Usefulness of carotid intima-media thickness measurement and peripheral B-mode ultrasound scan in the clinical screening of patients with coronary artery disease

Carotid Atherosclerosis in Predicting Coronary Artery Disease: A Systematic Review and Meta-Analysis

[Figure: see text].

Diagnostic Role of Carotid Intima-Media Thickness for Coronary Artery Disease: A Meta-Analysis

Background

The present meta-analysis was conducted to confirm whether carotid intima-media thickness (IMT) could serve as an accurate diagnostic method for coronary artery disease (CAD).

Methods

Databases of PubMed, Google Scholar, and Embase were searched for potential articles. The articles were selected according to inclusion criteria. Pooled sensitivity and specificity with corresponding 95% confidence interval (CI) were used to confirm the diagnostic role of IMT for CAD. I ² and P value were used to assess the existence of heterogeneity. I ² and P value were used to assess the existence of heterogeneity.

Results

22 eligible articles were selected in the present meta-analysis. Pooled sensitivity and specificity of IMT for diagnosing CAD were 0.68 (0.57-0.77) and 0.70 (0.64-0.75), respectively. The corresponding AUC was 0.74 (0.70-0.78). Subgroup analyses based on cutoff value of IMT were performed. A cutoff value of 1 mm was demonstrated to be much more accurate diagnostic criteria for CAD (sensitivity: 0.66; specificity: 0.79; AUC: 0.80). Sensitivity analysis indicated that the pooled results were robust. Deek's funnel plot indicated no significant publication bias (P value were used to assess the existence of heterogeneity.

Conclusion

Carotid IMT may serve as an accurate diagnostic tool. A cutoff value of 1 mm seems to provide much more accurate diagnostic results for CAD.

Circulating adipocyte fatty acid-binding protein levels predict the development of subclinical atherosclerosis in type 2 diabetes

OBJECTIVE

The aim of this study was to investigate the prospective association of circulating adipocyte fatty acid-binding protein (A-FABP) levels with the development of subclinical atherosclerosis in patients with type 2 diabetes in an 8-year prospective study.

METHODS

A total of 170 patients with newly diagnosed type 2 diabetes were recruited in the study and 133 patients completed the follow-up of 8 years. Baseline plasma A-FABP levels were measured with enzyme-linked immunosorbent assays. The role of A-FABP in predicting the development of subclinical atherosclerosis over 8 years was analyzed using multiple logistic regression.

RESULTS

Of the 133 patients without subclinical atherosclerosis at baseline, a total of 100 had progressed to subclinical atherosclerosis over 8 years. Baseline A-FABP level was significantly higher in patients who had progressed to subclinical atherosclerosis at year 8 compared with ones who had not developed subclinical atherosclerosis after adjustment for sex (15.3 [12.1-23.2] versus 13.3 [10.0-18.9] ng/ml, P = 0.021). High baseline A-FABP level was an independent predictor for the development of subclinical atherosclerosis in patients with type 2 diabetes (odds ratio: 16.24, P = 0.022).

CONCLUSIONS

Circulating A-FABP levels predict the development of subclinical atherosclerosis in type 2 diabetes patients.

Relationship between Syntax Score and prognostic localization of coronary artery lesions with conventional risk factors, plasma profile markers, and carotid atherosclerosis (CAPP Study 2)

BACKGROUND

Data concerning the relationship between cardiovascular risk factors, plasmatic markers, carotid disease and extent of coronary lesions are lacking.

OBJECTIVES

To evaluate the role of cardiovascular risk factors, plasmatic levels of high sensitivity C-reactive protein (hs-CRP), fibrinogen, lipoprotein(a), and carotid plaque extension in predicting the severity of coronary artery disease (CAD).

METHODS

We analyzed 574 subjects undergoing first coronary angiography. For angiographic analysis, we used the Syntax Score and we defined the prognostic localization of CAD as a critical stenosis of the left main and/or proximal segment of left anterior descending artery. Levels of hs-CRP >3mg/L, lipoprotein(a) plasma levels >30mg/dL and plasma fibrinogen >300mg/dL were considered critical. Significant carotid disease (SCD) was defined by the presence of lesions producing a 50% diameter stenosis with a peak systolic velocity >125cm/s. A mean carotid intima media thickness (IMT) >0.9mm was considered abnormal.

RESULTS

In the adjusted analysis the presence of SCD was found to be an independent predictor of high Syntax Score (p<0.001), while high fibrinogen levels were independently associated with the presence of CAD in prognostic localization (p=0.04). In the sub-group of patients without SCD, IMT >0.9mm was found to be an independent predictor of the presence of CAD (p<0.001).

CONCLUSIONS

SCD strongly predicts high Syntax Score, while IMT shows excellent positive predictive value for the presence of CAD. In addition, high plasma fibrinogen levels are associated with coronary stenoses in prognostic localization.

Long-term effects intensive medical therapy on the development and progression of subclinical atherosclerosis and the metabolic syndrome in Chinese patients with type 2 diabetes mellitus

BACKGROUND

Few studies have investigated the progression of subclinical atherosclerosis and metabolic syndrome (MetS) in Chinese patients with type 2 diabetes mellitus (T2DM). This study was to compare the long-term effects of intensive medical therapy on the development and progression of subclinical atherosclerosis and MetS in Chinese T2DM patients with that of a conventional treatment regimen.

