Reproducibility of carotid intima-media thickness measurements in young adults

Impact of repeated sportive chokes on carotid intima media thickness and brain injury biomarkers in grappling athletes

PURPOSE

Vascular neck compression techniques, referred to as 'chokes' in combat sports, reduce cerebral perfusion, causing loss of consciousness or voluntary submission by the choked athlete. Despite these chokes happening millions of times yearly around the world, there is scant research on their long-term effects. This pilot study evaluated whether repeated choking in submission grappling impacts the carotid intima media thickness (CIMT) and brain injury biomarkers (NFL, hGFAP, t-Tau, and UCH-L1).

METHODS

Participants (n = 39, 29 male; ages 27-60 years) were assigned to one of two study arms: Grapplers (n = 20, 15 male) and 19 age/sex/body size matched controls. Grapplers had been exposed to >500 choke events while training for >5 years in a choke-inclusive sport. Exclusion criteria were recent TBI or deficits from a past TBI or stroke. Bilateral ultrasound measurement of the CIMT was performed, and blood was collected for quantitative analysis of four brain injury markers. Subgroup analyses were performed within the Grappler group to account for blunt head trauma as a possible confounder.

RESULTS

There was no overall difference in CIMT measurements between Grapplers (mean 0.55 mm, SD 0.07) and Controls (mean 0.57 mm, SD 0.10) p = 0.498 [95% CI -0.04-0.08], nor were there CIMT differences between Grappler subgroups of blunt Trauma and No-Trauma. There were no significant differences in any biomarkers comparing Grapplers and Controls or comparing Grappler subgroups of Trauma and No-Trauma.

CONCLUSION

This study found no significant difference in CIMT and serum brain injury biomarkers between controls and grapplers with extensive transient choke experience, nor between grapplers with extensive past blunt head trauma and those without.

Composite carotid intima-media thickness as a risk predictor of coronary heart disease in a selected population in Sri Lanka

Background

Segment-specific variations of carotid intima-media thickness (CIMT) have not been assessed in South Asian populations. The purpose of this study was to determine if segment-specific CIMTs or a composite-CIMT score is a better risk predictor of coronary heart disease in South Asian populations.

Methods

A comparative prospective study was conducted from November 2019 to October 2020 in a hospital in Colombo, Sri Lanka. Based on pre-defined inclusion and exclusion criteria, cases (having a diagnosis of Coronary Heart Disease (CHD), n = 338) and controls (non-CHD group, n = 356) were recruited. Ultrasound examination of the common carotid (CCA), the carotid bulb (CB) and the internal carotid segments (ICA) of the carotid vessels was conducted by a radiologist, and CIMTs were measured. A composite-CIMT score defined as the average value of all six segments of the left and right sides was derived.

Results

694 participants were enrolled (male n = 399, 57.5%). The mean (±SD) age of the study sample was 60.2 (±9.86) years. There were variations in segment-specific values between the left and right vessels. The mean composite-CIMT value of the CHD group was significantly higher than that of the non-CHD group. A composite-CIMT score of 0.758 had a sensitivity of 98.4% and a specificity of 64.6% in distinguishing CHD from non-CHD groups (Area under the curve (AUC): 0.926).

Conclusions

Carotid artery segment-specific CIMT variations were present in this population. The composite CIMT score is better than segment-specific CIMTs in predicting CHD and may be used to predict CHD in this population.

Proprotein convertase subtilisin/kexin type 9 is associated with atherosclerosis in patients with Behcet's disease

OBJECTIVES

The incidence of cardiovascular disease is increased in patients with Behcet's disease (BD). Proprotein convertase subtilisin/kexin type 9 (PCSK9) causes the acceleration of atherosclerosis. We aimed to investigate whether there is a relationship between PCSK9 with carotid artery intima-media thickness (cIMT), a marker of subclinical atherosclerosis, and BD disease activity.

METHODS

Fifty-eight patients with BD and 58 age-, gender-, and body mass index (BMI)-matched healthy control subjects were included in the study. The disease activity of the patients was estimated. Individuals' cIMT values were measured, and PCSK9 levels were studied.

RESULTS

Patients with BD' cIMT (0.51 ± 0.1 vs 0.41 ± 0.1 mm, p < .001) and PCSK9 (623.2 ± 101.7 ± 10.1 vs 528.3 ± 242.7 ng/ml, p = .007), values were significantly higher than the control group. In stepwise regression analysis, there was an independent relationship between cIMT with PCSK9 (β = 0.179, p < .050). There was no independent relationship between disease activities with PCSK9. Based on the ROC curve analysis, the PCSK9 optimal cutoff value for cIMT was 595.1 ng/ml, sensitivity 66.7%, specificity 64.7% (AUC = 0.672; 95% CI: 0.530-0.815, p = .040).

CONCLUSION

There is a strong independent association between subclinical atherosclerosis and PCSK9 in patients with BD. There may be no independent association between PCSK9 and disease activity.

Automated measurement of compression-decompression in arterial diameter and wall thickness by image-free ultrasound

BACKGROUND AND OBJECTIVE

The manual measurement of arterial diameter and wall thickness using imaging modalities demand expertise, and the state-of-art automated or semi-automated measurement features are seldom available in the entry-level systems. The advanced ultrasound modalities are expensive, non-scalable, and less favorable for field and resource-constrained settings. In this work, we present a novel method to measure arterial diameter (D), surrogate intima-media thickness (sIMT), and with them their intra-cardiac cycle changes by employing an affordable image-free ultrasound technology.

METHODS

The functionality of the method was systematically validated on a simulation testbed, phantoms and, 40 human subjects. The accuracy, agreement, inter-beat, and inter-operator variabilities were quantified. The in-vivo measurement performance of the method was compared against two reference B-mode tools - Carotid Studio and CAROLAB.

