Predictive value of noninvasive measures of atherosclerosis for incident myocardial infarction: the Rotterdam Study

Increased prevalence of coronary artery disease risk markers in patients with chronic hepatitis C--a cross-sectional study

Objective

Chronic hepatitis C is a global health problem and has been associated with coronary artery disease. Our aim was to examine the prevalence of coronary artery disease risk markers including endothelial biomarkers in patients with chronic hepatitis C and matched comparisons without manifest cardiovascular disease or diabetes in a cross-sectional design.

Methods

Sixty patients with chronic hepatitis C (mean age 51 years) were recruited from the Department of Infectious Diseases at Copenhagen University Hospital, and compared with 60 age-matched non-hepatitis C virus-infected individuals from a general population survey. We examined traditional coronary artery disease risk factors, metabolic syndrome, carotid intima media thickness, and a range of endothelial biomarkers.

Results

Patients with chronic hepatitis C had more hypertension (40% versus 25%, prevalence ratio [PR] 1.6; 95% confidence interval [CI] 0.9–2.7) and smoked more (53% versus 38%, PR 1.4; 95% CI 0.9–2.1). The two groups had similar body mass index (mean 25.0 versus 25.7 kg/m²), whereas those with chronic hepatitis C had less dyslipidemia (including significantly lower low-density lipoprotein and cholesterol/high-density lipoprotein ratio), higher glycosylated hemoglobin level (mean 6.2 versus 5.7, difference of means 0.5; 95% CI 0.3–0.8), and a higher prevalence of metabolic syndrome (28% versus 18%, PR 1.6; 95% CI 0.8–3.0). Increased carotid intima media thickness above the standard 75th percentile was seen more frequently in chronic hepatitis C (9% versus 3%, PR 1.7; 95% CI 0.4–6.7), though difference of means was only 0.04 mm (95% CI 0.00–0.10). Patients with chronic hepatitis C had increased hsCRP (high-sensitivity C-reactive protein), sICAM-1 (soluble intercellular adhesion molecule-1), sVCAM-1 (soluble vascular cell adhesion molecule-1), and soluble E-selectin, but lower levels of tPAI-1 (tissue-type plasminogen activator inhibitor-1), MMP9 (matrix metallopeptidase 9), and MPO (myeloperoxidase) than their comparisons.

Conclusion

Our findings indicate that patients with chronic hepatitis C have increased prevalence of several coronary artery disease risk markers. These results may be important when evaluating the appropriateness of screening for coronary artery disease and its risk factors in chronic hepatitis C.

Abdominal aortic calcification and renal resistive index in patients with chronic kidney disease: is there a connection?

BACKGROUND

We aimed to evaluate the relationship between abdominal aortic calcification (AAC) and renal resistive index (RRI), parameters associated with cardiovascular outcome, in non-dialysis chronic kidney disease (CKD) patients.

METHODS

Seventy-seven stable patients mainly in CKD stages 3B and 4 (44 and 28%), median age 69 years, with a positive history of systemic atherosclerosis were prospectively enrolled. RRI, carotid intima-media thickness (IMT), Kauppila score for AAC (AACs), cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) were assessed. Traditional and non-traditional atherosclerosis risk factors were also evaluated.

RESULTS

Vascular (50%), diabetic (26%) and primary glomerular nephropathies (8 %) were the main causes of CKD. AAC was highly prevalent (77%). In the whole cohort, RRI was directly related to AACs (rs = 0.35, p < 0.001). AACs correctly identified patients with RRI >0.7 in 69% (56-81%) of cases, a cut-off of 5 resulting the best combination of sensitivity (65%) and specificity (68%). Compared to those with AACs <5, patients with AACs >5 were older, had higher serum cholesterol, C-reactive protein and IMT, lower ABI, but similar CAVI, estimated glomerular filtration rate, serum calcium and phosphate. In the whole cohort, AACs was negatively correlated with ABI (rs = -0.51, p < 0.001) and positively with IMT (rs = 0.27, p = 0.01), supporting a role for Kauppila score in integrating information on both intra- and extrarenal atherosclerosis.

CONCLUSIONS

As Kauppila score correlates with RRI in non-dialysis CKD patients, it could be a fast, convenient and relatively inexpensive tool for estimating RRI, and consequently the intrarenal vascular status, but further research is warranted.

Risk factors associated with myocardial infarction in venous thromboembolism patients

BACKGROUND

Although risk factors for MI have been described in the general population, there is a lack of data on the assessment of risk factors associated with MI in venous thromboembolism (VTE) patients.

OBJECTIVE

The purpose of this study was to identify risk factors associated with MI in VTE patients.

PATIENTS AND METHODS

Health insurance claims between January 2004 and September 2008 from the Ingenix IMPACT database were analyzed. Patients aged ≥18 years were identified as of the date of their first VTE diagnosis with ≥1 year of continuous insurance coverage before the index VTE. The risk of MI for VTE patients with 1, 2, and ≥3 major risk factors as identified by published guidelines was calculated. Multivariate Cox proportional hazard models were conducted to identify the most predictive risk factors associated with MI.

RESULTS

A total of 177,885 VTE patients were identified; 4412 (2.5%) developed an MI during a mean follow-up period of 1.3 years. Previous MI, age (≥65 years), and coronary artery disease were the most predictive risk factors of MI with adjusted hazard ratios (HRs; 95% CI) of 5.47 (5.01-5.97), 1.78 (1.66-1.91), and 1.60 (1.48-1.74), respectively. Adjusted HRs (95% CI) for VTE patients with 1, 2, and ≥3 major risk factors relative to no major risk factor were 2.34 (1.94-2.81), 3.21 (2.67-3.85), and 6.93 (5.85-8.22), respectively.

LIMITATIONS

These included possible inaccuracies or omissions in diagnoses, classification bias such as the identification of false-positive MI events, and the likely undercoding of some risk factors such as social issues.

CONCLUSIONS

Traditional major cardiovascular risk factors are also predictive of MI in VTE patients. Having multiple major risk factors significantly increases the probability of developing MI events in VTE patients.

The prevalence of aortic calcification on vertebral fracture assessment imaging among patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) are at increased risk of osteoporosis (OP) and cardiovascular disease (CVD). Dual-energy X-ray absorptiometry scans have been validated for identifying patients with RA at risk for fracture. Reliable CVD risk stratification remains an unmet need in this population. Vertebral fracture assessment (VFA)-detected abdominal aortic calcification (AAC) has been validated as a marker of CVD in other populations, but the prevalence among patients with RA is unknown. In this study, we determined the prevalence and severity of AAC on VFA scans in a cohort of patients with RA. AAC was detected in 211 of the 603 (35%) eligible subjects; 24% were graded as severe. In multivariable analyses, the presence of AAC was significantly associated with longer disease duration and higher disease activity (p<0.05). Further studies are needed on the relationship between AAC and CVD in patients with RA.

Carotid intima-media thickness: Current evidence, practices, and Indian experience

As the developed and developing nations cope up with increasing predisposition to cardiovascular diseases (CVD) by adopting lifestyle changes the burden of coronary artery disease continues to rise globally. The presence of modifiable risk factors, which account for more than 90% of the cardiovascular (CV) risk, cannot always be interpreted as the presence of atherosclerotic heart disease and absence of modifiable risk factors do not guarantee absence of atherosclerotic changes in the arterial tree. Increasing awareness about primordial prevention and primary prevention of CVD is of vital importance in such scenarios. Ultrasonographic measurement of intima media thickness has been reported as a procedure to detect the early stages of atherosclerosis. Carotid intima media thickness (CIMT) testing is a safe, noninvasive and cost effective method to detect early atherosclerotic vascular diseases. This method of CV risk evaluation drew attention worldwide and of Indian physicians because of its feasibility in Indian population. Hence, detection and management of atherosclerosis in asymptomatic individuals will go a long way in preventing atherosclerotic diseases and prolonging survival and improving quality of life.

Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events

BACKGROUND

The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN

An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS

Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS

In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women.