METHODS

A total of 316 T2DM patients were randomized to receive conventional pharmacological treatment or intensive medical therapy, consisting of diet and exercise counseling, from 2002 to 2014 at our hospital in Changsha, China. Clinical indicators of subclinical atherosclerosis and MetS were evaluated over the 12-year follow-up period. A χ analysis or t tests was used to compare the data between the 2 groups. Risk factors for subclinical atherosclerosis were identified using Cox proportional hazard models.

RESULTS

The incidence of subclinical atherosclerosis increased in both groups over time, and did not differ significantly between the 2 groups at the end of the study. However, after 6 years of treatment, the risk of subclinical atherosclerosis was significantly lower in the intensive medical therapy group, based on intima-media thickness (IMT) measurements, compared with that in the conventional treatment (44.2% vs. 69.7%; P < 0.01). Age, creatinine, and IMT of the common iliac artery were significantly associated with subclinical atherosclerosis. Although the indicators of MetS did not differ significantly at the end of study, the success rate for the management of MetS in the intensive medical therapy group was significantly higher than that in the conventional treatment group in 2006, 2008, 2010, and 2012.

CONCLUSIONS

The incidence of atherosclerosis in the intensive medical therapy group was significantly lower than that in the conventional treatment group from 2006 to 2010 (P < 0.05), and the incidence of MetS in the intensive medical therapy group was significantly higher than that in the conventional treatment group from 2006 to 2012. Kaplan-Meier estimations showed that the risk of subclinical atherosclerosis in the intensive medical therapy group was significantly lower than that in the conventional treatment group (P < 0.001), whereas the risk of MetS was not significantly different between the treatment groups (P > 0.05).

Review: Endothelial dysfunction and pre-symptomatic atherosclerosis in type 1 diabetes — pathogenesis and identification

The vascular endothelium offers an attractive model for detecting functional abnormalities prior to structural changes in the vasculature. Demonstration of progression from endothelial dysfunction through to atherosclerosis is required. Measurements of forearm bloodflow, biochemical markers and biophysical assessments of the endothelium have been employed as research tools for investigating pre-symptomatic atherosclerosis.

However, studies examining endothelial function in type 1 diabetes have been sparse and conflicting. Differences in methodology and the study populations were potential confounding factors. Augmented vasodilatory prostanoids compensate for reduced nitric oxide bioavailability in determining endothelial function in type 1 diabetes. Hyperglycaemia appears to be the initiating event in type 1 diabetes which promotes a variety of biochemical events which are pathogenic to the endothelium.

Improved understanding of the endothelium may facilitate the development of novel diagnostic tools and interventions targeting the accelerated atherosclerosis associated with type 1 diabetes.

Carotid atherosclerosis is associated with left ventricular diastolic function

BACKGROUND

It has been reported that carotid intima-media thickness (IMT) correlates with the risk of stroke or cardiovascular disease. The purpose of this study was to analyze the relationships between echocardiographic findings and carotid atherosclerosis.

METHODS

A total of 234 patients (62 ± 15 years) were referred for echocardiography to evaluate the left ventricular (LV) function. The LV ejection fraction, the ratio of the peak velocity of early rapid filling and the peak velocity of atrial filling (E/A), and the peak early diastolic mitral annular velocity (e') were obtained by echocardiography. The maximum IMT (Max-IMT) and plaque score (PS) were measured by carotid ultrasonography within 1 month of the echocardiographic examination.

RESULTS

The mean values of Max-IMT and carotid PS were 2.41 ± 1.23 mm and 8.5 ± 6.3, respectively. The decreased mean E/A (0.94 ± 0.39) and mitral e' (5.5 ± 1.9 cm/s) indicated LV diastolic dysfunction. A good correlation was observed between Max-IMT and PS (r = 0.83, p < 0.0001). It was shown that 2.8 mm of Max-IMT was equivalent to 10.1 of carotid PS, which indicated severe carotid atherosclerosis. In multiple logistic stepwise regression analysis, among the echocardiographic parameters, only e' was independently associated with severe carotid atherosclerosis (Max-IMT ≥ 2.8 mm or PS ≥ 10.1).

CONCLUSIONS

The present study demonstrated that decreased early diastolic mitral annular velocity relates to the parameter reflecting carotid atherosclerosis. Therefore, the presence of severe carotid atherosclerosis may affect LV diastolic dysfunction.

Serum fibroblast growth factor 21 levels are related to subclinical atherosclerosis in patients with type 2 diabetes

BACKGROUND

Fibroblast growth factor 21 (FGF21), a glucose and lipid metabolic regulator, has recently been demonstrated to be associated with cardiovascular diseases (CVD) such as carotid atherosclerosis, coronary heart disease and carotid artery plaques. However, the relationship between circulating FGF21 and subclinical atherosclerosis or atherosclerosis of other arteries such as the femoral and iliac artery remains unclear. In this study, we evaluated the association of serum FGF21 with intima-media thickness (IMT) and subclinical atherosclerosis in type 2 diabetic patients.

METHODS

Serum FGF21 levels were detected by enzyme-linked immunosorbent assay in 212 newly diagnosed type 2 diabetic patients without clinical symptoms of atherosclerosis or cardiovascular diseases. IMT of the carotid, femoral, and iliac arteries were measured by high-resolution B-mode ultrasound to determine the presence of subclinical atherosclerosis, which was defined as having an IMT > 1.0 mm and/or plaque on one or more of the three arteries without any clinical manifestations. The relationship between serum FGF21 levels and subclinical atherosclerosis was analyzed.