RESULTS

Simulations revealed that for the A-mode frames with SNR > 10 dB, the proposed method identifies the desired arterial wall interfaces with an RMSE < 20 μm. The RMSE for the diameter and wall thickness measurements from the static phantom were 111 μm and 14 μm, and for the dynamic phantom were 117 μm and 18 μm, respectively. Strong agreement was seen between the in-vivo measurements of the proposed method and the two reference tools. The mean absolute errors against the two references and the inter-beat variability were smaller than 0.18 mm for D and smaller than 36 μm for sIMT measurements. Likewise, the respective inter-observer variabilities were 0.16 ± 0.23 mm and 43 ± 25 μm.

CONCLUSION

Acceptable accuracy and repeatability were observed during the validation, that were on a par with the recently reported B-mode techniques in the literature. The technology being real-time, automated, and relatively inexpensive, is promising for field and low-resource settings.

Ambulatory blood pressure and carotid intima media thickness in children with type 1 diabetes

BACKGROUND/OBJECTIVE

Blood pressure abnormalities may play an important role in macrovascular damage in type 1 diabetes. Little is known about blood pressure abnormalities and macrovascular damage in children with type 1 diabetes.

METHODS

Children with type 1 diabetes (n = 57) for a short (3 months-2 years; n = 24) or long duration (≥5 years; n = 33) and a group of control children without diabetes (n = 29) completed 24-h ambulatory blood pressure monitoring (ABPM). Carotid intima media thickness (cIMT), a subclinical indicator of atherosclerosis, was assessed by carotid ultrasound.

RESULTS

ABPM abnormalities were more prevalent (57% vs 24%, respectively), and daytime, nighttime and 24-h systolic, diastolic, and mean arterial blood pressure indices were higher in children with type 1 diabetes compared to control children. The odds estimate of an ABPM abnormality was 6.68 (95% confidence interval: 1.95, 22.9; P = .003) in children with type 1 diabetes compared to controls after adjusting for age, sex, and BMI standardized for age and sex (zBMI). An interaction between ABPM and zBMI on cIMT was observed. In children with type 1 diabetes and ABPM abnormalities, every 1 SD increase in zBMI was associated with a 0.030 mm increase in cIMT (95% confidence interval: 0.002, 0.041; P = .031). This was not observed in control children with ABPM abnormalities or in children with normal ABPM, regardless of type 1 diabetes status.

CONCLUSIONS

Children with type 1 diabetes have a high prevalence of ABPM abnormalities independent of disease duration and this is related to early indicators of cardiovascular damage.

Association of vascular calcification of breast with carotid intima media thickness

Purpose

To assess the relationship between breast arterial calcification (BAC) on mammography and carotid intima medial thickness (C-IMT) by comparing these patients with healthy control subjects.

Material and methods

The study included 100 women divided into two groups based on presence of BAC on mammography using the WIPRO GE – DMR PLUS mammography unit. The groups included 50 BAC(+) (case group) and 50 BAC(–) (control group). BAC is defined as two linear calcific deposits forming the rail-road track pattern, with ring-like appearance in cross section. Relevant previous clinical and surgical history was taken and C-IMT was measured using B-mode ultrasonography Aplio XG (Toshiba medical systems corp., Japan) using an 8-13 MHz linear transducer within 1 cm from the proximal and distal portion of the common carotid artery and the mean value was taken.

Results

All the participants included in this study were within the age group of 40-70 years. Mean age with BAC(+) was 59.18 ± 8.59 years and BAC(–) was 50.70 ± 7.93 years. Mean C-IMT in the BAC(+) group was 0.86 ± 0.21 mm vs. 0.71 ± 0.12 mm in the BAC(–) group. Chi-square test, independent t test and Spearman’s rho correlation to assess the association of the breast arterial calcification were performed. The study showed significant difference in mean C-IMT between two groups (p value < 0.001) when correlated with age, diabetes, hypertension, presence of BAC and history of surgery and drug intake.

Conclusions

BAC in mammography is independently associated with C-IMT. Furthermore, apart from age and menopausal status a statistically significant positive correlation with C-IMT was observed.

Effect of Metabolically Healthy Obesity on the Development of Carotid Plaque in the General Population: A Community-Based Cohort Study

Aim: Obesity and metabolic syndrome (MetS) frequently coexist and are both important risk factors for cardiovascular disease. However, the pathophysiological role of obesity without MetS, also referred to as metabolically healthy obesity (MHO), remains unclear. In this study, we aim to clarify the effect of MHO on the development of carotid plaque using a community-based cohort.

Methods: We examined 1,241 subjects who underwent health checkups at our institute. Obesity was defined as body mass index of ≥ 25.0 kg/m². Subjects were divided into three groups: non-obese, MHO, and metabolically unhealthy obesity (MUO).

Results: The prevalence of carotid plaque, defined as intima-media thickness (IMT) ≥ 1.1 mm, was higher in subjects with MUO and MHO than in non-obese subjects. Multivariable analysis demonstrated that MHO (odds ratio 1.6, p = 0.012) and MUO (odds ratio 1.9, p = 0.003) as well as age of ≥ 65 years, male sex, hypertension, and diabetes mellitus were independently associated with carotid plaque formation. A similar trend was observed in each subgroup according to age and sex.

Conclusions: MHO increased the prevalence of carotid plaque when compared with non-obese subjects, suggesting the potential significance of MHO in the development of subsequent cardiovascular diseases.

Carotid Intima-Media Thickness Manual Measurements: Intraoperator and Interoperator Agreements Under A Strict Protocol in a Large Sample

PURPOSE

The aim of this study was to assess the intraoperator and interoperator agreement for manual measurements of intima-media thickness (IMT) performed under a strict carotid ultrasound technical protocol.

METHODS

Two blinded experienced operators independently performed an ultrasound examination at the distal common carotid of 242 subjects in the same patient's position, diastolic phase, probe type, zooming, and depth. Thirty-six subjects were reevaluated in another time point. Three different-angle manual measurements (IMTindiv) were obtained. Interoperator agreements for each IMTindiv, and their mean (IMTmean) and maximum (IMTmax) values, were assessed with the intraclass correlation coefficient and Bland-Altman analysis. Intraoperator agreement was tested taking advantage of the second ultrasound round in 36 subjects.

