Carotid Wall Volume Research Articles

Exposure to air pollutants and subclinical carotid atherosclerosis measured by magnetic resonance imaging: A cross-sectional analysis.

Long-term exposure to air pollution has been associated with higher risk of cardiovascular mortality. Less is known about the association of air pollution with initial development of cardiovascular disease. Herein, the association between low-level exposure to air pollutants and subclinical carotid atherosclerosis in adults without known clinical cardiovascular disease was investigated. Cross-sectional analysis within a prospective cohort study. The Canadian Alliance for Healthy Hearts and Minds Cohort Study; a pan-Canadian cohort of cohorts. Canadian adults (n = 6645) recruited between 2014-2018 from the provinces of British Columbia, Alberta, Ontario, Quebec, and Nova Scotia, were studied, for whom averages of exposures to nitrogen dioxide (NO2), ozone (O3), and fine particulate matter (PM2.5) were estimated for the years 2008-2012. Carotid vessel wall volume (CWV) measured by magnetic resonance imaging (MRI). In adjusted linear mixed models, PM2.5 was not consistently associated with CWV (per 5 μg/m3 PM2.5; adjusted estimate = -8.4 mm3; 95% Confidence Intervals (CI) -23.3 to 6.48; p = 0.27). A 5 ppb higher NO2 concentration was associated with 11.8 mm3 lower CWV (95% CI -16.2 to -7.31; p<0.0001). A 3 ppb increase in O3 was associated with 9.34 mm3 higher CWV (95% CI 4.75 to 13.92; p<0.0001). However, the coarse/insufficient O3 resolution (10 km) is a limitation. In a cohort of healthy Canadian adults there was no consistent association between PM2.5 or NO2 and increased CWV as a measure of subclinical atherosclerosis by MRI. The reasons for these inconsistent associations warrant further study.

Reproducibility for carotid wall segmentation using T1-weighted DANTE-SPACE sequence on high-resolution 3-T carotid MRI.

T1-weighted (T1W) magnetic resonance imaging (MRI) using the delay alternating with nutation for excitation-sampling perfection with application-optimized contrasts using different flip angle evolution (DANTE-SPACE) is the preferred imaging technique for evaluation of the vessel wall. To evaluate the intra- and inter-rater reproducibility of carotid wall segmentation on T1W DANTE-SPACE in patients with symptomatic (acute stroke or transient ischemic attack) internal carotid artery (ICA) stenosis. This prospective study included 25 patients with acute (≤3 months) stroke or transient ischemic attack and 50%-99% stenosis of the ICA. All patients underwent 3.0-T high-resolution carotid MRI. Two radiologists independently performed the manual segmentation of the vessel wall and inner lumen of the bilateral carotid artery on DANTE-SPACE. The intraclass correlation coefficient (ICC), Dice similarity coefficient (DSC), and Hausdorff distance (HD) were calculated. The ICCs for intra-rater reproducibility of carotid wall volume, inner lumen volume, and normalized wall index were 0.965, 0.990, and 0.962, respectively. The ICCs for inter-rater reproducibility of carotid wall volume, inner lumen, and normalized wall index were 0.856, 0.981, and 0.904. DSC and HD for intra- and inter-rater reproducibility of carotid wall segmentation were as follows: 0.873 and 0.809 (DSC); and 0.079 and 0.118 (HD), respectively. For evaluation of reproducibility only in the carotid artery with symptomatic stenosis, the ICCs for intra- and inter-rater reproducibility indicated all perfect agreement. T1W DANTE-SPACE is a reproducible sequence for evaluation of the carotid wall using carotid MRI in patients with symptomatic ICA stenosis.

