The echogenecity of the intima–media complex in the common carotid artery is closely related to the echogenecity in plaques

Amyloid beta is associated with carotid wall echolucency and atherosclerotic plaque composition

Circulating amyloid-beta 1-40 (Αb40) has pro-atherogenic properties and could serve as a biomarker in atherosclerotic cardiovascular disease (ASCVD). However, the association of Ab40 levels with morphological characteristics reflecting atherosclerotic plaque echolucency and composition is not available. Carotid atherosclerosis was assessed in consecutively recruited individuals without ASCVD (n = 342) by ultrasonography. The primary endpoint was grey scale median (GSM) of intima-media complex (IMC) and plaques, analysed using dedicated software. Vascular markers were assessed at two time-points (median follow-up 35.5 months). In n = 56 patients undergoing carotid endarterectomy, histological plaque features were analysed. Plasma Αb40 levels were measured at baseline. Ab40 was associated with lower IMC GSM and plaque GSM and higher plaque area at baseline after multivariable adjustment. Increased Ab40 levels were also longitudinally associated with decreasing or persistently low IMC and plaque GSM after multivariable adjustment (p < 0.05). In the histological analysis, Ab40 levels were associated with lower incidence of calcified plaques and plaques without high-risk features. Ab40 levels are associated with ultrasonographic and histological markers of carotid wall composition both in the non-stenotic arterial wall and in severely stenotic plaques. These findings support experimental evidence linking Ab40 with plaque vulnerability, possibly mediating its established association with major adverse cardiovascular events.

A comparison of intima media thickness in the common carotid artery, the bulb and plaque area as predictions of incident atherosclerotic events

BACKGROUND AND AIMS

There is a debate on how to evaluate carotid artery intima-media thickness (IMT). We here compared IMT of the common carotid artery (CCA) and bulb with plaque area regarding incident atherosclerotic disease.

METHODS

In the PIVUS study (age 70 at baseline, 53% women, n = 856), IMT-CCA, IMT-bulb and plaque area were measured at ages 70, 75 and 80 years and these three measurements were used in updated Cox proportional hazard analysis.

RESULTS

Over 15 years follow-up, 135 individuals experienced a first-time atherosclerotic disease (myocardial infarction or ischemic stroke). IMT-CCA was not significantly related to this composite endpoint (p = 0.10). IMT-bulb was significantly related to the endpoint (p = 0.003), but this relationship was attenuated following adjustment for CVD risk factors (p = 0.02). On the contrary, plaque area was consistently related to incident atherosclerotic disease also following adjustment for CVD risk factors (p<0.001). When added on top of traditional risk factors, both IMT-bulb and plaque area, but not IMT-CCA, improved the discrimination compared to the traditional risk factors (+5.2%, p = 0.0026 for IMT-bulb, +3.8%, p = 0.013 for plaque area and 0.0% for IMT-CCA).

CONCLUSION

In elderly subjects, both IMT-bulb and plaque area improved the discrimination regarding incident atherosclerotic disease when added to traditional risk factors. This was not seen for IMT-CCA. IMT-CCA was therefore inferior compared to the other two carotid artery ultrasonographic measurements in this sample of elderly subjects.

Plasma levels of per- and polyfluoroalkyl substances (PFAS) and cardiovascular disease - Results from two independent population-based cohorts and a meta-analysis

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals that have been linked to increased cholesterol levels and thus may have a role in the development of cardiovascular disease (CVD).

OBJECTIVES

To investigate associations between PFAS exposure and incident CVD (a combined CVD end-point consisting of myocardial infarction, ischemic stroke, or heart failure) in two independent population-based cohorts in Sweden. In addition, we performed a meta-analysis also including results from previous studies.

METHODS

In 2,278 subjects aged 45-75 years from the EpiHealth study, the risk of incident CVD in relation to relative plasma levels of perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) was investigated. Associations between plasma levels of six PFAS and incident CVD were also examined in the PIVUS-study (n = 1,016, all aged 70 years). In addition, a meta-analysis was performed including three previous prospective studies, together with the results from the present study.

RESULTS

There were no overall statistically significant associations between levels of the different PFAS and incident CVD, neither in EpiHealth nor in PIVUS. However, there was a significant sex interaction for PFOS in EpiHealth (p = 0.008), and an inverse association could be seen only in men (Men, HR: 0.68, 95 % CI: 0.52, 0.89) (Women, HR: 1.13, 95 % CI: 0.82, 1.55). A meta-analysis of five independent studies regarding PFOA and incident CVD showed a risk ratio (RR) of 0.80 (CI: 0.66, 0.94) when high levels were compared to low levels.

CONCLUSIONS

This longitudinal study using data from two population-based cohort studies in Sweden did not indicate any increased risk of incident CVD for moderately elevated PFAS levels. A meta-analysis of five independent cohort studies rather indicated a modest inverse association between PFOA levels and incident CVD, further supporting that increasing PFAS levels are not linked to an increased risk of CVD.

Changes in carotid artery texture by ultrasound and elastin features in a murine model

OBJECTIVE

In humans, arterial grayscale ultrasound texture features independently predict adverse cardiovascular disease (CVD) events and change with medical interventions. We performed this study to examine how grayscale ultrasound texture features and elastin fibers change in plaque-free segments of the arterial wall in a murine model prone to atherosclerosis.

METHODS

A total of 10 Apoetm1Unc/J mice (n = 5 male, n = 5 female) were imaged at 6, 16, and 24 weeks of age. Two mice were euthanized at 6 and 16 weeks and the remaining mice at 24 weeks. Texture features were extracted from the ultrasound images of the distal 1.0 mm of the common carotid artery wall, and elastin measures were extracted from histology images. Two-way analysis of variance was used to evaluate associations between week, sex, and grayscale texture features. Texture feature and elastin number comparisons between weeks were conducted using the sex-by-week two-way interaction contrasts. Sex-specific correlations between the number of elastin fibers and grayscale texture features were analyzed by conducting non-parametric Spearman's rank correlation analyses.

RESULTS

Arterial wall homogeneity changed significantly in male mice from 6 to 24 weeks, with a mean (SD) of 0.14 (0.03) units at 6 weeks and 0.18 (0.03) units at 24 weeks (p = 0.026). Spatial gray level dependence matrices-homogeneity (SGLD-HOM) also correlated with carotid artery plaque score (rs = 0.707, p = 0.033). Elastin fibers in the region of interest decreased from 6 to 24 weeks for both male and female mice, although only significantly in male mice. The mean (SD) number of elastin fibers for male mice was 5.32 (1.50) at 6 weeks and 3.59 (0.38) at 24 weeks (p = 0.023). For female mice, the mean (SD) number of elastin fibers was 3.98 (0.38) at 6 weeks and 3.46 (0.19) at 24 weeks (p = 0.051).

CONCLUSION

Grayscale ultrasound texture features that are associated with increased risk for CVD events in humans were used in a murine model, and the grayscale texture feature SGLD-HOM was shown to change in male mice from 6 weeks to 24 weeks. Structural alterations of the arterial wall (change in elastin fiber number) were observed during this time and may differ by sex.

Large-Scale Metabolomics and the Incidence of Cardiovascular Disease

Background The study aimed to show the relationship between a large number of circulating metabolites and subsequent cardiovascular disease (CVD) and subclinical markers of CVD in the general population. Methods and Results In 2278 individuals free from CVD in the EpiHealth study (aged 45-75 years, mean age 61 years, 50% women), 790 annotated nonxenobiotic metabolites were measured by mass spectroscopy (Metabolon). The same metabolites were measured in the PIVUS (Prospective Investigation of Vasculature in Uppsala Seniors) study (n=603, all aged 80 years, 50% women), in which cardiac and carotid artery pathologies were evaluated by ultrasound. During a median follow-up of 8.6 years, 107 individuals experienced a CVD (fatal or nonfatal myocardial infarction, stroke, or heart failure) in EpiHealth. Using a false discovery rate of 0.05 for age- and sex-adjusted analyses and P<0.05 for adjustment for traditional CVD risk factors, 37 metabolites were significantly related to incident CVD. These metabolites belonged to multiple biochemical classes, such as amino acids, lipids, and nucleotides. Top findings were dimethylglycine and N-acetylmethionine. A lasso selection of 5 metabolites improved discrimination when added on top of traditional CVD risk factors (+4.0%, P=0.0054). Thirty-five of the 37 metabolites were related to subclinical markers of CVD evaluated in the PIVUS study. The metabolite 1-carboxyethyltyrosine was associated with left atrial diameter as well as inversely related to both ejection fraction and the echogenicity of the carotid artery. Conclusions Several metabolites were discovered to be associated with future CVD, as well as with subclinical markers of CVD. A selection of metabolites improved discrimination when added on top of CVD risk factors.