RESULTS

IMTmean agreements (intraoperator, 0.665-0.913; interoperator, 0.856-0.897) were higher than IMTmax (intraoperator, 0.435-0.793; interoperator, 0.631-0.718) and any IMTindiv (intraoperator, 0.355-0.676; interoperator, 0.590-0.717). Despite the small systematic error for IMTmean (intraoperator, ≤0.03; interoperator, ≤0.02 mm), at best of times, the sampling error size reached at least 0.28 and 0.25 mm for intraoperator and interoperator agreements, respectively, and was never less than 0.13 mm.

CONCLUSIONS

Although IMTmean agreement is excellent under a strict protocol, limits of agreement might be too wide to consider carotid ultrasound a robust cardiovascular risk biomarker.

Carotid Intima-Media Thickness Is Associated with Increased Androgens in Adolescents and Young Adults with Classical Congenital Adrenal Hyperplasia

BACKGROUND/AIMS

Youth with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency develop cardiovascular disease (CVD) risk factors of obesity and hypertension. Carotid intima-media thickness (CIMT), a marker of CVD risk, is increased in CAH young adults. We examined CIMT and its relationship with androgens and obesity in adolescents/young adults with CAH.

METHODS

Twenty CAH subjects (age 16 ± 3.3 years, 50% female) and 20 matched controls were studied cross-sectionally. Eight additional obese patients with CAH were included in within-group comparisons. CIMT by high-resolution ultrasound, androgens, anthropometry, bone age (BA), and metabolic/inflammatory markers were assessed.

RESULTS

Within the CAH group, CIMT correlated with 17-hydroxyprogesterone (r = 0.48, p < 0.05) and androstenedione (r = 0.46, p < 0.05), and was greater in obese subjects. CIMT was greater in CAH males than females, but similar among CAH females with advanced BA, CAH males with normal BA, and control males. There was no difference in CIMT between CAH and controls, although high-density lipoprotein was inversely correlated with CIMT in both groups.

CONCLUSION

CIMT is associated with increased androgens in CAH adolescents and young adults, with loss of sex differences in CAH females with excess androgen exposure. Our findings highlight the importance of hormonal control for CVD prevention in CAH.

Non-invasive assessment of endothelial function in children with obesity and lipid disorders

BACKGROUND

Digital tonometry is designed to non-invasively screen for endothelial dysfunction by the detection of impaired flow-induced reactive hyperaemia in the fingertip. We determined whether digital reactive hyperaemia correlated with risk factors for atherosclerosis in two groups of children at increased risk for endothelial dysfunction.

METHODS

A total of 15 obese children and 23 non-obese, dyslipidaemic children, 8-21 years of age, were enrolled, and their medical histories, anthropometric measurements, carotid wall thickness by means of ultrasonography, and fasting blood samples for cardiovascular risk factors were obtained. The standard endoPAT index of digital reactive hyperaemia was modified to reflect the true peak response or the integrated response of the entire post-occlusion period. In each group, age, sex, pubertal status, carotid wall thickness, and multiple cardiovascular risk factors were tested as predictors of endothelial dysfunction.

RESULTS

In the non-obese, dyslipidaemic group, but not in the obese group, both indices strongly correlated with height (r=0.55, p=0.007, by peak response) followed by weight, waist circumference, and age. In both groups, neither index of reactive hyperaemia significantly correlated with any other cardiovascular risk factor.

CONCLUSIONS

Contrary to the known age-related increase in atherosclerosis, digital reactive hyperaemia increased with age and its correlates in non-obese, dyslipidaemic children and was not related to other cardiovascular risk factors in either group. The reason for the lack of this relationship with age in obese children is unknown. The age-dependent physiology of digital microvascular reactivity and the endothelium-independent factors controlling the peak hyperaemic response need further study in children with a wide age range.

The vascular phenotype of children with systemic lupus erythematosus

BACKGROUND

The increased risk of cardiovascular disease (CVD) in adults with systemic lupus erythematosus (SLE) has been known since the 1970s, but studies in juvenile-onset SLE (JSLE) have reported conflicting results and more data are needed. The aim of this cross-sectional study was to establish the baseline risk of CVD in a cohort of UK patients with JSLE.

METHODS

Data were collected to establish disease duration, disease activity, medication use and activity levels, as well as demographic data, including family history of CVD. Vascular phenotype was established using well-validated measures of carotid intima media thickness (cIMT) and pulse wave velocity (PWV).

RESULTS

In total, 45 children (39 female; mean age 13.5 ± 2.9 years) with JSLE were recruited to the study. Of these, 24 had a history of biopsy-proven lupus nephritis and five had an estimated glomerular filtration rate of <90 ml/min/1.73 m(2). Comparison of these JSLE patients with healthy controls previously scanned at our hospital revealed that the cIMT value was significantly higher in the former (0.45 vs. 0.37 mm, respectively; p < 0.0001). This difference was associated with the use of antihypertensives (p = 0.04) and higher or lower doses of prednisolone (p < 0.0001). PWV was not significantly different in the patient and control group (5.27 vs. 5.34 m/s, respectively; p = 0.77). In the patient group, the mean body mass index percentile was 65.63 ± 28.8, and the median physical activity score was 1,773 (676-2,854) metabolic equivalents of task (METs). None of the patients admitted to cigarette smoking, and ten had a positive family history of cardiovascular disease (CVD).

CONCLUSION

This study shows that our patients with JSLE had increased cIMT without an increase in PWV, suggesting possible early adaptive changes in JSLE. Follow-up data are needed to determine whether these changes result in clinically significant CVD.

A New 2D-Based Method for Carotid Intima-Media Thickness Quantification From Ultrasound Sequences

Background:

Ultrasound measurement of carotid Intima-Media Thickness (IMT) is a suitable method to evaluate subclinical arteriosclerosis.

Objectives:

The current study aimed to present a new computerized algorithm to detect instantaneous changes of the IMT to Common Carotid Artery (CCA) of IMT in sequential ultrasound images by applying the maximum gradient and the dynamic programming.