CONCLUSIONS

An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

The Rotterdam Study: 2014 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Distribution of abdominal aortic calcium by computed tomography: impact of analysis method on quantitative calcium score

RATIONALE AND OBJECTIVES

Abdominal aortic calcification (AAC) can be quantified using computed tomography (CT), but imaging planes are prescribed based on bony landmarks, so that individual variation between the landmark and the aortoiliac junction can result in variable aortic coverage. In the Framingham CT substudy, we scanned a 15-cm (Z-direction) abdominal segment cranial to the S1 vertebral body. We sought to determine the range and distribution of length of aorta scanned and the distribution of AAC within the abdominal aorta and to compare burden of AAC measured from fixed-length segments versus AAC from all slices cranial to the aortoiliac bifurcation.

MATERIALS AND METHODS

AAC was quantified by modified Agatston score (AS) in 100 Framingham Heart Study participants (60 ± 13 years old, 51 men). We compared the AS measured from 5-cm and 8-cm segments with the ASALL (total visualized aorta).

RESULTS

Of 100, 73 participants had AAC >0. The total length of aorta imaged was ≥8 cm in 84% of participants. Qualitatively, 5-cm and 8-cm segments correctly identified 96% and 99%, respectively, of participants as having or not having AAC. Quantitatively, AS8cm was within 20% of ASALL in four-fifths and within 30% of ASALL in nine-tenths of participants. AS5cm more severely underestimated ASALL.

CONCLUSION

The use of S1 as the caudal imaging landmark in a 15-cm slab yields ≥8 cm aortic coverage in most adults. Both 5-cm and 8-cm analysis strategies are comparable to analyzing the total visualized abdominal aorta for prevalent AAC, but only 8-cm segment analysis yields quantitatively similar measures of AAC.

Vertebral fractures and abdominal aortic calcification in postmenopausal women. A cohort study

INTRODUCTION

Vertebral fracture assessment (VFA) imaging with a bone densitometer can simultaneously detect prevalent vertebral fractures (VFs) and abdominal aortic calcification (AAC).

OBJECTIVE

To study the relation between the prevalence of VFs using VFA in asymptomatic women and the prevalence and severity of AAC.

DESIGN

This is a cross-sectional study.

SETTINGS

Subjects were recruited in a third care center from asymptomatic women selected from the general population.

PARTICIPANTS

We enrolled 908 post-menopausal women with a mean age of 60.9 years ± 7.7 (50 to 91) with no prior known diagnosis of osteoporosis or taking medication interfering with bone metabolism.

PRIMARY AND SECONDARY OUTCOME MEASURES

Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative (SQ) approach and morphometry. VFA images were scored for AAC using a validated 24 point scale.

RESULTS

VFA images showed that 179 of the participants (19.7%) had at least one grade 2/3 VF, 81% did not have any detectable AAC whereas the prevalence of significant atherosclerotic burden, defined as AAC score of 5 or higher, was 12%. The group of women with 2/3 VFs had a statistically significant higher AAC score and higher proportion of subjects with extended AAC, and lower weight, height, and lumbar spine and hip BMD and T-scores than those without VFA-identified VFs. Multiple regression analysis showed that the presence of grade 2/3 VFs was significantly associated with age, BMI, history of peripheral fracture, AAC score ≥ 5 and densitometric osteoporosis.

CONCLUSION

In post-menopausal women, extended AAC is independently associated with prevalent VFs regardless of age, BMI, history of fractures, and BMD.

Clinical factors associated with carotid plaque and intima-medial thickness in HIV-infected patients

PURPOSE

HIV-infected patients are at increased risk for cardiovascular disease, which may be mediated in part by inflammation. This study aimed to evaluate the risk factors of carotid plaque, and clinical factors associated with carotid atherosclerosis measured by carotid intima-medial thickness (cIMT) in HIV patients.

MATERIALS AND METHODS

Clinical and cardiometabolic factors as well as cIMT were prospectively measured in 145 HIV-infected participants who had received combined antiretroviral therapy for ≥6 months. The mean value of the bilateral average cIMT level was used as Mean-IMT in the analysis, and the greatest value among the measured cIMT levels was used as Max-IMT.

RESULTS

Among 145 patients, 34 (23.4%) had carotid plaque. Multivariate logistic regression analysis revealed three independent risk factors of carotid plaque: old age [odds ratio (OR) 6.16, 95% confidence interval (CI) 1.09-34.88; p=0.040], hypertension (OR 12.62, 95% CI 1.72-92.49; p=0.013) and higher low-density lipoprotein cholesterol (LDL-C) (OR 1.08, 95% CI 1.01-1.16; p=0.039). Levels of estimated glomerular filtration rate were inversely associated with Mean-IMT (r=-0.379, p<0.001) and Max-IMT (r=-0.389, p<0.001). Stepwise multivariate regression analyses revealed that age, total cholesterol and fasting glucose were positively correlated with cIMT, independent of other risk factors.

CONCLUSION

The presence of hypertension, old age and a higher level of LDL-C were independent risk factors of carotid plaque among HIV-infected subjects.

Automated analysis of intima-media thickness: analysis and performance of CARES 3.0

OBJECTIVES

In recent years, the use of computer-based techniques has been advocated to improve intima-media thickness (IMT) quantification and its reproducibility. The purpose of this study was to test the diagnostic performance of a new IMT automated algorithm, CARES 3.0, which is a patented class of IMT measurement systems called AtheroEdge (AtheroPoint, LLC, Roseville, CA).

METHODS

From 2 different institutions, we analyzed the carotid arteries of 250 patients. The automated CARES 3.0 algorithm was tested versus 2 other automated algorithms, 1 semiautomated algorithm, and a reader reference to assess the IMT measurements. Bland-Altman analysis, regression analysis, and the Student t test were performed.

RESULTS

CARES 3.0 showed an IMT measurement bias ± SD of -0.022 ± 0.288 mm compared with the expert reader. The average IMT by CARES 3.0 was 0.852 ± 0.248 mm, and that of the reader was 0.872 ± 0.325 mm. In the Bland-Altman plots, the CARES 3.0 IMT measurements showed accurate values, with about 80% of the images having an IMT measurement bias ranging between -50% and +50%. These values were better than those of the previous CARES releases and the semiautomated algorithm. Regression analysis showed that, among all techniques, the best t value was between CARES 3.0 and the reader.

CONCLUSIONS

We have developed an improved fully automated technique for carotid IMT measurement on longitudinal ultrasound images. This new version, called CARES 3.0, consists of a new heuristic for lumen-intima and media-adventitia detection, which showed high accuracy and reproducibility for IMT measurement.

Carotid artery segmentation in ultrasound images and measurement of intima-media thickness

Background. The segmentation of the common carotid artery (CCA) wall is imperative for the determination of the intima-media thickness (IMT) on B-mode ultrasound (US) images. The IMT is considered an important indicator in the evaluation of the risk for the development of atherosclerosis. In this paper, authors have discussed the relevance of measurements in clinical practices and the challenges that one has to face while approaching the segmentation of carotid artery on ultrasound images. The paper presents an overall review of commonly used methods for the CCA segmentation and IMT measurement along with the different performance metrics that have been proposed and used for performance validation. Summary and future directions are given in the conclusion.

Hypertriglyceridemic waist is associated with increased carotid atherosclerosis in chronic kidney disease patients

BACKGROUND

Patients with chronic kidney disease (CKD) have an unacceptably high risk of death, primarily as a result of cardiovascular disease (CVD). The 'hypertriglyceridemic waist' phenotype has been proposed as a simple and strong predictor of CVD risk. Therefore, we investigated the relationship between the hypertriglyceridemic waist phenotype and carotid atherosclerosis in CKD patients.

METHODS

In a cross-sectional study, we enrolled 785 prevalent CKD patients [416 males, aged 44.6 years (21.7-69.4), glomerular filtration rate 52.5 ml/min/1.73 m(2) (5.3-119.4)]. We divided the patients into three groups: group 1: waist circumference >90 cm in men or >85 cm in women and triglycerides ≥2 mmol/l (n = 109); group 3: waist circumference ≤90 cm in men or ≤85 cm in women and triglycerides <2 mmol/l (n = 379), and group 2: the remaining patients (n = 297). Routine biochemical parameters and carotid artery intima-media thickness (IMT) were measured.

