Is plaque formation in the common carotid artery representative for plaque formation and luminal stenosis in other atherosclerotic peripheral arteries? A post mortem study

Association Between Serum Bilirubin, Lipid Levels, and Prevalence of Femoral and Carotid Atherosclerosis: A Population-Based Cross-Sectional Study

BACKGROUND

Bilirubin may prevent lipid peroxidation and have important antiatherosclerotic effects. We determined associations of serum bilirubin and lipid with peripheral atherosclerosis.

METHODS

We included 4290 participants (35% men; median age, 60 years) from the southeast China who underwent B-mode ultrasound examination. Increased intima-media thickness or a focal structure encroaching into the arterial lumen by at least 0.5 mm or >50% of the surrounding intima-media thickness value was regarded as having atherosclerosis. Fasting serum bilirubin and lipid levels were measured. Cholesterol/(HDL [high-density lipoprotein] cholesterol+bilirubin), and LDL (low-density lipoprotein cholesterol)/(HDL+bilirubin) ratios were calculated. Unconditional and multinomial logistic regression models were used to examine associations of bilirubin or lipid with prevalence of peripheral atherosclerosis. Mediation analyses were performed to assess the effect of bilirubin on atherosclerosis risk mediated via lipid.

RESULTS

Compared with participants with the lowest levels of bilirubin, those with the highest tertile were less likely to have carotid or femoral atherosclerosis (odds ratios were 0.55-0.74). The highest levels of bilirubin significantly reduced the odds of concurrent carotid and femoral atherosclerosis by 35% to 45%. Participants with the highest levels of cholesterol, LDL, cholesterol/(HDL+bilirubin), and LDL/(HDL+bilirubin) ratios had 2.8- to 3.7-fold increased odds of concurrent carotid and femoral atherosclerosis. LDL accounted for 25.65% of the total bilirubin-atherosclerosis association. LDL and cholesterol mediated the associations between direct bilirubin and atherosclerosis (proportion: 20.40%, 9.67%, respectively).

CONCLUSIONS

Increased serum bilirubin levels are inversely associated with the prevalence of carotid or femoral atherosclerosis. LDL and cholesterol may mediate these associations.

Toxic Metals and Subclinical Atherosclerosis in Carotid, Femoral, and Coronary Vascular Territories: The Aragon Workers Health Study

OBJECTIVE

Studies evaluating the association of metals with subclinical atherosclerosis are mostly limited to carotid arteries. We assessed individual and joint associations of nonessential metals exposure with subclinical atherosclerosis in 3 vascular territories. Approach and Results: One thousand eight hundred seventy-three Aragon Workers Health Study participants had urinary determinations of inorganic arsenic species, barium, cadmium, chromium, antimony, titanium, uranium, vanadium, and tungsten. Plaque presence in carotid and femoral arteries was determined by ultrasound. Coronary Agatston calcium score ≥1 was determined by computed tomography scan. Median arsenic, barium, cadmium, chromium, antimony, titanium, uranium, vanadium, and tungsten levels were 1.83, 1.98, 0.27, 1.18, 0.05, 9.8, 0.03, 0.66, and 0.23 μg/g creatinine, respectively. The adjusted odds ratio (95% CI) for subclinical atherosclerosis presence in at least one territory was 1.25 (1.03-1.51) for arsenic, 1.67 (1.22-2.29) for cadmium, and 1.26 (1.04-1.52) for titanium. These associations were driven by arsenic and cadmium in carotid, cadmium and titanium in femoral, and titanium in coronary territories and mostly remained after additional adjustment for the other relevant metals. Titanium, cadmium, and antimony also showed positive associations with alternative definitions of increased coronary calcium. Bayesian Kernel Machine Regression analysis simultaneously evaluating metal associations suggested an interaction between arsenic and the joint cadmium-titanium exposure.

CONCLUSIONS

Our results support arsenic and cadmium and identify titanium and potentially antimony as atherosclerosis risk factors. Exposure reduction and mitigation interventions of these metals may decrease cardiovascular risk in individuals without clinical disease.

Immune cells in carotid artery plaques: what can we learn from endarterectomy specimens?

INTRODUCTION

Endarterectomy specimens represent a unique opportunity to study atherosclerosis. This review aims to summarize the recent knowledge of atherogenesis from studies characterizing a cellular composition of carotid endarterectomy specimens.

EVIDENCE ACQUISITION

A non-systematic literature review was carried out to summarize recent knowledge regarding ex vivo analysis of carotid artery plaque composition. Upon evaluation of their relevance, and elaborate forward and backward search, 95 articles were included in the review.

EVIDENCE SYNTHESIS

Despite the significant advancement of in vivo imaging techniques, the stroke prediction based on carotid artery plaque morphology is not reliable. Besides analyses of plaque morphology, present studies focus on precise characterization of the different immune cell types and elucidation of their role in plaque development. Plaque content analyses revealed the presence of various immune cells in carotid artery plaques. Presence of different immune cells subpopulations can be connected to some undesirable changes in plaque stability.

