases of atherosclerosis where plaque occurrence is relatively infrequent.

Inflammation and endothelial function-related gene polymorphisms are associated with carotid atherosclerosis-A study of community population in Southwest China

OBJECTIVES

To investigate the relationships between 18 single nucleotide polymorphisms with carotid atherosclerosis and whether interactions among these genes were associated with an increased risk of carotid atherosclerosis.

METHODS

Face-to-face surveys were conducted with individuals aged 40 or older in eight communities. A total of 2377 individuals were included in the study. Ultrasound was used to detect carotid atherosclerosis in the included population. 18 loci of 10 genes associated with inflammation and endothelial function were detected. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR).

RESULTS

Among the 2377 subjects, 445 (18.7%) subjects had increased intima-media thickness in the common carotid artery (CCA-IMT), and 398 (16.7%) subjects were detected with vulnerable plaque. In addition, NOS2A rs2297518 polymorphism was associated with increased CCA-IMT, IL1A rs1609682, and HABP2 rs7923349 polymorphisms were associated with vulnerable plaque. Besides, GMDR analysis showed significant gene-gene interactions among TNFSF4 rs1234313, IL1A rs1609682, TLR4 rs1927911, ITGA2 rs1991013, NOS2A rs2297518, IL6R rs4845625, ITGA2 rs4865756, HABP2 rs7923349, NOS2A rs8081248, HABP2 rs932650.

CONCLUSION

The prevalences of increased CCA-IMT and vulnerable plaque were high in Southwestern China's high-risk stroke population. Furthermore, inflammation and endothelial function-related gene polymorphisms were associated with carotid atherosclerosis.

Lipoprotein(a) Is Associated With the Progression and Vulnerability of New-Onset Carotid Atherosclerotic Plaque

BACKGROUND

Although important progress has been made in understanding Lp(a) (lipoprotein[a])-mediated stroke risk, the contribution of Lp(a) to the progression of vulnerable plaque features associated with stroke risk remains unclear. This study aims to evaluate whether Lp(a) is associated with carotid plaque progression, new-onset plaque features, and plaque vulnerability in a prospective community-based cohort study.

METHODS

Baseline Lp(a) levels were measured using latex-enhanced turbidimetric immunoassay among 804 participants aged 45 to 74 years and free of cardiovascular disease in the Chinese Multi-provincial Cohort Study-Beijing project. Carotid atherosclerosis was measured twice by B-mode ultrasonography over a 10-year interval during the 2002 and 2012 surveys to assess the progression of total, vulnerable and stable plaques, and plaque vulnerability. The total plaque area and plaque vulnerability score were calculated.

RESULTS

The median baseline Lp(a) level was 10.20 mg/dL (interquartile range, 6.20 to 17.18 mg/dL). Modified Poisson regression analysis showed that Lp(a) ≥50 mg/dL was significantly associated with 10-year progression of total carotid plaque (relative risk [RR], 1.41 [95% CI, 1.21-1.64]; E-value=2.17), vulnerable plaque (RR, 1.93 [95% CI, 1.54-2.41]), and stable plaque (RR, 1.51 [95% CI, 1.11-2.07]) compared with Lp(a) <50 mg/dL. Moreover, among participants without plaque at baseline, Lp(a) ≥50 mg/dL was related to an increased total plaque area (β=0.36 [95% CI, 0.06-0.65]; P=0.018) and increased plaque vulnerability score (β=0.30 [95% CI, 0.01-0.60]; P=0.045) in multivariable linear regression.

CONCLUSIONS

Elevated Lp(a) levels were associated with 10-year carotid plaque progression and plaque vulnerability, providing a basis for Lp(a) as a treatment target for stroke prevention.

Sex-specific association between inflammation and endothelial function relevant gene and vulnerable carotid plaque

Objectives: We aimed to explore sex-specific association between genes involved in inflammation and endothelial function and vulnerable carotid plaque, a subclinical precursor of ischemic stroke.

Methods: Carotid plaque and plaque phenotype were assessed by carotid ultrasound in high-risk participants for stroke drawn from a multicenter, cross-sectional survey in southwestern China. We examined 18 single nucleotide polymorphisms (SNPs) in 10 genes related to inflammation and endothelial function. Sex differences in the genotype of the candidate SNPs and risk of vulnerable carotid plaques were assessed. Interaction tests were performed to identify the SNPs that might modify the association between the sex and vulnerable plaques. For SNPs with suggestive evidence for interaction with sex (p for interaction&lt;0.05), stratification analysis by sex was performed to evaluate the sex-specific association between the SNP and vulnerable plaques.

Results: 2,644 high-risk individuals were enrolled, comprising 1,202 (45.5%) men and 1,442 (54.5%) women. Vulnerable carotid plaques were detected in 425 (16.1%) participants. Among candidate SNPs, the genotype frequencies of 5 SNPs (TNFSF4 rs11811788, TNFSF4 rs1234313, IL6R rs4845625, VCAM1 rs2392221, and ITGA2 rs1991013) were significantly different between sex (all p &lt; 0.05). Univariable and multivariable analyses suggested that male individuals had a significantly higher prevalence of vulnerable carotid plaques (20.0% vs. 12.8%, adjusted OR 1.72, 95% CI 1.12–2.66, p = 0.014), while none of the candidate SNPs was significantly associated with vulnerable plaques (all p &gt; 0.05). Interaction tests found the association between sex and vulnerable plaques is affected by the genotype of IL6R rs4845625 (p for interaction = 0.031). Stratification analysis revealed a strong association between IL6R rs4845625 and vulnerable carotid plaque in man (dominant model TT vs. CT + CC: adjusted OR 1.52, 95% CI 1.12–2.07, p = 0.007; codominant model TT vs. CC: adjusted OR 1.50, 95% CI 1.00–2.25, p = 0.048) but not in women (p &gt; 0.05 in all genetic models).

Conclusion: The rs4845625 polymorphism in IL6R has sex-specific effects on vulnerable carotid plaque in Chinese Han high-risk individuals for stroke. Our findings provide a plausible genetic basis underlying the sex difference in carotid plaque vulnerability.

Evaluation of the effect of tofogliflozin on the tissue characteristics of the carotid wall—a sub-analysis of the UTOPIA trial

Background

Since sodium-glucose cotransporter 2 (SGLT2) inhibitors have a pleiotropic antiatherogenic effect, they are expected to attenuate the progression of atherosclerosis. However, whether SGLT2 inhibitors affect the tissue characteristics of the human arterial wall remains unclear. This study aimed to evaluate the effects of tofogliflozin, a selective SGLT2 inhibitor, on the tissue characteristics of the human arterial wall in type 2 diabetes (T2DM) patients without apparent cardiovascular disease (CVD).

Methods

The present study was a post hoc analysis based on data obtained from the Using Tofogliflozin for Possible Better Intervention against Atherosclerosis for Type 2 Diabetes Patients (UTOPIA) trial, which was a multicenter prospective, randomized, open-label, blinded-endpoint study conducted to evaluate the efficacy of tofogliflozin in preventing the progression of atherosclerosis in patients with T2DM. We evaluated the longitudinal change in the ultrasonic tissue characteristics of the carotid wall using gray-scale median (GSM), an established index of ultrasonic tissue characteristics. The right and left intima-medial areas were delineated, and the GSM values were evaluated (right GSM-CCA and left GSM-CCA). The average values of the right and left carotid arteries were defined as “mean GSM-CCA value.”

