A new automated computerized analyzing system simplifies readings and reduces the variability in ultrasound measurement of intima-media thickness

Multi-organ expression profiling uncovers a gene module in coronary artery disease involving transendothelial migration of leukocytes and LIM domain binding 2: the Stockholm Atherosclerosis Gene Expression (STAGE) study

Environmental exposures filtered through the genetic make-up of each individual alter the transcriptional repertoire in organs central to metabolic homeostasis, thereby affecting arterial lipid accumulation, inflammation, and the development of coronary artery disease (CAD). The primary aim of the Stockholm Atherosclerosis Gene Expression (STAGE) study was to determine whether there are functionally associated genes (rather than individual genes) important for CAD development. To this end, two-way clustering was used on 278 transcriptional profiles of liver, skeletal muscle, and visceral fat (n = 66/tissue) and atherosclerotic and unaffected arterial wall (n = 40/tissue) isolated from CAD patients during coronary artery bypass surgery. The first step, across all mRNA signals (n = 15,042/12,621 RefSeqs/genes) in each tissue, resulted in a total of 60 tissue clusters (n = 3958 genes). In the second step (performed within tissue clusters), one atherosclerotic lesion (n = 49/48) and one visceral fat (n = 59) cluster segregated the patients into two groups that differed in the extent of coronary stenosis (P = 0.008 and P = 0.00015). The associations of these clusters with coronary atherosclerosis were validated by analyzing carotid atherosclerosis expression profiles. Remarkably, in one cluster (n = 55/54) relating to carotid stenosis (P = 0.04), 27 genes in the two clusters relating to coronary stenosis were confirmed (n = 16/17, P<10(-27 and-30)). Genes in the transendothelial migration of leukocytes (TEML) pathway were overrepresented in all three clusters, referred to as the atherosclerosis module (A-module). In a second validation step, using three independent cohorts, the A-module was found to be genetically enriched with CAD risk by 1.8-fold (P<0.004). The transcription co-factor LIM domain binding 2 (LDB2) was identified as a potential high-hierarchy regulator of the A-module, a notion supported by subnetwork analysis, by cellular and lesion expression of LDB2, and by the expression of 13 TEML genes in Ldb2-deficient arterial wall. Thus, the A-module appears to be important for atherosclerosis development and, together with LDB2, merits further attention in CAD research.

Blood glutathione and subclinical atherosclerosis in African men: the SABPA Study

BACKGROUND

Sub-Saharan Africans face an increasing burden of hypertension and related cardiac and cerebrovascular morbidity and mortality, making the identification of factors leading to early vascular abnormalities imperative.

METHODS

We investigated the possible influence of the antioxidant glutathione (GSH) on early subclinical atherosclerosis in 63 hypertensive (aged 45.2 years) and 34 normotensive (aged 38.9 years; P < 0.001) nondiabetic African men. We measured ambulatory daytime systolic and diastolic blood pressure (SBP, DBP) as well as daytime mean arterial pressure (MAP), carotid intima-media thickness (CIMT), and calculated the cross-sectional wall area. We determined the reduced form of GSH in whole blood and blood glucose in serum.

RESULTS

Blood glucose (110 vs. 92 mg/dl; P < 0.001) and CIMT (0.75 vs. 0.61 mm; P < 0.001) were higher in hypertensives compared to normotensives. No significant difference existed for GSH. Associations in normotensives suggested the hypotensive effect of GSH after single (SBP: r = -0.35, P < or = 0.05; DBP: r = -0.37, P < or = 0.05; MAP: r = -0.38, P < or = 0.05) and multiple (SBP: B = -0.015, P < 0.05; DBP: B = -0.011, P < 0.05; MAP: B = -0.012, P < 0.05) regression analyses. In hypertensives, CIMT (B = -0.00027, P < 0.01) and cross-sectional wall area (CSWA) (B = -0.0066, P < 0.05) correlated negatively with GSH. These findings were consistent after excluding 10 human immunodeficiency virus (HIV)-positive hypertensive subjects.

CONCLUSIONS

In hypertensive African men, CIMT is negatively associated with GSH, suggesting a possible contributory role of attenuated GSH levels in the development of subclinical atherosclerosis.

Carotid artery wall thickness: comparison between sonography and multi-detector row CT angiography

INTRODUCTION

Prospective studies have shown that an increased thickness of the carotid wall is a significant predictor of coronary and cerebrovascular complications. Our purpose was to assess the agreement between multi-detector row computed tomography (CT) angiography (MDCTA) and colour Doppler ultrasound (CD-US) in measuring carotid artery wall thickness (CAWT) and the intima-media thickness (IMT).

METHODS

Altogether, 97 subjects (age range 64-84 years) were prospectively analysed using a four-detector row CT and a sonographic scanner. In total, 46 subjects had shown cerebral ischaemic symptoms. CAWT and IMT were measured in each patient using MDCTA and CD-US (by applying a digital calliper), respectively. Continuous data were described as the mean value +/- standard deviation and were compared using the Mann-Whitney U test. A p value <0.05 was considered significant. Bland-Altman statistics was employed to measure the agreement between MDCTA and CD-US.

RESULTS

CAWT ranged from 0.5 to 1.53 mm, with a mean value of 0.9072 mm. IMT ranged from 0.46 to 1.5 mm, with a mean value of 0.8839 mm. By analysing the Bland-Altman plot, we observed an excellent agreement between CD-US and MDCTA with a bias between methods of 0.023 +/- 0.0424 mm. A limit of agreement from -0.06 to 0.106 was recorded. Correlation coefficient r was 0.9855 (95% confidence interval 0.9808-0.989). Mann-Whitney U test indicated a p value of 0.377.

CONCLUSIONS

Obtained results indicated a significant agreement between MDCTA and CD-US in the measurement of CAWT and IMT.

Preclinical atherosclerosis covaries with individual differences in reactivity and functional connectivity of the amygdala

BACKGROUND

Cardiovascular disease (CVD) is a major source of medical comorbidity for patients with mood and anxiety disorders, and it remains the leading public health burden for the general population in industrialized nations. Indirect neurobiological evidence suggests that preclinical risk for atherosclerosis, the main contributor to CVD, may be conferred by interindividual variation in the functionality of the amygdala, a brain system jointly involved in processing behaviorally salient stimuli and regulating the cardiovascular system.

METHODS

In a neuroimaging study of 36 middle-aged adults (18 women) who were screened for confounding clinical cardiovascular and psychiatric disorders, we examined the direct covariation between a marker of preclinical atherosclerosis, carotid artery intima-media thickness (IMT), and interindividual variation in amygdala reactivity and functional connectivity assessed during the processing of behaviorally salient stimuli (angry and fearful facial expressions).

RESULTS

After accounting for traditional CVD risk factors, a thickening of carotid IMT across individuals covaried with greater amygdala reactivity and a more positive functional connectivity between the amygdala and perigenual anterior cingulate cortex, a corticolimbic area also implicated in behavioral salience processing and cardiovascular regulation.

CONCLUSIONS

Individual differences in amygdala reactivity and functional connectivity may reflect facets of a novel, systems-level neural phenotype conferring risk for atherosclerosis and CVD.