RESULTS

Serum FGF21 levels were significantly higher in patients with subclinical atherosclerosis compared to those without [261.3 (135.1-396.4) versus 144.9 (95.9-223.0) ng/L, P < 0.001]. These differences were also observed in both men and women with subclinical atherosclerosis compared to their respective groups without [men: 243.2 (107.6-337.0) versus 136.8 (83.6-212.8) ng/L, P = 0.048; women: 292.4 (174.2-419.9) versus 160.4 (115.3-258.5) ng/L, P = 0.001]. Moreover, serum FGF21 levels showed a significantly positive correlation with carotid IMT in women (r = 0.23, P = 0.018) and with iliac IMT in both genders (women: r = 0.27, P = 0.005; men: r = 0.22, P = 0.024). Multiple logistic regression analysis further showed that serum FGF21 was an independent impact factor for subclinical atherosclerosis in patients with type 2 diabetes.

CONCLUSIONS

Serum FGF21 is elevated in newly diagnosed type 2 diabetes, and positively correlates with carotid and iliac lesions in patients with subclinical atherosclerosis, especially in women. High levels of FGF21 may be a compensatory reaction to offset atherosclerosis.

Circulating lipocalin-2 and retinol-binding protein 4 are associated with intima-media thickness and subclinical atherosclerosis in patients with type 2 diabetes

BACKGROUND

The lipocalin family proteins, including lipocalin-2 and retinol-binding protein 4 (RBP4), are adipokines closely associated with obesity-related metabolic disorders. In this study, we evaluated the association of serum lipocalin-2 and RBP4 with intima-media thickness (IMT) and subclinical atherosclerosis in type 2 diabetic patients.

METHODS AND RESULTS

Serum levels of lipocalin-2 and RBP4 were measured in 284 type 2 diabetic patients. Subclinical atherosclerosis was assessed by IMT at carotid, femoral and iliac arteries with ultrasound. Patients with subclinical atherosclerosis showed significantly higher circulating concentrations of lipocalin-2 and RBP4 when compared to those without [112.9 (86.4 to 202.1) µg/L versus 77.2(55.0-150.4) µg/L, 37.1(32.3-40.8) mg/L versus 23.2(20.1-29.2) mg/L, respectively; P = 0.002, P<0.001, respectively]. Moreover, positive correlations were observed between carotid IMT and lipocalin-2 (r = 0.170, P = 0.018) or RBP4 (r = 0.132, P = 0.040), femoral IMT and lipocalin-2 (r = 0.160, P = 0.027), as well as between iliac IMT and RBP4 (r = 0.241, P<0.001). Multiple logistic regression analysis further demonstrated that these two adipokines were independent risk factors for subclinical atherosclerosis in type 2 diabetes.

CONCLUSION

Circulating levels of lipocalin-2 and RBP4 are positively correlated with carotid IMT and subclinical atherosclerosis in type 2 diabetes, which suggests a potential role of these two lipid-binding chaperones in the pathogenesis of vascular complications of diabetes.

Correlation between coronary artery disease severity, left ventricular mass index and carotid intima media thickness, assessed by radio-frequency

Background

Intima-media thickness of the common carotid artery (CCA-IMT) is a validated marker of systemic atherosclerosis process. The aim of this study was to evaluate the association between coronary artery disease (CAD), left ventricular hypertrophy (LVH) and CCA-IMT, assessed by Radio Frequency-Quality Intima Media Thickness (^RFQIMT) method, the next generation of IMT real-time measurement, based on the direct analysis of the radiofrequency signal and endowed with high accuracy and reproducibility in early detection of arterial wall thickness.

Methods

115 patients (76 men, mean age: 65.1 ± 12 years) referred to our department and shown significant (≥ 70% luminal obstruction) stenosis at least in one major epicardial coronary artery were studied. Coronary angiograms were divided for severity and extent of the disease: 79 patients (69%) had one, 24 patients (21%) two, 12 patients (10%) three major epicardial coronary arteries with ≥ 70% stenosis. All patients underwent echocardiography and carotid ultrasound examination, assessed by RF.

Results

Dividing ^RFQIMT data in tertiles, dyslipidaemia (31 patients with IMT ≥ 1.20 mm vs 16 with IMT = 0.91-1.19 vs 25 with IMT ≤ 0.9, p = 0.004), LVMI (153.5 ± 20.6 g/m² in IMT ≥ 1.20 mm vs 131.2 ± 8.4 g/m² in IMT = 0.91-1.19 mm vs 114.3 ± 11.1 g/m² in IMT ≤ 0.9 mm, P < 0.001) and number of high stenosed coronary arteries (IMT ≥ 1.20 mm population more often showed three vessel diseases than IMT ≤ 0.90 mm one, P < 0.001) seemed to be significantly related to CCA-IMT increases. Furthermore, LVMI is positively related to IMT (r = 0.91; P < 0.001). In a multivariate regression model (R² = 0.88), ^RFQIMT remained significantly associated with the dyslipidemia (regression coefficient ± standard error [SE]: 0.057 ± 0.023; p = 0.017), LVMI (regression coefficient ± SE: 0.01 ± 0.001; P < 0.0001) and number of damaged coronaries (regression coefficient ± SE: 0.0174 ± 0.028; P < 0.0001).