RESULTS

The prevalence of the hypertriglyceridemic waist phenotypes was 13.8% in the CKD patients. Triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol concentrations in group 1 were significantly higher than those in group 3. Carotid artery IMT of the hypertriglyceridemic waist group was the highest.

CONCLUSION

The hypertriglyceridemic waist phenotype was associated with worse carotid atherosclerosis in CKD patients. This suggests that the hypertriglyceridemic waist phenotype may be useful for predicting CVD risk in CKD patients.

Abdominal aortic calcification detection using dual-energy X-ray absorptiometry: validation study in healthy women compared to computed tomography

Abdominal aortic calcification (AAC) is an independent determinant of cardiovascular events. Computed tomography (CT) is currently the gold standard measure of AAC but is limited by high radiation exposure. Lateral dual-energy X-ray absorptiometry (DXA) has the potential to detect AAC at a fraction of the radiation dose. Our objective was to determine the accuracy of lateral-DXA in detecting AAC compared to CT in healthy women. Women from the TwinsUK registry aged 52-80 years (n = 105) underwent noncontrast CT and lateral-DXA imaging of the abdominal aorta at lumbar vertebrae L1-L4. Presence of calcium on CT was scored using the volume method. Lateral-DXA images were scored using the previously validated semiquantitative 24-point score and simplified 8-point score. Calcification was present in 81 % of women as determined by CT and 49 % with lateral-DXA. The mean volume score and the 24- and 8-point scores of AAC were 0.20 ± 0.41 cm(2), 2.39 ± 3.91 arbitrary units, and 1.47 ± 2.13 arbitrary units, respectively. There was moderate agreement between CT and 24-point lateral-DXA (Spearman's rank correlation coefficient r = 0.58, P < 0.0001). The sensitivity of lateral-DXA for detecting AAC was 56 % and specificity was 80 %. Sensitivity and specificity of lateral-DXA improved to 64 and 84 % when analysis was limited to calcium volumes ≥0.008 cm(3) as detected by CT. Lateral-DXA imaging may provide a useful alternative to CT in detecting AAC with minimal radiation exposure, which may be used with concurrent bone mineral density assessment.

Sex differences in the prevalence and clinical outcomes of subclinical peripheral artery disease in the Health, Aging, and Body Composition (Health ABC) study

The objective of the study was to determine if there are sex-based differences in the prevalence and clinical outcomes of subclinical peripheral artery disease (PAD). We evaluated the sex-specific associations of ankle-brachial index (ABI) with clinical cardiovascular disease outcomes in 2797 participants without prevalent clinical PAD and with a baseline ABI measurement in the Health, Aging, and Body Composition study. The mean age was 74 years, 40% were black, and 52% were women. Median follow-up was 9.37 years. Women had a similar prevalence of ABI < 0.9 (12% women versus 11% men; P = 0.44), but a higher prevalence of ABI 0.9-1.0 (15% versus 10%, respectively; P < 0.001). In a fully adjusted model, ABI < 0.9 was significantly associated with higher coronary heart disease (CHD) mortality, incident clinical PAD and incident myocardial infarction in both women and men. ABI < 0.9 was significantly associated with incident stroke only in women. ABI 0.9-1.0 was significantly associated with CHD death in both women (hazard ratio 4.84, 1.53-15.31) and men (3.49, 1.39-8.72). However, ABI 0.9-1.0 was significantly associated with incident clinical PAD (3.33, 1.44-7.70) and incident stroke (2.45, 1.38-4.35) only in women. Subclinical PAD was strongly associated with adverse CV events in both women and men, but women had a higher prevalence of subclinical PAD.

Cardio-metabolic risk factors and cortical thickness in a neurologically healthy male population: Results from the psychological, social and biological determinants of ill health (pSoBid) study

INTRODUCTION

Cardio-metabolic risk factors have been associated with poor physical and mental health. Epidemiological studies have shown peripheral risk markers to be associated with poor cognitive functioning in normal healthy population and in disease. The aim of the study was to explore the relationship between cardio-metabolic risk factors and cortical thickness in a neurologically healthy middle aged population-based sample.

METHODS

T1-weighted MRI was used to create models of the cortex for calculation of regional cortical thickness in 40 adult males (average age = 50.96 years), selected from the pSoBid study. The relationship between cardio-vascular risk markers and cortical thickness across the whole brain, was examined using the general linear model. The relationship with various covariates of interest was explored.

RESULTS

Lipid fractions with greater triglyceride content (TAG, VLDL and LDL) were associated with greater cortical thickness pertaining to a number of regions in the brain. Greater C reactive protein (CRP) and intercellular adhesion molecule (ICAM-1) levels were associated with cortical thinning pertaining to perisylvian regions in the left hemisphere. Smoking status and education status were significant covariates in the model.

CONCLUSIONS

This exploratory study adds to a small body of existing literature increasingly showing a relationship between cardio-metabolic risk markers and regional cortical thickness involving a number of regions in the brain in a neurologically normal middle aged sample. A focused investigation of factors determining the inter-individual variations in regional cortical thickness in the adult brain could provide further clarity in our understanding of the relationship between cardio-metabolic factors and cortical structures.

The value of carotid artery plaque and intima-media thickness for incident cardiovascular disease: the multi-ethnic study of atherosclerosis

BACKGROUND

Carotid artery plaques are associated with coronary artery atherosclerotic lesions. We evaluated various ultrasound definitions of carotid artery plaque as predictors of future cardiovascular disease (CVD) and coronary heart disease (CHD) events.

METHODS AND RESULTS

We studied the risk factors and ultrasound measurements of the carotid arteries at baseline of 6562 members (mean age 61.1 years; 52.6% women) of the Multi-Ethnic Study of Atherosclerosis (MESA). ICA lesions were defined subjectively as >0% or ≥25% diameter narrowing, as continuous intima-media thickness (IMT) measurements (maximum IMT or the mean of the maximum IMT of 6 images) and using a 1.5-mm IMT cut point. Multivariable Cox proportional hazards models were used to estimate hazard ratios for incident CVD, CHD, and stroke. Harrell's C-statistics, Net Reclassification Improvement, and Integrated Discrimination Improvement were used to evaluate the incremental predictive value of plaque metrics. At 7.8-year mean follow-up, all plaque metrics significantly predicted CVD events (n=515) when added to Framingham risk factors. All except 1 metric improved the prediction of CHD (by C-statistic, Net Reclassification Improvement, and Integrated Discrimination Improvement. Mean of the maximum IMT had the highest NRI (7.0%; P=0.0003) with risk ratio of 1.43/mm; 95% CI 1.26-1.63) followed by maximum IMT with an NRI of 6.8% and risk ratio of 1.27 (95% CI 1.18-1.38).

CONCLUSION

Ultrasound-derived plaque metrics independently predict cardiovascular events in our cohort and improve risk prediction for CHD events when added to Framingham risk factors.

Semiautomated and automated algorithms for analysis of the carotid artery wall on computed tomography and sonography: a correlation study

OBJECTIVES

The purpose of this study was to compare automated and semiautomated algorithms for analysis of carotid artery wall thickness and intima-media thickness on multidetector row computed tomographic (CT) angiography and sonography, respectively, and to study the correlation between them.

METHODS

Twenty consecutive patients underwent multidetector row CT angiographic and sonographic analysis of carotid arteries (mean age, 66 years; age range, 59-79 years). The intima-media thickness of the 40 carotid arteries was measured with novel and dedicated automated software analysis and by 4 observers who manually calculated the intima-media thickness. The carotid artery wall thickness was automatically estimated by using a specific algorithm and was also semiautomatically quantified. The correlation between groups was calculated by using the Pearson ρ statistic, and scatterplots were calculated. We evaluated intermethod agreement using Bland-Altman analysis.