CONCLUSIONS

Since the destabilization of the atherosclerotic plaque is a multifactorial process, a combination of various methods should be used to characterize the unstable plaques more accurately. In this context, studies characterizing plaque content from a cellular point of view could elucidate some processes underlying the plaque progression. Together with morphological evaluation, these analyses could enable more precise assessment of plaque stability.

Polyvascular subclinical atherosclerosis in familial hypercholesterolemia: The role of cholesterol burden and gender

BACKGROUND AND AIM

Heterozygous familial hypercholesterolemia (HeFH) is a genetic disease characterized by a heterogeneous phenotype. The assessment of cardiovascular (CV) risk is challenging for HeFH. Cholesterol burden (CB) allows to estimate the lifelong exposure to high levels of cholesterol. The aim of this study was to analyze the distribution of subclinical atherosclerosis and the relationship between atherosclerosis and the CB in a sample of HeFH patients, focusing on sex-related differences.

METHODS AND RESULTS

154 asymptomatic HeFH subjects underwent coronary-artery-calcium score (CACs) and Doppler ultrasound of carotid and femoral arteries. Yearly lipid profiles and HeHF history were obtained from patients' files in order to calculate total CB. Atherosclerotic burden was defined by the presence of CACs > 0 or by the presence of carotid or femoral plaque. Study population was stratified according to gender. The prevalence of CAC, carotid and femoral atherosclerosis was of 62%, 55% and 56%, respectively. Coronary district was the least involved in women, who had a higher prevalence in carotid atherosclerosis. When two vascular districts were affected, women had an increased prevalence of femoral and carotid atherosclerosis whereas men had a higher prevalence of coronary and femoral atherosclerosis. CB correlated to the presence of atherosclerosis in any of the three vascular districts with a significant increasing trend depending on the number of affected areas.

CONCLUSIONS

A polyvascular atherosclerotic burden is found in asymptomatic HeFH patients. Gender differences in the territory distribution were observed. The early and lasting exposure to high cholesterol, as expressed by CB, is a major determinant of atherosclerotic burden.

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.

Plasma Galectin-3 and Sonographic Measures of Carotid Atherosclerosis in the Atherosclerosis Risk in Communities Study

Galectin-3 is a β-galactoside-binding lectin that plays a role in the regulation of several conditions that are associated with atherosclerosis. The goal of this cross-sectional study was to assess the association of plasma galectin-3 concentrations with sonographic measures of carotid atherosclerosis in the Atherosclerosis Risk in Communities study. Linear regression was used to determine the difference and 95% confidence intervals (CIs) for carotid intima-media thickness (cIMT) by categorical and continuous representations of galectin-3. Logistic regression was used to determine the odds ratio and 95% CI, separately, for dichotomized cIMT (75th percentile = 0.9 mm) and carotid plaque and/or shadowing. Compared to those in the first quintile of galectin-3, those in the fifth quintile of galectin-3 level had higher cIMT (mean difference: 0.020 mm after multivariable adjustment; P trend = .04). Moreover, compared to those in the lowest galectin-3 quintile, those in the highest galectin-3 quintile had higher odds of carotid plaque/and or shadowing (odds ratio 1.13 after multivariable adjustment; P trend = .014). Higher levels of galectin-3 are associated with greater carotid atherosclerosis. Our findings provide support for the role of inflammatory biomarkers in the pathogenesis of atherosclerosis and suggest galectin-3 as a possible target for intervention in the prevention or management of atherosclerotic disease.

Relationship of femoral artery ultrasound measures of atherosclerosis with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is strongly associated with peripheral artery disease (PAD). Detection of subclinical PAD may allow early interventions for or prevention of PAD in persons with CKD. Whether the presence of atherosclerotic plaque and femoral intima-media thickness (IMT) are associated with kidney function is unknown.

METHODS

We performed a cross-sectional observational study of 1029 community-living adults. We measured superficial and common femoral artery IMT and atherosclerotic plaque presence by ultrasound. Estimated glomerular filtration rate (eGFR; continuous) and eGFR <60 mL/min/1.73 m2 (binary) were evaluated as outcomes.

RESULTS

Mean age was 70 ± 10 years, mean eGFR was 78 ± 17 mL/min/1.73 m2, and 156 (15%) individuals had eGFR <60 mL/min/1.73 m2; 260 (25%) had femoral artery plaque. In models adjusted for demographics and cardiovascular risk factors, individuals with femoral artery plaque had mean eGFR approximately 3.0 (95% confidence interval, -5.3 to -0.8) mL/min/1.73 m2 lower than those without plaque (P < .01). The presence of plaque was also associated with a 1.7-fold higher odds of eGFR <60 mL/min/1.73 m2 (95% confidence interval, 1.1-2.8; P < .02). Associations were similar in persons with normal ankle-brachial index. The directions of associations were similar for femoral IMT measures with eGFR and CKD but were rendered no longer statistically significant with adjustment for demographic variables and cardiovascular disease risk factors.

CONCLUSIONS

Femoral artery plaque is significantly associated with CKD prevalence in community-living individuals, even among those with normal ankle-brachial index. Femoral artery ultrasound may allow evaluation of relationships and risk factors linking PAD and kidney disease earlier in its course.