Results

In a mixed-effects model for repeated measures, mean GSM-CCA, along with the right and left GSM-CCA values, did not significantly change in either the tofogliflozin (n = 168) or conventional treatment group (n = 169). In addition, the tofogliflozin and conventional treatment groups did not significantly differ regarding the change of the mean GSM-CCA (mean difference [95% CI] − 1.24[− 3.87, 1.38], P = 0.35), along with the right (mean difference [95% CI] − 2.33[− 5.70, 1.05], P = 0.18) and the left GSM-CCA (mean difference [95% CI] − 0.29 [− 3.53, 2.95], P = 0.86) values. Similar findings were obtained even after adjusting for traditional cardiovascular risk factors and/or the administration of drugs at baseline.

Conclusions

The tissue characteristics of the carotid arterial wall did not change in either the tofogliflozin or conventional treatment group during the 104-week treatment period, and there was no significant difference between the treatment groups.

Clinical trial registration UMIN000017607 (https://www.umin.ac.jp/icdr/index.html)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01451-6.

Feasibility of longitudinal monitoring of atherosclerosis with pulse wave imaging in a swine model

Objective.Atherosclerosis is a vascular disease characterized by compositional and mechanical changes in the arterial walls that lead to a plaque buildup. Depending on its geometry and composition, a plaque can ruptured and cause stroke, ischemia or infarction. Pulse wave imaging (PWI) is an ultrasound-based technique developed to locally quantify the stiffness of arteries. This technique has shown promising results when applied to patients. The objective of this study is to assess the capability of PWI to monitor the disease progression in a swine model that mimics human pathology.Approach.The left common carotid of three hypercholesterolemic Wisconsin miniature swines, fed an atherogenic diet, was ligated. Ligated and contralateral carotids were imaged once a month over 9 months, at a high-frame-rate, with a 5-plane wave compounding sequence and a 5 MHz linear array. Each acquisition was repeated after probe repositioning to evaluate the reproducibility. Wall displacements were estimated from the beamformed RF-data and were arranged as spatiotemporal maps depicting the wave propagation. The pulse wave velocity (PWV) estimated by tracking the 50% upstroke of the wave was converted in compliance using the Bramwell-Hill model. At the termination of the experiment, the carotids were extracted for histology analysis.Main results.PWI was able to monitor the evolution of compliance in both carotids of the animals. Reproducibility was demonstrated as the difference of PWV between cardiac cycles was similar to the difference between acquisitions (9.04% versus 9.91%). The plaque components were similar to the ones usually observed in patients. Each animal presented a unique pattern of compliance progression, which was confirmed by the plaque composition observed histologically.Significance.This study provides important insights on the vascular wall stiffness progression in an atherosclerotic swine model. It therefore paves the way for a thorough longitudinal study that examines the role of stiffness in both the plaque formation and plaque progression.

Serum Biomarkers in Carotid Artery Disease

Carotid artery disease is considered a major cause of strokes and there is a need for early disease detection and management. Although imaging techniques have been developed for the diagnosis of carotid artery disease and different imaging-based markers have been proposed for the characterization of atherosclerotic plaques, there is still need for a definition of high-risk plaques in asymptomatic patients who may benefit from surgical intervention. Measurement of circulating biomarkers is a promising method to assist in patient-specific disease management, but the lack of robust clinical evidence limits their use as a standard of care. The purpose of this review paper is to present circulating biomarkers related to carotid artery diagnosis and prognosis, which are mainly provided by statistical-based clinical studies. The result of our investigation showed that typical well-established inflammatory biomarkers and biomarkers related to patient lipid profiles are associated with carotid artery disease. In addition to this, more specialized types of biomarkers, such as endothelial and cell adhesion, matrix degrading, and metabolic biomarkers seem to be associated with different carotid artery disease outputs, assisting vascular specialists in selecting patients at high risk for stroke and in need of intervention.

Using Serum Biomarkers for Identifying Unstable Carotid Plaque: Update of Current Evidence

Carotid atherosclerosis is responsible for a great proportion of ischemic strokes. Early identification of unstable or vulnerable carotid plaques, and therefore, of patients at high risk for stroke, is of significant medical and socioeconomical value. We reviewed the current literature and discussed the potential role of the most important serum biomarkers in identifying patients with carotid atherosclerosis who are at high risk for atheroembolic stroke.

Relationship between Circulating PCSK9 and Markers of Subclinical Atherosclerosis-The IMPROVE Study

(1) Background and purpose: circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) is one of the key regulators of cholesterol metabolism. Despite this, its role as a player in atherosclerosis development is still matter of debate. Here, we investigated the relationships between this protein and several markers of subclinical atherosclerosis. (2) Methods: the IMPROVE study enrolled 3703 European subjects (54–79 years; 48% men; with ≥3 vascular risk factors), asymptomatic for cardiovascular diseases. PCSK9 levels were measured by ELISA. B-mode ultrasound was used to measure markers of carotid subclinical atherosclerosis. (3) Results: in the crude analysis, PCSK9 levels were associated with several baseline measures of carotid intima-media thickness (cIMT) (all p < 0.0001); with cIMT change over time (Fastest-IMTmax-progr) (p = 0.01); with inter-adventitia common carotid artery diameter (ICCAD) (p < 0.0001); and with the echolucency (Grey Scale Median; GSM) of both carotid plaque and plaque-free common carotid IMT (both p < 0.0001). However, after adjustment for age, sex, latitude, and pharmacological treatment, all the afore-mentioned correlations were no longer statistically significant. The lack of correlation was also observed after stratification for sex, latitude, and pharmacological treatments. (4) Conclusions: in subjects who are asymptomatic for cardiovascular diseases, PCSK9 plasma levels do not correlate with vascular damage and/or subclinical atherosclerosis of extracranial carotid arteries.

Carotid Atherosclerosis, Ultrasound and Lipoproteins

Carotid artery plaques are considered a measure of atherosclerosis and are associated with an increased risk of atherosclerotic cardiovascular disease, particularly ischemic strokes. Monitoring of patients with an elevated risk of stroke is critical in developing better prevention strategies. Non-invasive imaging allows us to directly see atherosclerosis in vessels and many features that are related to plaque vulnerability. A large body of evidence has demonstrated a strong correlation between some lipid parameters and carotid atherosclerosis. In this article, we review the relationship between lipids and atherosclerosis with a focus on carotid ultrasound, the most common method to estimate atherosclerotic load.

Cardiac troponin I measured with a very high sensitivity assay predicts subclinical carotid atherosclerosis: The Akershus Cardiac Examination 1950 Study

AIMS

Concentrations of cardiac troponin I (cTnI) are associated with incident ischemic stroke and predict the presence and severity of coronary atherosclerosis. Accordingly, we hypothesized that concentrations of cTnI measured with a very high sensitivity (hs-) assay would be associated with subclinical stages of carotid atherosclerosis in the general population.