RESULTS

By comparing automated carotid artery wall thickness, automated intima-media thickness, semiautomated carotid artery wall thickness, and semiautomated intima-media thickness analyses, a statistically significant association was found, with the highest values obtained for the association between semiautomated and automated intima-media thickness analyses(Pearson ρ = 0.9; 95% confidence interval, 0.82-0.95; P = 0.0001). The lowest values were obtained for the association between semiautomated intima-media thickness and automated carotid artery wall thickness analyses (Pearson ρ = 0.44; 95% confidence interval, 0.15-0.66; P = 0.0047). In the Bland-Altman analysis, the better results were obtained by comparing the semiautomated and automated algorithms for the study of intima-media thickness, with an interval of -16.1% to +43.6%.

CONCLUSIONS

The results of this preliminary study showed that carotid artery wall thickness and intima-media thickness can be studied with automated software, although the CT analysis needs to be further improved.

Carotid atherosclerosis and risk of subsequent coronary event in outpatients with atherothrombosis

BACKGROUND AND PURPOSE

The presence of carotid plaque reflects overall atherosclerotic burden and may predict coronary artery disease events. We examined the association among carotid atherosclerosis, history of atherothrombotic events, and risk of coronary events.

METHODS

Among 45 227 patients in the Reduction of Atherothrombosis for Continued Health (REACH) Registry with 4-year follow-up, 23 364 patients with information on carotid atherosclerosis at baseline were analyzed. The primary outcome was the composite of first occurrence of cardiovascular death, myocardial infarction, or coronary hospitalization.

RESULTS

The carotid atherosclerosis was present in 46% of patients (n=10 725) and was associated with increasing conventional cardiovascular risk factors and extent of symptomatic vascular disease. During 4-year follow-up, 4304 patients experienced ≥1 coronary event. After adjustment for cardiovascular risk factors and geographic region, the risk of coronary events increased by 22% (95% confidence interval [CI], 14%-30%) in patients with versus without carotid atherosclerosis. The relative increase was 18% (95% CI, -7%-51%) in patients enrolled with multiple risk factors only, 25% (95% CI,16%-35%) in patients with coronary artery disease, 46% (95% CI,28%-65%) in patients with cerebrovascular disease, and 37% (95% CI,17%-60%) in patients with peripheral artery disease. Carotid atherosclerosis was associated with increased risk, even among patients with previous myocardial infarction but no known stroke (P=0.001) or among patients with previous stroke but no known myocardial infarction (P<0.001).

CONCLUSIONS

Carotid atherosclerosis was an independent predictor of coronary events across all types of symptomatic vascular disease and had an incremental effect on risk regardless of risk factors or location of vessel disease.

Fully automated segmentation and tracking of the intima media thickness in ultrasound video sequences of the common carotid artery

The robust identification and measurement of the intima media thickness (IMT) has a high clinical relevance because it represents one of the most precise predictors used in the assessment of potential future cardiovascular events. To facilitate the analysis of arterial wall thickening in serial clinical investigations, in this paper we have developed a novel fully automatic algorithm for the segmentation, measurement, and tracking of the intima media complex (IMC) in B-mode ultrasound video sequences. The proposed algorithm entails a two-stage image analysis process that initially addresses the segmentation of the IMC in the first frame of the ultrasound video sequence using a model-based approach; in the second step, a novel customized tracking procedure is applied to robustly detect the IMC in the subsequent frames. For the video tracking procedure, we introduce a spatially coherent algorithm called adaptive normalized correlation that prevents the tracking process from converging to wrong arterial interfaces. This represents the main contribution of this paper and was developed to deal with inconsistencies in the appearance of the IMC over the cardiac cycle. The quantitative evaluation has been carried out on 40 ultrasound video sequences of the common carotid artery (CCA) by comparing the results returned by the developed algorithm with respect to ground truth data that has been manually annotated by clinical experts. The measured IMT(mean) ± standard deviation recorded by the proposed algorithm is 0.60 mm ± 0.10, with a mean coefficient of variation (CV) of 2.05%, whereas the corresponding result obtained for the manually annotated ground truth data is 0.60 mm ± 0.11 with a mean CV equal to 5.60%. The numerical results reported in this paper indicate that the proposed algorithm is able to correctly segment and track the IMC in ultrasound CCA video sequences, and we were encouraged by the stability of our technique when applied to data captured under different imaging conditions. Future clinical studies will focus on the evaluation of patients that are affected by advanced cardiovascular conditions such as focal thickening and arterial plaques.

Differences of ankle-brachial index according to ischemic stroke subtypes: the peripheral artery disease in Korean patients with ischemic stroke (PIPE) study

BACKGROUND/AIMS

Although previous studies showed a high prevalence of abnormal ankle-brachial index (ABI) in patients with ischemic stroke, few data exist regarding ABI in Asian patients with ischemic stroke. The purpose of the present study was to determine the prevalence and factors associated with abnormal ABI (≤0.9) in a cohort of ischemic stroke patients.

METHODS

In this prospective multicenter study, 1,293 patients diagnosed with acute ischemic stroke or transient ischemic attack underwent ABI measurement to evaluate an association between abnormal ABI and vascular risk factors and clinical characteristics. Differences in ABI by stroke subtypes were also assessed.

RESULTS

Abnormal ABI of ≤0.9 was found in 13.0%. Patients with abnormal ABI were more likely to be older and had higher initial stroke severity. The prevalence of abnormal ABI was 18.4% in large artery atherosclerosis, 7% in small artery disease, and 19.2% in cardioembolism (p < 0.001). Multiple logistic regression analysis showed that age, hyperlipidemia, diabetes, and large artery atherosclerosis subtype were independent factors associated with abnormal ABI.

CONCLUSIONS

These data suggest that the prevalence of abnormal ABI in Korean patients with ischemic stroke was lower than that in Caucasian patients, which might be associated with ethnic differences in underlying stroke subtypes.

Diagnosis and management of peripheral artery disease in women

Peripheral artery disease (PAD) is a significant cause of morbidity and mortality in the USA. Not only is it a major cause of functional impairment and limb loss, but it is also strongly associated with an increased risk of myocardial infarction, stroke, and death. Large population studies have demonstrated high rates of PAD in women, but this is not widely recognized by the public or by clinicians. One potential reason for this is that women with PAD are more likely than men to be asymptomatic or have atypical symptoms. In addition, women with PAD experience higher rates of functional decline and may have poorer outcomes after surgical treatment for PAD compared with men. Currently, it is not known if there are sex-specific differences in risk factors for the onset, progression, and surgical outcomes of PAD. This review will focus on the diagnosis and management of PAD in women and examine sex-specific differences in the prevalence, risk factors, presentation, and outcomes of this disease.

Carotid plaque burden as a measure of subclinical atherosclerosis: comparison with other tests for subclinical arterial disease in the High Risk Plaque BioImage study

OBJECTIVES

The purpose of this study was to compare carotid plaque burden, carotid intima-media thickness (cIMT), ankle-brachial index (ABI), and abdominal aortic diameter (AAD) to coronary artery calcium score (CACS) in people without known cardiovascular disease.

BACKGROUND

The clinical utility of risk factors to predict cardiovascular events is limited. Detection of subclinical atherosclerosis by noninvasive tests such as CACS, cIMT, carotid plaque burden, AAD, and ABI may improve risk prediction above that of established risk scoring models, namely, Framingham Risk Score.

METHODS

The High Risk Plaque BioImage study investigated 6.101 asymptomatic persons and reports baseline CACS, cIMT, ABI, and AAD. In addition, we present findings from a new 3-dimensional-based ultrasound approach, where the carotid artery was investigated in cross section from proximal in the neck to as distal as possible. From the resulting 10-s video, plaque was outlined on cross-sectional images and all plaque areas were summarized into "plaque burden."

RESULTS

The mean age was 68.8 years, and 65.3% of subjects had intermediate Framingham Risk Score (6% to 20% 10-year risk). Carotid plaques were identified in 78% of cases, abnormal ABI in 10%, AAD >20 mm in 28%, and coronary calcium in 68% of participants. Carotid plaque burden was found to correlate stronger with CACS (chi-square 450, p < 0.0001) than did cIMT (chi-square 24, p < 0.0001), AAD (chi-square 2.9, p = 0.091), and ABI (chi-square 35.2, p < 0.0001).