Inter-observer and intra-observer reliability between manual segmentation and semi-automated segmentation for carotid vessel wall volume measurements on three-dimensional ultrasonography

Carotid vessel wall volume (VWV) measurement on three-dimensional ultrasonography (3DUS) outperforms conventional two-dimensional ultrasonography for carotid atherosclerosis evaluation. Although time-saving semi-automated algorithms have been introduced, their clinical availability remains limited due to a lack of validation, particularly an extensive reliability analysis. This study compared inter-observer and intra-observer reliability between manual segmentation and semi-automated segmentation for carotid VWV measurements on 3DUS. Thirty-one 3DUS volume datasets were prospectively acquired from 20 healthy subjects, aged >18 years, without previous stroke, transient ischemic attack, or cardiovascular disease. Five observers segmented all volume datasets both manually and semi-automatically. The process was repeated five times. Reliability was expressed by the intraclass correlation coefficient, supplemented by the coefficient of variation. Carotid VWV measurements using the common carotid artery (CCA) were more reliable than those using the internal carotid artery (ICA) or external carotid artery (ECA) for both manual and semiautomated segmentation (manual segmentation, CCA: inter-observer, 0.935; intra-observer, 0.934 to 0.966; ICA: inter-observer, 0.784; intra-observer, 0.756 to 0.878; ECA: inter-observer, 0.732; intraobserver, 0.919 to 0.962; semi-automated segmentation, CCA: inter-observer, 0.986; intra-observer, 0.954 to 0.993; ICA: inter-observer, 0.977; intra-observer, 0.958 to 0.978; ECA: inter-observer, 0.966; intra-observer, 0.884 to 0.937). Total carotid VWV measurements by manual (inter-observer, 0.922; intra-observer, 0.927 to 0.961) and semi-automated segmentation (inter-observer, 0.987; intra-observer, 0.968 to 0.989) were highly reliable. Semi-automated segmentation showed higher reliability than manual segmentation for both individual and total carotid VWV measurements. 3DUS carotid VWV measurements of the CCA are more reliable than measurements of the ICA and ECA. Total carotid VWV measurements are highly reliable. Semi-automated segmentation has higher reliability than manual segmentation.

Diabetes, Brain Infarcts, Cognition, and Small Vessels in the Canadian Alliance for Healthy Hearts and Minds Study.

Diabetes is a risk factor for cerebrovascular disease and cognitive impairment. The anatomical basis for this is uncertain. The Canadian Alliance for Healthy Hearts and Minds collected brain and carotid magnetic resonance imaging (MRI) and 2 cognitive tests (the Digit Symbol Substitution Test and the Montreal Cognitive Assessment test) in a cross-sectional sample of men and women. Brain MRIs identified brain infarcts (BI), lacunar BI, high white matter hyperintensity (WMH), vascular brain injury (VBI; BI or high WMH), and small vessel VBI (lacunar BI or high WMH). Carotid MRIs estimated carotid wall volume, a measure of subclinical atherosclerosis. Cognitive scores were standardized to each site's mean score, and cognitive impairment was identified by 1 or both test scores ≤1 standard deviation below the site's mean score on that test. The 7733 participants included 495 participants (6.4%) with diabetes, of whom 388 were taking diabetes drugs. After age and sex adjustment, diabetes was independently associated with BI (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.05, 2.24), VBI (OR 1.64, 95% CI 1.26, 2.13), small vessel VBI (OR 1.67, 95% CI 1.28, 2.19), and cognitive impairment (OR 1.47, 95% CI 1.20, 1.80). The association between diabetes and small vessel VBI persisted after adjustment for cerebrovascular disease risk factors and nonlacunar infarcts (OR 1.52, 95% CI 1.15, 2.01), and the association with cognitive impairment persisted after adjustment for small vessel VBI (OR 1.27, 95% CI 1.03, 1.56). Small vessel disease characterizes much of the relationship between diabetes and VBI. However, additional factors are required to disentangle the relationship between diabetes and cognitive impairment.

Coronary CT Angiography and Carotid MRI Improve Phenotyping of Disease Extent Compared with ACC/AHA Risk Score Alone.