Conclusions

^RFQIMT is a sophisticated method for carotid ultrasound evaluation. Its evaluation in patients with at least one important major epicardial coronary vessel stenosis would help the accuracy in the general assessment of the number of coronary lesions in these patients.

Carotid artery intima-media thickness: normal and percentile values in the Italian population (camp study)

AIMS

Carotid intima-media thickness (IMT) is one of the best non-invasive parameters for evaluating previous vascular lesions and could be used to identify a preclinical stage of the atherosclerotic process. The aim of our research was to develop an epidemiological study of the normal mean values of IMT of the common carotid artery, adjusted for age and sex, in the Italian population.

METHODS AND RESULTS

In this multicenter study, a total of 1017 patients (596 males, mean age: 58.5 + 13.2 years) were enrolled at four different Italian centers. Inclusion criteria were the absence of cardiovascular risk factors or presence of not more than one. Patients underwent two-dimensional echo-color Doppler scanning of the carotid arteries, adopting a high-definition vascular echographic apparatus and a 11-3 MHz linear electronic probe. The arithmetical mean of the IMT value was calculated. Data obtained from this study show the carotid IMT changes in relation to age and sex. In particular, it grows higher with increasing age, and is always higher in men than in women.

CONCLUSION

In relation to the percentile distribution of the values in the population analyzed, the normal range of m-IMT could be established just on the basis of the patient's age and sex. In this way, the ultrasound scan operator can rely on a simple reference scheme. This will help to refine the use of carotid ultrasound as an excellent tool for detecting asymptomatic carotid alterations and patients at high risk for cerebral and cardiovascular disease.

Cross-sectional analysis of baseline data to identify the major determinants of carotid intima-media thickness in a European population: the IMPROVE study

AIMS

The 'IMPROVE study' was designed to investigate whether cross-sectional carotid artery intima-media thickness (IMT) and overall IMT progression are predictors of new vascular events in European individuals at high risk of cardiovascular diseases. This paper reports the results of the baseline analyses aimed at identifying the major determinants of increased carotid IMT (C-IMT).

METHODS AND RESULTS

IMPROVE is a prospective, multicentre, longitudinal, observational study. A total of 3711 subjects (age range 54-79 years) with at least three vascular risk factors (VRFs) were recruited in seven centres in Finland, France, Italy, the Netherlands, and Sweden. Collected variables included clinical, biochemical, genetic, socioeconomic, psychological, nutritional, and educational data, personal and family history of diseases, drug intake, and physical activity. By multiple linear regression analysis, C-IMT was positively associated with latitude, age, gender, pulse pressure, pack-years, and hypertension, and inversely with educational level (all P < 0.0001 for IMT(mean-max)). Latitude was the strongest independent determinant of C-IMT (partial r(2) for IMT(mean-max) = 0.109, P < 0.0001) and alone accounted for nearly half of the variation explained by the regression model (partial r(2) for IMT(mean-max) = 0.243, P < 0.0001). The geographical gradient for C-IMT paralleled the well-known north-to-south cardiovascular mortality gradient (r(2) for IMT(mean) = 0.96).

CONCLUSION

Latitude is an important determinant of C-IMT, which is not explained by between-country differences in established VRFs. Other unknown contributory mechanisms such as heritable, nutritional, or environmental factors may be important in the genesis of this geographical gradient.

Carotid Ultrasound Screening for Coronary Heart Disease: Results Based on a meta-analysis of 18 Studies and 44,861 Subjects

Background

Carotid artery ultrasound is a possible screening test for future coronary heart disease (CHD) events to select individuals for preventive treatment.

Objectives

To assess the screening performance of carotid artery intima-media thickness (IMT) and carotid plaque in the identification of individuals with CHD.

Methods

meta-analysis of case-control and cohort studies, reporting carotid IMT or plaque in individuals with and without CHD. Screening performance (detection rates [DRs] for specified false-positive rates [FPRs]) was assessed from the relative Gaussian distributions of IMT among individuals with and without CHD and from the proportion of affected and unaffected individuals with plaque.

Results

Eighteen studies, involving 2920 individuals with CHD (mean age range 46–73 years) and 41,941 without (aged 44–73 years) were included in the meta-analysis. For plaque the DR was 62% for an FPR of 30%; likelihood ratio (2.1 [95% CI 1.6–2.4]). For IMT, the DR was 65% for the same 30% FPR (IMT cut-off ≥0.82 mm); likelihood ratio 2.2 (1.9–2.5). The results were similar in case-control and cohort studies.

Conclusion

Neither carotid plaque nor IMT has a CHD screening performance that is sufficiently discriminatory between affected and unaffected individuals to be a worthwhile screening test.

A novel 3-dimensional micro-ultrasound approach to automated measurement of carotid arterial plaque volume as a biomarker for experimental atherosclerosis

Improved methods for non-invasive in vivo assessment are needed to guide development of animal models of atherosclerosis and to evaluate target engagement and in vivo efficacy of new drugs. Using novel 3D-micro-ultrasound technology, we developed and validated a novel protocol for 3D acquisition and analysis of imaging to follow lesion progression in atherosclerotic mice. The carotid arteries of ApoE receptor knockout mice and normal control mice were imaged within the proximal 2mm from the aortic branch point. Plaque volume along that length was quantified using a semi-automated 3D segmentation algorithm. Volumes derived by this method were compared to those calculated using 3-D histology post-mortem. Bland-Altman comparison revealed close correlation between these two measures of plaque volume. Furthermore, using a segmentation technique that captures early positive and 33 week negative remodeling, we found evidence that plaque volume increases linearly over time. Each animal and each plaque served as its own control, allowing accurate comparison. The high fidelity anatomical registration of this protocol provides increased spatial resolution and therefore greater sensitivity for measurement of plaque wall size, an advance over 2-dimensional measures of intimal-medial-thickening. Further, 3-dimensional analysis ensures a point of registration that captures functional markers in addition to the standard structural markers that characterize experimental atherosclerosis. In conclusion, this novel imaging protocol provides a non-invasive, accurate surrogate marker for experimental atherosclerosis over the life of the entire lesion.