CONCLUSIONS

In the BioImage study, a new 3-dimensional-based ultrasound method identified more carotid plaques than in previous studies. Compared to other methods, carotid plaque burden was the strongest cross-sectional predictor of CACS, and its clinical utility as predictor of future cardiovascular events is being evaluated in the BioImage study. (BioImage Study: A Clinical Study of Burden of Atherosclerotic Disease in an At-Risk Population; NCT00738725).

Identification of the BCAR1-CFDP1-TMEM170A locus as a determinant of carotid intima-media thickness and coronary artery disease risk

BACKGROUND

Carotid intima-media thickness (cIMT) is a widely accepted marker of subclinical atherosclerosis. To date, large-scale investigations of genetic determinants of cIMT are sparse.

METHODS AND RESULTS

To identify cIMT-associated genes and genetic variants, a discovery analysis using the Illumina 200K CardioMetabochip was conducted in 3430 subjects with detailed ultrasonographic determinations of cIMT from the IMPROVE (Carotid Intima Media Thickness [IMT] and IMT-Progression as Predictors of Vascular Events in a High Risk European Population) study. Segment-specific IMT measurements of common carotid, bifurcation, and internal carotid arteries, and composite IMT variables considering the whole carotid tree (IMT(mean), IMT(max), and IMT(mean-max)), were analyzed. A replication stage investigating 42 single-nucleotide polymorphisms for association with common carotid IMT was undertaken in 5 independent European cohorts (total n=11,590). A locus on chromosome 16 (lead single-nucleotide polymorphism rs4888378, intronic in CFDP1) was associated with cIMT at significance levels passing multiple testing correction at both stages (array-wide significant discovery P=6.75 × 10(-7) for IMT(max); replication P=7.24×10(-6) for common cIMT; adjustments for sex, age, and population substructure where applicable; minor allele frequency 0.43 and 0.41, respectively). The protective minor allele was associated with lower carotid plaque score in a replication cohort (P=0.04, n=2120) and lower coronary artery disease risk in 2 case-control studies of subjects with European ancestry (odds ratio [95% confidence interval] 0.83 [0.77-0.90], P=6.53 × 10(-6), n=13 591; and 0.95 [0.92-0.98], P=1.83 × 10(-4), n=82 297, respectively). Queries of human biobank data sets revealed associations of rs4888378 with nearby gene expression in vascular tissues (n=126-138).

CONCLUSIONS

This study identified rs4888378 in the BCAR1-CFDP1-TMEM170A locus as a novel genetic determinant of cIMT and coronary artery disease risk in individuals of European descent.

Association between conventional risk factors and different ultrasound-based markers of atherosclerosis at carotid and femoral levels in a middle-aged population

Ultrasound detection of sub-clinical atherosclerosis (ATS) may help identify individuals at high cardiovascular risk. Most studies evaluated intima-media thickness (IMT) at carotid level. We compared the relationships between main cardiovascular risk factors (CVRF) and five indicators of ATS (IMT, mean and maximal plaque thickness, mean and maximal plaque area) at both carotid and femoral levels. Ultrasound was performed on 496 participants aged 45-64 years randomly selected from the general population of the Republic of Seychelles. 73.4 % participants had ≥ 1 plaque (IMT thickening ≥ 1.2 mm) at carotid level and 67.5 % at femoral level. Variance (adjusted R2) contributed by age, sex and CVRF (smoking, LDL-cholesterol, HDL-cholesterol, blood pressure, diabetes) in predicting any of the ATS markers was larger at femoral than carotid level. At both carotid and femoral levels, the association between CVRF and ATS was stronger based on plaque-based markers than IMT. Our findings show that the associations between CVRF and ATS markers were stronger at femoral than carotid level, and with plaque-based markers rather than IMT. Pending comparison of these markers using harder cardiovascular endpoints, our findings suggest that markers based on plaque morphology assessed at femoral artery level might be useful cardiovascular risk predictors.

Constrained snake vs. conventional snake for carotid ultrasound automated IMT measurements on multi-center data sets

Accurate intima-media thickness (IMT) measurement of the carotid artery from minimal plaque ultrasound images is a relevant clinical need, since IMT increase is related to the progression of atherosclerosis. In this paper, we describe a novel dual snake-based model for the high-performance carotid IMT measurement, called Carotid Measurement Using Dual Snakes (CMUDS). Snakes (which are deformable contours) adapt to the lumen-intima (LI) and media-adventitia (MA) interfaces, thus enabling the IMT computation as distance between the LI and MA snakes. However, traditional snakes might be unable to maintain a correct distance and in some spatial location along the artery, it might even collapse between them or diverge. The technical improvement of this work is the definition of a dual snake-based constrained system, which prevents the LI and MA snakes from collapsing or bleeding, thus optimizing the IMT estimation. The CMUDS system consists of two parametric models automatically initialized using the far adventitia border which we automatically traced by using a previously developed multi-resolution approach. The dual snakes evolve simultaneously and are constrained by the distances between them, ensuring the regularization of LI/MA topology. We benchmarked our automated CMUDS with the previous conventional semi-automated snake system called Carotid Measurement Using Single Snake (CMUSS). Two independent readers manually traced the LIMA boundaries of a multi-institutional, multi-ethnic, and multi-scanner database of 665 CCA longitudinal 2D images. We evaluated our system performance by comparing it with the gold standard as traced by clinical readers. CMUDS and CMUSS correctly processed 100% of the 665 images. Comparing the performance with respect to the two readers, our automatically measured IMT was on average very close to that of the two readers (IMT measurement biases for CMUSS was equal to -0.011±0.329mm and -0.045±0.317mm, respectively, while for CMUDS, it was 0.030±0.284mm and -0.004±0.273mm, respectively). The Figure-of-Merit of the system was 98.5% and 94.4% for CMUSS, while 96.0% and 99.6% for CMUDS, respectively. Results showed that the dual-snake system CMUDS reduced the IMT measurement error accuracy (Wilcoxon, p<0.02) and the IMT error variability (Fisher, p<3×10(-2)). We propose the CMUDS technique for use in large multi-centric studies, where the need for a standard, accurate, and automated IMT measurement technique is required.

25-Hydroxyvitamin D is lower in deprived groups, but is not associated with carotid intima media thickness or plaques: results from pSoBid

OBJECTIVE

The association of the circulating serum vitamin D metabolite 25-hydroxyvitamin D (25OHD) with atherosclerotic burden is unclear, with previous studies reporting disparate results.

METHOD

Psychological, social and biological determinants of ill health (pSoBid) is a study of participants aged 35-64 years from Glasgow who live at extremes of the socioeconomic spectrum. Vitamin D deficiency was defined as 25OHD < 25nmol/L, as per convention. Cross-sectional associations between circulating 25OHD concentrations and a range of socioeconomic, lifestyle, and biochemistry factors, as well as carotid intima media thickness (cIMT) and plaque presence were assessed in 625 participants.

RESULTS

Geometric mean levels of circulating 25OHD were higher among the least deprived (45.6 nmol/L, 1-SD range 24.4-85.5) versus most deprived (34.2 nmol/L, 1-SD range 16.9-69.2; p < 0.0001). In the least deprived group 15% were "deficient" in circulating 25OHD versus 30.8% in the most deprived (χ(2)p < 0.0001). Log 25OHD was 27% lower among smokers (p < 0.0001), 20% higher among the physically active versus inactive (p = 0.01), 2% lower per 1 kg/m(2) increase in body mass index (BMI) (p < 0.0001), and showed expected seasonal variation (χ(2)p < 0.0001). Log 25OHD was 13% lower in the most versus least deprived independent of the aforementioned lifestyle confounding factors (p = 0.03). One unit increase in log 25OHD was not associated with atherosclerotic burden in univariable models; cIMT (effect estimate 0.000 mm [95% CI -0.011, 0.012]); plaque presence (OR 0.88 [0.75, 1.03]), or in multivariable models.