Circulating CD34+ Cell Count is Associated with Extent of Subclinical Atherosclerosis in Asymptomatic Amish Men, Independent of 10-Year Framingham Risk

BACKGROUND

Bone-marrow derived progenitor cells (PCs) may play a role in maintaining vascular health by actively repairing damaged endothelium. The purpose of this study in asymptomatic Old Order Amish men (n = 90) without hypertension or diabetes was to determine if PC count, as determined by CD34+ cell count in peripheral blood, was associated with 10-year risk of cardiovascular disease (CVD) and measures of subclinical atherosclerosis.

METHODS AND RESULTS

CD34+ cell count by fluorescence-activated cell sorting, coronary artery calcification (CAC) by electron beam computed tomography, and CVD risk factors were obtained. Carotid intimal-medial thickness (CIMT) also was obtained in a subset of 57 men. After adjusting for 10-year CVD risk, CD34+ cell count was significantly associated with CAC quantity (p = 0.03) and CIMT (p < 0.0001). A 1-unit increase in natural-log transformed CD34+ cell count was associated with an estimated 55.2% decrease (95% CI: -77.8% to -9.3%) in CAC quantity and an estimated 14.3% decrease (95% CI: -20.1% to -8.1%) in CIMT.

CONCLUSIONS

Increased CD34+ cell count was associated with a decrease in extent of subclinical atherosclerosis in multiple arterial beds, independent of 10-year CVD risk. Further investigations of associations of CD34+ cell count with subclinical atherosclerosis in asymptomatic individuals could provide mechanistic insights into the atherosclerotic process.

Automated detection of the carotid artery wall in B-mode ultrasound images using active contours initialized by the Hough Transform

Automatic segmentation of the arterial lumen from ultrasound images is an important and often challenging task in clinical diagnosis. We previously used the Hough Transform (HT) to automatically extract circles from sequences of B-mode ultrasound images of transverse sections of the carotid artery. In this paper, an active-contour-based methodology is suggested, initialized by the HT circle, in an attempt to extend previous findings and to accurately detect the arterial wall boundary. The methodology is based on the generation of a gradient vector flow field, an approach attempting to overcome conventional active contours constraints. Contour estimation is then achieved by deforming the initial curve (circle) based on the gradient vector flow field. In ten normal subjects, the specificity and accuracy of the segmentation were on average higher than 0.98, whereas the sensitivity was higher than 0.82. The methodology was also applied to four subjects with atherosclerosis, in which sensitivity, specificity and accuracy were comparable to those of normal subjects. In conclusion, the HT-initialized active contours methodology provides a reliable tool to detect the carotid artery wall in ultrasound images and can be used in clinical practice.

Albuminuria within the normal range and ultrasound-assessed atherosclerosis in the AIR study: a 9-year follow-up of 58-year-old clinically healthy men

BACKGROUND

Microalbuminuria, traditionally defined as 30-300 mg urinary albumin/24 h, predicts renal impairment and cardiovascular disease. Studies suggest that also a far lower urinary albumin excretion (UAE) can predict clinical outcome. Intima media thickness (IMT) is an established estimate of atherosclerosis. In this study, we investigated the predictive value of UAE within the normal rate (UAE-n) for the progression of IMT in the carotid and femoral arteries.

METHODS

We included 325 clinically healthy men with normoalbuminuria. Anthropometrics, urine and blood samples were taken and IMT in the carotid and femoral arteries were assessed by B-mode ultrasound at baseline and after 3 and 9 years. The annual progression rate of IMT (r-IMT) was calculated.

RESULTS

UAE-n correlated with carotid IMT at baseline and after 3 and 9 years, but not with r-IMT. In a regression analysis, only HDL and baseline IMT remained as statistically significant co-variates to mean IMT at 9 years. IMT in the femoral artery and r-IMT at any time-point did not correlate to baseline UAE.

CONCLUSION

UAE-n was associated with carotid IMT after 3 and 9 years but not r-IMT or with femoral artery IMT. Carotid IMT after 9 years' follow-up was independently related to baseline IMT and HDL cholesterol. In this cohort of 58-year-old men, our interpretation is that UAE-n is not associated with the increase in carotid and femoral artery IMT observed after 9 years.

Relation of common carotid artery lumen diameter to general arterial dilating diathesis and abdominal aortic aneurysms: the Tromsø Study

In a cross-sectional, population-based study in Tromsø, Norway, the authors investigated correlations between lumen diameter in the right common carotid artery (CCA) and the diameters of the femoral artery and abdominal aorta and whether CCA lumen diameter was a risk factor for abdominal aortic aneurysm (AAA). Ultrasonography was performed in 6,400 men and women aged 25-84 years during 1994-1995. An AAA was considered present if the aortic diameter at the level of renal arteries was greater than or equal to 35 mm, the infrarenal aortic diameter was greater than or equal to 5 mm larger than the diameter of the level of renal arteries, or a localized dilation of the aorta was present. CCA lumen diameter was positively correlated with abdominal aortic diameter (r = 0.3, P < 0.01) and femoral artery diameter (r = 0.2, P < 0.01). In a multivariable adjusted model, CCA lumen diameter was a significant predictor of AAA in both men and women (for the fifth quintile vs. the third, odds ratios were 1.9 (95% confidence interval: 1.2, 2.9) and 4.1 (95% confidence interval: 1.5, 10.8), respectively). Thus, CCA lumen diameter was positively correlated with femoral and abdominal aortic artery diameter and was an independent risk factor for AAA.

Association between AMPD1 Gene Polymorphism and Coagulation Factors in Patients with Coronary Heart Disease

The aim of this study was to investigate whether the C34T and G468T variations in the adenosine monophosphate deaminase-1 (AMPD1) gene were associated with intima-media thickness of the carotid and brachial artery, endothelial function of the brachial artery, glucose metabolism, haemostatic variables and cardiac hypertrophy in patients (n = 109) with coronary heart disease. The plasminogen activator inhibitor-1 activity and the von Willebrand factor were higher in the CC homozygote group compared to the CT/TT group (p < 0.05). There were no differences between the groups regarding intima-media complex of the carotid and brachial artery, presence of plaque in the carotid region, flow-mediated dilatation, ejection fraction or dimensions of the heart. In conclusion, there were no differences between the mutant AMPD1 allele carriers and CC homozygotes regarding surrogate values for atherosclerosis, endothelial function, dimensions and ejection fraction of the heart, glucose tolerance and other well-known cardiovascular risk factors, whereas plasminogen activator inhibitor-1 activity and von Willebrand levels were lower in the mutant AMPD1 allele carriers.

High apoB/apoA-I ratio is associated with increased progression rate of carotid artery intima-media thickness in clinically healthy 58-year-old men: experiences from very long-term follow-up in the AIR study

OBJECTIVES

The aim of the present study was to investigate the relationship between atherosclerotic progression rate as measured by carotid artery IMT during very long-term follow-up in clinically healthy men and a number of baseline risk factors of potential importance for atherosclerosis progression including apoA-I, apoB, apoB/apoA-I ratio, other lipid variables including LDL particle size, body composition variables, blood pressure, smoking, fasting blood glucose and insulin, and also hsCRP.

BACKGROUND

Low-density lipoprotein (LDL) is associated with increased carotid IMT progression rate during long-term follow-up, whereas the relationship between newer biomarkers such as apoB/apoA-I ratio and carotid artery IMT progression rate has been less investigated.