Comparison of intensive and low-dose atorvastatin therapy in the reduction of carotid intimal-medial thickness in patients with coronary heart disease

BACKGROUND

Intensive statin therapy has been shown to improve prognosis in patients with coronary heart disease (CHD). It is unknown whether such benefit is mediated through the reduction of atherosclerotic plaque burden.

AIM

To examine the efficacy of high-dose atorvastatin in the reduction of carotid intimal-medial thickness (IMT) and inflammatory markers in patients with CHD.

DESIGN

Randomised trial.

SETTING

Single centre.

PATIENTS

112 patients with angiographic evidence of CHD.

INTERVENTIONS

A high dose (80 mg daily) or low dose (10 mg daily) of atorvastatin was given for 26 weeks.

MAIN OUTCOME MEASURES

Carotid IMT, C-reactive protein (CRP) and proinflammatory cytokine levels were assessed before and after therapy.

RESULTS

The carotid IMT was reduced significantly in the high-dose group (left: mean (SD), 1.24 (0.48) vs 1.15 (0.35) mm, p = 0.02; right: 1.12 (0.41) vs 1.01 (0.26) mm, p = 0.01), but was unchanged in the low-dose group (left: 1.25 (0.55) vs 1.20 (0.51) mm, p = NS; right: 1.18 (0.54) vs 1.15 (0.41) mm, p = NS). The CRP levels were reduced only in the high-dose group (from 3.92 (6.59) to 1.35 (1.83) mg/l, p = 0.01), but not in the low-dose group (from 2.25 (1.84) to 3.36 (6.15) mg/l, p = NS). A modest correlation was observed between the changes in carotid IMT and CRP (r = 0.21, p = 0.03).

CONCLUSIONS

In patients with CHD, intensive atorvastatin therapy results in regression of carotid atherosclerotic disease, which is associated with reduction in CRP levels. On the other hand, a low-dose regimen only prevents progression of the disease.

Carotid intima-media thickness as a surrogate marker for cardiovascular disease in intervention studies

BACKGROUND

Cardiovascular trials using clinical endpoints to assess efficacy typically require follow-up of large numbers of participants for 3-5 years. This disadvantage has encouraged the search for well-validated surrogate markers for cardiovascular disease (CVD). These markers may provide earlier indications of efficacy in trials involving fewer participants. One approach gaining interest in recent years is the measurement of atherosclerotic progression, a major underlying cause of CVD.

SCOPE

This review article aims to further substantiate the evidence supporting the use of measurement of carotid intima-media thickness (CIMT) as a surrogate marker for atherosclerosis and cardiovascular risk.

FINDINGS

CIMT has consistently been related to future CVD events in population studies. CIMT is significantly related with other markers for CVD risk, such as elevated levels of risk factors and presence of atherosclerosis in the coronary arteries. Furthermore, almost all lipid-lowering trials and a large number of blood pressure lowering trials have consistently shown a reduction in progression of CIMT. In addition, the ultrasound technique for measuring CIMT is safe and highly reproducible.

CONCLUSION

Thus, CIMT may be used as a surrogate endpoint in clinical trials to enable the benefits of new therapies or regimens to be more rapidly translated into clinical practice.

Atherosclerosis found on carotid ultrasonography is associated with atherosclerosis on coronary intravascular ultrasonography

OBJECTIVE

Little has been reported on the relationship between left main coronary artery atherosclerosis and carotid ultrasonographic results. We evaluated the association between carotid and coronary atherosclerosis assessed by coronary intravascular ultrasonography (IVUS) in 45 patients.

METHODS

We counted the number of plaques with intima-media thickness (IMT) greater than or equal to 1.1 mm and calculated a plaque score by summing all plaque thicknesses. With the use of IVUS, the percent plaque area was calculated at the proximal, middle, and distal sites of the left main coronary artery. The maximum percent plaque area and mean percent plaque area of the 3 sites were also calculated. Relationships among the degree of left main coronary artery atherosclerosis and carotid atherosclerosis and vascular risk factors were evaluated.

RESULTS

The mean percent plaque area and maximum percent plaque area were increased in men and in patients with hypertension compared with women and those without hypertension (P < .1). Both the average of the maximum common carotid IMT and plaque number were correlated with both the mean percent plaque area and maximum percent plaque area (P < .05). Men, the presence of hypertension, and the average of the maximum common carotid IMT were correlated with both the mean percent plaque area and maximum percent plaque area by multiple linear regression analysis (P < .05).

CONCLUSIONS

The average of the maximum common carotid IMT was significantly correlated with left main coronary artery atherosclerosis evaluated by IVUS.