CONCLUSION

There is no strong association of 25OHD with cIMT or plaque presence, despite strong evidence 25OHD associates with lifestyle factors and socioeconomic deprivation.

Endothelial Function and Carotid Intimal Medial Thickness in Asymptomatic Subjects With and Without Cardiovascular Risk Factors

BACKGROUND

The study was performed to assess endothelial function and carotid intimal-medial thickness (IMT) in asymptomatic patients, with and without risk factors for cardiovascular disease.

METHODS

A cross sectional survey of asymptomatic patients, aged 21 - 60 years, with and without risk factors for cardiovascular disease was recruited from the outpatient department of Cardiology. Endothelial function was evaluated by flow mediated dilatation (FMD) of the brachial artery and carotid IMT was determined using a high resolution B mode ultrasonography system.

RESULTS

A total of 104 patients were included in the study. The mean carotid IMT was 0.67 ± 0.05 mm in the group without risk factors and 0.78 ± 0.12 mm in the group with risk factors (P value < 0.05). Endothelial dysfunction (ED) and increased carotid IMT were more significant in the group with risk factors (P value < 0.001). Age, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood pressure, body mass index and HbA1c had a significant correlation with both IMT and FMD response. A higher proportion of subjects with diabetes mellitus (87%), metabolic syndrome (86%) and family history of premature coronary artery disease (78%) had ED. In subjects with normal coronary angiogram, 71% had abnormal FMD response and 36% had increased carotid IMT.

CONCLUSION

In asymptomatic subjects, risk factors for cardiovascular disease are significantly associated with objective evidence of ED and increased carotid IMT. FMD response and carotid IMT values are likely to yield additional information beyond traditional risk factors for classifying patients in regard to the likelihood of cardiovascular event. Therapeutic measures with the aim of improving endothelial function and reducing carotid IMT may reduce the burden of cardiovascular disease.

From circulating biomarkers to genomics and imaging in the prediction of cardiovascular events in the general population

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. In the last decades numerous markers have been considered and investigated for the prediction of CV events, but only a few of them resulted in improved global risk assessment beyond traditional risk factors when incorporated into coronary evaluation scores. Recent genetic studies have pointed out a few but consistent loci or genes which are independently associated with CV risk. The idea is fascinating that these genetic markers could lead to improved individual CV risk assessment and tailored pharmacological interventions. In this brief review we will not make a systematic review of all non-genetic and genetic markers of CV risk but we will try to make a brief overview of the most interesting ones with the aim to underline potential 'pros' and 'cons' of their implementation in clinical practice.

Influence of cigarette smoking on coronary artery and aortic calcium among random samples from populations of middle-aged Japanese and Korean men

BACKGROUND

Cigarette smoking is a risk factor of coronary heart disease. Vascular calcification such as coronary artery calcium (CAC) and aortic calcium (AC) is associated with coronary heart disease. The authors hypothesised that cigarette smoking is associated with coronary artery and aortic calcifications in Japanese and Koreans with high smoking prevalence.

METHODS

Random samples from populations of 313 Japanese and 302 Korean men aged 40-49 years were examined for calcification of the coronary artery and aorta using electron beam CT. CAC and AC were quantified using the Agatston score. The authors examined the associations of cigarette smoking with CAC and AC after adjusting for conventional risk factors and alcohol consumption. Current and past smokers were combined and categorised into two groups using median pack-years as a cut-off point in each of Japanese and Koreans. The never-smoker group was used as a reference for the multiple logistic regression analyses.

RESULTS

The ORs of CAC (score ≥10) for smokers with higher pack-years were 2.9 in Japanese (p<0.05) and 1.3 in Koreans (non-significant) compared with never-smokers. The ORs of AC (score ≥100) for smokers with higher pack-years were 10.4 in Japanese (p<0.05) and 3.6 in Koreans (p<0.05).

CONCLUSION

Cigarette smoking with higher pack-years is significantly associated with CAC and AC in Japanese men, while cigarette smoking with higher pack-years is significantly associated with AC but not significantly with CAC in Korean men.

Fully automated dual-snake formulation for carotid intima-media thickness measurement. A new approach

Automated computer-aided detection systems for measurement of the carotid intima-media thickness (IMT) are becoming popular. These systems yield lumen-intima (LI) and media-adventitia (MA) borders. In this work, we developed and validated a novel and patented completely automated IMT measurement system called carotid measurement using dual snakes (CMUDS): a class of AtheroEdge system (Global Biomedical Technologies, Inc, Roseville, CA). CMUDS is modeled as a dual parametric system corresponding to LI and MA borders with initialization from the far adventitia layer. The novelty of CMUDS is the first-order absolute moment-based external energy, which provides stable deformation. The dual snakes evolve simultaneously and are forced to maintain a regularized distance to prevent collapsing or bleeding. Two independent readers manually traced the LI/MA boundaries of a multi-institutional, multi-ethnic, and multi-scanner database of 665 longitudinal images for performance evaluation. CMUDS was also benchmarked against a previously developed automated technique. CMUDS correctly processed 660 images (99.2% success). The differences between the CMUDS and two manual IMT measurements (mean ± SD) were 0.013 ± 0.216 and -0.021 ± 0.197 mm, respectively. The corresponding figures of merit for CMUDS compared to reader tracings were 98.4% and 97.5%. Compared to the previous technique (IMT differences, 0.022 ± 0.276 and -0.012 ± 0.266 mm), CMUDS improved accuracy (Wilcoxon P < 0.009) and variability (Fisher P < 10(-8)). Among different resolution images from original equipment manufacturer ultrasound scanners, CMUDS performed best with high-resolution images corresponding to 0.0789 mm/pixel. Accuracy in IMT measurement with the proposed automated CMUDS technique makes this system adaptable to large multi-center studies, in which such an IMT measurement system would be very useful tool.

The measurement of lipids currently and 9 years ago--which is more associated with carotid intima-media thickness?

BACKGROUND

Massive evidence supports that increase of lipids bring more risk of atherosclerosis. However, it is not clear if lipids measured a long time ago bear more risk than the current measurement.

HYPOTHESIS

Lipids measured currently is more associated with carotid atherosclerosis than lipids measured long time ago.

METHODS

A cohort of 1195 participants age 35 to 64 years was examined in both 1993-1994 and 2002 for serum lipids, and in 2002 for carotid intima-media thickness (CIMT) with B mode ultrasound. The associations of lipids at baseline and at reexamination with CIMT were analyzed and compared using multiple linear regressions.

RESULTS

All lipid variables, except for high-density lipoprotein cholesterol (HDL-C) both at baseline and reexamination, were significantly associated with age-adjusted CIMT in both males and females (all P(trend) <0.01). The age-adjusted mean of CIMT in all of the population was 0.696 mm in those having low low-density lipoprotein cholesterol (LDL-C) at both examinations, 0.719 mm in those having high LDL-C only at baseline, 0.706 mm in those having high LDL-C only at reexamination, and 0.727 mm in those having high LDL-C at both examinations. Further analysis showed that lipids measured at baseline remained significant, whereas lipids at reexamination became not significant in all models, except those for HDL-C and total cholesterol (TC)/HDL-C, which allow the lipids at different times to compete in association with CIMT.

CONCLUSIONS

Both the current measurement of lipids (TC, LDL-C, non-HDL-C, TC/HDL-C, and LDL-C/HDL-C) and the measurement from 9 years ago are significantly associated with CIMT, but the measurement from 9 years ago had an even stronger association.

Relationship between vertebral fracture prevalence and abdominal aortic calcification in men

OBJECTIVE

To study the relationship between the prevalence of vertebral fractures (VFs) using VF assessment (VFA) in asymptomatic men and the prevalence and severity of abdominal aortic calcification (AAC).

METHODS

We enrolled 709 men with mean (s.d.) age 62.4 (8.6) (range 45-89) years. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of the Genant semi-quantitative (SQ) approach and morphometry. VFA images were scored for AAC using a validated 24-point scale.