Comparison of Cardiovascular Disease Risk Factors Between 2 Subclinical Atherosclerosis Measures in Healthy Postmenopausal Women: Carotid Artery Wall Thickness and Echogenicity: Carotid Artery Wall Thickness and Echogenicity

OBJECTIVES

Although carotid artery intima media thickness (CIMT) is a widely used determinant of subclinical atherosclerosis, gray-scale median of the intima-media complex (IM-GSM) of the common carotid artery is a relatively novel measure of echogenicity reflecting composition of the arterial wall. It is important to compare cardiovascular disease (CVD) risk factor correlates across CIMT and IM-GSM to determine whether these measures reflect distinct aspects of atherosclerosis.

METHODS

Baseline information from a completed randomized clinical trial of 643 healthy postmenopausal women without clinically apparent CVD was included in this cross-sectional study. The women were on average ± SD 61 ± 7 years old, and predominantly non-Hispanic White. CIMT and IM-GSM were measured by high-resolution B-mode ultrasonogram in the far wall of the right common carotid artery. CVD risk factors including age, race, body mass index (BMI), smoking, weekly hours of physical activity, systolic (SBP) and diastolic blood pressure (DBP), lipids, glucose, and inflammatory markers were measured at baseline. Linear regression models were used to assess associations of CVD risk factors with CIMT and IM-GSM. Multivariable models included groups of risk factors added one at a time with and withoutbasic demographic factors (age, race, BMI, physical activity) with model R2 values compared between CIMT and IM-GSM.

RESULTS

In multivariable analysis, age, Black race, BMI, SBP, and DBP were associated with CIMT (all P < .05), whereas age, Hispanic race, BMI, SBP, physical activity, LDL-cholesterol, and leptin were correlates of IM-GSM (all P < .05). Adjusted for age, race, BMI, and physical activity, the R2 value for SBP was greater for CIMT association, whereas R2 values for lipids, glucose, inflammatory markers, and adipokines were greater for IM-GSM associations.

CONCLUSIONS

CIMT and IM-GSM assess different attributes of subclinical atherosclerosis. Integrating both measures may provide improved assessment of atherosclerosis in asymptomatic individuals.

Effect of menopausal hormone therapy on arterial wall echomorphology: Results from the Early versus Late Intervention Trial with Estradiol (ELITE)

OBJECTIVE

To evaluate the effect of hormone therapy (HT) on arterial wall composition by ultrasound.

BACKGROUND

The effect of HT on the progression of subclinical atherosclerosis has been well-described using measurements of common carotid artery (CCA) wall thickness. However, it is unknown whether the change in arterial wall anatomic structure is accompanied by an effect of HT on arterial wall composition.

METHODS

A total of 643 healthy postmenopausal women divided into two strata according to the time since menopause (<6 years, the early-postmenopause group; or >10 years, the late-postmenopause group) were randomized to receive either active treatment or placebo. For hysterectomized women, the active treatment was oral micronized 17β-estradiol 1 mg/day; for women with a uterus, 4% vaginal micronized progesterone gel 45 mg/day for 10 days each month was added to the estradiol regimen. Gray-scale median of the CCA intima-media complex (IM-GSM), a (unitless) measurement of arterial wall composition based on echogenicity, was determined by high-resolution B-mode ultrasonography. Lower IM-GSM, or less echogenicity, indicates more atherosclerosis. IM-GSM and serum estradiol (E2) concentration were assessed every 6 months over a median 4.8-year trial period. Linear mixed effects regression models were used for all analyses.

RESULTS

Overall, IM-GSM progression/year had a negative trajectory, reflecting reduction in echogenicity over time (worsening atherosclerosis). HT effects on IM-GSM progression/year differed by postmenopause strata (interaction p-value = 0.02). IM-GSM progression/year (95% CI) in the early postmenopause group randomized to HT was -0.50 (-0.82, -0.18)/year compared with -1.47 (-1.81, -1.13)/year among those randomized to placebo (p-value <0.0001). In the late postmenopause group, the annual IM-GSM progression rate did not significantly differ between HT and placebo (p = 0.28). Higher mean on-trial E2 (pg/ml) levels were associated with higher IM-GSM progression, indicating less atherosclerosis progression in all women (β (95% CI) = 0.006 (0.0003, 0.01), p = 0.04). For each pg/dl E2, IM-GSM progression/year was 0.007 ((-0.0002, 0.01), p = 0.056) in the early and 0.003 ((-0.006, 0.01), p = 0.50) in the late postmenopause group (interaction p-value = 0.51). CIMT progression rate (μm/year) was significantly inversely associated with the IM-GSM progression (β (95% CI) = -4.63 (-5.6, -3.7), p < 0.001).

CONCLUSIONS

HT, primarily with oral estradiol, reduced atherogenic progression of arterial wall composition in healthy postmenopausal women who were within 6 years from menopause.

TRIAL REGISTRATION NUMBER

NCT01553084.

The metabolomic profile of carotid artery intima-media thickness and echogenicity

BACKGROUND AND AIMS

Nuclear magnetic resonance (NMR)-based metabolomics analyses have defined the lipoprotein profile of carotid artery intima-media thickness (IMT) in detail. In this study, the aim was to use multi-modal mass spectroscopy (MS) to relate multiple metabolites from different chemical classes to IMT and also to the echogenicity of the intima-media complex (IM-GSM).

METHOD

Multi-modal MS with 791 annotated non-xenobiotic metabolites was measured in two different population-based samples (PIVUS at age 80, n = 586 and POEM at age 50, n = 495) in which also carotid IMT and IM-GSM have been assessed by ultrasound.

RESULTS

Four metabolites were significantly (false discovery rate, FDR<0.05) related to IMT in a meta-analysis of POEM and PIVUS. The top finding was adenosine 3',5'-cyclic monophosphate (cAMP), being inversely related to IMT. Fifty metabolites were significantly related to IM-GSM in a meta-analysis of POEM and PIVUS. The top findings were branched-chained amino acids (BCAA), fructosyllysine, metabolonic lactone sulfate, a ceramide together with some sphingomyelins and phosphatidylcholines. All these top findings represented inverse relationships. Two metabolites identified by lasso regression in PIVUS increased discrimination of an echolucent IM-GSM by 3.3% in POEM compared to traditional cardiovascular risk factors (p = 0.020).

CONCLUSIONS

IMT, especially IM-GSM, was related to multiple metabolites from different chemical classes. Although such metabolites improved the discrimination of an echolucent IM-GSM, it remains to be investigated if any of those metabolites are involved in the pathogenesis of carotid arteriopathy.

Association of Intima-Media Texture With Prevalence of Clinical Cardiovascular Disease

Recent studies have suggested that textural characteristics of the intima-media complex (IMC) may be more useful than the intima-media thickness (IMT) in evaluating cardiovascular risk. The primary aim of our study was to investigate the association between texture features of the common carotid IMC and prevalent clinical cardiovascular disease (CVD). The secondary aim was to determine whether IMT and IMC texture features vary between the left and right carotid arteries. The study was performed on 2208 longitudinal-section ultrasound images of the left (L) and right (R) common carotid artery (CCA), acquired from 569 men and 535 women out of which 125 had clinical CVD. L and R sides of the IMC were intensity normalized and despeckled. The IMC was semiautomatically delineated for all images using a semiautomated segmentation system, and 61 different texture features were extracted. The corresponding IMT semiautomated measurements (mean±SD) of the L and R sides were 0.73±0.21 mm/0.69±0.19 mm for the normal population and 0.83±0.17 mm/0.79±0.18 mm for those with CVD. IMC texture features did not differ between the right- and left-hand sides. Several texture features were independent predictors of the presence of CVD. The multivariate logistic regression analysis combining age, IMT, and texture features produced a receiver operating characteristic curve with an area under the curve of 89%. A correct classification rate of 77% for separating the normal subject (NOR) versus CVD subjects was achieved using the support vector machine classifier with a combination of clinical features, IMT, and extracted texture features. Texture features provide additional information on the presence of clinical CVD, which is over and above that provided by conventional risk factors or IMT alone. The value of IMC texture features in the prediction of future cardiovascular events should be tested in prospective studies.