Distinguishing between ischemic and non-ischemic dilated cardiomyopathy based on non-invasive ultrasonic evaluation of peripheral arteries

BACKGROUND: Recently, high-frequency transducers have been introduced in echocardiography laboratories to non-invasively evaluate peripheral arteries. Our aim was to assess the usefulness of these non-invasive vascular ultrasonic techniques in differentiating between ischemic and non-ischemic dilated cardiomyopathy. METHODS: Forty patients with dilated cardiomyopathy of uncertain origin who underwent echocardiographic examination were studied. In all patients, carotid, femoral, and brachial arteries were scanned using high-frequency transducers in order to detect atherosclerotic plaques and to measure intima-media wall thickness. Also, flow-mediated vasodilation was measured at the brachial artery. RESULTS: Of the 40 patients studied, 24 (60%) had significant coronary lesions. In patients with ischemic cardiomyopathy, carotid plaques were found more frequently (79% vs. 25%, p=0.001), and intima-media wall thickness was higher in carotid (1.14+/-0.23 vs. 0.84+/-0.20 mm, <0.001), femoral (1.21+/-0.15 vs. 0.90+/-0.17 mm, p<0.001), and brachial (0.85+/-0.11 vs. 0.68+/-0.12, p<0.001) arteries. Carotid intima-media thickness of 1 mm or more was 83% sensitive and 69% specific for the diagnosis of ischemic cardiomyopathy. The highest diagnostic accuracy for any isolated vascular finding was obtained for femoral intima-media thickness greater than 1.1 mm (83% sensitivity, 88% specificity) and for brachial intima-media thickness greater than 0.7 mm (88% sensitivity and 81% specificity). The highest sensitivity (92%) was obtained for the presence of 1 or more vascular findings, and the highest specificity (94%) for 3 or more vascular findings. CONCLUSION: Non-invasive assessment of peripheral arteries is of help in differentiating between ischemic and non-ischemic dilated cardiomyopathy. These ultrasonic techniques should be considered as complementary examinations in the evaluation of patients with dilated cardiomyopathy in echocardiography laboratories.

Atherosclerotic disease regression with statins: studies using vascular markers

Vascular imaging techniques enable identification of atherosclerosis in the sub-clinical phase and allow assessment of interventions to modify disease progression. Angiography has limited utility for tracking the progression of atherosclerosis because of its invasive nature, limited sensitivity for detecting early lesions and relatively low interscan reproducibility. Intravascular ultrasound (IVUS)an electron beam computed tomography (EBCT) are more sensitive and reproducible; however, available data on their ability for tracking disease progression are few. Measurement of carotid intima media thickness (CIMT) by B-mode ultrasound is a well-validated procedure for this application. In comparison with angiography, CIMT demonstrates greater sensitivity for detecting early atherosclerosis and lipid-rich plaques that are vulnerable to rupture. Continued validation and development of imaging techniques, such as magnetic resonance imaging (MRI), will facilitate the assessment of atherosclerosis progression in intervention studies. Stains are effective low-density lipoprotein cholesterol (LDL-C) lowering agents, and imaging studies have demonstrated their ability to slow progression and promote regression of atherosclerosis. The benefits of therapy on atherosclerosis regression appear to extend to soft atherosclerotic plaques that are still developing and treatment effects are independent of baseline LDL-C level. Hence, imaging studies support early intervention with statins in coronary heart disease patients, irrespective of lipid level.

Carotid intima-media thickness and coronary artery disease: an Indian perspective

To determine whether carotid intima-media thickness is associated with coronary artery disease and cardiovascular risk factors in the Indian population, carotid intima-media thickness was measured using high-resolution B-mode ultrasonography in 101 patients with coronary artery disease and 140 control subjects. Carotid intima-media thickness was measured at 3 predefined sites on each side. The maximum carotid intima-media thickness was significantly higher in the coronary disease group compared to the controls (1.02 vs. 0.80 mm). The average intima-media thickness was also significantly higher in the coronary disease group (0.82 vs. 0.67 mm). On multivariate logistic regression analysis, carotid intima-media thickness was the only factor found to be an independent predictor of coronary artery disease. There was a significant association between risk factor count and the average and maximum intima-media thickness values in the combined study population. These results indicate that raised values of average and maximum carotid intima-media thickness are significantly associated with the presence of coronary artery disease and this association is independent of the presence of other conventional cardiovascular risk factors.

Recognition of patients with cardiovascular disease by artificial neural networks

BACKGROUND

Artificial neural networks (ANNs) are computer algorithms inspired by the highly interactive processing of the human brain. When exposed to complex data sets, ANNs can learn the mechanisms that correlate different variables and perform complex classification tasks.

AIMS

A database, of 949 patients and 54 variables, was analysed to evaluate the capacity of ANNs to recognise patients with (VE+, n = 196) or without (VE-, n = 753) a history of vascular events on the basis of vascular risk factors (VRFs), carotid ultrasound variables (UVs) or both.

METHOD

The performance of ANN was assessed by calculating the percentage of correct identifications of VE+ and VE- patients (sensitivity and specificity, respectively) and the prediction accuracy (weighted mean between sensitivity and specificity).

RESULTS

The results showed that ANNs can be trained to identify VE+ and VE- subjects more accurately than discriminant analyses. When VRFs and UVs were used as input variables, the prediction accuracies of the ANN providing the best results were 80.8% and 79.2%, respectively. The addition of gender, age, weight, height and body mass index to UVs increased accuracy of prediction to 83.0%. When the ANNs were allowed to choose the relevant input data automatically (I.S. system-Semeion), 37 variables were selected among 54, five of which were UVs. Using this set of variables as input data, the performance of the ANNs in the classification task reached a prediction accuracy of 85.0%. with the 92.0% correct classification of VE+ patients.