RESULTS

VFA images showed that 68 (14.2%) of the participants had at least one grade 2/3 VF, 82% did not have any detectable AAC, whereas the prevalence of significant atherosclerotic burden, defined as an AAC score of ≥5, was 2.8%. The group of men with grade 2/3 VFs had a statistically significant higher AAC score and higher proportion of subjects with extended AAC, and lower weight, height and lumbar spine and hip BMD and T-scores than those without a VFA-identified VF. Multiple regression analysis showed that the presence of grade 2/3 VFs was significantly associated with BMI [odds ratio (OR 0.915; 95% CI 0.589, 0.975; P = 0.006], AAC score ≥5 (OR 4.509; 95% CI 1.505, 13.504; P = 0.007) and osteoporosis in any site (OR 5.159; 95% CI 3.116, 8.540; P ≤ 0.0001).

CONCLUSION

In elderly men, extended AAC is an indicator of the increased risk for prevalent VFs regardless of age, BMI, history of fractures, smoking and BMD.

Evaluation of carotid intima-media thickness, a marker of subclinical atherosclerosis, in children with cerebral palsy

BACKGROUND

Respiratory and cardiovascular diseases are the most common causes of death in children with cerebral palsy.

OBJECTIVE

To evaluate sonographic carotid intima-media thickness, an early marker of atherosclerosis, in children with cerebral palsy and in healthy controls.

MATERIALS AND METHODS

One hundred children with cerebral palsy (65 boys), mean age 6.2 (SD, 2.1) years, and 35 age-matched and sex-matched healthy controls were included. Common carotid artery intima-media thickness was measured sonographically. Differences between patients and controls were evaluated with an independent samples t-test.

RESULTS

Age, sex distribution and levels of serum lipids were comparable between patients and controls. Average, right and left carotid artery intima-media were thicker in patients compared with controls (mean ± SD, 0.61 ± 0.13 mm vs 0.40 ± 0.03 mm; 0.61 ± 0.14 mm vs 0.40 ± 0.03 mm; 0.61 ± 0.13 mm vs 0.40 ± 0.03 mm, respectively; all P < 0.001).

CONCLUSION

Carotid intima-media is sonographically thicker in children with cerebral palsy compared with healthy controls, which may express an increased risk of atherosclerotic diseases.

Significance of the intima-media thickness of carotid and thoracic aorta in coronary artery disease in the South Indian population

Background:

Ultrasound detected intima-media thickness (IMT) of the carotid artery and thoracic aorta are possible screening tests to assess the risk of coronary artery disease (CAD) in asymptomatic individuals.

Objective:

Aim of the study was to assess the utility of carotid and aortic IMT as a predictor of CAD and to assess the extent of IMT with severity of CAD in a South Indian population.

Patients and Methods:

A cross-sectional and analytical study was carried out among 40 cases, who had angiographic evidence of CAD against 30 healthy control subjects with a normal treadmill test. At plaque-free regions, the carotid IMT was evaluated by B-mode ultrasonography and thoracic aorta IMT was evaluated by trans-esophageal echocardiography (TEE). The significance of difference in means between two groups was analyzed using one-way ANOVA F-test and the significance of difference in proportions by Chi-square test. Multiple comparisons were done by Bonferroni t test. The correlation between IMT and severity of CAD was assessed by Spearman's method.

Results:

There were 38 males and 2 females among cases with age 51.7 ± 8.3 years, and 28 males and 2 females among control subjects with age 52.2 ± 7.1 years. Increased carotid IMT was noted among 24 cases and 2 control subjects, and the association was significant for CAD [P < 0.001, Chi-square = 20.89, odds ratio (OR) = 21.00, and 95% confidence interval (CI) = 4.78-89.59]. Similarly, 19 cases and one control subject had abnormal IMT with positive correlation for CAD (P < 0.001, Chi-square = 16.39, OR = 28.24, and 95% CI = 4.06-163.21). There was no association between IMT and diabetes, hypertension, or smoking; however, IMT was significantly associated with age and dyslipidemia. Also, there was no correlation between extent of IMT and severity of CAD.

Conclusions:

IMT of the carotid and thoracic aorta is strongly associated with risk of CAD in a South Indian population, and may be used as a non-invasive screening tool for coronary atherosclerosis in resource-limited settings. The presence of dyslipidemia influenced IMT and may be used as a tool to follow patients on hypolipidemic drugs.

Atherosclerotic calcification relates to cognitive function and to brain changes on magnetic resonance imaging

BACKGROUND

Increasing evidence suggests a role of atherosclerosis in the pathogenesis of cognitive impairment and dementia. Calcification volume measured with computed tomography (CT) is a valid marker of atherosclerosis. This study investigates associations of atherosclerosis (measured using CT) at four locations with cognition and brain changes on magnetic resonance imaging (MRI).

METHODS

To quantify calcification volume, 2414 nondemented people from the Rotterdam Study underwent CT of the coronary arteries, aortic arch, extracranial carotid arteries, and intracranial carotid arteries. To assess global cognition and performance on memory, executive function, information processing speed, and motor speed, they also underwent neuropsychological tests. In a random subgroup of 844 participants, brain MRI was performed. Automated segmentation and quantification of brain MRI scans yielded brain tissue volumes in milliliters. Diffusion tensor imaging was used to measure the microstructural integrity of the white matter. Relationships of atherosclerotic calcification with cognition, brain tissue volumes, and diffusion tensor imaging measures were assessed with linear regression models and adjusted for relevant confounders.

RESULTS

With larger calcification volumes, lower cognitive scores were observed. When calcification volumes were larger, total brain volumes were also smaller. Specifically, larger coronary artery calcification volumes related to smaller gray matter volumes, and extracranial and intracranial carotid calcification volumes related to smaller white matter volumes. Larger calcification volume in all vessel beds was accompanied by worse microstructural integrity of the white matter.

CONCLUSIONS

Larger calcification volume is associated with worse cognitive performance. It also relates to smaller brain tissue volumes and worse white matter microstructural integrity, revealing possible mechanisms through which atherosclerosis may lead to poorer cognition.

Can metabolic syndrome presence predict carotid intima-media thickness?

The aim of this investigation was to analyze metabolic syndrome (MS) impact on carotid intima-media thickness (cIMT). Prospective study of 300 patients with suspected coronary artery disease admitted for an elective coronary angiography were evaluated. Patients with previously known cardiac disease were excluded. In the population, 23.0% were diabetics and 40.5% had MS (but no diabetes). cIMT was not significantly different in patients with MS, but was significantly higher in diabetic patients compared with MS and control patients. Independent predictors of cIMT were age, male gender, insulin, and high-density lipoprotein (HDL) cholesterol (the last one with an inverse association). In patients without MS, only age and HDL cholesterol were associated. In patients with MS, independent predictors were age, male gender, and glucose, and abdominal obesity showed an inverse relationship. In patients with stable angina, MS is not an independent predictor of cIMT. Nonmodifiable variables (age and gender) are the most important determinants of cIMT, as well as blood glucose, in MS patients. Abdominal obesity was protective. J Clin Hypertens (Greenwich). 2012;00:00-00. ©2012 Wiley Periodicals, Inc.

Carotid artery recognition system: a comparison of three automated paradigms for ultrasound images

PURPOSE

The development of completely automated techniques for arterial wall segmentation and intima-media thickness measurement requires the recognition of the artery in the image frame. Conceptually, automated techniques can be thought of as the combination of two cascaded stages: artery recognition and wall segmentation. In this paper, the authors show three carotid artery recognition systems (CARS) that are fully automated.

METHODS

The first technique is based on a first-order derivative Gaussian edge analysis (CARSgd). The second method is based on an integrated approach (CARSia) that combines image feature extraction, fitting, and classification. The third strategy is based on signal analysis (CARSsa). The output of all the three paradigms provide tracing of the far adventitial (AD(F)). The authors validated CARSgd, CARSia, and CARSsa on a dataset of 365 longitudinal B-Mode carotid images, acquired by different sonographers. Performance evaluation of the carotid recognition process was done in three ways: (1) visual inspection by experts; (2) by measuring the Hausdorff distance (HD) between the automatic far adventitial (AD(F)) and the manually traced AD(F), and (3) by measuring the HD between AD(F) and the lumen-intima (GT(LI)) and media-adventitia (GT(MA)) borders of the arterial walls.