Effect of new statin treatment on carotid artery intima-media thickness: A real-life observational study over 10 years

BACKGROUND AND AIMS

Randomized clinical trials (RCT) have shown statin treatment to slow down the increase in carotid artery intima-media thickness (IMT) seen with ageing. However, those RCTs usually have a limited follow-up (1-3 years). Here an observational study was used to investigate the real-life effect of new statin treatment over a 10-year follow-up.

METHODS

In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, 954 individuals all aged 70 years at baseline were investigated regarding carotid artery IMT three times during 10 years (n = 771 at age 75, and n = 591 at age 80).

RESULTS

At age 70, 503 subjects were statin-naïve and did not receive statin during the 10-year follow-up period (the never-statin group), while 197 subjects were statin-naïve but received statins during the follow-up period (the received-statin group). Low-density lipoprotein (LDL)-cholesterol increased over time in the never-statin group (+0.1 mmol/l, p = 0.0012), but decreased in the group receiving statin treatment (-1.1 mmol/l, p < 0.0001). The never-statin group increased significantly in IMT over the 10 years (+0.07 mm, p < 0.0001), while the numerical increase seen in the received-statin group was not significant (+0.02 mm, p = 0.22) A significant difference in the change in IMT over time was seen between the received-statin group and the never-statin group (p < 0.0001 for interaction between time and group, adjusted for a propensity score).

CONCLUSIONS

This real-life observational study showed that new statin treatment reduced the increase in IMT seen over 10 years compared to subjects not treated with statins.

A Multi-Cohort Metabolomics Analysis Discloses Sphingomyelin (32:1) Levels to be Inversely Related to Incident Ischemic Stroke

BACKGROUND AND PURPOSE

To search for novel pathophysiological pathways related to ischemic stroke using a metabolomics approach.

METHODS

We identified 204 metabolites in plasma by liquid chromatography mass spectrometry in 3 independent population-based samples (TwinGene, Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) and Uppsala Longitudinal Study of Adult Men). TwinGene was used for discovery and the other 2 samples were meta-analyzed as replication. In PIVUS, traditional cardiovascular (CV) risk factors, multiple markers of subclinical CV disease, markers of coagulation/fibrinolysis were measured and analyzed in relation to top metabolites.

RESULTS

In TwinGene (177 incident cases, median follow-up 4.3 years), levels of 28 metabolites were associated with incident ischemic stroke at a false discover rate (FDR) of 5%. In the replication (together 194 incident cases, follow-up 10 and 12 years, respectively), only sphingomyelin (32:1) was significantly associated (HR .69 per SD change, 95% CI .57-0.83, P value = .00014; FDR <5%) when adjusted for systolic blood pressure, diabetes, smoking, low density lipoportein (LDL)- and high density lipoprotein (HDL), body mass index (BMI) and atrial fibrillation. In PIVUS, sphingomyelin (32:1) levels were significantly related to both LDL- and HDL-cholesterol in a positive fashion, and to serum triglycerides, BMI and diabetes in a negative fashion. Furthermore, sphingomyelin (32:1) levels were related to vasodilation in the forearm resistance vessels, and inversely to leukocyte count (P < .0069 and .0026, respectively).

CONCLUSIONS

An inverse relationship between sphingomyelin (32:1) and incident ischemic stroke was identified, replicated, and characterized. A possible protective role for sphingomyelins in stroke development has to be further investigated in additional experimental and clinical studies.

A detailed lipoprotein profile in relation to intima-media thickness and echogenicity of three major arteries

OBJECTIVE

To investigate differences in risk-factor profile, with special emphasis on detailed characterization of the lipoprotein profile, for intima-media thickness (IMT) and echogenicity of the intima-media complex (IM-GSM) in three major arteries: the carotid, femoral and brachial arteries.

METHODS

IMT and IM-GSM were measured by ultrasound in the carotid, femoral and brachial arteries in 778 subjects, all aged 75 years (50% women), in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, in which a detailed lipoprotein profile was also determined by nuclear magnetic resonance spectroscopy.

RESULTS

First, IMT was considerably lower, and IM-GSM higher, in the brachial artery compared to the other two arteries. Second, IMT and IM-GSM in the arteries were related to each other. Third, significant different traditional risk-factor profiles were seen for both IMT and IM-GSM, with generally weaker relationships for IMT in the femoral and brachial arteries compared with the carotid artery. Fourth, the strength of associations between an atherogenic lipoprotein profile and IMT in the carotid artery was attenuated in the femoral artery and virtually absent in the brachial artery. Fifth, slightly different lipoprotein profiles were seen for IM-GSM in the three arteries.

CONCLUSION

Differences between the carotid, femoral and brachial artery IMT and IM-GSM were seen regarding the traditional risk factors, as well as the lipoprotein profile.

Carotid Artery Echolucency, Texture Features, and Incident Cardiovascular Disease Events: The MESA Study

Background We hypothesized that measures of common carotid artery echolucency and grayscale texture features were associated with cardiovascular disease ( CVD ) risk factors and could predict CVD events. Methods and Results Using a case-cohort design, we measured common carotid artery ultrasound images from 1788 participants in Exam 1 of the MESA study (Multi-Ethnic Study of Atherosclerosis) to derive 4 grayscale features: grayscale median, entropy, gray level difference statistic-contrast, and spatial gray level dependence matrices-angular second moment. CVD risk factor associations were determined by linear regression. Cox proportional hazard models with inverse selection probability weighting and adjustments for age, sex, race/ethnicity, CVD risk factors, and C-reactive protein were used to determine if standardized values for grayscale median, entropy, gray level difference statistic-contrast, and spatial gray level dependence matrices-angular second moment could predict incident coronary heart disease, stroke, and total CVD events over a median 13 years follow-up. Participants were mean ( SD ) 63.1 (10.3) years of age, 52.6% female, 32.1% white, 27.8% black, 23.3% Hispanic, and 16.8% Chinese. There were 283 coronary heart disease, 120 stroke, and 416 CVD events. Several associations of grayscale features with CVD risk factors were identified. In fully adjusted models, higher gray level difference statistic-contrast was associated with a lower risk of incident coronary heart disease (hazard ratio 0.82, 95% CI 0.71-0.94, padj=0.005) and CVD events (hazard ratio 0.87, 95% CI 0.77-0.98, padj=0.018); higher spatial gray level dependence matrices-angular second moment was associated with a higher risk of CVD events (hazard ratio 1.09, 95% CI 1.00-1.19, padj=0.044). Conclusions Gray level difference statistic-contrast and spatial gray level dependence matrices-angular second moment predicted CVD events independent of risk factors, indicating their potential use as biomarkers to assess future CVD risk.

Influence of Ultrasound System and Gain on Grayscale Median Values

OBJECTIVES

The purpose of this study was to determine the reliability of grayscale median (GSM) measurements across different ultrasound (US) systems and effects of gain on GSM values.

METHODS

Two vessels in a grayscale vascular phantom were imaged with 7 US systems at 3 gain settings. Two human participants were imaged at 3 gain settings. Each image was normalized, standardized, and segmented by expert and novice readers using grayscale analysis software. The concordance correlation coefficient (CCC) assessed agreement of GSM values for each system across gain settings and vessels and between readers. The intraclass correlation coefficient (ICC) assessed system-level reader concordance across gain settings and vessels. A general linear mixed model for repeated measures was used to assess within- and between-system mean GSM values.

RESULTS

Grayscale median measurements performed on images from the same US system yielded excellent (CCC) (95% confidence intervals): 0.85 (0.75, 0.92) to 0.96 (0.92, 0.98). ICC per system were 0.94 to 0.98 for the expert reader and 0.85 to 0.95 for the novice reader. Gain adjustments above and below an optimal setting contributed to significantly different intrasystem GSM values on 4 of 7 systems in the near zone and 5 of 7 systems in the far zone (P < .05). Intersystem GSM values differed on 5 of 7 systems (P < .05). Images from the human participants showed differences in GSM values at optimum gain values ± 10 dB/%.

CONCLUSIONS

Grayscale median measurements are highly reproducible when obtained from the same US system with similar gain settings. Grayscale median values differ significantly across gain values and between systems. Researchers should consider the impact of US system and gain settings on GSM values when working to minimize system- and operator-dependent factors.

Ultrasound carotid plaque features, cardiovascular disease risk factors and events: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

It is not known if ultrasound carotid plaque features are associated with cardiovascular disease (CVD) risk factors or if they predict future CVD events.