CONCLUSIONS

Artificial neural network technology is highly promising in the development of accurate diagnostic tools designed to recognize patients at high risk of cardiovascular diseases.

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study: design and baseline characteristics

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) trial is a three-arm, randomized, placebo-controlled, double-blind study to determine the effect of tibolone 2.5 mg (Org OD 14) and continuous combined conjugated equine estrogens plus medroxyprogesterone acetate (0.625 mg/2.5 mg respectively) on progression of intima-media thickness of the carotid arteries and bone mineral density of the lumbar vertebrae and proximal femur in postmenopausal women. A total of 866 healthy postmenopausal women were recruited in six U.S. centers and five European centers. Duplicate carotid ultrasound examinations of the common carotid artery, the carotid bifurcation, and the internal carotid artery were performed at baseline. Single measurements of bone mineral density of the lumbar vertebrae and proximal femur were obtained at baseline. After randomization, ultrasound examinations were repeated every 6 months for 36 months following baseline, with a duplicate examination at the end of the study. Bone mineral density was measured every 12 months throughout the trial. The primary outcome is change in mean common carotid intima-media thickness (CIMT), defined as the average of the intima-media thickness measurements performed circumferentially at predefined angles for the near and far wall of 10-mm segments of the right and left distal common carotid arteries. Unique new features of the OPAL study are the specifically developed OPAL ultrasound protocol, yielding highly reproducible CIMT measurements, and the use of two experienced core laboratories for CIMT readings (one in the United States and one in Europe) with one common quality assurance and control program. The OPAL study is a large, placebo-controlled trial evaluating the effects of tibolone, as well as one of the first large randomized studies to determine the effects of continuous combined estrogen-progestin therapy on carotid atherosclerosis in healthy postmenopausal women. The OPAL study results are expected to complement other studies on atherosclerosis progression in healthy postmenopausal women.

Carotid intima-media thickness measurements in intervention studies: design options, progression rates, and sample size considerations: a point of view

BACKGROUND

Carotid intima-media thickness (CIMT) measurements are currently widely used in randomized controlled trials (RCTs) to study the efficacy of interventions. In designing a RCT with CIMT as a primary outcome, several ultrasound options may be considered. We discuss the various options and provide a pooled estimate of CIMT progression. In addition, we quantify the effect of these choices on the sample size for a RCT.

SUMMARY OF COMMENT

To estimate the average CIMT progression rate, we performed a pooled analysis using CIMT progression rates of control groups from published RCTs. The pros and cons of the following ultrasound options are discussed: which arterial segments may be studied; whether near and far wall CIMT measurements should be performed; whether a single image (1 angle of interrogation) or multiple images (more angles of interrogation) should be used; whether a manual or an automated edge detection reading system should be used; and whether images should be read in a random fashion or in batches. The pooled analysis showed an annual rate of change in mean common CIMT of 0.0147 mm (95% CI, 0.0122 to 0.0173) and in mean maximum CIMT of 0.0176 mm (95% CI, 0.0149 to 0.0203).

CONCLUSIONS

Given the current evidence together with our experience with recently developed ultrasound protocols, we favor the use of mean maximum CIMT rather than mean common CIMT as the primary outcome measure in RCTs designed to evaluate the efficacy of pharmacological and nonpharmacological interventions in carotid artery atherosclerosis.

Extent and severity of atherosclerotic vascular disease in patients undergoing coronary angiography--the Kuwait Vascular Study

Only a few angiographic studies have correlated the presence and severity of coronary artery disease with atherosclerosis in other arteries. The presence of disease in more than 1 area clearly has important implications on management. One hundred and seventy eight patients had angiographic evaluation of their peripheral arteries and abdominal aorta after routine diagnostic coronary angiography. The extent and severity of vascular disease was correlated with those of coronary artery disease. Of the 178 patients, 73.6% were men (mean age +/- sd was 52.93 +/- 10.12 years). Hypercholesterolemia (59%), systemic hypertension (56.7%) and diabetes mellitus (50.6%) were the major risk factors. Triple-vessel coronary artery disease was present in 48.9%, and 13.5% had normal coronaries. A new atherosclerotic vascular disease score, which reflects the presence and severity of atherosclerotic vascular disease elsewhere, was seen to correlate significantly with the extent of coronary artery disease. Of particular interest was the involvement of the first part of the vertebral artery in 41.6% of patients. The combined involvement of the abdominal aorta, renal artery, and iliac artery segments (together referred to as the lower body segment) was seen almost exclusively in those with 2- or 3-vessel coronary artery disease. Also there was a direct correlation between the extent of coronary artery disease and the score in the lower body segment as opposed to the upper body segment (subclavian, vertebral, and internal mammary arteries). The presence of atherosclerotic vascular disease correlated with the severity of coronary artery disease, particularly in respect to disease in the lower body segment. Thus early detection of such disease in the iliac or femoral arteries has a potential for early diagnosis of significant coronary artery disease.

Carotid artery intimal-medial thickness: indicator of atherosclerotic burden and response to risk factor modification

BACKGROUND

A number of studies have used B-mode ultrasound to measure carotid intimal-medial thickness as an indicator of the severity of carotid atherosclerosis.