METHODS

58-year-old men identified by screening in the community (n=391) with varying degrees of obesity and insulin sensitivity were examined with high-resolution B-mode ultrasound at baseline and after 3, and 8.9 years of follow-up (n=305 investigated after 8.9 years). The carotid arteries were examined bilaterally, and the mean intima-thickness was calculated for 10mm sections of the composite of common carotid arteries and bulbs (IMT(composite)). Serum levels of apoB and apoA-I were measured using a turbidimetric method. Uni- and multi-variable analyses were performed to study the relationship between carotid IMT(composite) progression rate and risk factors.

RESULTS

In a multi-variable analysis including all baseline variables only the apoB/apoA-I ratio (p=0.003; beta=0.181, standard error=0.003) and serum insulin (p=0.026; beta=-0.133, standard error=0.000) was significantly related to IMT(composite) progression rate.

CONCLUSION

The results indicate that apoB/apoA-I ratio is an important risk factor for predicting atherosclerotic progression rate during very long-term follow-up in clinically healthy middle-aged men.

Matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 in blood as markers for early atherosclerosis in subjects with chronic periodontitis

BACKGROUND AND OBJECTIVE

An association has been found between periodontal disease and the development of atherosclerosis. We investigated the hypothesis that periodontal disease triggers the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in blood. Increased levels of these parameters might then indicate early atherosclerosis.

MATERIAL AND METHODS

In this cross-sectional study, the material comprised 80 subjects with chronic periodontitis and 31 subjects with no periodontal disease. Sixteen years after diagnosis of periodontal disease ultrasonography revealed a statistically significant difference (p < 0.001) of carotid intima-media thickness between the subjects with chronic periodontitis and the periodontally healthy subjects. Matrix metalloproteinase-9 and TIMP-1 were analyzed from blood as periodontal and systemic inflammatory markers. The relationship between MMP-9, TIMP-1 and MMP-9/TIMP-1 as dependent variables and several independent variables (age, sex, smoking, education, body mass index, hypertension, periodontal disease and cholesterol) were analyzed in multiple logistic regression models to assess the value of the inflammatory markers in predicting carotid atherosclerosis.

RESULTS

Matrix metalloproteinase-9 and TIMP-1 were significantly higher in plasma from subjects with periodontal disease and atherosclerosis. Periodontal disease was identified as the principal independent predictor both for atherosclerosis (odds ratio 3.89 for increase in bilateral carotid intima-media thickness) and for increased MMP-9, TIMP-1 and MMP-9/TIMP-1 (odds ratio 2.58, 5.53 and 3.41, respectively). Classical atherosclerosis risk factors, such as increased total cholesterol, age and sex (women), were significant predictors in the model.

CONCLUSION

Matrix metalloproteinase-9, TIMP-1 and MMP-9/TIMP-1 in blood from subjects with periodontal disease could be useful laboratory markers for increased carotid artery intima-media thickness.

A practical protocol to measure common carotid artery intima-media thickness

OBJECTIVE

To describe and test a practical protocol to measure common carotid intima-media thickness that uses the combined values of two longitudinal examination angles to increase sensitivity.

METHOD

Between February and September 2005, 206 patients underwent duplex scan examination of carotid vessels, and the intima-media thickness of 407 common carotids were measured in three angles: transversal, longitudinal posterolateral, and anterolateral, with three intima-media thickness measurements for each near and far wall. In addition to numbers obtained from the three angles of measurement, a fourth visual perspective was obtained by combining the intima-media thickness results of posterolateral and anterolateral longitudinal views and considering the thickest wall measurement.

RESULTS

Two hundred seventy (66.3%) carotid arteries had an intima-media thickness thicker than 1mm. The mean intima-media thickness values achieved by the different incidences were 1.26+/-0.6 mm (transversal), 1.17+/-0.54 mm (longitudinal anterolateral), and 1.18+/-0.58 mm (longitudinal posterolateral). A significant difference in intima-media thickness measurement values was observed when the three angles of examination plus the combined positive results of both longitudinal angles were compared by ANOVA (P=0.005). The LSD Post-Hoc test determined that the combined longitudinal view results were similar to the transversal views (P=0.28) and had greater intima-media thickness means than isolated anterolateral or posterolateral longitudinal views (P=0.02 and 0.05, respectively).

CONCLUSIONS

The protocol presented is a practical method for obtaining common carotid artery intima-media thickness measurements. The combined longitudinal posterolateral and anterolateral longitudinal views provide a more sensitive evaluation of the inner layers of the carotid walls than isolated longitudinal views.

Prospective analysis of carotid arterial wall structure in pediatric renal transplants with ambulatory normotension and in treated hypertensive recipients

Increased carotid IMT was found to be associated with cardiovascular risk factors. As pediatric renal transplants are at high risk for cardiovascular disease, we examined whether there is a relationship between BP and IMT in normotensive and in treated hypertensive recipients after transplantation. Thirty-one recipients aged 10 +/- 3.5 yr (16 M, 15 F) underwent repeated carotid ultrasound examinations 5.4 +/- 3.2 yr after transplantation with a 4.1 +/- 1 yr interval and were followed with annual ambulatory BP monitoring. Baseline IMT was significantly higher in transplants compared with controls. When recipients were again investigated, follow-up IMT measurements were similar compared with measurements obtained at baseline. The analysis of variance showed that baseline IMT both in recipients with strict normotension, i.e., ambulatory normotension without antihypertensive therapy at baseline and throughout the study period (n = 9), and in recipients with treated hypertension or newly diagnosed hypertension (n = 22) was significantly higher than in healthy controls (n = 21). Baseline IMT did not differ between these subgroups of recipients. Similarly, pairwise comparisons showed that baseline and follow-up IMT within each subgroup of recipients were not significantly different. Overall and regardless of time-point, no significant associations were found between systolic and diastolic 24-h BP, daytime BP, night-time BP, ambulatory BP standard deviation scores, BP loads and IMT. Our results suggest that increased IMT in pediatric renal transplants does not seem to be related to BP but more likely to other factor(s) not investigated in this study.

Endothelium-dependent and -independent vasodilation of the superficial femoral artery in spinal cord-injured subjects

Extreme inactivity of the legs in spinal cord-injured (SCI) individuals does not result in an impairment of the superficial femoral artery flow-mediated dilation (FMD). To gain insight into the underlying mechanism, the present study examined nitric oxide (NO) responsiveness of vascular smooth muscles in controls and SCI subjects. In eight healthy men (34 +/- 13 yr) and six SCI subjects (37 +/- 10 yr), superficial femoral artery FMD response was assessed by echo Doppler. Subsequently, infusion of incremental dosages of sodium nitroprusside (SNP) was used to assess NO responsiveness. Peak diameter was examined on a second day after 13 min of arterial occlusion in combination with sublingual administration of nitroglycerine. Resting and peak superficial femoral artery diameter in SCI subjects were smaller than in controls (P < 0.001). The FMD response in controls (4.2 +/- 0.9%) was lower than in SCI subjects (8.2 +/- 0.9%, P < 0.001), but not after correcting for area under the curve for shear rate (P = 0.35). When expressed as relative change from baseline, SCI subjects demonstrate a significantly larger diameter increase compared with controls at each dose of SNP. However, when expressed as a relative increase within the range of diameter changes [baseline (0%) - peak diameter (100%)], both groups demonstrate similar changes in response to SNP. Changes in diameter during SNP infusion and FMD response are larger in SCI subjects compared with controls. When these results are corrected, superficial femoral artery FMD and NO sensitivity in SCI subjects are not different from those in controls. This illustrates the importance of appropriate data presentation and suggests that, subsequent to structural inward remodeling of conduit arteries as a consequence of extreme physical inactivity, arterial function is normalized.