METHODS

We measured hs-cTnI on the Singulex Clarity System in 1745 women and 1666 men participating in the prospective observational Akershus Cardiac Examination 1950 Study. All study participants were free from known coronary heart disease and underwent extensive cardiovascular phenotyping at baseline, including carotid ultrasound. We quantified carotid atherosclerosis by the carotid plaque score, carotid intima-media thickness (cIMT) and the presence of hypoechoic plaques.

RESULTS

Concentrations of hs-cTnI were measurable in 99.8% of study participants and were significantly associated with increased carotid plaque score (odds ratio for quartile 4 of hs-cTnI 1.59, 95% CI 1.22 to 2.07, p for trend < 0.001) and cIMT (odds ratio for quartile 4 of hs-cTnI 1.57, 95% CI 1.02 to 2.42, p for trend = 0.036), but not with the presence of hypoechoic plaques. hs-cTnI concentrations significantly improved reclassification and discrimination models in predicting carotid plaques when added to cardiovascular risk factors, no improvements were evident in predicting cIMT or hypoechoic plaques.

CONCLUSION

Concentrations of cTnI measured with a very high sensitivity assay are predictive of carotid atherosclerotic burden, a phenomenon likely attributable to common risk factors of subclinical myocardial injury, coronary and carotid atherosclerosis.

Vulnerable Plaque Is More Prevalent in Male Individuals at High Risk of Stroke: A Propensity Score-Matched Study

OBJECTIVES

To assess the gender differences in the prevalence of carotid vulnerable plaques in high-risk individuals for stroke in a multicenter, cross-sectional study.

METHODS

In the year 2015, 18595 residents who were at the age of 40 or older participated in a face-to-face study in eight communities in southwestern China. Totally 2,644 participants at high risk of stroke were enrolled. Before and after propensity score matching (PSM), the prevalence of carotid plaques and vulnerable plaques were compared between men and women. Multivariate analyses were applied to explore the association between the gender and carotid plaques. Stratified analyses and interaction tests were performed to identify factors that might modify the association between the gender and carotid plaques.

RESULTS

Among 2644 high-risk individuals enrolled, there were 1,202 (45.5%) men and 1442 (54.5%) women. Carotid plaques were detected in 904 (34.2%) participants, while vulnerable plaques were found in 425 (16.1%) participants. Before PSM, carotid plaques were more prevalent in male individuals than the female (36.7% vs. 32.1%, p = 0.01), as well as vulnerable plaque (20.0% vs. 12.8%, p < 0.01). Men tend to have a higher prevalence of vulnerable plaques in multivariate analyses (adjusted OR 1.70, 95% CI 1.10-2.62, p = 0.02). Stratified analyses and interaction tests demonstrated that the association between male sex and vulnerable carotid plaque did not change by age, family history of stroke, histories of chronic disease, smoking status, drinking status, physical activity, and BMI (all p for interaction > 0.05). After PSM, vulnerable plaques were still more prevalent in male individuals than the female (17.03% vs. 12.07%, p = 0.032).

CONCLUSION

Male individuals had a higher risk of vulnerable carotid plaque independent of classical vascular risk factors. Whether there is a gender-specific association between variations in genes related to inflammation, lipid metabolis, and endothelial function and plaque vulnerability needs to be further studied.

The Atherogenic Index of Plasma is Independently Associated with Symptomatic Carotid Artery Stenosis

INTRODUCTION

Small, dense low-density lipoprotein (sdLDL) is strongly associated with symptomatic carotid artery stenosis, but is not routinely evaluated in ischemic stroke patients. A method using the logarithmic transformation of the ratio of the plasma concentration of triglycerides (TGY) to HDL-cholesterol (HDL-C)[(Log[TGY/HDL-C])] has been described as a surrogate marker for sdLDL termed the atherogenic index of plasma (AIP).

OBJECTIVE

To determine if the AIP is independently associated with symptomatic carotid artery stenosis.

METHODS

We conducted a single center case-controlled study using a sample of ischemic stroke patients and compared risk factors of patients with and without symptomatic carotid artery stenosis. A multivariate logistic regression model was used to determine if the AIP divided into four quartiles was independently associated with symptomatic carotid artery stenosis. This model was compared to three other lipid models. Associations between non-lipid variables and the AIP were also identified.

RESULTS

31 cases of ischemic stroke due to symptomatic carotid artery stenosis and 236 controls of ischemic stroke not due to carotid artery stenosis were identified. Of the four lipid models assessed, only the model including the AIP (model 4) was found to be significantly associated with symptomatic carotid artery stenosis. The odd's ratio (OR) for quartile 3 was 3.82 (95% CI 1.03-14.17) and the OR for quartile 4 was 4.13 (95% CI 1.09-15.54) using quartile 1 as a reference. Metabolic syndrome was the only variable associated with the AIP (OR 5.06 95% CI 2.6-9.7).

CONCLUSION

At our single center, the AIP was the only lipid parameter independently associated with symptomatic carotid artery stenosis; and metabolic syndrome was independently associated with the AIP. The AIP may serve as a useful surrogate of sdLDL in patients with symptomatic carotid artery stenosis.

The Association of Paraoxonase-1 Polymorphism with Carotid Artery Stenosis among Elderly Chinese Population

Elderly population is in high risk of carotid atherosclerosis and artery stenosis (CAS). It has been proved that PON1 polymorphism is associated with low-density lipoprotein (LDL) oxidation, which plays an important role in artery atherosclerosis. CAS is an important cause of ischemic stroke. This study is aimed at investigating the association of PON1 (rs662) polymorphism with the risk of CAS among elderly Chinese population. Consecutive elderly patients with CAS were enrolled into the study. Genotyping for PON1 (rs662) polymorphism was performed on all participants. There were 310 CAS patients in this study, with 88 symptomatic CAS and 222 asymptomatic CAS. G allele had a frequency of 59.66% in symptomatic CAS (sCAS); and A allele had an incidence of 36.93% in asymptomatic CAS (aCAS) (P < 0.05). In all CAS patients with and without symptom, no associations were found in any genotype comparison. However, among aCAS subjects, based on GA phenotype, the odds ratio (OR) of the mutant GG with stenosis severity was 0.20 (P = 0.01). The OR of GG+GA mutation was 0.28 for moderate/severe severity, compared with GA type (P = 0.03). This study indicates that PON1 (rs662) polymorphism is not associated with the presence of symptom among CAS patients. Moreover, PON1 (rs662) polymorphism correlates with stenosis severity among aCAS.

Inflammation and Endothelial Function Relevant Genetic Polymorphisms and Carotid Plaque in Chinese Population

Aim: To examine the association between carotid plaque and variants in genes involved in inflammation and endothelial function.

Methods: This was a multicenter, cross-sectional survey in southwestern China. The residents aged ≥ 40 years volunteered to participate in the face-to-face survey in eight communities. A total of 2,377 subjects with high stroke risk were enrolled. Carotid plaque and plaque phenotype were assessed by carotid ultrasound. Genotypes of 19 variants in 10 genes related to inflammation and endothelial function were examined. Gene-gene interaction was analyzed by generalized multifactor dimensionality reduction (GMDR).