METHODS

We measured total carotid plaque area (TPA) and grayscale plaque features (grayscale median, black areas, and discrete white areas) by B-mode carotid ultrasound among 2205 participants who participated in the first (baseline) visit of the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine relationships between ultrasound plaque features and CVD risk factors at baseline. Cox proportional hazards models were used to assess if TPA, grayscale features, and carotid plaque score (number of arterial segments with a plaque) could predict incident coronary heart disease and cerebrovascular disease events over a mean follow-up of 13.3 years.

RESULTS

Participants were mean (standard deviation [SD]) 65.4 (9.6) years, 49% male, 39% White, 11% Chinese, 28% Black, and 22% Hispanic. Mean TPA 27.7 (24.7) mm², but no grayscale plaque features, was associated with CVD risk factors. In fully adjusted models, TPA but no grayscale features predicted incident coronary heart disease (CHD) events (HR 1.23; 95%CI 1.11-1.36; p<0.001), however, C-statistics for CHD were similar to carotid plaque score but less than for coronary artery calcium (CAC) scoring. Neither TPA nor grayscale features independently predicted cerebrovascular events.

CONCLUSIONS

In middle-aged adults free of known cardiovascular disease, TPA but not grayscale plaque features was associated with CVD risk factors and predicted incident CHD events. For CHD, prediction indices for TPA were similar to carotid plaque score but less than for CAC.

Carotid artery ultrasound texture, cardiovascular risk factors, and subclinical arterial disease: the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE

This pilot study determined if the ultrasound texture feature "contrast" was associated with cardiovascular disease (CVD) risk factors and subclinical arterial disease.

METHODS

We evaluated ultrasound images of the right common carotid artery (CCA) from a convenience sample of 151 participants and examined relationships between contrast, CVD risk factors, carotid intima-media thickness (IMT) and coronary artery calcium (CAC). Grey level difference statistics algorithms were used to evaluate the texture feature "contrast" from carotid ultrasound images. Right CCA IMT measurements were made in triplicate in the distal 1 cm segment of the far wall of the artery and CAC score was measured using the Agatston scoring method.

RESULTS

In individual models that included age, sex and race, grey level difference statistics contrast (outcome) was associated independently with age [beta (standard error) = -0.87 (0.38) per year; p = 0.02], C-reactive protein [-2.22 (0.96) per mg dl^-1; p = 0.02], high-density lipoprotein cholesterol [0.61 (0.24) per mg dl^-1; p = 0.01] and CCA IMT [-0.06 (0.02) microns; p = 0.001]. Other CVD risk factors and CAC were not associated independently with contrast.

CONCLUSION

These findings support the potential use of the ultrasound texture contrast for evaluating arterial injury and CVD risk. Advances in knowledge: This paper contributes to the literature in that it describes how the greyscale texture feature "contrast" is related to CVD risk factors.

Echogenicity of the carotid arterial wall in active smokers

This pilot study evaluated associations between carotid wall echogenicity, cardiovascular disease (CVD) risk factors, and three markers of smoking heaviness in a cohort of active smokers. Common carotid artery (CCA) grayscale median (GSM) values were measured from sonographic images. Univariable correlations and exploratory multivariable models were used to determine associations between CCA GSM, CVD risk factors, and measures of smoking heaviness. CCA GSM was measured in 162 smokers and was correlated inversely with cigarettes smoked/day (r=-0.16, p=0.048), pack-years (r=-0.204, p=0.009), CVD risk factors such as age, male sex, waist circumference, and low-density lipoprotein cholesterol (all p≤0.03) and positively with high-density lipoprotein cholesterol (p<0.001). Associations between CCA GSM and smoking heaviness markers were not statistically significant after adjustment for traditional risk factors. The results from this pilot study demonstrate the feasibility of measuring the GSM value of the CCA far wall and its association with measures of smoking heaviness and traditional CVD risk factors among current smokers.

Impact of physical activity on cardiovascular status in obesity

BACKGROUND

We have recently shown that being physically active (PA) counteracts, but not eliminates the increased risk of future cardiovascular disease in overweight and obese subjects. To investigate this further, we studied the impact of being normal weight, overweight and obese on multiple markers of subclinical cardiovascular disease in relation to physical activity.

MATERIALS AND METHODS

At age 70, 1016 subjects were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Being PA was defined as performing regular heavy exercise (self-reported). According to body mass index (BMI)/PA groups, the participants were categorized as PA/normal weight (BMI < 25 kg/m² , n = 104), non-PA/normal weight (n = 234), PA/overweight (BMI 25-29·9 kg/m² , n = 133), non-PA/overweight (n = 295), PA/obese (BMI ≥ 30 kg/m² , n = 54) and non-PA/obese (n = 169). Several different measurements of endothelial reactivity and arterial compliance (plethysmography and ultrasound), cartotid artery atherosclerosis and echocardiography were performed, and seven markers of coagulation/fibrinolysis were measured.

RESULTS

Physically active subjects with obesity showed impaired vasoreactivity in the forearm resistance vessels, increased left ventricular mass and impaired left ventricular systolic and diastolic functions, together with impaired coagulation/fibrinolysis when compared to PA/normal-weight subjects (P < 0·05 to <0·001). The majority of these disturbances were seen also in PA/overweight subjects when compared to PA/normal-weight subjects (P < 0·05 to <0·001).

CONCLUSIONS

Our data provide additional support for the notion that an increased level of self-reported physical activity does not fully eliminate the deleterious cardiovascular consequences associated with overweight and obesity.

Circulating levels of perfluoroalkyl substances (PFASs) and carotid artery atherosclerosis

BACKGROUND AND OBJECTIVE

During recent years, some persistent organic pollutants (POPs) have been linked to atherosclerosis. One group of POPs, the poly- and perfluoroalkyl substances (PFASs) have not been investigated with regard to atherosclerotic plaques.

METHODS

Carotid artery atherosclerosis was assessed by ultrasound in 1016 subjects aged 70 years in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Eight PFASs were detected in >75% of participants' plasma by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS).

RESULTS

No significant linear associations were observed between the PFASs and intima-media thickness (IMT), or the echogenicity in the intima-media complex (IM-GSM, a marker of lipid infiltration in the artery) when men and women were analyzed together. Neither was occurrence of carotid plaques related to PFASs levels. However, highly significant interactions were observed between some PFASs and sex regarding both IM-GSM and plaque prevalence. Perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), were all related to IM-GSM in a positive fashion in women (p=0.002-0.003), while these relationships were negative in men. The levels of PFUnDA were significantly related to carotid plaque in women (OR 1.59, 95%CI 1.03-2.43, p=0.03), but not in men (OR 0.93, 95%CI 0.62-1.42, p=0.75).

CONCLUSIONS

In this cross-sectional study, a pronounced gender difference was observed regarding associations between some PFASs, especially the long-chain PFUnDA, and markers of atherosclerosis, with more pronounced relationships found in women. These findings suggest a sex-specific role for PFASs in atherosclerosis.

Relation Between Adolescent Cardiovascular Risk Factors and Carotid Intima-Media Echogenicity in Healthy Young Adults: The Atherosclerosis Risk in Young Adults (ARYA) Study

Background

Echogenicity is an ultrasound measure that reflects arterial wall composition. In adult populations, lower carotid intima‐media echogenicity relates to an unfavorable cardiovascular risk burden yet appears to reflect a different aspect of arterial wall remodeling than carotid intima‐media thickness (CIMT). Since studies on carotid intima‐media echogenicity earlier in life are lacking, we investigated associations between adolescent cardiovascular risk factors and young adulthood carotid intima‐media echogenicity and compared this to CIMT.

Methods and Results

In 736 participants of the Atherosclerosis Risk in Young Adults study, information on adolescent anthropometrics, puberty stage, and systolic blood pressure (SBP) was available. In young adulthood, demographics, anthropometrics, and fasting plasma samples were collected. Common CIMT and echogenicity, quantified as gray‐scale median (GSM), were evaluated using B‐mode ultrasonography. Lower and higher GSM values, respectively, represented lower and higher echogenicity. Associations of adolescent body mass index and SBP with young adulthood GSM and CIMT were evaluated using linear regression analysis. Mean age was 13.5 years in adolescence and 28.4 years in young adulthood (difference: 14.9 years). After full adjustment, adolescent body mass index related to GSM (β=−1.62/SD; 95% CI: −2.79, −0.46; P=0.006), independent of CIMT. Adolescent SBP did not relate to GSM. Moreover, adolescent body mass index (β=8.06 μm/SD [95% CI: 4.12, 11.99], P<0.001) and SBP (β=4.69 μm/SD [95% CI: 0.84, 8.54], P=0.02) related to CIMT.