RESULTS

The average HD between AD(F) and the manual AD(F) was 1.53 ± 1.51 mm for CARSgd, 1.82 ± 3.08 mm for CARSia, and 2.56 ± 2.89 mm for CARSsa. The average HD between GT(LI) and AD(F) for CARSgd, CARSia, and CARSsa were 2.16 ± 1.16 mm, 2.71 ± 2.89 mm, and 2.66 ± 1.52 mm, respectively. The average HD between AD(F) and GT(MA) for CARSgd, CARSia, and CARSsa were 1.54 ± 1.19 mm, 1.86 ± 2.66 mm, and 1.95 ± 1.64 mm, respectively. Considering a maximum distance of 50 pixels (about 3 mm), CARSgd showed an identification accuracy of 100%, CARSia of 92%, and CARSsa of 96%. These identification accuracies were confirmed by visual inspection. All the three systems work on MATLAB, Windows OS, and on a PC based cross platform medical application written in Java called ATHEROEDGE™ with 1 s per image.

CONCLUSIONS

CARSgd showed very accurate AD(F) profiles coupled with a low computational burden and without the need for specific tuning. It can be thought of as a reference technique for carotid localization, to be used in automated intima-media thickness measurement strategies.

Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline focuses on antithrombotic drug therapies for primary and secondary prevention of cardiovascular disease as well as for the relief of lower-extremity symptoms and critical ischemia in persons with peripheral arterial disease (PAD).

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

The most important of our 20 recommendations are as follows. In patients aged ≥ 50 years with asymptomatic PAD or asymptomatic carotid stenosis, we suggest aspirin (75-100 mg/d) over no therapy (Grade 2B) for the primary prevention of cardiovascular events. For secondary prevention of cardiovascular disease in patients with symptomatic PAD (including patients before and after peripheral arterial bypass surgery or percutaneous transluminal angioplasty), we recommend long-term aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 1A). We recommend against the use of warfarin plus aspirin in patients with symptomatic PAD (Grade 1B). For patients undergoing peripheral artery percutaneous transluminal angioplasty with stenting, we suggest single rather than dual antiplatelet therapy (Grade 2C). For patients with refractory claudication despite exercise therapy and smoking cessation, we suggest addition of cilostazol (100 mg bid) to aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 2C). In patients with critical limb ischemia and rest pain unable to undergo revascularization, we suggest the use of prostanoids (Grade 2C). In patients with acute limb ischemia due to acute thrombosis or embolism, we recommend surgery over peripheral arterial thrombolysis (Grade 1B).

CONCLUSIONS

Recommendations continue to favor single antiplatelet therapy for primary and secondary prevention of cardiovascular events in most patients with asymptomatic PAD, symptomatic PAD, and asymptomatic carotid stenosis. Additional therapies for relief of limb symptoms should be considered only after exercise therapy, smoking cessation, and evaluation for peripheral artery revascularization.

Dual-energy X-ray absorptiometry in the evaluation of abdominal aortic calcifications

The objective of this study was to evaluate the diagnostic performance of the new dual-energy X-ray absorptiometry equipment vs digital radiography (DR) in the detection and scoring of abdominal aortic calcifications (AACs). Seventy-five patients with indication for morphometric evaluation of the spine underwent vertebral fracture assessment (VFA) and spinal DR (gold standard). The radiographic and VFA images were analyzed to detect AAC using a previously validated 24-point scale (AAC-24) and a simplified 8-point scale (AAC-8). The evaluation was conducted by 2 expert radiologists and repeated by the more experienced of the 2 after 7d to verify the results. Patients with a score of 5 or more in AAC-24 and 3 or more in AAC-8 were considered at risk for cardiovascular diseases (CVDs). The aorta was not completely visible in 11 VFA and 1 DR images. DR detected AAC in 42 of the 63 patients (66.7%), whereas 15 patients (23.8%) were considered at risk for CVD. The VFA showed sensitivity, specificity, and accuracy in the detection of AAC with values of 78.6%, 85.7%, and 81.0%, respectively, with both AAC-24 and AAC-8; in the identification of patients at risk for CVD, VFA demonstrated sensitivity, specificity, and accuracy, respectively, with values of 86.7%, 100%, and 96.8% using AAC-24 and 86.7%, 93.8%, and 92.1% using AAC-8. In the detection of AAC, intraobserver agreement was superimposable using both the techniques (κ=1.00), whereas in the identification of patients at risk for CVD, kappa values were 0.96 and 0.95 using AAC-24 and 1.00 and 0.96 using AAC-8 for DR and VFA, respectively. Interobserver agreement in the evaluation of the presence/absence of AAC showed a kappa value of 0.76 for DR and 0.71 for VFA, whereas kappa values of 0.91 and 0.87 for DR and 0.85 and 0.83 for VFA were achieved for CVD risk using AAC-24 and AAC-8, respectively. AAC can be easily and accurately diagnosed by VFA with satisfactory accuracy, reproducibility, and repeatability. VFA may be used in the assessment and monitoring of AAC.

Carotid intima-media thickness determined vascular age and the Framingham Risk Score

We examined carotid intima-media thickness (CIMT)-determined vascular age on the Framingham Risk Score (FRS) and the Framingham Heart Age in patients of diverse ethnic origin without a history of diabetes or established cardiovascular disease. In this cross-sectional study, 2291 men and women had CIMT obtained by high resolution B-mode ultrasound in a routine examination between August 1, 2000 and October 1, 2001. We randomly split the population into a training subset (n = 1114) and an analysis subset (n = 1177) using the training subset to regress the average CIMT for each individual on chronologic age. We compared the FRS using CIMT-determined vascular age versus chronologic age in the analysis subset. On average, CIMT-determined vascular age was less than chronologic age, which was less than FRS-heart age in all gender and ethnic groups. For estimated 10-year cardiovascular-disease risk among non-Hispanic whites, only 45.5% of male and 55.6% of female patients were concordant for both measures, and simple Kappa values were low (0.28 for males, 0.32 for females). Among non-Hispanic whites, 40.7% of males and 32.1% of females had greater risk using chronologic age rather than when using CIMT-determined vascular age. Conversely, 13.8% of males and 12.3% of females had a greater risk using CIMT-determined vascular age rather than when using chronologic age. A similar pattern was noted in the other ethnic groups. Our results suggest that CIMT may be very useful in improving risk discrimination in the FRS, and that substituting CIMT-determined vascular age may improve individual cardiovascular risk prediction.

Automatic segmentation of carotid B-mode images using fuzzy classification

This paper presents a new method for the automatic segmentation of the common carotid artery in B-mode images. This method uses the instantaneous coefficient of variation edge detector, fuzzy classification of edges and dynamic programming. Several discriminating features of the intima and adventitia boundaries are considered, like the edge strength, the intensity gradient orientation, the valley shaped intensity profile and contextual information of the region delimited by those boundaries. The adopted fuzzy classification of edges helps avoiding low-pass filtering. The method is suited to real-time processing and user interaction is not required. Both the near and far wall boundaries can be detected in arteries with plaques of different types and sizes. Both expert manual and automatic tracings are significantly better for the far wall, due to the better visibility of the intima and adventitia boundaries. The automatic detection of the far wall shows an accuracy similar to the manual detections. For this wall, the error coefficient of variation for the mean intima-media thickness is in the range [5.6, 6.6 %] for automatic detections and in [6.7, 7.1 %] for manual ones. In the case of the near wall, the same coefficient of variation is in [11.2, 13.0 %] for automatic detections and in [5.9, 9.0 %] for manual detections. The mean intima-media thickness measurement errors observed for the far wall [Formula: see text] are among the best values reported for other fully automatic approaches. The application of this approach in clinical practice is encouraged by the results for the far wall and the short processing time (mean of 2.1 s per image).