Results: Carotid plaques were found in 852 (35.8%) subjects, and 454 (53.3%) had stable plaques, whereas 398 (46.7%) had vulnerable plaques. PPARA rs4253655, HABP2 rs7923349, and IL1A rs1609682 were associated with the presence of carotid plaque, and NOS2A rs2297518 and PPARA rs4253655 were associated with vulnerable plaque in univariate analysis. The GMDR analysis revealed that there was a significant gene–gene interaction among HABP2 rs7923349, ITGA2 rs1991013, IL1A rs1609682, and NOS2A rs8081248, and the high-risk interactive genotype among the four variants was independently associated with a higher risk of carotid vulnerable plaque after adjusting the covariates (OR, 2.86, 95% CI: 1.32–7.13, P = 0.003).

Conclusion: The prevalence of carotid plaque was very high in the high-risk stroke population in southwestern China. Variants in genes involved in the endothelial function and inflammation were associated with the carotid plaque. The high-risk interactive genotype among rs7923349, rs1991013, rs1609682, and rs8081248 was independently associated with a higher risk of vulnerable plaque.

Review of serum biomarkers in carotid atherosclerosis

BACKGROUND

Carotid artery atherosclerotic stenosis is a preventable major cause of stroke, but there is still a need for definition of high-risk plaque in asymptomatic patients who might benefit from interventional therapies. Several image markers are recommended to characterize unstable plaques. The measurement of serum biomarkers is a promising method to assist in decision making, but the lack of robust evidence in the carotid environment burdens their potential as a standard of care. The goal of this review was to offer an updated state-of-the-art study of available serum biomarkers with clinical implications, with focus on those that may predict carotid symptom development.

METHODS

The Cochrane Library and MEDLINE databases were searched (all until September 2018) for studies on carotid plaque and serum biomarkers of atherosclerosis. Nonhuman, basic science, and histology studies were excluded, focusing on clinical studies. Selected abstracts were screened to include the most relevant articles on atherosclerotic plaque presence, progression, instability or symptom development.

RESULTS

Some well-established biomarkers for coronary disease are not relevant to carotid atherosclerosis and other inflammatory biomarkers, lipids, interleukins, homocysteine, and adipokines may be useful in quantifying carotid disease-related risk. Some serum biomarkers combined with image features may assist vascular specialists in selecting patients at high risk for stroke and in need of intervention.

CONCLUSIONS

Prospective studies applying a combination of biomarkers are essential to prove clinical usefulness.

Blood pressure at age 40 predicts carotid atherosclerosis two decades later: data from the Akershus Cardiac Examination 1950 Study

OBJECTIVE

We assessed the impact of a single time-point measurement of SBP, DBP and pulse pressure at the age of 40, on carotid plaque burden, echolucent plaques and carotid intima-media thickness late midlife.

METHODS

Individuals participating in two separate studies, 23 years apart, defined our cohort (n = 2714). 'The Age 40 Program', a nationwide Norwegian cardiovascular screening survey, performed 1985-1999, assessed cardiovascular risk factors and lifestyle variables at age 40. 'The ACE 1950 Study', a population-based cohort study on individuals born in 1950, performed 2012-2015, included ultrasound examinations of the carotid arteries. Blood pressure (BP) determinants of carotid atherosclerosis were assessed by regression models adjusted for cardiovascular risk factors at age 40, and late midlife BP.

RESULTS

The participants, 50.3% women, had a mean age of 40 (SD 0.3) years in the first study, and 64 (SD 0.6) years in the second. At age 40, mean SBP was 128 (SD 14) mmHg, mean DBP was 78 (SD 10) mmHg and mean pulse pressure was 50 (SD 9) mmHg. SBP and DBP at age 40 predicted carotid plaque burden in late midlife. Only DBP predicted echolucent plaques, and none of the BP components predicted carotid intima-media thickness.

CONCLUSION

A single time-point measurement of SBP and DBP at age 40 is associated with carotid plaque burden late midlife, also after adjustment for other cardiovascular risk factors at age 40, and of late midlife BP. Our findings emphasize the strong association between BP and atherosclerosis.

Using serum s100-β protein as a biomarker for comparing silent brain injury in carotid endarterectomy and carotid artery stenting

BACKGROUND

S100-β protein has been introduced as a sensitive biomarker of silent cerebral injury. This study compares its serum levels before, during, and 24 hours after carotid artery stenting (CAS) and carotid endarterectomy (CEA).

METHODS

We measured serum level of S100-β in arterial blood before (S100Ba), during (S100Bb), and 24 hours after (S100Bc) CAS and CEA. We assessed differences in S100-β levels using non-parametric tests. We analyzed the relationship between carotid plaque type (echolucency) and S100-β protein level. We also examined its relation to the oximetry results in the CEA group (ipsilateral and contralateral).

RESULTS

Thirty patients were enrolled, including 15 CAS and 15 CEA patients, with no significant differences in baseline atherosclerotic characteristics. There was no significant difference in S100Ba or S100Bb levels between CAS and CEA patients. However, a significant difference was found in S100Bc: 331.3 pg/mL (IQ range 56.4-583.5) for CAS vs. 76.3 pg/mL (IQ range 29.7-117.4) for CEA (P=0.01). Type I and II plaques were associated with the higher S100Bc levels in CAS (P=0.048). S100Bc was higher in CEA patients when the contralateral cerebral hemisphere had oximetry values less than 60% (P=0.043).

CONCLUSIONS

Our study suggests that CAS might produce silent brain injury. Moreover, vulnerable plaques might be associated with higher levels of S100-β protein, especially in CAS. This pilot study demonstrates that S100-β is a useful biomarker for silent brain injury in carotid revascularization. Large scale studies are still needed to confirm these findings.

Evaluation of Carotid Plaque Using Ultrasound Imaging

Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk.

Ultrasound and Biochemical Diagnostic Tools for the Characterization of Vulnerable Carotid Atherosclerotic Plaque

Stroke is a leading cause of morbidity and mortality worldwide, and characterization of vulnerable carotid plaque remains the spearhead of scientific research. Plaque destabilization, the key factor that induces the series of events leading to the clinical symptoms of carotid artery disease, is a consequence of complex mechanical, structural and biochemical processes. Novel imaging and molecular markers have been studied as predictors of disease outcome with promising results. The aim of this review is to present the current state of research on the association between ultrasound-derived echogenicity indices and blood parameters indicative of carotid plaque stability and activity. Bibliographic research revealed that there are limited available data. Among the biomarkers studied, those related to oxidative stress, lipoproteins and diabetes/insulin resistance are associated with echolucent plaques, whereas adipokines are associated with echogenic plaques. Biomarkers of inflammation and coagulation have not exhibited any conclusive relationship with plaque echogenicity, and it is not possible to come to any conclusion regarding calcification-, apoptosis- and neo-angiogenesis-related parameters because of the extremely limited bibliographic data.