Conclusions

Adolescent body mass index related to GSM and CIMT in young adulthood; SBP only related to CIMT. Hence, carotid intima‐media echogenicity appears to be involved in arterial wall remodeling, yet may mimic a different facet of this process than CIMT.

Echogenicity of the Common Carotid Artery Intima-Media Complex in Stroke

The grey-scale median of the common carotid artery intima-media complex (IM-GSM) characterizes arterial wall composition, and a low IM-GSM is associated with increased cardiovascular mortality in the elderly. We aimed to determine differences in the IM-GSM between a cohort with cerebrovascular disease and a healthy cohort. Eighty-two healthy individuals (control group: 63.2 ± 8.7 y) and 96 patients with either stroke or transient ischemic attacks (CRVD group: 68.6 ± 9.8 y) were studied. Common carotid artery intima-media thickness and IM-GSM obtained by ultrasound were analyzed using semi-automated edge-detection software. The IM-GSM was significantly lower in the CRVD group than in the control group (106 ± 24 vs. 124 ± 27 au, p < 0.001). The IM-GSM was similar for the infarct and non-infarct sides in CRVD. In the pooled cohort of all participants, the lower the quartile of IM-GSM, the greater were the carotid artery intima-media thickness and carotid artery remodeling. These results suggest the presence of an altered atherosclerotic phenotype in the intima-media complex of CRVD patients that can be detected by ultrasound.

Common carotid intima-media features determine distal disease phenotype and vulnerability in asymptomatic patients

OBJECTIVES

There is a growing awareness of the importance of carotid plaque features evaluation in stroke prediction. Carotid intima-media thickness (IMT) and recently its echogenicity were used for stroke prediction, although their clinical relevance was not well determined. The aim of this study was to assess the relationship between common carotid artery (CCA) ultrasound markers of atherosclerosis and distal, bifurcation and internal carotid artery (ICA), plaque features.

METHODS

We analyzed 137 carotid arteries in 87 asymptomatic patients with known carotid disease (mean age 69 ± 6 year, 34.5% females). Intima media thickness (IMT) and its gray scale median (IM-GSM) were measured at the CCA. Plaque textural features including gray scale median (GSM), juxtaluminal black area (JBA-mm(2)) without a visible cap, and plaque coarseness, at bifurcation and ICA were also determined. CCA measurements were correlated with those of the distal plaques.

RESULTS

An increased IMT in CCA correlated with plaque irregularities in the bifurcation and ICA (r=0.53, p<0.001), while IM-GSM was closely related to plaque echogenicity (GSM) (r=0.76, p<0.001), and other textural plaque features. Both, IMT and IM-GSM correlated weakly with stenosis severity (r=0.27, p=0.001 and r=-0.18, p=0.026) respectively.

CONCLUSION

In asymptomatic patients, measurements of CCA reflect distal, bifurcation and ICA disease, with IMT reflecting plaque irregularities and IM-GSM as markers of textural plaque abnormalities. Integrating measurements of both IMT and IM-GSM in a model could be used as a better marker of disease vulnerability over and above each measure individually.

Influence of physical activity and gender on arterial function in type 2 diabetes, normal and impaired glucose tolerance

To determine whether Nordic walking improves cardiovascular function in middle-aged women and men, we included 121 with normal glucose tolerance, 33 with impaired glucose tolerance and 47 with Type 2 diabetes mellitus in a randomized controlled study. The intervention group added Nordic walking 5 h/week for 4 months to their ordinary activities. Aortic pulse wave velocity, aortic augmentation index, stiffness index, reflection index, intima-media thickness in the radial and carotid arteries, echogenicity of the carotid intima-media and systemic vascular resistance were measured. While baseline blood pressure did not differ by gender or diagnosis, aortic augmentation index was found to be higher in women in all groups. Vascular function was unchanged with intervention, without differences by gender or diagnosis. In conclusion, 4 months of Nordic walking is an insufficient stimulus to improve vascular function. Future studies should consider hard endpoints in addition to measures of vascular health, as well as larger population groups, long-term follow-up and documented compliance to exercise training.

Flow-mediated vasodilation over five years in the general elderly population and its relation to cardiovascular risk factors

BACKGROUND

Flow-mediated vasodilation (FMD) has previously been shown to be related to cardiovascular risk factors in cross-sectional studies. The present study aims to investigate how FMD changes over time, and determine whether this change is paralleled by changes in cardiovascular risk factors.

METHODS

Of the participants in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, 750 individuals had measurements made of FMD in the brachial artery both at the ages of 70 and 75 years. In addition, the change over the 5 years in carotid artery intima-media thickness (IMT) was monitored, as well as traditional cardiovascular risk factors.

RESULTS

While no significant change in FMD occurred during the 5-year period (+0.1%, p = 0.53), large changes could be seen at the individual level. The Framingham risk score (excluding the age-variable) increased during the follow-up period (+0.54, p < 0.001). This change was inversely related to the individual change in FMD (beta -0.15, 95% CI -0.29 to -0.0059, p = 0.041). Of the eight individual CV risk factors tested, the change in FMD was only related to the change in LDL-cholesterol (inversely, p = 0.0028). The change in FMD was not related to the change in IMT seen over the 5-year period (p = 0.41).

CONCLUSION

While no change was seen in the mean FMD over a five-year period in elderly subjects attending both examinations despite ageing and a change in several risk factors, the individual change was mainly related to the change in LDL-cholesterol, further emphasizing the important role of lipids to determine vasoreactivity.

Serum levels of monobenzylphthalate (MBzP) is related to carotid atherosclerosis in the elderly

BACKGROUND AND OBJECTIVE

Background exposure to environmental contaminants has recently emerged as a new risk factor for cardiovascular disease in general and to atheroclerosis in particular. This cross-sectional study was performed to evaluate if serum concentrations of the phthalate metabolite monobenzylphthalate (MBzP) are related to atheroclerosis in the carotid arteries.

METHODS

In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1003 subjects all aged 70) the prevalence of overt plaques and echogenicity (gray-scale median, GSM) of carotid artery plaques were recorded by ultrasound in both of the carotid arteries. The intima-media thickness (IMT) and echogenicity (IM-GSM) of the intima-media complex were also measured. The phthalate metabolite MBzP was analyzed in serum by a liquid chromatograph/tandem mass spectrometer.

RESULTS

The circulating level of the phthalate MBzP was related to intima-media thickness (IMT) when adjusting for gender, blood pressure, body mass index (BMI), waist circumference, HDL- and LDL-cholesterol, serum triglycerides, blood glucose and smoking (p=0.034). High levels of MBzP were also strongly associated with an echogenic IM-GSM and plaque GSM (p=0.0001 for both outcomes after adjustment) but not to plaque prevalence (p=0.42).

CONCLUSION

The phthalate metabolite MBzP was strongly related to the echogenicity of intima-media and plaques and also to IMT, independently of traditional CV risk factors. This suggests a role for the phthalate MBzP in the development of atherosclerosis.

Relationship between cardiovascular risk factors and the echogenicity and pattern of the carotid intima-media complex in men

CONTEXT AND OBJECTIVE

The thickness of the carotid intima-media complex (C-IMC) is considered to be a marker of early atherosclerosis, but visual and echogenic changes to the C-IMC can also be noted. The objective here was to evaluate the relationship between cardiovascular risk factors and the echogenicity of the C-IMC and identify those most associated with an "abnormal" C-IMC.

DESIGN AND SETTING

Cross-sectional study in the ultrasound sector of the Department of Diagnostic Imaging, Universidade Federal de São Paulo.

METHODS

Eighty men were evaluated. Measurements of arterial blood pressure, waist circumference (WC), lipid profile, fasting glucose, uric acid and high-sensitivity C-reactive protein were obtained. The thickness of the C-IMC was measured by means of B-mode ultrasound, and the intima-media gray-scale mean (IM-GSM) and standard deviation (IM-SD) were calculated.

RESULTS

The following were discriminating variables: fasting glucose (r2 = 0.036; P = 0.013), uric acid (r2 = 0.08; P = 0.03), IM-SD (r2 = 0.43; P < 0.001), IM-GSM (r2 = 0.35; P < 0.001) and thickness of the C-IMC (r2 = 0.29; P < 0.001). IM-GSM showed significant correlations with WC (r = -0.22; P = 0.005), fasting glucose (r = -0.24; P = 0.002) and high-density lipoprotein cholesterol (HDL-C) (r = 0.27; P = 0.0007).