Progression and Characterization of the Accelerated Atherosclerosis in Iliac Artery of New Zealand White Rabbits: Effect of Simvastatin

OBJECTIVE

Although atherosclerosis is described in New Zealand White rabbit's iliac artery, yet details of time-dependent atherosclerosis progression are not well known. Further, a well characterized accelerated model of atherosclerosis is also required for the screening of candidate drugs to target specific steps of atherosclerosis development. The present study extensively characterizes the time-dependent plaque composition and functional responses of the atherosclerosis in rabbit iliac artery and its modification by simvastatin.

METHODS

Atherosclerosis was induced with a combination of balloon injury and atherogenic diet (AD) (1% cholesterol, 6% peanut oil) in rabbit's iliac artery. Atherosclerosis progression was evaluated on days 8, 10, 15, 21, 35, and 56 after AD feeding. The plaque characterization was done using histology, real-time reverse transcription-polymerase chain reaction, and vasoreactivity experiments. The standard anti-hyperlipidemic drug, simvastatin (5 mg·kg·d), was used to investigate its effect on atherosclerotic changes.

RESULTS

Plasma lipids were elevated in a progressive manner after AD feeding from days 8 to 56. Similarly, arterial lipids, Monocyte Chemoattractant Protein-1 (MCP-1) level along with infiltration of macrophages in the lesion area were also increased from day 15 onward. This resulted in a significant increase in the plaque area and intimal-medial thickness ratio in contrast to normal animals. Inflammatory milieu was observed with a significant increase in expression of pro-inflammatory regulators like MCP-1, Tumor Necrosis Factor-α (TNF-α) and Vascular Cell Adhesion Molecule-1 (VCAM-1), whereas anti-inflammatory cytokine interleukin 10 decreased as disease progressed. Endothelial dysfunction was also observed, specifically Acetylcholine (ACh)-induced vasorelaxation was reduced from day 8 onward, whereas the phenylephrine-induced vasoconstriction response was progressively reduced from day 15 in the iliac artery. Ground substances including proteoglycans, α-actin, and collagen content along with metalloproteinase-9 and Tissue inhibitor of metalloproteinases-1 (TIMP-1) inhibitors were significantly augmented at later time points, day 21 onward. Simvastatin treatment for 35 days, at a dose having no significant effect on plasma lipid levels, significantly reduced atherosclerotic progression as evident by reduced macrophage content, inflammatory burden, and extracellular matrix component like proteoglycans and metalloproteinase-9.

CONCLUSIONS

The authors observed that AD feeding with balloon injury in the rabbit iliac artery accelerated the progression of atherosclerosis and exhibited predominant features of type III human lesion within 8 weeks (56 days). Simvastatin treatment for 35 days exhibited anti-atherosclerotic efficacy without significantly lowering the circulating lipids. The current study thus provides an insight into the time-dependent atherosclerotic progression in rabbit iliac artery and highlights its utility for anti-atherosclerotic evaluation of the candidate drugs.

Carotid intima-media thickness in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): a narrative review

BACKGROUND

Carotid intima-media thickness (CIMT), as measured by ultrasound, has been used in large studies as a non-invasive marker for subclinical atherosclerosis. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a cohort of 15,105 civil servants in six Brazilian cities that included CIMT evaluation in its baseline assessment. The aim of the present narrative review was to provide an overview of ELSA-Brasil CIMT articles published up to July 31, 2017.

DESIGN AND SETTING

Narrative review of ELSA-Brasil CIMT studies using baseline assessment data.

METHODS

We searched PubMed for the terms "ELSA-Brasil" and "intima-media". This search yielded 21 published articles using CIMT data from the ELSA-Brasil baseline assessment, which were included in this review. We also present information about intima-media thickness assessment from ongoing onsite reevaluations of the study participants.

RESULTS

Most published studies focused on the association with traditional and novel cardiovascular risk factors. Studies also presented information about the ELSA-Brasil CIMT protocol at baseline and CIMT value distribution in this large sample.

CONCLUSIONS

Analyses on the ELSA-Brasil data led to important insights on CIMT interpretation and physiology. Besides the highlighted contributions which have already been made in this field, new data gathered during the ongoing third onsite assessment will enable investigation of substantially new research questions.

Factors predicting cardiovascular events in chronic kidney disease patients. Role of subclinical atheromatosis extent assessed by vascular ultrasound

Patients with chronic kidney disease (CKD) have an increased incidence of cardiovascular events (CVE). The contribution of subclinical atheromatosis extent, including femoral arteries, to CVE in CKD patients has not been investigated. In this paper, we examine the prognostic value of subclinical atheromatosis extent, assessed as the number of arterial territories with plaque, in predicting the incidence of major and minor CVE. The NEFRONA is a multicenter, prospective cohorts study that recruited 2445 CKD subjects and 559 controls, free from previous cardiovascular disease, in 81 medical centers across Spain. The presence of atheroma plaque was assessed by arterial ultrasound in ten arterial territories (carotid and femoral). The predictive power of the presence or absence of atheroma plaque in any territory was compared with the quantification of atheroma extent as the number of territories with plaque. During the median follow up of 48 months, 216 CVE were reported. Factors predicting the incidence of CVE in the whole cohort were being male, CKD patient, lower levels of 25(OH) vitamin D, higher levels of cholesterol and the extent of subclinical atheromatosis, yielding a higher concordance (C) index than the presence or absence of plaque. In stratified analysis including specific factors of CKD patients not on dialysis, the variables predicting CVE were the same as in the whole cohort, plus higher levels of potassium. Again, the inclusion of the information about atheromatosis as number of territories with plaque, presented a higher C index than the presence or absence of plaque. In the dialysis population, significant variables were older age, diabetes, dialysis vintage and higher levels of cholesterol and phosphate. In this case the higher C index was obtained with the information about plaque presence.