Carotid intima-media thickness and plaque in cardiovascular risk assessment

Carotid intima-media thickness (CIMT) has been shown to predict cardiovascular (CV) risk in multiple large studies. Careful evaluation of CIMT studies reveals discrepancies in the comprehensiveness with which CIMT is assessed-the number of carotid segments evaluated (common carotid artery [CCA], internal carotid artery [ICA], or the carotid bulb), the type of measurements made (mean or maximum of single measurements, mean of the mean, or mean of the maximum for multiple measurements), the number of imaging angles used, whether plaques were included in the intima-media thickness (IMT) measurement, the report of adjusted or unadjusted models, risk association versus risk prediction, and the arbitrary cutoff points for CIMT and for plaque to predict risk. Measuring the far wall of the CCA was shown to be the least variable method for assessing IMT. However, meta-analyses suggest that CCA-IMT alone only minimally improves predictive power beyond traditional risk factors, whereas inclusion of the carotid bulb and ICA-IMT improves prediction of both cardiac risk and stroke risk. Carotid plaque appears to be a more powerful predictor of CV risk compared with CIMT alone. Quantitative measures of plaques such as plaque number, plaque thickness, plaque area, and 3-dimensional assessment of plaque volume appear to be progressively more sensitive in predicting CV risk than mere assessment of plaque presence. Limited data show that plaque characteristics including plaque vascularity may improve CV disease risk stratification further. IMT measurement at the CCA, carotid bulb, and ICA that allows inclusion of plaque in the IMT measurement or CCA-IMT measurement along with plaque assessment in all carotid segments is emerging as the focus of carotid artery ultrasound imaging for CV risk prediction.

The risk factors associated with ultrasonic tissue characterization of carotid plaque in type 2 diabetic patients

AIMS

Little is known about the related factors of plaque echogenicity in diabetic subjects.

METHODS

This was a single-center, retrospective, study investigating a subgroup of patients of a previously published trial. We enrolled 179 middle-aged and older Japanese type 2 diabetic patients with carotid plaque, and examined the parameters related with echogenicity of carotid plaque evaluated by gray-scale median (GSM).

RESULTS

Proportion of males and body mass index (BMI) were significantly higher and HDL-cholesterol was significantly lower in the patients with low GSM (< 48) plaques (n = 89) as compared to those without it (n = 90). A multiple logistic regression analysis with gender, BMI, and HDL-cholesterol as independent variables and the presence of low GSM plaques as an objective variable showed that male (odds ratio (OR) 2.36, 95%CI 1.05-5.31, p = 0.037) and BMI (OR 1.12 [1.01-1.24], p = 0.029) were independently associated with low GSM plaques. Another multiple logistic regression analysis with gender, BMI, and low-HDL-cholesterolemia (HDL-C < 40 mg/dl) as independent variables showed that low-HDL-cholesterolemia (OR 2.30 [1.03-5.13], p = 0.042) and BMI (OR 1.11 [1.00-1.22], p = 0.046) were independently associated with low GSM plaques.

CONCLUSIONS

Our study suggests that gender, BMI and low-HDL-cholesterol are important determinants of the content of the vascular wall in diabetic subjects.

The impact of variability in ultrasound settings on the measured echolucency of the carotid intima-media

BACKGROUND

B-mode ultrasound measurements of the echolucency of the carotid intima-media may hold information on cardiovascular risk. The information obtained from this measurement may depend on which gain settings are used. We studied the effect of gain settings on echolucency measurements and its consequences on risk factor relations and treatment effects.

METHODS

We used two approaches. In the first, we examined the relationship between calibration, gain and common grey-scale median (GSM) from repeated ultrasound images obtained from four healthy individuals at gain settings ranging from -20 to 20 dB. In the second, we evaluated the effect of gain settings on the relation of risk factors and statin treatment with common GSM, using images from 325 participants of the Measuring Effects on Intima-Media Thickness: an Evaluation of Rosuvastatin (METEOR) study with documented gain settings. Echolucency of the carotid intima-media was measured from ultrasound images using PaintShop Pro and Artery Measurement Software and expressed as GSM.

RESULTS

In healthy individuals, common GSM increased with increments in gain setting, primarily when the measurements were not calibrated. In the METEOR study sample, age and sex were significantly related to gain setting. The risk factor relations with common GSM were of the same magnitude and direction after adjustment for gain setting. Furthermore, adjustment for gain setting did not alter the rates of GSM change over time.

CONCLUSION

Extreme variability in gain settings has a major impact on the echolucency measurements of the far wall common carotid intima-media. Calibration should be used to adjust for these effects of gain settings. Variability in gain settings, however, seems limited in real practice and did not change the direction and magnitude of the relations under study. However, as age and sex are major determinants of gain settings, adjustment for or stratification by age and sex is recommended in studies into echolucency of the carotid intima-media in situations in which gain settings are unknown.

Intravascular ultrasound analysis to determine the relationship between high-density lipoprotein cholesterol and lesion characteristics in patients with coronary artery disease

OBJECTIVES

This study utilized grayscale intravascular ultrasound (IVUS) to explore the relationship between high-density lipoprotein cholesterol (HDL-C) levels and culprit lesion characteristics in patients with coronary artery disease.

BACKGROUND

Low HDL-C is associated with an increased risk of cardiovascular events. Previous IVUS studies have suggested a significant association between lesion characteristics and cardiovascular events.

METHODS

According to HDL-C levels, 120 patients who underwent IVUS for native, de novo coronary lesions before any intervention were divided into a low HDL-C group (<40 mg/dL, n = 60) and a high HDL-C group (≥40 mg/dL, n = 60). Quantitative and qualitative IVUS analyses were performed to compare lesion characteristics.

RESULTS

Quantitative IVUS measurements showed no significant differences between the 2 groups. HDL-C level was not significantly correlated with remodeling index (r = 0.03, P = 0.78). However, attenuated plaque was more frequent in the low HDL-C group (48.3% vs. 28.3%, P = 0.02) and a greater percentage of attenuated plaque was found in this group (32.5 ± 21.3% vs. 21.0 ± 11.0%, P = 0.02). Moreover, when categorized into 4 groups according to HDL-C levels, the proportion of attenuated plaque (64.7% in group with <30 mg/dL, 41.9% in group with 30-39 mg/dL, 36.4% in group with 40-59 mg/dL, and 6.3% in group with ≥60 mg/dL; P = 0.001 for trend) was significantly different among groups. On multivariate analysis, only HDL-C and male gender were independently associated with the presence of attenuated plaque at the culprit lesions.

CONCLUSIONS

Patients with low levels of HDL-C may be at increased risk of having a higher incidence of attenuated plaques.

MRI lesions after invasive therapy of carotid artery stenosis: a risk-modeling analysis

BACKGROUND

Diffusion-weighted imaging (DWI) abnormalities can frequently be detected after carotid endarterectomy (CEA) and carotid angioplasty with stent placement (CAS) of the carotid arteries. We looked for possible predictors for the development of DWI lesions during the intervention.

METHODS

We investigated 41 patients who underwent CAS without protection devices and 93 patients who underwent CEA. DWI studies were performed 1 day before and after the intervention.

RESULTS

Ischemic complications consisted of two strokes (2.2%) in the CEA group and one stroke (2.4%) in the CAS group. DWI lesions were detected in 28.0% of all patients after intervention. Using a multivariate regression analysis, diabetes mellitus (DM), hyperlipidemia, symptomatic stenosis, age and CAS were found to be significant predictors for the occurrence of DWI lesions.

CONCLUSIONS

DWI is an objective and highly sensitive method for monitoring interventions of the carotid arteries. Our results point to an increased risk of patients with diabetes and hyperlipidemia to develop DWI lesions during invasive therapy of the ICA.