CONCLUSION

IM-GSM showed correlations with WC, fasting glucose and HDL-C. However, uric acid and IM-SD presented the greatest discriminating impact. These results suggest that visual changes in C-IMC may help identify patients with potential cardiovascular risk, independently of the thickness of the C-IMC.

Total atherosclerotic burden by whole body magnetic resonance angiography predicts major adverse cardiovascular events

OBJECTIVE

The purpose of the present study was to investigate the relationship between the Total Atherosclerotic Score (TAS), a measurement of the overall atherosclerotic burden of the arterial tree by whole body magnetic resonance angiography (WBMRA), and the risk of major adverse cardiovascular events (MACE), defined as cardiac death, myocardial infarction, stroke and/or coronary revascularization, assuming that TAS predicts MACE.

METHODS AND RESULTS

305 randomly selected 70 year-old subjects (47% women) underwent WBMRA. Their atherosclerotic burden was evaluated and TAS > 0, that is atherosclerotic changes, were found in 68% of subjects. During follow-up (mean 4.8 years), MACE occurred in 25 subjects (8.2%). Adjusting for multiple risk factors, TAS was associated with MACE (OR 8.86 for any degree of vessel lumen abnormality, 95%CI 1.14-69.11, p = 0.037). In addition, TAS improved discrimination and reclassification when added to the Framingham risk score (FRS), and ROC (Receiver Operator Curve) increased from 0.681 to 0.750 (p = 0.0421).

CONCLUSION

In a population-based sample of 70 year old men and women WBMRA, with TAS, predicted MACE independently of major cardiovascular risk factors.

The echogenicity of the intima-media complex in the common carotid artery is related to insulin resistance measured by the hyperinsulinemic clamp in elderly men

The echogenicity of the intima-media complex (IM-GSM) has recently been shown to be related to the echogenicity in carotid artery plaque and to predict cardiovascular (CV) mortality. The present study aims to evaluate the relationship between metabolic CV risk factors, with special emphasis on insulin resistance, and IM-GSM in the carotid artery. Carotid artery ultrasound with grey-scale median analysis of the intima-media complex, IM-GSM, was performed in a population sample of 480 men aged 75 years. In these subjects, a euglycemic hyperinsulinemic clamp to investigate insulin resistance was performed together with measurements of conventional CV risk factors at the age of 70. The metabolic syndrome (MetS) was defined by the NCEP/ATPIII-criteria. In univariate analysis, IM-GSM in the common carotid artery was inversely correlated with the intima-media thickness (IMT), body mass index (BMI), waist/hip ratio, fasting glucose, serum triglycerides, low HDL cholesterol and insulin resistance at the clamp (r = -0·24, P<0·001). In multiple regression analysis, only insulin resistance at the clamp and BMI were independently related to IM-GSM. Subjects with the MetS (22%) showed a reduced IM-GSM when compared to those without (64 ± 20 SD versus 68 ± 19, P<0·05). Because the echogenicity of the intima-media complex in the carotid artery is related to obesity and insulin resistance at clamp independently of IMT, this new vascular characteristic would serve as a marker of vascular alterations induced by insulin resistance and the MetS and has the advantage to be obtainable in almost all subjects.

Clinical trial of a farnesyltransferase inhibitor in children with Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare, fatal, segmental premature aging syndrome caused by a mutation in LMNA that produces the farnesylated aberrant lamin A protein, progerin. This multisystem disorder causes failure to thrive and accelerated atherosclerosis leading to early death. Farnesyltransferase inhibitors have ameliorated disease phenotypes in preclinical studies. Twenty-five patients with HGPS received the farnesyltransferase inhibitor lonafarnib for a minimum of 2 y. Primary outcome success was predefined as a 50% increase over pretherapy in estimated annual rate of weight gain, or change from pretherapy weight loss to statistically significant on-study weight gain. Nine patients experienced a ≥50% increase, six experienced a ≥50% decrease, and 10 remained stable with respect to rate of weight gain. Secondary outcomes included decreases in arterial pulse wave velocity and carotid artery echodensity and increases in skeletal rigidity and sensorineural hearing within patient subgroups. All patients improved in one or more of these outcomes. Results from this clinical treatment trial for children with HGPS provide preliminary evidence that lonafarnib may improve vascular stiffness, bone structure, and audiological status.

Body composition, C-reactive protein, carotid artery remodeling and subclinical atherosclerosis in a general Taiwanese population

Obesity, an escalating problem worldwide, increases the risk of serious disease, particularly atherosclerosis. A community-based cross-sectional study was designed to screen for undetected atherosclerosis. High-sensitivity C-reactive protein (hs-CRP), the presence of the metabolic syndrome (MetS), and ultrasound studies to detect fatty liver and measure carotid intimal-medial thickness were performed. A total of 1,005 subjects (595 men and 410 women; mean age of 52.4 ± 11.1 years) were included in the final study cohort. 237 subjects (23.7%) fulfilled National Cholesterol Education Program Adult Treatment Panel ATP-III criteria for MetS. Significant differences between female and male subjects were noted in body mass index (BMI), % body fat mass (Fat%), waist-to-hip ratio, waist circumference, fasting glucose levels, triglyceride levels, fatty liver, and carotid artery changes (P < 0.05). When female subjects were classified by hs-CRP levels, significant differences were reported among the three groups in age, BMI, Fat%, waist-to-hip ratio, waist circumference, blood pressure, fasting glucose, HDL, triglycerides, fatty liver grade and common carotid artery changes (P < 0.05). In this study, high hs-CRP was associated with increased cholesterol and cardiovascular changes supporting the idea that it may be a useful biomarker for detecting early asymptomatic vascular and coronary heart disease resulting from obesity.

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.

Effect of rosuvastatin on the echolucency of the common carotid intima-media in low-risk individuals: the METEOR trial

BACKGROUND

The echolucency of the carotid intima-media is related to increased cardiovascular risk factor levels, morbidity, and mortality. The aim of this study was to assess the effect of statins on the echolucency of the common carotid intima-media in a low-risk population.

METHODS

Data from the Measuring Effects on Intima-Media Thickness: An Evaluation of Rosuvastatin study were used. Ultrasound images from the far walls of the left and right common carotid arteries were used for evaluation of the echolucency of the carotid intima-media, measured by grayscale median (GSM). Low GSM values reflect echolucent structures, whereas high values reflect echogenic structures. The primary end point was the difference in the annual rate of change in GSM between rosuvastatin and placebo.

RESULTS

Two-year change in GSM did not significantly differ between rosuvastatin and placebo in the total population, with a mean difference in the rate of change in GSM of 1.13 (95% confidence interval, -1.00 to 3.25). The effect of rosuvastatin differed across quintiles of baseline GSM values (P for interaction = .01). In the lowest quintile (n = 175) (i.e., in those with the most echolucent intima-media), the difference in the rate of change in GSM between rosuvastatin and placebo was 4.18 (95% confidence interval, -0.23 to 8.58). Increases in GSM were significantly related to decreasing low-density lipoprotein cholesterol levels in the lowest quintile (β = 0.76; 95% confidence interval, 0.26 to 1.25).

CONCLUSIONS

Treatment with rosuvastatin did not affect the echolucency of the arterial wall in all low-risk individuals. However, a potential effect of rosuvastatin on the echolucency of the common carotid intima-media is most likely to be found in individuals with echolucent arterial walls at baseline.

Arterial structure and function in mild primary hyperparathyroidism is not directly related to parathyroid hormone, calcium, or vitamin D

Objective

Elevated levels of calcium and parathyroid hormone (PTH), characteristics of primary hyperparathyroidism (PHPT), may be associated with cardiovascular morbidity and mortality in the general population. We evaluated the possible vascular effects of these risk factors in patients with mild PHPT by using standard methods and new imaging techniques.

Design

A prospective case-control study.

Subjects and Methods

Forty-eight patients with mild PHPT without any known cardiovascular risk factors were studied at baseline and at one year after parathyroidectomy (PTX) in comparison with 48 healthy age- and gender-matched controls. We measured biochemical variables, augmentation index (AIx), aortic pulse wave velocity (PWV_ao), radial (IMT_rad) and common carotid artery (IMT_cca) intima media thicknesses, and the grayscale median (IM-GSM) of the latter.