Subclinical atheromatosis extent, including femoral arteries, influences CVE in CKD and its detection could improve the prediction of cardiovascular events.

Asymptomatic Plaques of Lower Peripheral Arteries and Their Association with Cardiovascular Disease: An Autopsy Study

Aims: Patients with peripheral artery disease (PAD) have a high prevalence of cardiovascular morbidity and mortality; however, majority of patients with PAD are asymptomatic. This study aimed to histologically evaluate whether asymptomatic, lower extremity artery plaques are associated with systemic atherosclerosis and the onset of cardiovascular disease (CVD) events using autopsy cases.

Methods: We histologically investigated the atherosclerotic plaques of the common iliac, common carotid, coronary, and renal arteries from 121 autopsy cases without symptoms of PAD (mean age: 67.6 years; 63% men; 83% non-CVD death). We evaluated the relationship between the degree of iliac artery atherosclerosis and that of other arteries, and also the presence of any CVD, myocardial infarction, stroke, and renal failure.

Results: Advanced atherosclerotic plaques (American Heart Association ≥ 4) were present in 86 (72%) common iliac arteries in these cases. These arteries also showed high frequencies of calcification (66%), intraplaque hemorrhage (42%), and plaque disruption (24%). These advanced lesions were associated with age (≥ 60 years), sex (male), hypertension, diabetes, and smoking habit (all P < 0.05). Additionally, it was significantly associated with CVD (odds ratio, 95% confidence interval; 6.2, 2.2–22), myocardial infarction (6.4, 1.2– 19), stroke (8.7, 1.7 –16), and renal failure/hemodialysis (5.8, 1.1 – 11). Cases with advanced iliac artery plaques had advanced coronary and carotid atherosclerosis.

Conclusion: These results indicate that asymptomatic advanced plaques are frequently observed in common iliac arteries, and are associated with generalized atherosclerosis and CVD events.

Clinical Characteristics of Young Type 2 Diabetes Patients with Atherosclerosis

Objective

The prevalence of type 2 diabetes is increasing rapidly in the young population. The clinical characteristics and risk factors for young type 2 diabetes patients with atherosclerosis are not fully explicated. The aim of the present study was to investigate various clinical and biochemical characteristics of young type 2 diabetic patients with atherosclerosis.

Design and Methods

This was a cross-sectional study. The study involved 2199 hospitalized patients with type 2 diabetes. The young patients were classified into the atherosclerotic group or the non-atherosclerotic group, and we also enrolled an older group with peripheral atherosclerosis disease and an age of at least 45 years. Comparisons were made between the different groups to investigate the cardiovascular and metabolic risk profiles of young type 2 diabetes patients with atherosclerosis. We also used logistic regression models to assess the atherosclerosis risk factors for young patients.

Results

Compared to older type 2 diabetes patients with atherosclerosis, young patients with atherosclerosis had more deleterious profiles of weight and hyperlipidemia. Only age and diabetes duration were found to be significant independent risk factors for atherosclerosis in young patients. The ratio of the presence of atherosclerosis in the lower extremity arteries alone was significantly higher in young patients than older patients (26.4% vs. 14.0%, P = 0.000).

Conclusion

Young type 2 diabetes patients with atherosclerosis have more adverse cardiovascular risk profiles and inadequate control of these risk factors. Lower extremity examination is of high importance in young patients.

Can and should carotid ultrasound be used in cardiovascular risk assessment?: the internist's perspective

Cardiovascular risk management is a major and challenging task for internists. Risk scores using algorithms based on traditional risk factors are helpful in identifying patients in whom intensive prevention strategies are warranted. However there remains a need for more accurate screening tools to allow clinicians to individualize the primary prevention programs to their patients. Approximately 40-80% of apparently healthy, asymptomatic subjects exhibit increased thickness of the lamina intima-media of the carotid artery or have atherosclerotic carotid plaques. These abnormalities can be measured safely and at low cost by ultrasound. Subclinical carotid lesions are strongly associated with generalized atherosclerotic burden and the risk of future cardiovascular events. Although many cardiovascular risk management guidelines recommend the use of these parameters incorporation in clinical practice is still not commonplace. Based on the current literature it can be stated that in high risk patients there is no additional value of carotid ultrasound because even in the absence of carotid lesions these patients should receive an intensive risk reduction regime. In the large low-intermediate risk group however carotid ultrasound findings carry subtle but possibly clinically relevant information about cardiovascular risk profile. The effect of treatment decisions based on carotid ultrasound parameters has not been studied. Sequential measurements to monitor progression and evaluate treatment response on an individual basis are not sufficiently reproducible. We therefore recommend the use of carotid ultrasound in low to intermediate risk patients but emphasize the importance of interpreting the results in conjunction with all cardiovascular risk factors and avoid follow-up measurements.