CD4⁺CD28⁻ lymphocytes and cerebral ischaemic stroke. Part II: CD4⁺CD28⁻ lymphocytes and carotid artery atherosclerotic plaque characteristics

BACKGROUND AND PURPOSE

CD4⁺CD28⁻ lymphocytes can directly contribute to the instability of atherosclerotic plaque. This paper attempts to answer the question of the potential influence of the CD4⁺CD28⁻ lymphocyte population on the ultrasound image of atherosclerotic plaque in the common carotid artery (CCA) wall.

MATERIAL AND METHODS

The study involved a group of 109 patients, aged 45 to 65 years, including 42 patients with first ever ischaemic stroke, experiencing symptoms resulting from disturbances of the anterior area of cerebral circulation, arterial hypertension and/or type 2 diabetes mellitus (group 1). Group 2 consisted of 34 patients with mentioned risk factors, without ischaemic stroke. The control group comprised 33 heal-thy individuals. The percentage of CD4⁺CD28⁻ lymphocytes was assessed with flow cytometry.

RESULTS

A significant difference in the incidence of heterogeneous plaques was noted between groups 1 and 3 (p = 0.0023) as well as between group 2 and 3 (p = 0.0005), whereas groups 1 and 2 did not differ from each other. The proportion of CD4⁺CD28⁻ lymphocytes was similar in groups 1 and 2 (p = 0.97), but it differed between groups 1 and 3 (p < 0.0001) and between groups 2 and 3 (p < 0.001). A correlation was found between the proportion of CD4⁺CD28⁻ lymphocytes in the blood and the number of CCA atherosclerotic plaques (Rs = 0.191, p = 0.046). The proportion of CD4⁺CD28⁻ lymphocytes in peripheral blood did not correlate with the ultrasound types of atherosclerotic plaques. No correlation between the proportion of CD4⁺CD28 ⁻lymphocytes and the area of atherosclerotic plaques was found.

CONCLUSIONS

The correlation between the proportion of CD4⁺CD28⁻ lymphocytes and the number of atherosclerotic plaques within the CCA suggests that the cells are involved in the mechanism of carotid plaque formation. There is no proof of the involvement of the above-mentioned cells in the mechanism of plaque destabilization in those arteries.

Increased age, high body mass index and low HDL-C levels are related to an echolucent carotid intima-media: the METEOR study

INTRODUCTION

Echolucent plaques are related to a higher cardiovascular risk. Studies to investigate the relationship between echolucency and cardiovascular risk in the early stages of atherosclerosis are limited. We studied the relationship between cardiovascular risk factors and echolucency of the carotid intima-media in low-risk individuals.

METHODS

Data were analysed from the Measuring Effects on Intima-Media Thickness: an Evaluation of Rosuvastatin (METEOR) study, a randomized placebo-controlled trial including 984 individuals which showed that rosuvastatin attenuated the rate of change of carotid intima-media thickness (CIMT). In this post hoc analysis, duplicate baseline ultrasound images from the far wall of the left and right common carotid arteries were used for the evaluation of the echolucency of the carotid intima-media, measured by grey-scale median (GSM) on a scale of 0-256. Low GSM values reflect echolucent, whereas high values reflect echogenic structures. The relationship between baseline GSM and cardiovascular risk factors was evaluated using linear regression models.

RESULTS

Mean baseline GSM (± SD) was 84 ± 29. Lower GSM of the carotid intima-media was associated with older age, high body mass index (BMI) and low levels of high-density lipoprotein cholesterol (HDL-C) [beta -4.49, 95% confidence interval (CI) -6.50 to -2.49; beta -4.51, 95% CI -6.43 to -2.60; beta 2.45, 95% CI 0.47 to 4.42, respectively]. Common CIMT was inversely related to GSM of the carotid intima-media (beta -3.94, 95% CI -1.98 to -5.89).

CONCLUSION

Older age, high BMI and low levels of HDL-C are related to echolucency of the carotid intima-media. Hence, echolucency of the carotid intima-media may be used as a marker of cardiovascular risk profile to provide more information than thickness alone.

Stratifying risk: asymptomatic carotid disease

Stroke generates significant healthcare expenses and it is also a social and economic burden. The carotid artery atherosclerotic plaque instability is responsible for a third of all embolic strokes. The degree of stenosis has been deliberately used to justify carotid artery interventions in thousands of patients worldwide. However, the annual risk of stroke in asymptomatic carotid artery disease is low. Plaque morphology and its kinetics have gained ground to explain cerebrovascular and retinal embolic events. This review provides the readers with an insightful and critical analysis of the risk stratification of asymptomatic carotid artery disease in order to assist in selecting potential candidates for a carotid intervention.

Carotid artery stenting without angioplasty and cerebral protection: a single-center experience with up to 7 years' follow-up

BACKGROUND AND PURPOSE

The use of cerebral protection during CAS in the treatment of carotid artery disease is matter of controversy. The purpose of this study was to evaluate the outcome of CASWBAP in a large cohort of patients, with ≤7 years' follow-up.

MATERIALS AND METHODS

Two hundred thirty-six patients with 255 symptomatic carotid stenoses and/or with high-risk-morphology plaques of >50% and asymptomatic plaques of >70% were prospectively identified. Patients underwent neurologic and carotid US examination before the procedure and during follow-up at 1, 3, 6, and 12 months and annually thereafter. Plain films of the neck were obtained immediately after the procedure and then at 1 and 3 months.

RESULTS

Technical success was achieved in 253/255 (99%) patients. Primary stent placement was successful in 248/253 (98%) patients. Neurologic periprocedural complications within 30 days included 1 (0.4%) nondisabling stroke, 1 (0.4%) disabling stroke, 11 (4.3%) TIAs, and 1 (0.4%) death. The mean duration of follow-up was 23 ± 1.4 months (range, 3-84 months). During the follow-up period, there were 9 additional deaths (7 unrelated to the carotid disease and 2 stroke-related) and 2 strokes (in other vascular territories). The degree of stenosis decreased from a mean of 82% before the procedure to a mean of 30% immediately after. During follow-up, 38 (14.8%) angioplasties were performed due to restenosis in 19 (7.4%) patients, lack of stent expansion in 14 (5.4%), or both in 5 (1.9%).

CONCLUSIONS

CASWBAP is effective and safe with a low incidence of periprocedural complications, providing satisfactory long-term clinical results.

Relationship between serum lipid values and atherosclerotic burden in the proximal thoracic aorta

BACKGROUND

We conducted a cross-sectional analysis in a population-based cohort to compare the strength of the associations among various lipid parameters and the presence of atherosclerotic plaque in the proximal thoracic aorta.

METHODS

As part of Aortic Plaques and Risk of Ischemic Stroke (APRIS) study, 464 subjects were studied (mean age 69.1 +/- 9.0, 251 males and 213 females), including 255 patients with first ischaemic stroke and 209 stroke-free controls. Presence and thickness of atherosclerotic plaque were assessed by transoesophageal echocardiography. Measured lipid parameters included total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, and non-high-density lipoprotein cholesterol, lipoprotein (a), apolipoprotein (Apo) B and A-I levels with their ratio.