Results

No significant differences were observed between PHPT patients and controls at baseline for AIx (28.6±12.2 vs. 27.7±12.8%), IMT_rad (0.271±0.060 vs. 0.255±0.053 mm), IMT_cca (0.688±0.113 vs. 0.680±0.135 mm), or IM-GSM (82.3±17.2 vs. 86.5±15.3), while PWV_ao was slightly higher in patients (8.68±1.50 vs. 8.13±1.55, p<0.05). Systolic blood pressure (SBP), calcium, and PTH were higher in patients compared with controls, and decreased after PTX, while vitamin D was lower in patients and increased after PTX. While AIx, PWV_ao, IMT_rad, and IMT_cca were related to SBP, neither correlated to vitamin D levels. Only PWV_ao correlated weakly to plasma PTH (r = 0.29, p<0.01) and ionized calcium (r = 0.22, p<0.05) but showed no relation when age and SBP were adjusted for.

Conclusion

We found normal arterial function despite high calcium, PTH, and low vitamin D levels, in patients with mild PHPT without cardiovascular risk factors. The cardiovascular risk associated with low vitamin D and/or high PTH and calcium levels may be explained by their coupling to blood pressure and other risk factors rather than direct effects on arterial structure.

Echogenicity of the carotid intima-media complex and cardiovascular risk factors

INTRODUCTION

Increased carotid intima-media thickness (IMT) has been associated with increased risk of myocardial infarction (MI) and stroke. A measure of echogenicity, the grey scale median (GSM), has been shown to be inversely correlated with cardiovascular risk factors and to be predictive of mortality in a community-based cohort. We assessed the factors associated with carotid IM-GSM in younger, non-diabetic patients with a recent MI.

METHODS AND RESULTS

A total of 122 patients (women, 25%) aged 31-80 years (61) were recruited 2-3 days after an acute MI. Ultrasound examinations of the carotid arteries were performed 1-12 months after the MI. IMT was 0·78 (SD 0·17) mm on the right side and 0·81 (0·20) mm on the left side (P = 0·05). GSM was 88·60 (range 46-132, SD 18·32) on the right side and 82·10 (40-126, 17·89) on the left side (P = 0·002). Triglycerides (TG) correlated with GSM on both sides (right, r = -0·27, P = 0·003; left, r = -0·18, P = 0·05). On the right side, GSM was 92·15 and 82·26 (P = 0·05) in patients with TG < and ≥1·7, and on the left side, it was 84·04 and 74·55 (P = 0·02) in patients with TG < and ≥2·3. On multivariate analysis, TG were significantly associated with GSM, both on the right side (P = 0·01) and on the left side (P = 0·009).

CONCLUSION

We found a negative association between TG and carotid IM-GSM on both sides in patients with a recent MI. Our results also suggest that atherosclerosis progression may be faster on the left side in patients with coronary heart disease.

Circulating levels of metals are related to carotid atherosclerosis in elderly

The aim of this study was to investigate if blood levels of trace and/or heavy metals are related to atherosclerosis in a cross-sectional study in elderly. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects, all aged 70), the prevalence of carotid artery plaques was recorded by ultrasound. The numbers of carotid arteries with plaques (0, 1 or 2) were recorded. Also the thickness (IMT) and gray scale (IM-GSM) of the intima-media complex were measured together with plaque echogenicity. Eleven heavy metals and trace elements were analyzed in whole blood, using inductively coupled plasma-sector field mass spectrometry. Nickel levels were related to the number of carotid arteries with plaques in an inverted U-shaped manner after multiple adjustment for gender, waist circumference, body mass index, fasting blood glucose, systolic and diastolic blood pressure, HDL and LDL cholesterol, serum triglycerides, smoking, antihypertensive treatment and statin use (p=0.026). IM-GSM and plaque echogenicity were both inversely related to chromium in a linear fashion, and to aluminum in an inverted U-shaped manner (both p<0.0001 for IM-GSM). The relationships between metals and IMT were modest. Circulating levels of some metals, like nickel, aluminum and chromium, were related to atherosclerotic plaques or the echogenicity of the IM-GSM and overt plaques independently of cardiovascular risk factors, including lipids.

Circulating levels of persistent organic pollutants (POPs) and carotid atherosclerosis in the elderly

BACKGROUND AND OBJECTIVE

Increased circulating levels of persistent organic pollutants (POPs) have been associated with myocardial infarction. Because myocardial infarction is an atherosclerotic disease, we investigated, in a cross-sectional study, whether POP levels are related to atherosclerosis.

METHODS

In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (n = 1,016 participants 70 years of age), the prevalence of carotid artery plaques was determined by ultrasound. The number of carotid arteries with plaques (0, 1, or 2) was recorded. Also, the intima-media thickness (IMT) and gray scale median of the intima-media complex (IM-GSM) were measured. Twenty-three POPs, comprising 16 polychlorinated biphenyls (PCBs), 5 pesticides, 1 dioxin, and 1 brominated compound (brominated diphenyl ether congener BDE-47), were analyzed by high-resolution chromatography coupled to high-resolution mass spectrometry.

RESULTS

Seven of the POPs (PCB congeners 153, 156, 157, 170, 180, 206, and 209) were significantly associated with the number of carotid arteries with plaques even after adjusting for multiple risk factors (sex, waist circumference, body mass index, fasting blood glucose, systolic and diastolic blood pressure, high-density lipoprotein and low-density lipoprotein cholesterol, serum triglycerides, smoking, antihypertensive treatment, and statin use; p = 0.002-0.0001). Highly chlorinated PCBs (congeners 194, 206, and 209) were associated with an echolucent IM-GSM (p < 0.0001 after adjustment), whereas associations between POPs and IMT were modest.

CONCLUSIONS

Circulating levels of PCBs were associated with atherosclerotic plaques and echogenicity of the intima-media complex independent of cardiovascular risk factors, including lipids. This suggests that POPs may be a risk factor for myocardial infarction, but associations need to be confirmed in prospective studies.

Mechanisms of premature vascular aging in children with Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome is a rare, segmental premature aging syndrome of accelerated atherosclerosis and early death from myocardial infarction or stroke. This study sought to establish comprehensive characterization of the fatal vasculopathy in Hutchinson-Gilford progeria syndrome and its relevance to normal aging. We performed cardiovascular assessments at a single clinical site on the largest prospectively studied cohort to date. Carotid-femoral pulse wave velocity was dramatically elevated (mean: 13.00±3.83 m/s). Carotid duplex ultrasound echobrightness, assessed in predefined tissue sites as a measure of arterial wall density, was significantly greater than age- and sex-matched controls in the intima-media (P<0.02), near adventitia (P<0.003), and deep adventitia (P<0.01), as was internal carotid artery mean flow velocity (P<0.0001). Ankle-brachial indices were abnormal in 78% of patients. Effective disease treatments may be heralded by normalizing trends of these noninvasive cardiovascular measures. The data demonstrate that, along with peripheral vascular occlusive disease, accelerated vascular stiffening is an early and pervasive mechanism of vascular disease in Hutchinson-Gilford progeria syndrome. There is considerable overlap with cardiovascular changes of normal aging, which reinforces the view that defining mechanisms of cardiovascular disease in Hutchinson-Gilford progeria syndrome provides a unique opportunity to isolate a subset of factors influencing cardiovascular disease in the general aging population.

Circulating levels of bisphenol A and phthalates are related to carotid atherosclerosis in the elderly

BACKGROUND AND OBJECTIVE

Bisphenol A (BPA) levels have previously been associated with coronary heart disease (CHD). Since CHD is an atherosclerotic disease, we investigated if circulating levels of BPA and phthalate metabolites are related to atherosclerosis in a cross-sectional study.

METHODS

In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects all aged 70), the prevalence of overt plaques and echogenectity (grey scale median, GSM) of carotid artery plaques were recorded by ultrasound in both of the carotid arteries. The thickness (IMT) and echogenicity (IM-GSM) of the intima-media complex were also measured. Bisphenol A (BPA) and 10 phthalate metabolites were analyzed in serum by a API 4000 liquid chromatograph/tandem mass spectrometer.

RESULTS

Mono-methyl phthalate (MMP) was related to carotid plaques in an inverted U-shaped manner. This pattern was significant after adjustment for gender, body mass index, blood glucose, blood pressure, HDL and LDL-cholesterol, serum triglycerides, smoking, antihypertensive treatment and statin use (p=0.004). High levels of BPA, mono-isobutyl phthalate (MiBP) and MMP were associated with an echogenic IM-GSM and plaque GSM, while high levels of mono-2-ethylhexyl phthalate (MEHP) were associated with an echolucent IM-GSM and plaque GSM (p<0.0001 after adjustment).

CONCLUSION

The phthalate metabolite MMP was related to atherosclerotic plaques in an inverted U-shaped manner independently of CV risk factors. Some phthalates and BPA were also related to the echogenicity of the plaques, suggesting a role for plaque-associated chemicals in atherosclerosis.