Risk for the development of atherosclerosis in women with a high amount [corrected] of dental plaque and severe gingival inflammation

INTRODUCTION

Chronic infection and inflammation are considered to be risk factors in the development of cardiovascular diseases; the chronic inflammatory and microbial burden caused by the dental plaque in these individuals may predispose them to atherosclerotic process.

AIMS

The aims were to study the involvement of a high level of dental plaque, severe gingival inflammation and periodontitis in the development of early atherosclerotic process in women.

METHODS

Forty-six randomly chosen women with periodontitis and 21 periodontally healthy women were subjected to a comprehensive clinical oral examination, including oral hygiene status and level of gingival inflammation. Atherosclerotic risk factor analysis and carotid ultrasonography were performed. Common carotid artery intima-media thickness (IMT) and lumen diameter were measured and intima-media area (cIMA) was calculated. The following statistical methods were used: analysis of variance, chi-squared tests and multiple logistic regression analysis.

RESULTS

There were highly significant differences between the patients and controls in the amount of dental plaque, gingival inflammation as well as bleeding on probing and pocket depth. The mean values of IMT and cIMA were significantly higher in women with periodontal disease than in controls. Multiple logistic regression analysis identified periodontitis as a principal-independent predictor of both the common carotid artery cIMA and IMT.

CONCLUSIONS

The present results indicate that a high amount of dental plaque, severe gingival inflammation as well as periodontitis seem to be associated with the development of atherosclerotic lesions in women already at its early and subclinical stages.

Using the Hough transform to segment ultrasound images of longitudinal and transverse sections of the carotid artery

Automatic segmentation of the arterial lumen from ultrasound images is an important task in clinical diagnosis. In this paper, the Hough transform (HT) was used to automatically extract straight lines and circles from sequences of B-mode ultrasound images of longitudinal and transverse sections, respectively, of the carotid artery. In 10 normal subjects, the specificity and accuracy of HT-based segmentation were on average higher than 0.96 for both sections, whereas the sensitivity was higher than 0.96 in longitudinal and higher than 0.82 in transverse sections. The intima-media thickness (IMT) was also estimated from images of longitudinal sections; the corresponding validation parameters were generally higher than 0.90. To further validate the results, arterial distension waveforms (ADW) were estimated from sequences of images using the HT technique as well as motion analysis using block matching (BM). In longitudinal sections, diastolic and systolic diameters and relative diameter changes using HT and BM were not significantly different. In transverse sections, diastolic and systolic diameters were significantly lower using the HT technique; the differences were <7%. Relative diameter changes in transverse sections were not significantly different from BM-estimated ones. The HT technique was also applied to four subjects with atherosclerosis, in which sensitivity, specificity and accuracy were comparable to those of normal subjects; the low values of sensitivity in transverse sections may reflect departure from the circular model because of the presence of plaque. In conclusion, the HT technique provides a reliable way to segment ultrasound images of the carotid artery and can be used in clinical practice to estimate indices of arterial wall physiology, such as the IMT and the ADW.

Sequential based analysis of Intima-Media Thickness (IMT) in common carotid artery studies

INTRODUCTION

Carotid Intima-Media Thickness (IMT) is used widely to assess an individual's risk of myocardial infarction and stroke. Although significant associations have been showed, IMT as used in major studies does not improve prediction of cardiovascular events much compared to traditional risk factors. Therefore, a new approach to IMT-measurements is sought-after by examining the wall structure continuously throughout several heart cycles.

MATERIALS AND METHODS

Computerized single-image analysis (IA) and sequential analysis (SA) were used to assess latter's capability in predicting risk of cardiovascular disease and to compare both. Healthy subjects (mean+/-S.D., age 46.1+/-5.6 years, n=490) were compared with subjects suffering from confirmed coronary artery disease (CAD) (mean+/-S.D., age 47.3+/-6.2 years, n=51).

RESULTS

SA could differentiate between both groups better then single IA, especially when looking at the maximal and mean IMT-values (SA<-->IA, p<0.01<-->p<0.05). The area under the curve (AUC) for maximal and mean IMT was greater for sequences then for single images as well.

DISCUSSION

Due to our findings sequential analysis can offer an extensive and complete examination of the carotid wall with a maximal reduction of bias. Commonly used IA may disguise vascular conditions and therefore the patient's risk, since IMT-values, as proven with SA, seems to usually be higher. Therefore, the need for further studies arises, examining if and to what extend common IMT-studies underestimate differences between groups.

Brachial artery intima-media thickness and echogenicity in relation to lipids and markers of oxidative stress in elderly subjects:--the prospective investigation of the vasculature in Uppsala Seniors (PIVUS) Study

The aim of the present study was to relate brachial artery intima-media thickness (IMT) and the grey scale median of the intima-media complex (IM-GSM) to traditional cardiovascular risk factors and markers of inflammation and oxidative stress. In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study, a population-based study of 1016 subjects aged 70, brachial artery IMT and IM-GSM, who were evaluated by ultrasound. Lipids, thirteen markers of inflammation and nine markers of oxidative stress were measured. The Framingham risk score was related to IMT (p < 0.0001), but not to the IM-GSM. In univariate analysis, HDL-cholesterol, serum triglycerides, fasting glucose, smoking, HOMA insulin resistance index and oxidized LDL levels were related to IMT. HDL and LDL-cholesterol, triglycerides, VCAM-1, e-selectin, leukocyte count, conjugated diens, baseline conjugated diens (BCD)-LDL, antibodies to oxLDL, the GSSG/GSH glutathione ratio and homocysteine were related to IM-GSM. In multiple regression models, HDL-cholesterol, fasting glucose and oxLDL levels were the independently related to IMT (p = 0.01-0.04), while serum triglycerides, BCD-LDL and the GSSG/GSH ratio were independently related to IM-GSM (p = 0.0001-0.004). In conclusion, in addition to traditional lipid variables, markers of oxidative stress were associated with both thickness and echogenicity of the brachial artery intima-media complex. Thus, both thickness and echogenicity of the brachial artery intima-media complex might be useful biomarkers in the future.

Carotid intima-medial thickness measured on multiple ultrasound frames: evaluation of a DICOM-based software system

Background

Carotid intima-media thickness (CIMT) measured by B-mode ultrasonography is a marker of atherosclerosis and is commonly used as an outcome in intervention trials. We have developed DICOM-based software that measures CIMT rapidly on multiple end-diastolic image frames. The aims of this study were to compare the performance of our new software with older bitmap-based CIMT measurement software and to determine whether a ten-fold increase in the number of measurements used to calculate mean CIMT would improve reproducibility.

Methods

Two independent sonographers recorded replicate carotid scans in thirty volunteers and two blinded observers measured CIMT off-line using the new DICOM-based software and older bitmap-based software. A Bland-Altman plot was used to compare CIMT results from the two software programs and t-tests were used to compare analysis times. F-tests were used to compare the co-efficients of variation (CVs) from a standard six-frame measurement protocol with CVs from a sixty-frame measurement protocol. Ordinary least products (OLP) regression was used to test for sonographer and observer biases.