Comparison of carotid and lower limb atherosclerotic lesions in both previously known and newly diagnosed type 2 diabetes mellitus

Aims/Introduction

To compare carotid and lower limb atherosclerotic lesions, and examine if carotid atherosclerotic lesions are in line with lower limb atherosclerotic lesions, and can reflect generalized atherosclerosis in inpatients with type 2 diabetes.

Materials and Methods

This was an observational study carried out in 867 Chinese inpatients with type 2 diabetes, including 573 previously known and 294 newly diagnosed patients. Ultrasonographic assessments of intima-media thickness (IMT), plaques, and stenosis in the carotid and lower limb arteries were evaluated. Atherosclerotic lesions between the carotid and lower limb arteries were compared in both previously known and newly diagnosed diabetes, respectively.

Results

In both the known (77.3% vs 49.4%, P < 0.001) and the newly diagnosed diabetes (55.4% vs 29.9%, P < 0.001), the prevalence of atherosclerotic plaques was significantly higher in the lower limb arteries than in the carotid arteries. Likewise, the prevalence of stenosis was also significantly higher (P < 0.001) in the lower limb arteries (16.9%) than in the carotid arteries (4.2%) in the established diabetes patients. However, there was no significant difference in the mean IMT between common carotid and common femoral arteries in both the previously known (0.90 ± 0.24 mm vs 0.89 ± 0.20 mm, P = 0.675) and the newly diagnosed diabetes patients (0.86 ± 0.22 mm vs 0.85 ± 0.16 mm, P = 0.436).

Conclusions

Carotid plaques might underestimate generalized plaques in inpatients with type 2 diabetes, as shown by its significantly lower prevalence compared with that of the lower extremity arteries. A combined carotid and lower limb ultrasound examination can improve the detection of atherosclerotic lesions in inpatients with type 2 diabetes.

Cholesterol diet withdrawal leads to an initial plaque instability and subsequent regression of accelerated iliac artery atherosclerosis in rabbits

Effect of long term cholesterol diet withdrawal on accelerated atherosclerosis in iliac artery of New Zealand White (NZW) rabbits has not been explored so far. Atherosclerosis was thus induced in rabbits by a combination of balloon injury and atherogenic diet (AD) (1% cholesterol and 6% peanut oil) feeding for 8 weeks (baseline) followed by chow diet (CD) feeding for 4, 8, 16, 32, 50 and 64 weeks. The plaque characterization was done using histology, real time RT-PCR and vasoreactivity studies. Significant elevation in plasma lipids with AD feeding was normalized following 16 weeks of CD feeding. However, baseline comparison showed advanced plaque features even after 8 weeks of CD period with significant elevation in intima/media thickness ratio and plaque area later showing reduction at 50 and 64 weeks CD periods. Lesion lipid accumulation and CD68 positivity was maintained till 16 weeks of CD feeding which significantly reduced from 32 to 64 weeks CD periods. Baseline comparison showed significant increase in ground substance, MMP-9 and significant decrease in α-actin and collagen content at 8 weeks CD period indicating features of unstable plaque. These features regressed up to 64 weeks of CD. Partial restoration of functional vasoconstriction and vasorelaxation was seen after 64 weeks of CD feeding. mRNA expression of MCP-1, VCAM-1, collagen type I and III, MMP-9, TIMP-1, IFN-γ, TNF-α, IL-10 and eNOS supported the above findings. The study thus reveals insights into initial plaque instability and subsequent regression on AD withdrawal in this model. These results are suggestive of an appropriate window for drug intervention for plaque stability/regression and restenosis as well as improves understanding of plaque regression phenomenon in this model.

Increased popliteal circumferential wall tension induced by orthostatic body posture is associated with local atherosclerotic plaques

OBJECTIVE

Lower limb arteries are exposed to higher hemodynamic burden in erectile posture. This study evaluated the effects of body posture on popliteal, carotid and brachial circumferential wall tension (CWT) and investigated the relationship between local CWT and atherosclerotic plaques in subjects with cardiovascular risk factors.

METHODS

Two hundred and three subjects (118 women and 85 men) with cardiovascular risk factors (smoking, hypertension or diabetes mellitus) underwent clinical and laboratory analysis and had their blood pressure measured in the arm and calf in supine and orthostatic positions. Arteries were evaluated by ultrasound analysis, while CWT was calculated according to Laplace's law.

RESULTS

Among the enrolled participants, 47%, 29% and none presented popliteal, carotid and brachial plaques, respectively. Carotid CWT measurements were not associated with local plaques after adjustment for potential confounders. Conversely, general linear model and logistic regression analyses adjusted for potential confounders demonstrated that peak orthostatic CWT was the only local hemodynamic parameter showing significant relationship with popliteal plaques in the whole sample. In gender-specific analyses, although positively correlated with popliteal plaques in both genders, local peak orthostatic CWT exhibited an independent association with popliteal plaques after adjustment for potential confounders only in women.