METHODS

We reviewed the available data on carotid intimal-medial thickness in defining severity of atherosclerosis, with the use of high-quality studies that addressed clinical end points.

RESULTS

Data from multiple studies demonstrate a high degree of reproducibility in measurements of intimal-medial thickness. A number of agents that include 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, angiotensin-converting enzyme inhibitors, and insulin sensitizers reduce carotid intimal-medial thickness and cardiovascular events, such as myocardial infarction and stroke.

CONCLUSIONS

In this review article, various methods of measuring carotid intimal-medial thickness are examined and critiqued. In addition, the effects of various lifestyle modifications and therapeutic agents on intimal-medial thickness and cardiovascular end points are evaluated.

Intima-media thickness of the common carotid arteries is related to coronary atherosclerosis and left ventricular hypertrophy in older adults

Increased intima-media thickness (IMT) of the common carotid arteries is related to generalized atherosclerosis and increased risk of future myocardial infarction and cerebrovascular disease. An association between IMT and the presence of coronary artery disease (CAD) has been documented, but controversial data have been found about the relation between increased IMT and the extent of CAD. An association between carotid atherosclerosis and cardiac remodeling has also been reported. It is still unclear whether increased IMT of the common carotid arteries might be associated with prevalent cardiovascular disease in older adults. This study included 70 patients, 37 with CAD and 33 matched for age and gender without CAD. All patients underwent a baseline clinical examination, B-mode ultrasound of the carotid arteries, and echocardiography. The authors evaluated the possible association between increased IMT with the presence and extent of CAD and the presence of left ventricular hypertrophy (LVH). The patients with CAD had significantly increased IMT compared to patients without CAD. IMT was found to increase with the number of coronary vessels affected, after adjustment for age, gender, hypertension, hypercholesterolemia, diabetes mellitus, and smoking habits. The test for trend was highly significant (p<0.001). Patients with LVH had significantly increased IMT as compared with patients without LVH. IMT of the common carotid arteries was increased in the presence of CAD and increased with the number of coronary vessels diseased. Second, the authors found that IMT of the common carotid arteries was significantly increased in patients with LVH. Increased IMT, as an indicator of subclinical cardiovascular disease, may help to identify patients who would benefit from aggressive therapeutic measures.

Association of carotid artery intima-media thickness with complex aortic atherosclerosis in patients with recent stroke

This study was undertaken to determine whether carotid intima-media thickness can predict complex aortic atherosclerosis. A retrospective review was conducted of 64 consecutive patients who underwent transesophageal echocardiography and carotid ultrasonography for evaluation of recent ischemic stroke at MCP Hahnemann University, Medical College of Pennsylvania Hospital between January 1, 1999, and December 31, 1999. The mean age was 65+/-14 years and 59% of the patients were women. Thirty-nine patients (61%) had carotid atherosclerosis (defined as an intima-media thickness > or =1 mm) and seven patients (11%) had complex aortic atherosclerosis (defined as the presence of protruding atheroma > or =4 mm thick, mobile atherosclerotic debris, or plaque ulceration in any aortic segment by transesophageal echocardiography). Compared to patients without complex aortic atherosclerosis, patients with complex aortic atherosclerosis were more likely to have hypercholesterolemia (19% vs 57%, p = 0.05) and a carotid intima-media thickness of 2 mm or greater (35% vs 86%, p = 0.02). A carotid intima-media thickness of 2 mm or more had 86% sensitivity, 65% specificity, 23% positive predictive value, 97% negative predictive value, 2.5 positive likelihood ratio, and 0.22 negative likelihood ratio for the diagnosis of complex aortic atherosclerosis. Carotid intimamedia thickness measurement can be used to noninvasively estimate the probability of complex aortic atherosclerosis. A carotid intima-media thickness less than 2 mm makes complex aortic atherosclerosis very unlikely.

Effect of postmenopausal hormone replacement on atherosclerosis in femoral arteries

OBJECTIVES

On the basis of epidemiological and experimental data, it has been supposed that hormone replacement therapy (HRT) inhibits atherosclerosis in postmenopausal women. This randomized controlled trial examined whether 1 mg 17beta-estradiol daily, combined cyclically with 0.025 mg gestodene in every month (HRT 1), or in every third month (HRT 2) slows the increase of intima-media thickness in femoral arteries compared with no HRT.

METHODS

Healthy postmenopausal women (n=321) with an increased risk for future vascular disease as indicated by >1 mm of intima-media thickness in the carotid arteries were equally randomized to one of the three groups for 48 weeks. Ultrasound scans of femoral arteries were recorded at study start and study end, together with a thorough clinical examination and laboratory work-up.

RESULTS

Complete scans were obtained in 260 of the 264 subjects who participated until study end. Mean maximum intima-media thickness of four femoral artery segments (common and superficial, both sides) was 0.93+/-0.37 mm (mean+/-S.D.) at study start. It increased by 0.02+/-0.05, 0.02+/-0.05, and 0.03+/-0.05 mm in the HRT 1, HRT 2 and no HRT groups, respectively (HRT 1 versus no HRT, HRT 2 versus no HRT; both P>0.2). Compared with no HRT, HRT significantly lowered follicle stimulating hormone, low-density lipoprotein cholesterol, and fibrinogen.

CONCLUSIONS

In this 1-year trial, irrespective of the progestogen dose used, HRT with 1 mg 17 beta-estradiol did not inhibit progression of femoral artery atheroslerosis in postmenopausal women with subclinical vascular disease.