Results

The new DICOM-based software was much faster than older bitmap-based software (average measurement time for one scan 3.4 ± 0.6 minutes versus 8.4 ± 1.8 minutes, p < 0.0001) but CIMT measurements were larger than those made using the alternative software (+0.02 mm, 95%CI 0.01–0.03 mm). The sixty-frame measurement protocol had worse reproducibility than the six-frame protocol (inter-observer CV 5.1% vs 3.5%, p = 0.004) and inter and intra-observer biases were more pronounced in the sixty-frame than the six-frame results.

Conclusion

While the use of DICOM-based software significantly reduced analysis time, a ten-fold increase in the number of measurements used to calculate CIMT did not improve reproducibility. In addition, we found that observer biases caused differences in mean CIMT of a magnitude commonly reported as significant in intervention trials. Our results highlight the importance of good study design with concurrent controls and the need to ensure that no observer drift occurs between baseline and follow-up measurements when CIMT is used to monitor the effect of an intervention.

Increased leukotriene concentrations in gingival crevicular fluid from subjects with periodontal disease and atherosclerosis

Recent studies indicate that periodontal disease is associated with the development of early atherosclerotic lesions in the carotid artery. Since inflammation is a key feature in both atherosclerosis and periodontal disease, a common mediator of the two diseases could be anticipated. Leukotrienes are lipid-derived inflammatory mediators recently implicated in the pathogenesis of atherosclerosis and previously shown to be produced in periodontitis. The aim of the present study was to detect leukotrienes in gingival crevicular fluid (GCF) from subjects with atherosclerosis. Carotid ultrasonography and oral clinical examination were performed in 19 periodontitis patients and 16 healthy subjects. Atherosclerotic plaques were detected on ultrasound examination in 13 subjects with periodontis, and in 5 of the healthy subjects. Elevated concentrations of leukotriene B(4) and cysteinyl-leukotrienes were detected in GCF from subjects with a high dental plaque index (PLI>0.3), supporting an increased leukotriene formation in periodontitis. In addition, subjects with atherosclerotic plaques had significantly elevated concentrations of cysteinyl-leukotrienes in their GCF as compared with subjects without a visible plaque. Finally, the increased cysteinyl-leukotriene concentrations in GCF from atherosclerotic subjects were observed also when sub groups of periodontis patients and healthy subjects were compared separately. In summary, increased GCF concentrations of cysteinyl-leukotrienes were correlated to measures of both periodontitis and atherosclerosis. These results suggest that increased leukotriene formation may represent a possible link between periodontitis and atherosclerosis and a risk factor marker for both diseases.

Robust border enhancement and detection for measurement of fetal nuchal translucency in ultrasound images

Ultrasonic measurement of nuchal translucency (NT) thickness in the first trimester of pregnancy has recently been proposed as the most useful marker in early screening for fetal chromosomal abnormalities. However, manual tracing of the two echogenic lines in the image, using on-screen calipers, is hampered by weak edges, together with noise and other artifacts, leading to variable results and inefficiency. Our semi-automatic method of fetal NT thickness measurement uses a coherence-enhancing diffusion filter to enhance the border and reduce noise, followed by detection of the NT by minimization of a cost function, that combines intensity, edge strength and continuity, using dynamic programming. This method has been validated by determining the correlation between manual and semi-automatic measurements.

Indian Asian men have less peripheral arterial disease than European men for equivalent levels of coronary disease

OBJECTIVES

Indian Asians have high rates of heart disease and stroke, but risks of peripheral arterial disease appear to be low. This paradox, and reasons for it, have not been explored. We compared ethnic differences in peripheral arterial disease for a given level of coronary disease.

METHODS

We studied 83 European and 84 Indian Asian men with a range of coronary disease. Extent of coronary atheroma was quantified by coronary artery calcification score on multislice CT. Femoral intima-media thickness (IMT) was measured by ultrasound.

RESULTS

Femoral IMT was 1.58, 2.06, 2.12, and 2.69 mm in Europeans, and 0.61, 1.41, 1.81 and 2.29 in Indian Asians by increasing categories of coronary atheroma (p=0.003 for ethnic difference, adjusted for age and lumen diameter). Adjustment for smoking and systolic blood pressure, the only risk factors adversely distributed in Europeans, only partly accounted for this ethnic difference (p=0.05). Other risk factors, including lipids, obesity, insulin and glycaemic status, more adversely distributed in Indian Asians, could not account for ethnic differences. Prevalence of abnormal ankle brachial index and lower limb atherosclerotic plaque was also greater in Europeans.

CONCLUSIONS

For a given level of coronary disease, Indian Asians have less lower limb atherosclerosis than Europeans, unexplained by established risk factors. Further study of these populations would help tease out relative contributions of risk factors to atherosclerosis in different vessel beds.

Measurement of the reflectivity of the intima-medial layer of the common carotid artery improves the discriminatory value of intima-medial thickness measurement as a predictor of risk of atherosclerotic disease

Our aim was to assess the predictive value of a measurement of intima-medial layer (IML) reflectivity in the differentiation of pathological from physiological increases in intima-medial thickness (IMT). Both common carotid arteries (CCA) of familial hypercholesterolemia (FH) patients and age- and sex-matched controls (no cardiovascular risk factors) were imaged using a 10- to 15-MHz linear array transducer (n = 30). Images of the CCA far wall were analyzed in the IMT "plug-in" of "HDI Lab." The IML reflectivity, averaged over an 8- to 12-mm length of arterial wall, was expressed as a ratio of reflectivity at a point 0.21-mm deep to the intima-medial interface divided by the reflectivity at the intima-medial interface, termed the intima-medial reflectivity index (IMRI). The risk of atherosclerosis was assessed in terms of IMT alone and IMT coupled with IMRI. Defining high risk of atherosclerosis in FH, in terms of both IMT alone and IMT coupled with IMRI, produced an appropriate, when compared with cholesterol-years score, statistically significant stratification (p < 0.01 and p < 0.005). Analysis of the low-risk subjects revealed a tendency to define a subject as "high risk" based on a physiological increase in IMT, but when IMRI is included in the assessment, all controls are correctly identified as low risk. This method of quantifying the reflectivity of the IML improved the discriminatory performance of IMT increase as an indicator of atherosclerotic risk by enabling a smaller, therefore earlier, increase in IMT to be considered pathologic when accompanied by an increase in IMRI.

Analysis of complex flow and the relationship between blood pressure, wall shear stress, and intima-media thickness in the human carotid artery

BACKGROUND

Previous clinical studies have observed relationships between increased intima-media thickness (IMT) in the carotid artery, elevated blood pressure, and low wall shear stress (WSS) calculated from the Poiseuille equation. This study used numerical methods to more accurately determine WSS in the carotid artery and to investigate possible determinants of increased IMT.

METHODS

IMT [common carotid artery (CCA) and bulb], CCA flow velocity, brachial systolic (SBP) and diastolic blood pressure (DBP), and carotid systolic pressure (cSBP) were measured in 14 healthy subjects (aged 44 +/- 16 yr). Flow patterns in the carotid bifurcation were determined by computational fluid dynamics (CFD) based on three-dimensional ultrasound geometry. Instantaneous and time-averaged wall shear stress (WSS(av)), oscillatory shear index (OSI), and wall shear stress angle gradients (WSSAG) were calculated.