CONCLUSION

Popliteal CWT measured in orthostatic posture, rather than in supine position, is associated with popliteal atherosclerotic plaques, particularly in women. These findings suggest that erectile posture might play a role in the atherogenesis of leg arteries by modifying local hemodynamic forces and that there may be gender differences in this regard.

The combination of carotid and lower extremity ultrasonography increases the detection of atherosclerosis in type 2 diabetes patients

OBJECTIVE

To evaluate the prevalence of atherosclerosis detected by both carotid and lower extremity ultrasonography in hospitalized Chinese type 2 diabetic patients and to examine whether plaque formation in the carotid arteries could be an indicator of generalized atherosclerosis in type 2 diabetes mellitus.

METHODS

Totally, 709 hospitalized Chinese type 2 diabetic patients (men 357, women 352) aged from 18 to 88 years were included. Both carotid and lower extremity atherosclerosis were assessed by Doppler ultrasound. Atherosclerosis was defined as the presence of either the carotid or lower extremity plaque in any of the above-mentioned arteries segments. The prevalence of atherosclerosis was calculated, and the risk factors associated with atherosclerosis were evaluated using binary logistic regression.

RESULTS

The prevalence of atherosclerosis was 81.23% in male and 77.56% in female type 2 diabetic patients, respectively. There was no significant difference in the prevalence of atherosclerosis in patients between the sexes. The prevalence of atherosclerosis was significantly higher in the lower extremity arteries than in the carotid arteries (73.91% and 44.43%, respectively, P<.001). Atherosclerosis was significantly associated with smoking, age, duration of diabetes, systolic blood pressure, total number of white blood cells, and mean carotid and femoral intima-media thickness (IMT).

CONCLUSIONS

The prevalence of atherosclerosis was very high in Chinese inpatients with type 2 diabetes. Carotid atherosclerosis could not be an indicator of generalized atherosclerosis in type 2 diabetes. The combination of carotid and lower extremity ultrasound examination can significantly improve the detection of atherosclerosis in type 2 diabetes.

Association of systemic inflammatory activity with coronary and carotid atherosclerosis in the very elderly

OBJECTIVE

To verify the existence of association between plasma levels of pro- or anti-inflammatory mediators and atherosclerotic burden at coronary and carotid arteries in individuals aged of 80 or more years old.

METHODS

Healthy individuals aged between 80 and 102 years old (n = 178) underwent evaluation of plasma cytokines and acute phase proteins, intima-media thickness (IMT) and presence of plaques in carotid arteries by ultrasound and coronary artery calcification (CAC) by cardiac computed tomography.

RESULTS

There was no association between CAC and carotid plaques (p = 0.8), maximum (p = 0.06) or mean IMT (p = 0.2). No association was found between the presence of carotid plaques and CRP (p = 0.4), TNF-α (p = 0.8) or IL-10 (p = 0.2). Likewise, individuals in the first three quartiles for CRP, TNF-α or IL-10 had similar values of CAC, mean and maximum IMT. In contrast, individuals above the 75th percentile for CRP or for TNF-α had enhanced maximum IMT (p = 0.017 and p < 0.0001) and CAC (p = 0.026 and p = 0.01) and subjects with IL-10 levels above the 75th percentile had lower maximum IMT (p = 0.027) and CAC (p = 0.006) as compared with those below this percentile. There was no difference in mean IMT for individuals above or below the 75th percentile for CRP, TNF-α or IL-10.

CONCLUSION

In very old individuals, CAC and maximum IMT were positively associated with systemic inflammatory activity only in those above the 75th percentile. The markers of atherosclerotic burden at coronary and carotid arteries were not related to each other and were distinctly associated with pro- and anti-inflammatory mediators, suggesting that atherosclerosis development is different in these vascular beds.

Correlation between carotid intimal/medial thickness and atherosclerosis: a point of view from pathology

A widely adopted surrogate for predicting rates of cardiovascular events involves measure of carotid intimal-medial thickness (CIMT) by B mode ultrasound, a technique available since the mid 1980s. The value of this modality remains in its ability to noninvasively assess cardiovascular risk beyond traditional factors identified by the Framingham risk score, and it is among the few available techniques for monitoring the effectiveness of pharmacotherapy on plaques. There are, however, existing limitations to this methodology. Perhaps the most important distinction is that IM thickness measurements are generally acquired in the common carotid artery, whereas advanced atherosclerotic disease occurs predominantly downstream in the internal carotid. Moreover, primary contributors to IM thickening are age and hypertension, which do not necessarily reflect the atherosclerotic process. Initiation of disease-related plaques begins as what is referred to as pathological intimal thickening; lesions characterized by the formation of lipid pools in the absence of a necrotic core. The eventual development of a necrotic core, however, is considered a key indicator of significant plaque advancement and recognized feature of lesion vulnerability. Necrotic cores are thought to arise from macrophage infiltration of lipid pools followed by secondary necrosis where defective clearance of debris, tissue disruption proteases, and intraplaque hemorrhage, likely contribute to its enlargement. Therefore, one of the primary limitations to CIMT is its inability to distinguish lesions with a necrotic core. Moreover, in most cases measures of plaque area or volume are generally considered better predictors of an inflammatory process consistent with atherosclerotic disease rather than intimal medial thickness.