Endothelial function in resistance and conduit arteries and 5-year risk of cardiovascular disease

BACKGROUND

Impaired endothelial function has been implicated as a cause of cardiovascular disease. Little is known of the relations of measures of endothelial function in resistance and conduit arteries to incident cardiovascular disease in the general population, and available techniques have not been compared.

METHODS AND RESULTS

In 1016 participants (70 years of age) of the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (52% women), we measured endothelium-dependent vasodilation using the invasive forearm technique with acetylcholine given in the brachial artery, the brachial artery ultrasound technique with measurement of flow-mediated dilatation, and the pulse-wave analysis-based method with β-2-agonist terbutaline provocation. During 5 years of follow-up, 101 participants experienced a composite end point of myocardial infarction, stroke, or death, excluding the 85 persons with a history of myocardial infarction or stroke at baseline. In logistic regression models adjusted for several established and novel cardiovascular disease risk factors and medications, endothelium-dependent vasodilation by the invasive forearm technique with acetylcholine was associated with risk of the end point (odds ratio, 0.72 per SD; 95% confidence interval, 0.56 to 0.93; P=0.01). Endothelial function by the other 2 methods was not related to risk of the end point. Addition of endothelium-dependent vasodilation to the Framingham risk score improved discrimination of risk of the end point.

CONCLUSIONS

Endothelium-dependent vasodilation in resistance arteries, but not in the brachial conduit artery (flow-mediated dilatation), was associated with 5-year risk of a composite end point of death, myocardial infarction, or stroke independently of major cardiovascular disease risk factors. This vascular measurement improved risk discrimination when added to an established risk score in an elderly population.

Multiscale amplitude-modulation frequency-modulation (AM-FM) texture analysis of ultrasound images of the intima and media layers of the carotid artery

The intima-media thickness (IMT) of the common carotid artery (CCA) is widely used as an early indicator of cardiovascular disease (CVD). Clinically, there is strong interest in identifying how the composition and texture of the media layer (ML) can be associated with the risk of stroke. In this study, we use 2-D amplitude-modulation frequency-modulation (AM-FM) analysis of the intima-media complex (IMC), the ML, and intima layer (IL) of the CCA to detect texture changes as a function of age and sex. The study was performed on 100 ultrasound images acquired from asymptomatic subjects at risk of atherosclerosis. To investigate texture variations associated with age, we separated them into three age groups: 1) patients younger than 50; 2) patients aged between 50 and 60 years old; and 3) patients over 60 years old. We also separated the patients by sex. The IMC, ML, and IL were segmented manually by a neurovascular expert and also by a snake-based segmentation system. To reject strong edge artifacts, we prefilter with an AM-FM filterbank that is centered along the horizontal frequency axis (parallel to the long axis of the IMC, ML, and IL), while removing the low-pass filter estimates and frequency bands with large, vertical frequency components. To investigate significant texture changes, we extract the instantaneous amplitude (IA) and the magnitude of the instantaneous frequency (IF) over each layer component, for low-, medium-, and high-frequency AM-FM components. We detected significant texture differences between the higher risk age group of >60 years versus the lower risk age group of <50 and the 50-60 group. In particular, between the <50 and >60 groups, we found significant differences in the medium-scale IA extracted from the IMC. Between the >60 and the 50-60 groups, we found significant texture changes in the low-scale IA and high-scale IF magnitude extracted from the IMC, and the low-scale IA extracted from the IL. Also, we noted that the IA for the ML showed significant differences between males and females for all age groups. The AM--FM features provide complimentary information to classical texture analysis features like the gray-scale median, contrast, and coarseness. These findings provide evidence that AM--FM texture features can be associated with the progression of cardiovascular risk for disease and the risk of stroke with age. However, a larger scale study is needed to establish the application in clinical practice.

Associations of circulating adiponectin with measures of vascular function and morphology

CONTEXT

Some previous studies have reported an association between circulating adiponectin and selected measures of vascular function and morphology, but most of these studies have been performed in small samples of patients with preexisting disease.

OBJECTIVE

We aimed to evaluate associations between circulating adiponectin and comprehensive measures of vascular function and morphology in a large sample of individuals from the community.

DESIGN, SETTINGS, AND PARTICIPANTS

We conducted a cross-sectional investigation of 981 70-yr-old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS).

MAIN OUTCOME MEASURES

Measures of outcome included vascular function [common carotid artery (CCA) distensibility, flow-mediated dilation, endothelium-dependent and endothelium-independent vasodilation using invasive methods] and vascular morphology [intima-media (IM) thickness, plaque presence, gray scale median (GSM) in the IM and plaques].

RESULTS

In age- and sex-adjusted models, adiponectin was positively associated with IM-GSM, plaque GSM, CCA distensibility, endothelium-dependent and endothelium-independent vasodilation. In multivariable models (with additional adjustment for body mass index; systolic blood pressure; antihypertensive, antidiabetic, and lipid-lowering medication; fasting blood glucose; total cholesterol; high-density lipoprotein cholesterol; creatinine; and smoking), adiponectin remained positively associated with IM-GSM [beta = 2.06; 95% confidence interval (CI), 0.54, 3.58], plaque GSM (beta = 3.11; 95% CI, 0.36, 5.86), and CCA distensibility (beta = 0.04; 95% CI, 0.00, 0.07).

CONCLUSIONS

Serum levels of adiponectin were positively associated with IM-GSM and plaque GSM (indicating lower fat content in the IM and plaques) and CCA distensibility (indicating higher wall elasticity), independent of potential confounders. Our results imply that adiponectin is associated with less arterial pathology.

Subclinical peripheral arterial disease in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with accelerated atherosclerosis in the carotid arteries, but little is known about the magnitude of this process in peripheral arteries. Assessing preclinical atherosclerosis in both arterial beds in RA might provide additional prognostic value during risk stratification for primary prevention. Therefore in the present structural study we examined femoral versus carotid subclinical atherosclerosis in RA and controls.

METHODS

Intima-media thickness (IMT) and atheromatous plaque presence and vulnerability in femoral versus carotid arteries were examined in 80 RA patients without overt cardiovascular disease or diabetes and 80 controls matched 1:1 for age, gender and traditional cardiovascular disease risk factors.

RESULTS

Femoral IMT and plaque prevalence were increased in RA than controls (p=0.001 and 0.008, respectively). These increases remained significant after adjustment for potentially confounding factors that differed between groups, such as C-reactive protein and HDL-cholesterol serum levels, and statin use. Femoral plaque vulnerability did not differ between RA and controls. The presence of RA was found to be an independent predictor of increased femoral IMT (p=0.004), after adjustment for traditional cardiovascular risk factors, C-reactive protein and treatment with angiotensin converting enzyme inhibitors and statins. Femoral plaques were less frequent than carotid plaques in RA patients (22.5% vs 45.0% respectively, p=0.003) and in contrast to carotid plaques were independent of age and glucose levels.

CONCLUSIONS

Subclinical peripheral atherosclerosis in RA is more advanced than in controls. Prospective studies are required to confirm that RA is an independent risk factor for peripheral arterial disease.

Brachial artery hyperemic blood flow velocities are related to carotid atherosclerosis

OBJECTIVE

Cardiovascular (CV) risk relates to the blood flow velocity pattern in the brachial artery during hyperemia, especially to the hyperaemic systolic to diastolic mean blood flow velocity (SDFV) ratio. Here, we investigated the relations between SDFV in the brachial artery and different characteristics of carotid atherosclerosis.

MATERIAL AND METHODS

Data were collected from 1016 70-year-olds participating in the Prospective Investigation of Uppsala Seniors study. Doppler recordings of blood flow velocity during hyperemia were analysed in the brachial artery. In the carotid artery, intima-media thickness (IMT) was recorded together with an assessment of echogenicity by the Grey scale median (GSM) method in both overt plaques and in the intima-media complex (IM-GSM).

RESULTS

The SDFV ratio was related to the number of carotid arteries affected by plaque (P = 0.018) and inversely to plaque echogenicity (P = 0.0003). The SDFV ratio was also related to IMT (P = 0.0022) and inversely to IM-GSM (P = 0.0001). These relations were statistically significant also after adjusting for major CV risk factors, individually as well as summarised as the Framingham risk score.

CONCLUSION

Our results indicate that the hyperemic systolic to diastolic blood flow velocity ratio in the brachial artery is related to atherosclerosis in the carotid artery.