RESULTS

IMT was positively related to SBP, DBP, cSBP, and WSSAG and inversely related to WSS(av) in the CCA. In the bulb, IMT was positively related to SBP and cSBP but was not significantly related to WSS(av) or WSSAG. IMT was unrelated to OSI in both the CCA and the bulb.

CONCLUSION

Increased carotid artery IMT in healthy subjects with no evidence of focal plaques is primarily a response to elevated pressure.

Measurement of pulse wave velocity: site matters

BACKGROUND

Aortic pulse wave velocity (PWV) predicts mortality from cardiovascular disease, ischaemic heart disease and stroke. However, a comparison of associations between PWV measured at different sites and atherosclerosis in coronary, carotid and femoral arteries has not been made.

METHODS

In 159 men (ages 45-82 years) with and without known coronary artery disease, PWV measurements were made between carotid-femoral, carotid-radial and femoral-posterior tibial sites, using an ultrasound technique. Coronary artery calcification (CAC) scores were measured by multislice computed tomography. Carotid and femoral intima-media thickness (IMT) and presence of plaque were determined by ultrasound. Known coronary artery disease was confirmed by angiography. Participants were grouped into four categories of CAC score: 0-10, 11-100, 101-400, > 400 Hounsfield Units (HU). Measurements of blood pressure, heart rate and fasting bloods were made in all individuals.

RESULTS

Carotid-femoral PWV correlated positively with CAC score and increased with incremental coronary calcification category (median carotid-femoral PWV 16.8 m/s in those with CAC score > 400 HU and 13.8 m/s in those with CAC score < 10 HU; P = 0.003). Carotid-femoral PWV also correlated with carotid and femoral IMT (P < 0.001, P = 0.004, respectively) and with carotid and femoral plaque (P = 0.001, P = 0.038, respectively). Increased carotid-femoral PWV also correlated with increasing age (P < 0.001), systolic blood pressure (P < 0.001), mean arterial pressure and pulse pressure (P < 0.001). Carotid-radial and femoral-posterior tibial PWV were not significantly associated with CAC score, carotid or femoral IMT or carotid plaque.

CONCLUSIONS

Carotid-femoral PWV is a better indicator of atherosclerosis than either carotid-radial or femoral-posterior tibial PWV, and should be used preferentially in studies of atherosclerosis and in stratifying risk in clinical settings.

Rosiglitazone and carotid IMT progression rate in a mixed cohort of patients with type 2 diabetes and the insulin resistance syndrome: main results from the Rosiglitazone Atherosclerosis Study

OBJECTIVE

Insulin resistance is associated with progression of atherosclerosis. We assessed the effect of 12 months of treatment with rosiglitazone (RSG) on the progression of carotid intima-media thickness (IMT) in people with type 2 diabetes mellitus (T2DM) or the insulin resistance syndrome (IRS).

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Malmö University Hospital, Malmö, Sweden.

SUBJECTS

555 subjects (200 with T2DM and 355 nondiabetics with IRS according to EGIR criteria), aged 35-80 years. 447 subjects (165 T2DM and 282 IRS) completed the study.

INTERVENTION

Participants were allocated to placebo or RSG 4 mg for 2 months and then 8 mg daily.

MAIN OUTCOME MEASURE

Change in composite IMT [mean IMT in the common carotid artery (CCA) and maximal IMT in the bulb] was the primary and various other IMT measures were secondary outcome variables.

RESULTS

There was no effect of RSG treatment in the mixed population. In T2DM patients there was a reduced progression of the composite IMT (mean change: 0.041 vs. 0.070 mm, P = 0.07), and of the mean IMT CCA (mean change: -0.005 mm vs. 0.021 mm, P = 0.007). RSG treatment led to significant reductions of HOMA-IR, fasting plasma glucose, HbA1c, PAI-1 activity, fibrinogen, C-reactive protein and matrix metalloproteinase-9.

CONCLUSIONS

In a mixed study population of patients with T2DM and IRS RSG treatment was not associated with a statistically significant reduction of carotid IMT progression rate. Separate analyses of these two patient groups indicated, however, a significant beneficial effect on CCA IMT in T2DM patients but no similar effect in subjects with IRS.

Snakes based segmentation of the common carotid artery intima media

Ultrasound measurements of the human carotid artery walls are conventionally obtained by manually tracing interfaces between tissue layers. In this study we present a snakes segmentation technique for detecting the intima-media layer of the far wall of the common carotid artery (CCA) in longitudinal ultrasound images, by applying snakes, after normalization, speckle reduction, and normalization and speckle reduction. The proposed technique utilizes an improved snake initialization method, and an improved validation of the segmentation method. We have tested and clinically validated the segmentation technique on 100 longitudinal ultrasound images of the carotid artery based on manual measurements by two vascular experts, and a set of different evaluation criteria based on statistical measures and univariate statistical analysis. The results showed that there was no significant difference between all the snakes segmentation measurements and the manual measurements. For the normalized despeckled images, better snakes segmentation results with an intra-observer error of 0.08, a coefficient of variation of 12.5%, best Bland-Altman plot with smaller differences between experts (0.01, 0.09 for Expert1 and Expert 2, respectively), and a Hausdorff distance of 5.2, were obtained. Therefore, the pre-processing of ultrasound images of the carotid artery with normalization and speckle reduction, followed by the snakes segmentation algorithm can be used successfully in the measurement of IMT complementing the manual measurements. The present results are an expansion of data published earlier as an extended abstract in IFMBE Proceedings (Loizou et al. IEEE Int X Mediterr Conf Medicon Med Biol Eng POS-03 499:1-4, 2004).

Reduced endothelial progenitor cells in European and South Asian men with atherosclerosis

BACKGROUND

Circulating endothelial progenitor cells (EPCs) play a role in the repair and regeneration of the endothelium and may represent a novel cardiovascular risk factor. South Asian subjects have an increased risk of cardiovascular disease which is not fully explained by known risk factors. This study examined associations of EPCs with atherosclerosis and possible ethnic differences in EPCs.

MATERIALS AND METHODS

A population sample of 58 European and South Asian adult men was enriched with the recruitment of an additional 59 European and South Asian men with known coronary disease. The coronary artery calcification score was measured by multi-slice computerized tomography (CT), carotid and femoral intima-media thickness (IMT), and femoral plaques were measured by ultrasound. The subjects were further subdivided into three categories of coronary artery disease on the basis of coronary artery calcification score and clinical history. Total EPCs and non-senescent EPCs (ns-EPCs) were quantified after 5 days cell culture and the number of late outgrowth colonies was measured over a 6-week test period. Circulating CD34+ haematopoietic precursor cells were measured by flow cytometry.

RESULTS

Individuals with femoral plaques had reduced total and ns-EPCs. The number of ns-EPCs were reduced in individuals with the most coronary atheroma and were inversely related to the coronary calcification score and femoral IMT. These relationships persisted after multivariate adjustment for other risk factors. The numbers of late outgrowth colonies or circulating CD34+ cells were unrelated to the presence of atherosclerosis. There were no differences in the number of EPCs between European and South Asian subjects.

CONCLUSION

The number of EPCs are reduced in subjects with atherosclerosis independent of other risk factors. Reduction in EPC numbers may be an independent risk factor for atherosclerosis but does not explain ethnic differences in cardiovascular risk.