To determine the relationship between the American College of Cardiology/American Heart Association (ACC/AHA) risk score and plaque phenotype of the coronary and carotid arteries assessed directly using CT angiography and MRI. Asymptomatic subjects eligible for statin therapy by risk score were enrolled in a prospective study of disease burden using coronary artery calcium (CAC) scoring, coronary CT angiography, and MRI of the carotid arteries. Quartiles were calculated for noncalcified plaque, CAC, and average carotid wall volume and were compared with ACC/AHA risk quartiles. Two hundred three subjects were studied (60% men; mean age, 65 years). There were weak correlations between risk and carotid wall volume (Kendall tau = 0.29), noncalcified plaque (tau = 0.16), and CAC (tau = 0.33). ACC/AHA risk alone misclassified plaque extent compared with measurement by carotid wall volume, CAC, and noncalcified plaque in 22.1%, 24.1%, and 29.6% of subjects, respectively. On average, 13% of the subjects were underclassified, and 12.5% were overclassified. Approximately 25% of subjects had large discrepancies between ACC/AHA risk and plaque burden at imaging. These results suggest that clinical risk score models alone do not fully reflect the amount of atherosclerotic disease present.© RSNA, 2020See also the commentary by Truong and Villines in this issue.

Explaining the variability in cardiovascular risk factors among First Nations communities in Canada: a population-based study

Historical, colonial, and racist policies continue to influence the health of Indigenous people, and they continue to have higher rates of chronic diseases and reduced life expectancy compared with non-Indigenous people. We determined factors accounting for variations in cardiovascular risk factors among First Nations communities in Canada. Men and women (n=1302) aged 18 years or older from eight First Nations communities participated in a population-based study. Questionnaires, physical measures, blood samples, MRI of preclinical vascular disease, and community audits were collected. In this cross-sectional analysis, the main outcome was the INTERHEART risk score, a measure of cardiovascular risk factor burden. A multivariable model was developed to explain the variations in INTERHEART risk score among communities. The secondary outcome was MRI-detected carotid wall volume, a measure of subclinical atherosclerosis. The mean INTERHEART risk score of all communities was 17·2 (SE 0·2), and more than 85% of individuals had a risk score in the moderate to high risk range. Subclinical atherosclerosis increased significantly across risk score categories (p<0·0001). Socioeconomic advantage (-1·4 score, 95% CI -2·5 to -0·3; p=0·01), trust between neighbours (-0·7, -1·2 to -0·3; p=0·003), higher education level (-1·9, -2·9 to -0·8, p<0·001), and higher social support (-1·1, -2·0 to -0·2; p=0·02) were independently associated with a lower INTERHEART risk score; difficulty accessing routine health care (2·2, 0·3 to 4·1, p=0·02), taking prescription medication (3·5, 2·8 to 4·3; p<0·001), and inability to afford prescription medications (1·5, 0·5 to 2·6; p=0·003) were associated with a higher INTERHEART risk score. Collectively, these factors explained 28% variation in the cardiac risk score among communities. Communities with higher socioeconomic advantage and greater trust, and individuals with higher education and social support, had a lower INTERHEART risk score. Communities with difficulty accessing health care, and individuals taking or unable to afford prescription medications, had a higher INTERHEART risk score. Cardiac risk factors are lower in communities with high socioeconomic advantage, greater trust, social support and educational opportunities, and higher where it is difficult to access health care or afford prescription medications. Strategies to optimise the protective factors and reduce barriers to health care in First Nations communities might contribute to improved health and wellbeing. Heart and Stroke Foundation of Canada, Canadian Partnership Against Cancer, Canadian Institutes for Health Research.

Segment-specific progression of carotid artery atherosclerosis: a magnetic resonance vessel wall imaging study.