Patients and Methods:

In a cross-sectional design, an examination was performed on thirty healthy human subjects with the mean age of 44 ± 6 years from April 2013 to June 2013 in Beheshti Hospital, Kashan, Iran. In all individuals, the instantaneous changes of the far wall IMT on the CCA were extracted. Local measurements of vessel intensity, intensity gradient, and boundary continuity were extracted for all of the sequential ultrasonic 2D-frames throughout three cardiac cycles. The Pearson correlation coefficients and Bland-Altman analysis were performed to assess the relationship and agreement between IMT measured by the proposed and conventional manual methods.

Results:

There was no significant difference between the proposed and manual methods with paired t-test analysis (in systole: 0.57 ± 0.10 vs. 0.56 ± 0.10 mm; P = 0.188 and in diastole: 0.63 ± 0.16 vs. 0.62 ± 0.10 mm; P = 0.122 for the manual and proposed methods, respectively). The Pearson correlation coefficients were r = 0.94 and r = 0.93 for IMT_s and IMT_d, respectively (both P < 0.001). Limit of agreements were narrow and considerable agreement was found between the two methods.

Conclusions:

The present study demonstrated that the proposed computerized analyzing method can provide accurate measurements of the IMT of the CCA in sequential 2D ultrasonic images.

Continuous assessment of carotid intima-media thickness applied to estimate a volumetric compliance using B-mode ultrasound sequences

Recent reports have shown that the carotid artery wall had significant movements not only in the radial but also in the longitudinal direction during the cardiac cycle. Accordingly, the idea that longitudinal elongations could be systematically neglected for compliance estimations became controversial. Assuming a dynamic change in vessel length, the standard measurement of cross-sectional compliance can be revised. In this work, we propose to estimate a volumetric compliance based on continuous measurements of carotid diameter and intima-media thickness (IMT) from B-mode ultrasound sequences. Assuming the principle of conservation of the mass of wall volume (compressibility equals zero), a temporal longitudinal elongation can be calculated to estimate a volumetric compliance. Moreover, elongations can also be estimated allowing small compressibility factors to model some wall leakage. The cross-sectional and the volumetric compliance were estimated in 45 healthy volunteers and 19 asymptomatic patients. The standard measurement underestimated the volumetric compliance by 25% for young volunteers (p < 0.01) and 17% for patients (p < 0.05). When compressibility factors different from zero were allowed, volunteers and patients reached values of 9% and 4%, respectively. We conclude that a simultaneous assessment of carotid diameter and IMT can be employed to estimate a volumetric compliance incorporating a longitudinal elongation. The cross-sectional compliance, that neglects the change in vessel length, underestimates the volumetric compliance.

Endothelial nitric oxide synthase gene intron 4 variable number tandem repeat polymorphism in β-thalassemia major: relation to cardiovascular complications

Endothelial nitric oxide synthase (eNOS), an enzyme that generates nitric oxide, is a major determinant of endothelial function. Several eNOS gene polymorphisms have been reported as 'susceptibility genes' in various human diseases states, including cardiovascular, pulmonary and renal diseases. We studied the 27-base pair tandem repeat polymorphism in intron 4 of eNOS gene in 60 β-thalassemia major (β-TM) patients compared with 60 healthy controls and assessed its role in subclinical atherosclerosis and vascular complications. Patients were evaluated stressing on transfusion history, splenectomy, thrombotic events, echocardiography and carotid intima-media thickness (CIMT). Analysis of eNOS intron 4 gene polymorphism was performed by PCR. No significant difference was found between β-TM patients and controls with regard to the distribution of eNOS4 alleles or genotypes. The frequency of eNOS4a allele (aa and ab genotypes) was significantly higher in β-TM patients with pulmonary hypertension or cardiomyopathy. Logistic regression analysis revealed that eNOS4a allele was an independent risk factor for pulmonary hypertension in β-TM patients [odds ratio (OR) 2.2, 95% confidence interval (95% CI) 1.19-5.6; P < 0.001]. We suggest that eNOS intron 4 gene polymorphism is related to endothelial dysfunction and subclinical atherosclerosis and could be a possible genetic marker for prediction of increased susceptibility to cardiovascular complications.

Carotid artery intima-media thickness measurements in the youth: reproducibility and technical considerations

BACKGROUND

Carotid artery intima-media thickness (CIMT), a marker of atherosclerosis, is increased in youth at risk for future cardiovascular disease. Some pediatric studies have used CIMT as a primary outcome in clinical trials, yet data are limited on the standardization of methodology in children. The goal of this study was to evaluate reproducibility of CIMT measurements using two different measurement techniques.

METHODS

Carotid artery ultrasound studies of children and adolescents obtained as a component of a research study in Kawasaki syndrome were retrospectively analyzed. The CIMTs of both common carotid arteries (CCAs) were measured by one of two sonographers at the time in the cardiac cycle when resolution subjectively was determined to be optimal (Opt-CIMT). These sonographers blindly remeasured a random sample of studies of their own and each other's, using the same method. Another observer made CIMT measurements using exclusively frames on the R wave (R-CIMT). A fourth observer independently measured a random sample of studies twice with the R-CIMT method.

RESULTS

Carotid artery images from 184 subjects (mean age, 14.7 ± 2.2 years) were analyzed. The intraclass correlation coefficient for interobserver variability was 0.86 (95% confidence interval [CI], 0.69-0.94) compared with 0.85 (95% CI, 0.65-0.93) for the right and 0.86 (95% CI, 0.67-0.94) versus 0.95 (95% CI, 0.87-0.98) for the left CCA for Opt-CIMT and R-CIMT, respectively. R-CIMT was significantly thicker than Opt-CIMT (right CCA, 0.439 ± 0.030 vs 0.428 ± 0.024 mm, P < .001; left CCA, 0.446 ± 0.030 vs 0.434 ± 0.025 mm, P < .001).

CONCLUSION

Pediatric CIMT measurements have excellent reproducibility when the same methodology is applied but vary significantly throughout the cardiac cycle. This report highlights the need to standardize CIMT measurements in the youth and supports the use of electrocardiographic timing, as recommended in adults, in pediatric longitudinal studies.