Circulating estradiol is an independent predictor of progression of carotid artery intima-media thickness in middle-aged men

CONTEXT

Estrogen treatment of men with prostate cancer is associated with increased cardiovascular morbidity and mortality; however, the role of endogenous estrogen levels for atherosclerotic disease in men is unknown.

OBJECTIVE

The objective of the study was to determine whether endogenous serum estradiol (E2) levels predict the progression of carotid artery intima-media thickness in men.

DESIGN, SETTING AND PARTICIPANTS

This was a population-based, prospective cohort study (the Atherosclerosis and Insulin Resistance study) conducted in Göteborg, Sweden, among 313 Caucasian men without cardiovascular or other clinically overt diseases. Carotid artery intima-media thickness, an index of preclinical atherosclerosis, was measured by ultrasound at baseline (58 yr of age) and after 3 yr of follow-up. Serum sex hormone levels and cardiovascular risk factors (body mass index, waist to hip ratio, systolic blood pressure, serum triglycerides, plasma c-peptide, and smoking status) were assessed at study entry.

INTERVENTION

There was no intervention.

MAIN OUTCOME MEASURES

Association between baseline total and free E2 levels and progression of carotid intima-media thickness over 3 yr with adjustments for cardiovascular risk factors was measured.

RESULTS

In univariate analyses, both total and free E2 levels at baseline were positively associated with the annual change in intima-media thickness. In linear regression models including E2 and cardiovascular risk factors, low-density lipoprotein and high-density lipoprotein cholesterol and E2 were identified as independent predictors of progression of carotid artery intima-media thickness (total E2 beta = 0.187, P = 0.001; and free E2 beta = 0.183, P = 0.003).

CONCLUSIONS

Circulating E2 is a predictor of progression of carotid artery intima-media thickness in middle-aged men. Further studies are needed to investigate the role of endogenous E2 for incident cardiovascular disease events.

Examination of lower targets for low-density lipoprotein cholesterol and blood pressure in diabetes--the Stop Atherosclerosis in Native Diabetics Study (SANDS)

Diabetes incidence is increasing rapidly in the United States. Diabetes increases the risk for cardiovascular disease, the major cause of death in diabetic individuals. The conventional cardiovascular risk factors of hyperlipidemia and hypertension worsen diabetic vascular disease. Treatment targets for low-density lipoprotein cholesterol (LDL-C) and blood pressure in diabetic individuals are being debated. The SANDS is a randomized, open-label, 3-year trial to examine the effects of aggressive LDL-C (goal <70 mg/dL) and blood pressure (BP) (goal <115/75 mm Hg) reduction versus the standard goals of <100 mg/dL for LDL-C and <130/85 mm Hg for BP. Five hundred forty-nine American-Indian men and women >40 years old with type 2 diabetes were randomized to 1 of 2 groups. Lipids and BP are managed using Food and Drug Administration-approved medications in an algorithmic approach. The presence and progression of atherosclerosis are evaluated by carotid ultrasonography; echocardiography assesses cardiac function. The primary end point is the composite outcome of change in carotid artery intimal medial thickness and fatal/nonfatal cardiovascular events. These outcomes are combined by using a ranked analysis for carotid thickness and assigning a "worst rank" for a cardiovascular event. Secondary end points include carotid plaque score, left ventricular geometry and function, serum C-reactive protein, and safety measures. Unique aspects of the study design and analysis plan involve the use of a composite outcome and changes during the trial of LDL-C treatment goals for participants with baseline or incident cardiovascular disease in the conventional group because of changes in the standard of care. Study results will further understanding of the effects of aggressive risk factor reduction on atherosclerosis burden and cardiac function in diabetic individuals in US populations and will help determine optimal LDL-C and BP treatment goals for diabetic patients.

Are serum adiponectin concentrations in a population sample of 64-year-old Caucasian women with varying glucose tolerance associated with ultrasound-assessed atherosclerosis?

OBJECTIVE

To examine whether serum adiponectin concentrations were associated with subclinical atherosclerosis assessed as intima media thickness (IMT) in the carotid arteries in Caucasian women with varying degrees of glucose tolerance.

RESEARCH DESIGN AND METHODS

From a population-based cohort of 64-year-old Swedish women, 533 subjects with type 2 diabetes (DM2, n=177), impaired glucose tolerance (IGT; n=178) or normal glucose tolerance (NGT, n=178) were recruited. Anthropometrics, usual cardiovascular risk factors were examined and ultrasound examination of the carotid arteries was performed.

RESULTS

Women with low adiponectin concentrations were characterized by thick IMT, higher prevalence of DM2, history of previous myocardial infarction, angina pectoris, anti-hypertensive treatment and high body mass index (BMI), waist circumference, plasma insulin, serum triglycerides, fasting glucose, HbA1c, and low serum HDL cholesterol levels. Carotid IMT correlated with HbA1c (r=0.24, P<0.001), waist circumference (r=0.22, P<0.001), plasma insulin (r=0.19, P<0.001), BMI (r=0.18, P<0.001), DM2 (r=0.16, P<0.001), systolic blood pressure (r=0.16, P<0.001), blood glucose (r=0.16, P<0.001), triglycerides (r=0.15, P<0.001), and reversely to adiponectin (r=-0.11, P=0.01), HDL cholesterol (r=-0.13, P=0.004), and alcohol intake (r=-0.087, P<0.05). A more detailed analysis of underlying associations was difficult due to a high co-linearity between these variable.

CONCLUSIONS

Low serum adiponectin concentrations were associated with increased carotid artery IMT, and several risk factors for cardiovascular diseases, mainly those constituting the metabolic syndrome.

Atorvastatin normalizes endothelial function in healthy smokers

Endothelial function is known to predict cardiovascular disease. The aim of the present study was to examine whether endothelial function in smokers with normal cholesterol levels could be normalized by treatment with 80 mg of atorvastatin in comparison with a control group. Healthy smokers (n=20) and non-smokers (n=20) were randomized to receive 80 mg of atorvastatin or placebo in an open randomized cross-over study, followed by measurement of endothelial functional [FMD (flow-mediated dilation)]. At baseline, smokers had a lower FMD compared with the non-smoking group (2.2+/-0.5 and 4.5+/-0.8% respectively; P<0.05). In the smoking group, FMD increased significantly (P<0.05) to 4.0+/-0.8% during treatment with atorvastatin and returned to basal levels during placebo (2.3+/-0.6%). In the non-smoking group, FMD was unaffected by both atorvastatin and placebo. The net change of total cholesterol or LDL (low-density lipoprotein)-cholesterol was not associated with the net change in FMD when the study group was considered as a whole or the smoking group was considered separately. In conclusion, improved endothelial function was observed in a group of smokers when they were received 80 mg of atorvastatin, whereas atorvastatin had no effect on endothelial function in the non-smoking group. The improved FMD among smokers was independent of the decrease in LDL-cholesterol during atorvastatin treatment. The results show that poor endothelial function in smokers with normal lipid levels can be improved by a statin treatment.