RESULTS

Overall, atherosclerotic plaque was detected in 326 subjects (70.4%) and 37.6% of these subjects (n=174) had atherosclerotic plaque > or =4 mm. After adjusting for other significant predictors of atherosclerosis, high-density lipoprotein cholesterol level and Apo B/A-I ratio emerged as the strongest predictors of any atherosclerotic plaque (P<0.001 and P=0.004, respectively), followed by individual Apo B (P=0.015) and A-I (P=0.016) levels, triglycerides (P=0.027) and non-high-density lipoprotein cholesterol level (P=0.021). Total and low-density lipoprotein cholesterol levels were not significant predictors for any atherosclerotic plaque (P=0.273 and P=0.081, respectively). High-density lipoprotein cholesterol level (P=0.008) and Apo A-I (P=0.006) were also significant predictors of atherosclerotic plaque > or =4 mm. Similar trends were observed after exclusion of subjects on cholesterol lowering drugs.

CONCLUSION

High-density lipoprotein cholesterol level and Apo B/A-I ratio, but not total or low-density lipoprotein cholesterol levels, were strongly associated with degree of proximal aortic atherosclerosis.

Prospective studies on the relationship between high-density lipoprotein cholesterol and cardiovascular risk: a systematic review

Epidemiological studies have extensively evaluated the association between high-density lipoprotein cholesterol (HDL-C) and cardiovascular disease (CVD) risk. The objective of this systematic review was to enumerate the number of original prospective studies that showed a significant association between HDL-C and CVD risk and provided evidence of the consistency of this association across other lipid risk factors. A systematic MEDLINE literature search identified 53 prospective cohort and five nested case-control studies that provided multivariate assessments of the association between HDL-C and CVD risk. Among these 58 prospective studies, 31 studies found a significant inverse association between HDL-C and CVD risk for all CVD outcomes and subpopulations studied, whereas 17 studies found a significant association for some CVD outcomes and/or subpopulations assessed. The ratio of studies that found a significant association out of the total studies identified was similar across all CVD outcomes, although there was less evidence for stroke and atherosclerotic outcomes. Only seven studies tested for the consistency of this association across other lipid risk factors, of which six studies suggested that the association was consistent across other lipid levels. In conclusion, the association between HDL-C and CVD risk is significant and strong, although further evidence may be needed to establish whether this association is consistent across other lipid risk factors. Furthermore, uncertainties remain regarding the mechanism in which HDL-C exerts its effects, suggesting a need for further research focused on new methods for reliable measurement.

The carotid artery plaque size and echogenicity are related to different cardiovascular risk factors in the elderly: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Carotid plaques can be characterised by ultrasound by size and echogenicity. Both size and echogenicity are predictors of cardiovascular events. The aim of this study was to examine whether traditional risk factors and markers of inflammation and oxidation were associated with plaque size and echogenicity. Computerised analysis of carotid plaque size and echogenicity (grey scale median, GSM) were performed by ultrasound in a population-based health survey in 1,016 subjects aged 70 years (PIVUS study). Information on cardiovascular risk factors was collected, together with markers of inflammation and oxidation. Increased Framingham risk score, systolic blood pressure, higher BMI and decreased HDL, lower glutathione levels were related to echolucent plaques. Previous or present smoking was common with significantly more pack-years related to the echorich plaques. Plaque size was associated with increased Framingham risk score, systolic blood pressure, blood glucose levels, smoking, ApoB/A1 ratio, OxLDL, TNF alpha, HOMA insulin resistance, leucocyte count, decreased BCD-LDL and low levels of l-selectin. Low HDL, increased BMI and decreased glutathione levels were associated with the echolucency of carotid plaques, implying metabolic factors to play a role for plaque composition. Markers of inflammation were related to plaque size alone, implying inflammation to be predominantly associated with the amount of atherosclerosis. These results suggest that plaque size and echogenicity are influenced by different risk factors.

Elevated levels of platelet microparticles in carotid atherosclerosis and during the postprandial state

BACKGROUND

Platelet microparticles (PMPs) possess proatherogenic and procoagulant properties which may play a role in atherogenesis and subsequent thromboembolic complications. The present study was conducted to investigate the possible relationship between carotid atherosclerosis and plasma concentrations of PMPs, and elucidate if plasma levels of PMPs were affected by postprandial hypertriglyceridemia.

METHODS AND RESULTS

Subjects with ultrasound-assessed carotid atherosclerotic plaques (echogenic; n=20 and echolucent; n=20), assessed by ultrasonography, and subjects without carotid plaques (n=20) were recruited from a population-based study and underwent a standard fat tolerance test. Subjects with carotid plaques had significantly higher levels of large PMPs than subjects without carotid atherosclerotic plaques (96.7+/-50.4 microg/l versus 56.1+/-34.9 microg/l), after adjustments for traditional cardiovascular risk factors and use cardiovascular drugs (p=0.021). Plasma PMPs were not associated with plaque echogenicity. Postprandial hypertriglyceridemia induced a similar increase in plasma PMPs within all groups. Significant correlations were found between an increase in plasma triglycerides and percent elevation in total PMPs (r=0.29, p<0.05) and large PMPs (r=0.34, p<0.01) in the postprandial phase.

CONCLUSIONS

Individuals with echogenic and echolucent carotid atherosclerotic plaques have statistically significant elevation of large plasma PMPs compared to age/sex-matched normal controls. Postprandial hypertriglyceridemia induces a significant, similar increase in plasma PMPs in individuals with and without carotid atherosclerotic plaques which could be of pathophysiological importance in atherogenesis.

Associations between cardiovascular risk factors and carotid atherosclerosis in middle-aged Japanese men with multiple risk factors

To examine the relationship between cardiovascular risk factors and prevalence of carotid atherosclerosis in Japanese middle-aged men with multiple risk factors, 110 Japanese men aged 36 to 60 yr were recruited based on the presence of all of the following factors detected during a screening survey: 1) body mass index (BMI) > or = 25 kg/m2; 2) systolic blood pressure (SBP) > or = 140 mmHg and/or diastolic blood pressure > or = 90 mmHg; 3) serum levels of triglycerides (TG) > or = 150 mg/dl and/or total cholesterol (T-ChoL) levels > or = 220 mg/dl and/or high density lipoprotein cholesterol (HDL-C) levels < 40 mg/dl; and 4) fasting serum glucose > or = 110 mg/dl and/or hemoglobin A1C > or = 5.6%. After adjustment for age and cardiovascular risk factors, the odds ratio (95% confidence interval) of carotid atherosclerosis associated with a 1-SD increment in HDL-C was 0.4 (95%CI: 0.2 to 0.9). We also detected a borderline association for anti-hypertension medication use, an indicator for advanced hypertension, with an odds ratio of 2.7 (95%CI: 1.0 to 7.4) after multivariable adjustment. The other risk factors, i.e. BMI, SBP, T-ChoL, TG, diabetes, smoking and drinking status did not show significant associations with carotid atherosclerosis. In conclusion, low HDL-C and advanced hypertension were significant correlates of carotid atherosclerosis for middle-aged Japanese men with multiple risk factors.

Echogenecity of the carotid intima-media complex is related to cardiovascular risk factors, dyslipidemia, oxidative stress and inflammation: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

BACKGROUND

Increased carotid artery intima-media thickness (IMT), measured by ultrasound, is related to an increased risk of cardiovascular disease. Since presence of echolucent plaques increases the risk further, we investigated if echogenecity of the carotid intima-media complex is related to markers of cardiovascular risk. Our aim was therefore to investigate if intima-media echogenecity is related to cardiovascular risk factors, or to markers of inflammation and oxidation in an exploratory investigation.