Quality Control and Reproducibility in M-Mode, Two-Dimensional, and Speckle Tracking Echocardiography Acquisition and Analysis: The CARDIA Study, Year 25 Examination Experience

INTRODUCTION

Few large studies describe quality control procedures and reproducibility findings in cardiovascular ultrasound, particularly in novel techniques such as speckle tracking echocardiography (STE). We evaluate the echocardiography assessment performance in the Coronary Artery Risk Development in Young Adults (CARDIA) study Year 25 (Y25) examination (2010-2011) and report findings from a quality control and reproducibility program conducted to assess Field Center image acquisition and reading center (RC) accuracy.

METHODS

The CARDIA Y25 examination had 3475 echocardiograms performed in 4 US Field Centers and analyzed in a RC, assessing standard echocardiography (LA dimension, aortic root, LV mass, LV end-diastolic volume [LVEDV], ejection fraction [LVEF]), and STE (two- and four-chamber longitudinal, circumferential, and radial strains). Reproducibility was assessed using intraclass correlation coefficients (ICC), coefficients of variation (CV), and Bland-Altman plots.

RESULTS

For standard echocardiography reproducibility, LV mass and LVEDV consistently had CV above 10% and aortic root below 6%. Intra-sonographer aortic root and LV mass had the most robust values of ICC in standard echocardiography. For STE, the number of properly tracking segments was above 80% in short-axis and four-chamber and 58% in two-chamber views. Longitudinal strain parameters were the most robust and radial strain showed the highest variation. Comparing Field Centers with echocardiography RC STE readings, mean differences ranged from 0.4% to 4.1% and ICC from 0.37 to 0.66, with robust results for longitudinal strains.

CONCLUSION

Echocardiography image acquisition and reading processes in the CARDIA study were highly reproducible, including robust results for STE analysis. Consistent quality control may increase the reliability of echocardiography measurements in large cohort studies.

Vascular Dysfunction in Patients With Young β-Thalassemia

We aimed to study the endothelial dysfunction among children and adolescents with transfusion-dependent β-thalassemia using von Willebrand factor antigen (VWF:Ag) and flow cytometric analysis of circulating CD144+ endothelial microparticles (EMPs) and endothelial progenitor cells (CD34+VEGFR2+) and assess their relation to iron overload, erythropoietin and chelation therapy as well as echocardiographic parameters and carotid intima–media thickness. The VWF:Ag, EMPs, and CD34+VEGFR2+ cells were significantly higher among patients with β-thalassemia than controls ( P < .001). The type of chelation and patients’ compliance did not influence the results. No significant correlations were found between the studied vascular markers. Patients with evident heart disease had higher VWF: Ag, EMPs, and CD34+VEGFR2+ cells than those without. Carotid intima–media thickness was increased among patients but not correlated with vascular markers. We suggest that procoagulant EMPs and VWF: Ag are involved in cardiovascular complications in patients with young β-thalassemia. CD34+VEGFR2+ cells were further increased in response to tissue injury contributing to reendothelialization and neovascularization.

Plasminogen activator inhibitor-1 (PAI-1) in children and adolescents with type 1 diabetes mellitus: relation to diabetic micro-vascular complications and carotid intima media thickness

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is a fast-acting inhibitor of fibrinolysis that has been linked to increase risk of thrombosis. We determined PAI-1 levels in 80 children and adolescents with type 1 diabetes (T1DM) compared with 40 healthy controls as a potential marker for micro-vascular complications and assessed the relation to carotid intima media thickness (CIMT) as a synergistic risk factor for development of atherosclerosis.

METHODS

Patients were divided into 2 groups according to micro-vascular complications. Hemoglobin A1c (HbA1c), urinary albumin excretion, fasting serum lipid profile and PAI-1 levels were measured. CIMT of the common carotid artery was assessed using high resolution ultrasonography.

RESULTS

PAI-1 levels were significantly elevated in the group with diabetes compared with control group (p<0.001). PAI-1 levels were also increased in patients with micro-vascular complications compared with those without (p<0.001). CIMT was significantly higher in patients, particularly those with micro-vascular complications than patients without complications or controls (p<0.001). Positive correlations were found between PAI-1 levels and random blood glucose, HbA1c, triglycerides, total cholesterol and CIMT (p<0.05).

CONCLUSIONS

Increased plasma PAI-1 may be involved in the state of hypofibrinolysis in patients with T1DM leading to the occurrence of micro-vascular complications and increased risk of atherosclerosis.

Neurosonological Examination: A Non-Invasive Approach for the Detection of Cerebrovascular Impairment in AD

There has been a growing interest in vascular impairment associated with Alzheimer’s disease (AD). This interest was stimulated by the findings of higher incidence of vascular risk factors in AD. Signs of vascular impairment were investigated notably in the field of imaging methods. Our aim was to explore ultrasonographic studies of extra- and intracranial vessels in patients with AD and mild cognitive impairment (MCI) and define implications for diagnosis, treatment, and prevention of the disease. The most frequently studied parameters with extracranial ultrasound are intima-media thickness in common carotid artery, carotid atherosclerosis, and total cerebral blood flow. The transcranial ultrasound concentrates mostly on flow velocities, pulsatility indices, cerebrovascular reserve capacity, and cerebral microembolization. Studies suggest that there is morphological and functional impairment of cerebral circulation in AD compared to healthy subjects. Ultrasound as a non-invasive method could be potentially useful in identifying individuals in a higher risk of progression of cognitive decline.

Segmentation of the common carotid artery walls based on a frequency implementation of active contours: segmentation of the common carotid artery walls

Atherosclerosis is one of the most extended cardiovascular diseases nowadays. Although it may be unnoticed during years, it also may suddenly trigger severe illnesses such as stroke, embolisms or ischemia. Therefore, an early detection of atherosclerosis can prevent adult population from suffering more serious pathologies. The intima-media thickness (IMT) of the common carotid artery (CCA) has been used as an early and reliable indicator of atherosclerosis for years. The IMT is manually computed from ultrasound images, a process that can be repeated as many times as necessary (over different ultrasound images of the same patient), but also prone to errors. With the aim to reduce the inter-observer variability and the subjectivity of the measurement, a fully automatic computer-based method based on ultrasound image processing and a frequency-domain implementation of active contours is proposed. The images used in this work were obtained with the same ultrasound scanner (Philips iU22 Ultrasound System) but with different spatial resolutions. The proposed solution does not extract only the IMT but also the CCA diameter, which is not as relevant as the IMT to predict future atherosclerosis evolution but it is a statistically interesting piece of information for the doctors to determine the cardiovascular risk. The results of the proposed method have been validated by doctors, and these results are visually and numerically satisfactory when considering the medical measurements as ground truth, with a maximum deviation of only 3.4 pixels (0.0248 mm) for IMT.