Elderly patients with minimal common carotid atherosclerosis not infrequently have severe coronary atherosclerosis and myocardial infarction

BACKGROUND

The presence of discordances between common carotid and coronary atherosclerosis in the same individual has not been previously reported.

METHODS AND RESULTS

The subjects of the present study were 1,518 consecutive autopsy cases at a general geriatric hospital. All were aged 60 years or older (821 men, 697 women) with an average age of 80 years. The atherosclerotic index of the common carotid artery (CC-AI) and coronary stenotic index (CSI) were semi-quantitatively evaluated. The simple correlation coefficient between the CC-AI and CSI was 0.456 (p<0.0001). Among 689 cases with minimal common carotid atherosclerosis (CC-AI < or =2), 74 (11%) had severe coronary atherosclerosis (CSI > or =12), 68 (10%) had coronary heart disease, and 80 (12%) had pathologically-verified myocardial infarction (MI). Among those with minimal common carotid atherosclerosis, the serum total cholesterol level, diabetes mellitus, and history of smoking were significantly higher or more frequent in cases with a CSI > or =12 than in the patients with a CSI <12.

CONCLUSIONS

A considerable proportion of cases with minimal common carotid atherosclerosis had severe coronary atherosclerosis and MI. This discordance can potentially lead to an underestimation of coronary risks if normal common carotid morphology is obtained by ultrasound.

Vasa vasorum neovascularization and lesion distribution among different vascular beds in ApoE-/-/LDL-/- double knockout mice

OBJECTIVE

To increase understanding of the substantial variation in the incidence and distribution of atherosclerotic lesions among different vascular beds. In view of some evidence that there are different distributions of adventitial vasa vasorum (VV) in different vascular beds, and that this correlates with lesion formation, we explored this possible linkage in apoE-/-/LDL-/- double knockout mice, which develop VV at age beyond 16 weeks.

METHODS AND RESULTS

Samples from the aorta, coronary, pulmonary, carotid, and cerebral arteries in apoE-/-/LDL-/- double knockout mice at the age of 16-80 weeks (n=24) were scanned by micro-CT. Using those 3D images, we characterized plaque volume, vessel luminal diameter and VV luminal volume along the vessels. Results were complemented by histology. Advanced atherosclerotic lesions were found in the aorta, pulmonary artery and carotid artery. Occluded intramyocardial vessels (vessel diameter approximately 0.1mm) with concomitant myocardial infarctions were found without any evidence of adventitial VV neovascularization. VV luminal volume follows the order: aorta>pulmonary arteries>carotid arteries. VV were only observed in atherosclerotic diseased vessels with a lumen diameter>0.4mm. No atherosclerotic lesions, and no VV, were observed in cerebral arteries.

CONCLUSION

The spatial heterogeneity in the development of atherosclerotic lesions among different vascular beds is linked to appearance of VV and to vessel lumen diameter.

Experimental hypercholesterolemia differentially affects adventitial vasa vasorum and vessel structure of the left internal thoracic and coronary arteries

OBJECTIVE

Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the vasa vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial vasa vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial vasa vasorum in the left internal thoracic and coronary arteries.

METHODS

Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, vasa vasorum count, vasa vasorum density, mean diameter of first- and second-order vasa vasorum, and second-order/first-order vasa vasorum ratio.

RESULTS

Vasa vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher vasa vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order vasa vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery.

CONCLUSION

This study demonstrated that low vasa vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.

Athero-express: Differential atherosclerotic plaque expression of mRNA and protein in relation to cardiovascular events and patient characteristics. Rationale and design

In clinical practice, biological markers are not available to routinely assess the progression of atherosclerotic disease or the development of restenosis following endarterectomy or catheter based interventions. Endarterectomy procedures provide an opportunity to study mechanisms of restenosis and progression of atherosclerotic disease since atherosclerotic tissue is obtained. Athero-Express is an ongoing prospective study, initiated in 2002, with the objective to investigate the etiological value of plaque characteristics for long term outcome. Patients are included who undergo an endarterectomy of the carotid artery. At baseline blood is withdrawn, patients fill in an extensive questionnaire and diagnostic examinations are performed. Atherosclerotic plaques are freshly harvested, immunohistochemically stained and examined for the presence of macrophages, smooth muscle cells, collagen and fat. Parts of the atherosclerotic plaques are freshly frozen to study protease activity and protein and RNA expressions. Patients undergo a duplex follow up to assess procedural restenosis (primary endpoint) at 3 months, 1 year and 2 years. Secondary endpoints encompass major adverse cardiovascular events. In the future, the creation of this biobank with atherosclerotic specimen will allow the design of cross-sectional and follow up studies with the objective to investigate the expression of newly discovered genes and proteins and their interaction with patients and plaque characteristics in the progression of atherosclerotic disease. Objective is to include 1000-1200 patients in 5 years. In January 2004, 289 patients had been included. It is expected that 250 patients will be included yearly.