METHODS

The PIVUS cohort study is an observational study of 1016 (509 women and 507 men) randomly chosen individuals aged 70 living in Uppsala, Sweden. Carotid artery ultrasound measurements were performed. IMT and the grey scale median (GSM) value were calculated in the intima-media complex (IM-GSM) in the far wall of the common carotid artery. Traditional risk factors were evaluated together with indices of oxidative stress and inflammation.

RESULTS

In the multiple regression analysis, HDL-cholesterol, body mass index, conjugated diens, glutathione, e-selectin and TNF alfa were significantly related to IM-GSM. IMT was independently related to blood pressure, smoking and body mass index.

CONCLUSION

The echolucency of the carotid intima-media was related to several cardiovascular risk factors not related to IMT, such as dyslipidemia, oxidative stress and inflammation. Since the echogenecity of the carotid intima-media complex was related to different risk factors compared to carotid IMT, it is worthwhile to further explore the usefulness of this new marker of the vascular wall.

Sonographic carotid plaque morphologic characteristics and vascular risk factors: results from a population study

OBJECTIVE

The role of vascular risk factors in atherosclerosis development is well established, whereas risk factors involved in determining plaque vulnerability are still a matter of debate. We investigated the vascular risk factor distribution in patients with carotid plaques.

METHODS

We consecutively assessed sonographic plaque morphologic characteristics, the degree of stenosis, and the common carotid artery intima-media thickness (IMT) in 1655 patients. Demographic data, a documented history of symptomatic cerebrovascular disease (CVD), and the presence of vascular risk factors were collected. According to literature, heterogeneous hypoechoic plaques with an irregular surface or ulcerations and those with a severe degree of stenosis (>or=70%) have been considered "complex" plaques at "major" risk of stroke; homogeneous hyperechoic plaques with smooth surface lesions have been considered "simple" plaques at minor risk.

RESULTS

Univariate analysis showed that all vascular risk factors were associated with the presence of carotid atherosclerotic lesions. Multiple logistic regression showed an independent association of hypertension and diabetes with complex plaques, which also had a thicker IMT. A history of CVD was observed more frequently in complex plaques, which had a higher stenosis percentage even after patients with a severe degree of stenosis (>or=70%) and indications for carotid surgery were excluded.

CONCLUSIONS

Hypertension and diabetes are related to a thicker IMT and more severe complex plaques, which may reflect the instability of atherosclerotic process. Because two-thirds of the patients with complex plaques were asymptomatic for CVD, this raises the importance of surveillance sonography to monitor plaque evolution for prevention of symptomatic CVD.

Carotid stenting without use of balloon angioplasty and distal protection devices: preliminary experience in 100 cases

BACKGROUND AND PURPOSE

A major concern during carotid artery stent placement is the potential for cerebral embolism. Diminishing the number of device manipulations across the lesion might reduce procedural stroke risk. For this purpose, we report our initial experience with carotid stent placement without the use of either balloon angioplasty or distal protection devices.

MATERIALS AND METHODS

Eighty-seven consecutive patients with 100 carotid stenoses compose this series. Ninety four of the 100 hundred stented carotid arteries were either symptomatic (58 [58%]) or had a greater than 70% stenosis (36 [36%]). Six percent of them were asymptomatic and had stenosis between 50% and 70%. Patients underwent neurologic evaluation before the procedure and during follow-up at 1, 3, 6, and 12 months and annually thereafter. Carotid sonography and plain films of the neck were performed immediately after the procedure and then at the same time intervals.

RESULTS

Primary stent placement was successful in 98 of 100 case subjects. In 2 case subjects, predilation was necessary before stent deployment. Neurologic periprocedural complications included 1 nondisabling and 1 disabling stroke and 5 transient ischemic attacks. The mean duration of follow-up was 23 months (range: 10-36 months). During the follow-up period, there were 5 deaths, all unrelated to the carotid disease, and no major stroke. The degree of stenosis decreased from a mean of 78.85% before the procedure to a mean of 21.23% immediately after.

CONCLUSIONS

In this series, carotid stent placement without the use of either balloon angioplasty or distal protection devices was safe and effective with a low incidence of periprocedural complications.

Metabolic Syndrome Less Strongly Associated With Target Organ Damage Than Syndrome Components in a Healthy, Working Population

The authors investigated the associations between target organ damage and individual components of the metabolic syndrome (MS) compared with the MS itself. Carotid intima-media thickness (IMT), carotid plaque, and left ventricular mass index (LVMI) were assessed by ultrasonography in 356 participants who were free of overt cardiovascular disease. Participants with the MS (n=33) had higher LVMI and carotid IMT than those without the MS (n=323), but the percentage of patients who had carotid plaque was similar. Individually, each component of the MS was significantly associated with the 3 measures of target organ damage. In bivariate and multivariate analyses, the association of clinic systolic blood pressure to both LVMI and carotid IMT and the negative association of high-density lipoprotein cholesterol with carotid plaque were stronger than and independent of the MS. The data suggest that physicians should evaluate blood pressure and high-density lipoprotein cholesterol as well as other cardiovascular risk factors without regard to whether a patient meets the criteria for the MS.

High-density lipoproteins: a therapeutic target for atherosclerotic cardiovascular disease

Despite great progress being made during the last two decades in cardiovascular disease prevention, especially by lowering low-density lipoprotein-cholesterol with statins, cardiovascular events continue to occur. Plasma high-density lipoprotein (HDL) exerts multiple protective effects on the arterial wall, through promotion of reverse cholesterol transport, prevention of endothelial dysfunction and inhibition of lipid oxidation. Therapeutic interventions raising plasma HDL levels or directly mimicking its beneficial effects represent the next frontier in the prevention and treatment of cardiovascular disease.

Association of high-density lipoprotein levels and carotid atherosclerotic plaque characteristics by magnetic resonance imaging

A low level of high-density lipoprotein cholesterol (HDL-C) is a risk factor for atherosclerotic disease. Magnetic resonance imaging (MRI) can provide detailed information on carotid atherosclerotic plaque size and composition. The purpose of this study was to correlate HDL levels with carotid plaque burden and composition by MRI. Thirty-four patients with coronary artery disease (CAD) receiving simvastatin plus niacin or placebo for both drugs for three years were randomly selected to undergo MRI of carotid arteries. Atherosclerotic plaque wall volumes (WVs) and plaque components including lipid rich/necrotic core (LR/NC), calcium, fibrous tissue, and loose matrix were measured. Mean WV or atherosclerotic burden was significantly associated with total HDL-C levels (r = -0.39, P = 0.02), HDL(2) (r = -0.36, P = 0.03), HDL(3) (r = -0.34, P = 0.04), and LDL/HDL ratio (r = 0.42, P = 0.02). Plaque lipid composition or LR/NC was significantly associated with HDL(3) (r = -0.68, P = 0.02). Patients with low HDL levels (<or=35 mg/dL) had increased WV (97 +/- 23 vs. 81 +/- 19 mm(3), P = 0.05) compared with patients with HDL levels > 35 mg/dL. Among CAD patients, low HDL-C levels were significantly associated with increased carotid atherosclerotic plaque burden and lipid content by MRI.