Fully automated on-screen carotid intima-media thickness measurement: a screening tool for subclinical atherosclerosis

PURPOSE

Carotid intima-media thickness (CIMT) is generally considered an appropriate direct vascular method for cardiovascular risk assessment. The objective of this study was to evaluate the feasibility and reproducibility of a newly developed automated on-screen carotid ultrasound with respect to manual measurement with a conventional system.

METHODS

We assessed CIMT in 50 consecutive patients (age 62 ± 5 years, range 21-79 years, 36 men) twice, using a newly developed automated ultrasound (CardioHealth Station) and a conventional system with manual measurement (Acuson, Sequoia). For each patient, three frozen frames of the distal 10 mm of the right and left common carotid arteries were acquired on the two systems, by operators blinded to each other. The average of the mean value of three readings of each system was calculated.

RESULTS

The intraclass correlation coefficient of the interoperator variability was 0.95 and 0.94 for the automated and manual measurements, respectively. The comparative coefficient of variation of the interoperator variability was 8.2 and 8.7% for the automated and manual measurements, respectively. There was no clinically relevant difference between measurements obtained by the two systems (intraclass correlation coefficient = 0.98). The acquisition time of the automated system was significantly shorter than the conventional system (p < 0.01).

CONCLUSIONS

Fully automated on-screen measurements of CIMT are feasible, faster, and as reproducible as conventional manual measurements and may be suitable and cost-effective for screening application in community medicine.

Inter- and intra-observer variability analysis of completely automated cIMT measurement software (AtheroEdge™) and its benchmarking against commercial ultrasound scanner and expert Readers

The purpose of this study was to evaluate the measurement error and inter- and intra-observer variability of completely off-line automated and semi-automated carotid intima-media thickness (cIMT) measurement software (AtheroEdge™). Two hundred carotid ultrasound images from 50 asymptomatic women were analyzed. AtheroEdge™ was benchmarked against a commercial system (Syngo, Siemens) using automated and semi-automated modes. The measurement error and inter- and intra-observer variability of AtheroEdge™ were tested using three readings. The measurement error of AtheroEdge™ compared to the commercial software was 0.002±0.019mm (r=0.99) in the automated mode and -0.001±0.004mm in the semi-automated mode (r=0.99). The measurement error of AtheroEdge™ compared to the mean value of the three expert Readers (cIMT bias) for the automated and semi-automated methods was -0.0004±0.158mm and -0.008±0.157mm, respectively. The Figure-of-Merit was 99.8% and 99.9% when compared to the commercial ultrasound scanner (using the automated and semi-automated method, respectively) and was 99.9% and 98.9% when compared to the mean value of the three expert Readers. Regarding inter- and intra-observer variability, the intra-class correlation coefficient of the three independent users using the semi-automated AtheroEdge™ was 0.98. AtheroEdge™ showed a measurement performance comparable to the commercial ultrasound scanner software and the expert Readers' tracings. AtheroEdge™ belongs to a class of automated systems that could find application in processing large datasets for common carotid arteries, avoiding subjectivity in cIMT measurements.

Sonography of common carotid arteries' intima: media thickness in the normal adult population in Sudan

Background:

Carotid ultrasonography is a useful diagnostic tool for assessing carotid disease. It is highly reliable, has no radiation risk, and has no risks when compared to conventional angiography.

Aim:

The study was to determine the common carotid artery (CCA) intima–media thickness (IMT) in the normal adult Sudanese so as to create standards for defining abnormalities.

Materials and Methods:

In 440 participants, the intima–media thickness was obtained sonographically in the supine position at the point of 1 cm section distal to the carotid bulb. Due to ethnic variations, participants were divided into a five ethnic groups according to their geographic distribution in Sudan.

Results:

The ranges of IMT found in the study were from 0.04 cm to 0.07 cm in carotids. Ethnically, males and females from West and East of Sudan show the highest IMT (0.070 ± 0.00 cm and 0.065 ± 0.01 cm) for CCA while males and females from the South of Sudan show the lowest IMT (0.055 ± 0.01 cm and 0.058 ± 0.004 cm).

Conclusion:

Mean carotids’ IMT was slightly higher in females compared to males. No significant differences were found between IMT and different ethnics but significance was noted among participants’ age and IMT of both sexes.

Mannheim carotid intima-media thickness and plaque consensus (2004-2006-2011). An update on behalf of the advisory board of the 3rd, 4th and 5th watching the risk symposia, at the 13th, 15th and 20th European Stroke Conferences, Mannheim, Germany, 2004, Brussels, Belgium, 2006, and Hamburg, Germany, 2011

Intima-media thickness (IMT) provides a surrogate end point of cardiovascular outcomes in clinical trials evaluating the efficacy of cardiovascular risk factor modification. Carotid artery plaque further adds to the cardiovascular risk assessment. It is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. The scientific basis for use of IMT in clinical trials and practice includes ultrasound physics, technical and disease-related principles as well as best practice on the performance, interpretation and documentation of study results. Comparison of IMT results obtained from epidemiological and interventional studies around the world relies on harmonization on approaches to carotid image acquisition and analysis. This updated consensus document delineates further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT. Standardized methods will foster homogenous data collection and analysis, improve the power of randomized clinical trials incorporating IMT and plaque measurements and facilitate the merging of large databases for meta-analyses. IMT results are applied to individual patients as an integrated assessment of cardiovascular risk factors. However, this document recommends against serial monitoring in individual patients.