Decreased heart rate variability may predict the progression of carotid atherosclerosis in type 2 diabetes

Heart rate variability (HRV), a measure of autonomic function, can predict survival outcomes. Cardiovascular disease is a known complication of diabetes, and we aimed to determine if autonomic dysfunction was associated with carotid artery atherosclerotic plaques in type 2 diabetic patients. We assessed frequency domain HRV from power spectral analysis of 24 h Holter ECG recordings, expiration/inspiration (E/I) ratio during deep breathing, acceleration index (AI) of R-R interval in response to head-up tilt, and the degree of carotid artery atherosclerosis in 61 type-2 diabetic patients (39 males, 45-69 years). Studies were carried out 5-6 years after diagnosis (baseline) and repeated 8 years after diagnosis (follow-up). At baseline, patients diagnosed with autonomic neuropathy, with abnormal E/I ratio and abnormal AI measurements, had decreased low frequency (LF) HRV. Baseline E/I ratio correlated with day (r = 0.34; P < 0.001) and night-time (r = 0.44; P < 0.001) LF power. Night-time HRV did not differ in patient with and without autonomic neuropathy. Reduced common carotid artery diameter and atherosclerotic intima-media thickness (IMT) both correlated with HRV at baseline. At follow-up, all HRV variables decreased significantly. Furthermore, patients with lower LF power at baseline, had a larger increase in the thickness of the carotid bulb intima-media at follow-up. Our results show that LF HRV power is associated with the extent and progression of carotid atherosclerosis in type 2 diabetes. A low LF HRV may predict the progression of atherosclerosis in these patients.

Microalbuminuria in patients with previous myocardial infarction

Microalbuminuria (MA) is a cardiovascular risk factor. The aim of this study was to examine the relationship between MA and the intima-media complex of the carotid and brachial artery, endothelial function, glucose metabolism, haemostatic variables and cardiac hypertrophy in patients with coronary heart disease. A total of 123 patients, aged 31-80 years, with a history of previous myocardial infarction and without known diabetes mellitus were examined with B-mode ultrasound of common carotid and brachial arteries, flow-mediated dilatation of the brachial artery and echocardiography. A standard oral glucose tolerance test with 75 g of glucose was performed. MA was defined as excretion of 20-200 microg albumin/min. MA was present in 11% of patients. Patients with MA had significantly higher level of 2-h plasma glucose, a lower displacement of the atrioventricular plane, a thicker septum wall and a higher prevalence of impaired glucose tolerance test compared with patients with normoalbuminuria (P<0.05). Urinary albumin excretion (UAE) was significantly and positively associated with calculated intima-media area (cIMa) in both brachial and common carotid arteries as well as with age and interventricular septum thickness. In conclusion, UAE was significantly and positively associated with cIMa in both the common carotid and the brachial arteries as well as with left ventricular septum thickness and glucose intolerance in patients with a history of previous myocardial infarction without known diabetes mellitus.

Frequency of spousal interaction and 3-year progression of carotid artery intima medial thickness: the Pittsburgh Healthy Heart Project

OBJECTIVE

We employed Ecological Momentary Assessment (EMA) real-time recording in the natural setting to determine whether spousal interaction frequency predicts 3-year progression of carotid artery intima medial thickening (IMT).

METHODS

Participants were 250 healthy, older adults (M age = 61, 48% female) who, at baseline, underwent 6 days of ambulatory monitoring using electronic diaries to collect data on mood, activity, and posture, as well as current or recent (past 10 minutes) social interactions. Participants also underwent ultrasound imaging of the carotid arteries at baseline and 3-year follow-up. Spousal interaction frequency was computed as the sum of total interactions with only the spouse during the 6 days of monitoring.

RESULTS

Spousal interaction frequency did not predict IMT change in the sample as a whole (p = .87). However, a sex by spousal interaction by marital adjustment interaction (p = .02) indicated that more frequent spousal interaction was associated with less IMT progression among men with better marital adjustment (p = .03). In contrast, frequent spousal interaction predicted greater IMT progression among women with better martial adjustment (p < .01). This effect lost significance when women's total social interactions (sum of all interactions) were included in the model. Total social interaction frequency was an independent predictor of IMT among women but not men.

CONCLUSIONS

These findings extend those of previous research by suggesting that frequent spousal interactions may be associated with long-term cardiovascular health among happily married older men and demonstrate how sampling daily experience may enhance our understanding of the possible health benefits of marriage.

Glucose intolerance is associated with C-reactive protein and intima-media anatomy of the common carotid artery in patients with coronary heart disease

AIMS

The purpose of this study was to examine the relationship between glucose intolerance and levels of hsCRP, calculated intima-media area (cIMa) of the carotid artery and flow-mediated dilation of the brachial artery in 122 patients with a myocardial infarction 1-12 months before inclusion and without known diabetes mellitus.

METHODS

A standard oral glucose test (OGTT) was performed. Diabetes mellitus and impaired glucose tolerance (IGT) were defined according to the WHO criteria. Ultrasound measurement of cIMa of the carotid artery and flow-mediated dilation of the brachial artery were analyzed.

RESULTS

Patients with diabetes mellitus had higher hs-CRP compared with patients with IGT and those patients with normal glucose tolerance (P < 0.05). The greater cIMa of the carotid artery in those with diabetes mellitus compared with normal subjects failed to reach conventional levels of significance (P = 0.058). hs-CRP and cIMa were associated with plasma glucose 120 min after the glucose load (P < 0.05). A multiple stepwise regression analysis, including all variables significantly associated with plasma-glucose 120 min after glucose ingestion as independent variables, revealed an independent and significant association between plasma-glucose 120 min after glucose ingestion in the OGTT and CRP (P < 0.05). No association was observed between glucose intolerance and endothelial function.

CONCLUSION

Glucose intolerance was associated with hs-CRP and cIMa in patients with coronary heart disease without known diabetes mellitus. Thus, inflammation, atherosclerosis and impaired glucose tolerance are tightly interrelated disorders even in subjects without known diabetes mellitus.

Changing associations between progressive cardiovascular autonomic neuropathy and carotid atherosclerosis with increasing duration of type 2 diabetes mellitus

To clarify associations between cardiovascular autonomic neuropathy (CAN) and the progression of carotid artery atherosclerosis in Type 2 diabetic patients, cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients, 5 and 8 years after the diagnosis of diabetes. Between 5 and 8 years after diagnosis, age-adjusted acceleration index (AI) decreased (from -0.306+/-1.034 to -0.702+/-1.072; P=.0139), whereas age-adjusted expiration/inspiration (E/I) ratio was unchanged (-0.583+/-1.038 and -0.828+/-1.028; P=.1164). Intima-media thickness (IMT) increased in both the common carotid artery (CCA; from 0.854+/-0.219 to 0.913+/-0.241 mm; P<.0001) and the carotid bulb (from 1.789+/-0.714 to 2.128+/-0.881 mm; P<.0001), corresponding to a yearly IMT increase of 0.032+/-0.039 mm in the CCA and 0.146+/-0.204 mm in the carotid bulb. This value did not correlate with the AI or E/I ratios. In age-controlled partial correlation in the first examination, AI correlated inversely with mean (r=-.33, P=.018) IMT in the CCA, but not with IMT in the carotid bulb (r=-.14, P=.303). However, in contrast to the first examination, at follow-up, AI correlated inversely with the mean IMT of the carotid bulb (r=-.40, P=.007), lumen diameter of the CCA (r=-.31, P=.034), and plaque score (r=-.29, P=.041), but not with IMT of the CCA (r=-.04, P=.861). There were no correlations between the E/I ratio and carotid variables. In conclusion, CAN was associated with features of carotid atherosclerosis, which, in the carotid bulb, might affect baroreceptor function with the progression of Type 2 diabetes.