Adventitial vasa vasorum heterogeneity among different vascular beds

INTRODUCTION

Different vascular beds show substantial variation in their susceptibilities for development of vascular disease like atherosclerosis, and thereby exhibit a variety of different clinical presentations. Yet, the underlying mechanism of this heterogeneity is not well defined. Recent evidence suggests a role for the vasa vasorum (VV) in vascular disease. We hypothesized that there is a differential distribution structure of adventitial VV in different vascular beds. Hence, the current study was designed to characterize and compare the structure of the adventitial VV in the coronary and the peripheral circulation.

METHODS

Samples of vessels from different vascular beds were obtained from 6 female crossbred domestic pigs. The samples were scanned using micro-computed tomography, and the images reconstructed and analyzed to characterize VV architecture, including vessel wall area, VV count, VV density, intravessel spatial distribution, mean diameter of first- and second-order VVs and the ratio of second- to first-order VVs.

RESULTS

There were significant differences in VV density among different vascular beds. Density was highest in coronary arteries (2.91 +/- 0.26 vessels/mm2, P <.05, vs renal, carotid, and femoral arteries), intermediate in renal arteries (1.45+/- 0.22 vessels/mm2, P <.05, vs femoral artery) and carotid arteries (0.64 +/- 0.08 vessels/mm2, P <.05, vs femoral artery), and lowest in femoral arteries (0.23 +/- 0.05 vessels/mm2 ). A similar pattern for the ratio of second- to first-order VV was also observed. Random intravessel spatial distribution of VVs was seen in all vascular beds.

CONCLUSION

The current study demonstrates a differential structure of the adventitial VV in different vascular beds. This intra- and intervessel heterogeneity in VV anatomy is a phenotypic variability that might determine a differential local response to systemic risk factors and, thereby, variable propensity for vascular disease among different vascular beds.

Dynamic contrast-enhanced MR angiography from the distal aorta to the ankle joint with a step-by-step technique

OBJECTIVE

The aim of this study was to visualize the arteries from the distal aorta to the ankle joint and to determine the accuracy of MR angiography for detecting stenoses and occlusions.

SUBJECTS AND METHODS

Twenty-four patients with peripheral arterial occlusive disease underwent digital subtraction angiography and were examined on a 1.5-T MR scanner. The transit time for contrast material was determined with a test bolus injection. A T1-weighted three-dimensional gradient-echo sequence with short TR and TE was used for a dynamic measurement at the level of the iliac arteries, the upper leg, and the lower leg arteries. For each level a single dose of gadolinium was injected into an antecubital vein with an MR power injector. Maximal-intensity-projection reconstructions were calculated after subtraction of the first measurement at each level. Two experienced MR radiologists who were unaware of the digital subtraction angiography results interactively evaluated both the MIP reconstructions and the single slices on a workstation, first independently and then in a consensus interpretation.

RESULTS

With digital subtraction angiography, 80 hemodynamically significant stenoses and 39 occlusions were detected. For the stenoses and occlusions, a sensitivity of 100% was found for MR angiography. The specificity for the assessment of stenoses and occlusions was 98% and 94%, respectively, for the iliac arteries; 98% and 94%, respectively, for the upper leg arteries; and 94% and 95%, respectively, for the lower leg arteries. Most false-positive findings of occlusion were due to metal stents present in the iliac (n = 3) and upper leg (n = 4) arteries.

CONCLUSION

The MR imaging technique that we used revealed the arteries from the distal aorta to the ankle and proved to be reliable at showing arterial stenoses and occlusions.

Impaired fetal growth and atherosclerosis of carotid and peripheral arteries

BACKGROUND

Although epidemiological studies suggest that people with low birthweight are at higher risk of coronary heart disease and stroke in adult life than those of higher birthweight, the mechanisms underlying this relation are unclear. We investigated whether impaired fetal growth leads to an increased risk of atherosclerosis by assessment of the carotid and lower-limb arteries in a group of people aged around 70 years for whom birthweight data were available.

METHODS

2232 singleton babies were born to married mothers at a maternity hospital in Sheffield, UK, between 1922 and 1926, and had complete birth records. We traced 829 survivors and invited 395 who still lived in Sheffield to take part in this study. 322 agreed; they were interviewed at home and 181 underwent duplex ultrasonographic examination of the extracranial parts of the carotid arteries. Atherosclerosis in the arteries of the lower limb was assessed in 186 people by the ankle-brachial-pressure index (ABPI).

FINDINGS

The prevalence and severity of carotid atherosclerosis was greatest in those with the lowest recorded birthweight. The risk of carotid stenosis was greater for people who had weighed 6.5 lb or less at birth than for those who weighed over 7.5 lb (odds ratio 5.3 [95% CI 2.0-14.0]), after adjustment for cardiovascular risk factors and gestational age at birth. The odds ratio for atherosclerotic disease in the lower limbs (low ABPI) was highest in people with the lowest recorded birthweight, but this relation was not significant (odds ratio 2.3 [1.0-5.6]).

INTERPRETATION

Increased atherogenesis may be one mechanism mediating the observed epidemiological link between impaired fetal growth and cardiovascular disease. Adaptations made by the fetus in response to influences that retard its growth may have long-term consequences for the structure and metabolism of the vascular system.