Repeatability and reproducibility of ultrasonographic measurement of carotid intima thickness

PURPOSE

To evaluate the repeatability and reproducibility of intima thickness (IT) measurements at different sites along the common carotid artery and compare with intima-media thickness (IMT) measurements.

METHODS

Ultrasound examinations of common carotid artery were performed in 30 healthy subjects and 20 patients with diabetes mellitus. Carotid IT and IMT were measured at 10 mm, 13 mm, and 16 mm upstream from the carotid bulb. Each subject was scanned by three operators to evaluate inter-operator reproducibility. Each operator scanned the subjects twice to evaluate intra-operator repeatability. Inter-equipment reproducibility of the measurements was evaluated.

RESULTS

The inter-operator reproducibility for measuring carotid IT at the three sites was 81.5%, 81.9% and 69.1%, respectively, slightly lower than carotid IMT measurement (89.7%, 86.5%, 75.2%, respectively). The intra-operator repeatability for carotid IT measurement at the three sites ranged 76.9-89.5%, 67.4-90.3%, and 55.2-70.5%, respectively, and was lower than for IMT measurement (86.5-96.9%, 87.6-95.7%, 79.9-86.5%, respectively). The inter-equipment reproducibility of IMT (75.7-86.6%) was slightly better than for IT measurement (71.4-75.9%).

CONCLUSIONS

Ultrasonographic measurement of carotid IT is repeatable and reproducible, although not as good as IMT. Measurements preformed 10 mm to 13 mm upstream from the carotid bulb yield more repeatable and reproducible results.

Adiposity predicts carotid intima-media thickness in healthy children and adolescents

OBJECTIVE

To examine whether anthropometric measurements, blood pressure (BP), fasting total cholesterol, and low-density lipoprotein are related to ultrasound measures of carotid intima-media thickness (CIMT) in children and teenagers with no known risk factors for cardiovascular disease.

STUDY DESIGN

This cross-sectional study included 599 subjects, 6 to 20 years of age (292 males, 307 females; 224 Hispanics, 210 European-Americans, 126 African-Americans, and 39 Asian-Americans) whose body mass index, waist circumference, BP, lipid profiles, and values for CIMT were determined.

RESULTS

Measures of CIMT were significantly greater in males than females (P=.006) and in African-Americans when compared with other ethnic groups (all P < .05). There were no relations between age, diastolic BP, or fasting levels of triglycerides, total cholesterol, or low-density lipoprotein values and CIMT measures, regardless of sex or ethnic background. Stratified multiple regression analysis indicated that body mass index and waist circumference independently predicted CIMT in both males and females, even after controlling for age, weight, BP, fasting lipid levels, and ethnic background.

CONCLUSION

Increased body mass and adiposity are associated with increased intima-media thickness in children and teenagers. This association is present in children not considered overweight, underscoring the need for the continued promotion of adequate nutritional and physical exercise behavior during childhood.

Variations in carotid artery intima-media thickness during the cardiac cycle in children

BACKGROUND

There is paucity of research looking at variations in carotid artery intima-media thickness (CIMT) during the cardiac cycle in children. The aim of this study was to ascertain variations, if any, in CIMT during the cardiac cycle in a population of high-risk children.

METHODS

Forty-nine children aged 6 to 19 years with dyslipidemia and other atherosclerosis-promoting risk factors underwent a carotid ultrasound. CIMT was measured using commercially available, semiautomated edge-detection software. The region of interest was the far wall of the common carotid artery. CIMT was measured at various points during the cardiac cycle using the electrocardiogram (EKG) as a reference. CIMT measurements two frames before, during, and after the QRS complex (end diastole) were analyzed separately (designated as "QRS CIMT") from the other CIMT measurements (designated as "non-QRS CIMT"). Demographics, heart rate, blood pressure, anthropometric measures, lumen diameter, family history, and presence of other atherosclerosis-promoting risk factors were documented.

RESULTS

"QRS CIMT" was significantly thicker than "non-QRS CIMT" (P = .01), with the age group 10 to 14 years showing the most significant variation between "QRS CIMT" and "non-QRS CIMT" (P = .005). CIMT values between right and left carotid arteries differed by 2.5%. Age, systolic blood pressure, and blood glucose were significant predictors of mean CIMT by simple linear regression; systolic blood pressure was the only significant predictor of mean CIMT by stepwise multiple linear regression analysis.

CONCLUSION

CIMT measurements vary during the cardiac cycle in children. It is thicker during the QRS complex on EKG. Carotid ultrasound should be performed with an EKG, and CIMT should be measured at the same point on the EKG to overcome this variation. Furthermore, we recommend that CIMT be measured at the R-wave on EKG because this is an easily discernible point in the cardiac cycle.

Targeting treatment using calculated cardiovascular disease risk: effective? A shot in the dark? Or is it time to change the paradigm?

BACKGROUND

The current paradigm for cardiovascular risk screening is one of screen and treat; i.e. a risk calculation is used to screen the population to determine who should receive therapy. This is marginally effective with somewhere between 199 and 999 people receiving lipid-lowering therapy and consequently being exposed to the drug-related risk without receiving any benefit.

HYPOTHESIS

New evidence suggests that a diagnostic test could be applied to decide which patients will benefit from treatment.

CONCLUSION

Changing the paradigm from 'screen and treat' to 'screen, diagnose and treat' could save large amounts of money by avoiding drugs and could prevent many people from being exposed to side effects.

Risk factors associated with aortic and carotid intima-media thickness in adolescents and young adults: the Muscatine Offspring Study

OBJECTIVES

This study sought to determine whether cardiovascular risk factors are associated with aortic intima-media thickness (aIMT) and carotid intima-media thickness (cIMT) in adolescents and young adults.

BACKGROUND

Atherosclerotic lesions begin developing in youth, first in the distal abdominal aorta and later in the carotid arteries. Knowledge of how risk factors relate to aIMT and cIMT may help in the design of early interventions to prevent cardiovascular disease.

METHODS

Participants were 635 members of the Muscatine Offspring cohort. The mean aIMT and cIMT were measured using an automated reading program.

RESULTS

The mean (SD) values of aIMT and cIMT were 0.63 (0.14) and 0.49 (0.04) mm, respectively. In adolescents (age 11 to 17 years), aIMT was associated with triglycerides, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and waist/hip ratio, after adjusting for age, sex, and height. In young adults (age 18 to 34 years), aIMT was associated with those same 5 risk factors, plus high-density lipoprotein cholesterol and pulse pressure. In adolescents, cIMT was associated with SBP, pulse pressure, heart rate, BMI, and waist/hip ratio. In young adults, cIMT was associated with total cholesterol, low-density lipoprotein cholesterol, triglycerides, SBP, DBP, BMI, waist/hip ratio, and glycosylated hemoglobin. In both age groups, aIMT and cIMT were significantly correlated with the Pathobiological Determinants of Atherosclerosis in Youth coronary artery risk score.

CONCLUSIONS

Both aIMT and cIMT are associated with cardiovascular risk factors. Using aIMT in adolescents gives information beyond that obtained from cIMT alone. Measurement of aIMT and cIMT may help identify those at risk for premature cardiovascular disease.

Association between blood pressure and carotid intima-media thickness

OBJECTIVE

To investigate the association between blood pressure and carotid intima-media thickness (IMT) in healthy adolescents.

STUDY DESIGN

Study participants included 285 first-year high school students (mean age, 15.2 years) at a rural high school in Korea. Systolic and diastolic blood pressure (SBP and DBP) were measured with an oscillometric automated sphygmomanometer. The carotid arteries were evaluated with high-resolution B-mode ultrasound scanning. IMT value was determined with the average of the maximal IMT at each common carotid artery. Increased IMT was defined as sex-specific top quartile. The odds ratio (OR) for increased IMT per 1 SD increase of SBP and DBP was estimated after adjusting for age, sex, body mass index, waist circumference, fasting glucose level, and total/high-density lipoprotein cholesterol ratio.

RESULTS

Adjusted OR for increased IMT was 1.70 (P = .003) per 12.4 mm Hg SBP and 1.25 (P = .125) per 7.0 mm Hg DBP. When the analyses were performed by sex, increased IMT was associated with both SBP (OR, 2.67; P = .003) and DBP (OR, 1.68; P = .019) in girls, but it was not associated with either SBP (OR, 1.46; P = .093) or DBP (OR, 0.99; P = .972) in boys.

CONCLUSION

These results suggest that higher blood pressure level may be associated with increased carotid IMT in apparently healthy adolescents.

Increased carotid artery intima-media thickness following venoarterial extracorporeal membrane oxygenation in the neonatal period

OBJECTIVE

To compare left carotid intima-media thickness (CIMT) and biochemical markers for atherogenesis in neonatal venoarterial extracorporeal membrane oxygenation (ECMO) survivors with normal controls during childhood.

METHODS

Venoarterial ECMO survivors and healthy patients between 12 and 18 years of age were enrolled in a matched control prospective study. ECMO survivors were matched to controls based on chronological age and percentage of body mass index (BMI). Measured CIMT of the posterior left carotid artery and CIMT values corrected for carotid artery size were used for data analysis.

RESULTS

Thirty-one neonatal venoarterial ECMO survivors were matched to 31 healthy controls. No significant differences were found between ECMO survivors and controls for age, weight, percentage of BMI, total fat composition, lipid profiles, ultrasensitive C-reactive protein or homocysteine levels. Significant differences between ECMO and controls patients were found in systolic, diastolic and mean left CIMT.

CONCLUSION

Compared with controls, the thickness of the left carotid intima media is significantly increased at the age of 12 to 18 years in neonatal venoarterial ECMO survivors. The clinical significance of this increased CIMT is unknown. ECMO centers may want to incorporate assessment of CIMT in their follow-up protocols.

Carotid intima-media thickness measurements: techniques and clinical relevance

Atherosclerosis is a systemic disease that is responsible for most cardiovascular events and stroke. Epidemiologic studies and intervention trials based on the incidence of acute vascular disease end points require years of follow-up, the participation of large populations, or both. As a consequence, such studies consume considerable time and financial resources. The use of surrogate markers, therefore, is of paramount relevance because it allows researchers to have reliable data in less time and from reduced populations. Intima-media thickness (IMT) measured by B-mode ultrasound is the most studied surrogate marker and has been validated by official medical agencies. In this article, we review the most important technical considerations related to its measurement and highlight issues that should be systematically addressed in IMT-related studies. In summary, the use of IMT as an end point in clinical studies is of great value, but several technical limitations might jeopardize its interpretation.

Differential effect of marrow adiposity and visceral and subcutaneous fat on cardiovascular risk in young, healthy adults

Background

Adipose tissue is an endocrine organ that influences many metabolic processes and accumulates in different depots, including the bone marrow. While the negative associations between visceral fat (VF) or subcutaneous fat (SF) and cardiovascular disease (CVD) risks are well known, the relation between marrow fat (MF) and metabolic risk is unexplored.

Objectives

We examined the relations between these three fat depots and whether CVD risks are associated to marrow adiposity.

Design

observational cross sectional study

Subjects and Methods

Computed tomography was used to measure VF, SF and MF depots in 131 healthy young adults (60 females, 71 males; 16-25 years of age). Weight, body mass index (BMI), waist and hip circumferences, blood pressure (BP), carotid intima media thickness (CIMT) and serum levels of lipids, glucose and insulin were also measured.

Results

Regardless of gender, MF was not associated to values of VF or SF, anthropometric measures, or lipid or carbohydrate serum levels (P >0.05 for all). In contrast, VF was associated to SF (r’s= 0.74 for females, 0.78 for males; both P’s <0.0001) and these depots were related to anthropometric parameters (r’s between .69 and .87; all P’s <0.0001) and to most measures of lipids, glucose or insulin (r’s between .25 and .62).

Conclusions

Marrow adiposity in young men and women is independent of visceral and subcutaneous fat, and is not associated to CVD risk. These findings do not support the concept that marrow adiposity is involved in the comorbidities related to fat accumulation in other compartments.