This study aimed to investigate the segment-specific progression of atherosclerotic carotid plaques using serial multi-contrast magnetic resonance (MR) imaging. Symptomatic patients with carotid 30-70% stenosis were recruited and underwent carotid MR vessel wall imaging at baseline and follow-up time point (≥ 6months after baseline). The location of plaques was determined according to the maximum wall thickness located above or below carotid bifurcation. The baseline and changing characteristics of carotid plaques were compared between plaques above and below carotid bifurcation, and the risk factors for segment-specific plaque progression were analyzed with logistic regression. Ninety-six carotid plaques from 73 patients (mean age 66.5 ± 11.4years old) were eligible for statistical analysis. Compared with plaques located below carotid bifurcation, those above bifurcation had significantly greater stenosis at baseline (57.2 ± 13.0% vs. 50.4 ± 13.5%, p = 0.016, adjusted p = 0.005) and greater progression rate of carotid wall volume (35.2 ± 68.8mm3/year vs. 4.2 ± 65.0mm3/year, p = 0.026, adjusted p = 0.005) before and after adjusting for all clinical risk factors and baseline stenosis and wall volume of carotid arteries. Logistic regression showed that the related risk factors were age, hypertension, and smoke for the progression of plaques located above the bifurcation and age for plaques below the bifurcation, respectively. Plaques located above the bifurcation of carotid arteries had greater annual progression and correlated with more cardiovascular risk factors compared with those located below the bifurcation.

Cardiovascular risk scoring and magnetic resonance imaging detected subclinical cerebrovascular disease.

Aims Cardiovascular risk factors are used for risk stratification in primary prevention. We sought to determine if simple cardiac risk scores are associated with magnetic resonance imaging (MRI)-detected subclinical cerebrovascular disease including carotid wall volume (CWV), carotid intraplaque haemorrhage (IPH), and silent brain infarction (SBI).Methods and resultsA total of 7594 adults with no history of cardiovascular disease (CVD) underwent risk factor assessment and a non-contrast enhanced MRI of the carotid arteries and brain using a standardized protocol in a population-based cohort recruited between 2014 and 2018. The non-lab-based INTERHEART risk score (IHRS) was calculated in all participants; the Framingham Risk Score was calculated in a subset who provided blood samples (n = 3889). The association between these risk scores and MRI measures of CWV, carotid IPH, and SBI was determined. The mean age of the cohort was 58 (8.9) years, 55% were women. Each 5-point increase (∼1 SD) in the IHRS was associated with a 9 mm3 increase in CWV, adjusted for sex (P < 0.0001), a 23% increase in IPH [95% confidence interval (CI) 9–38%], and a 32% (95% CI 20–45%) increase in SBI. These associations were consistent for lacunar and non-lacunar brain infarction. The Framingham Risk Score was also significantly associated with CWV, IPH, and SBI. CWV was additive and independent to the risk scores in its association with IPH and SBI.Conclusion Simple cardiovascular risk scores are significantly associated with the presence of MRI-detected subclinical cerebrovascular disease, including CWV, IPH, and SBI in an adult population without known clinical CVD.

Abstract 17054: Sex-Related Differences in Atherosclerosis Burden and Composition Evaluated by Magnetic Resonance: A Complex Interaction Between Visceral Adiposity and Atherogenic Lipoproteins

Introduction: Visceral adiposity increases the level of atherogenic lipoproteins and is linked to sex-related differences in cardiovascular risk. Hypothesis. Atherogenic lipoproteins could mediate the relationship between visceral fat and sex-related differences in atherosclerosis burden and composition, including the lipid-rich necrotic core (LRNC). Methods: This study included 294 women (39.4 ± 15.0 years) and 324 men (39.5 ± 13.8 years), matched for age and risk factors (hypertension, dyslipidemia, obesity, diabetes, smoking). Carotid atherosclerosis, visceral abdominal fat (VAT) and cardiac fat (CAT) were studied by magnetic resonance imaging. Results: For similar age and risk profile, women had less VAT ( p &lt;0.001) and CAT ( p &lt;0.001) than men. Carotid atherosclerosis prevalence ( p &lt;0.001) and carotid wall volume ( p &lt;0.001) were higher in men. Although LRNC prevalence was similar in women and men ( p =0.23), men had a greater LRNC volume ( p &lt;0.001). An interaction was observed between waist-to-hip ratio (WHR) and sex on LRNC volume ( p =0.025). There was also an interaction between sex, VAT, and total cholesterol/high-density lipoprotein cholesterol ratio (TC/HDL-C) on LRNC volume ( p =0.012), beyond age and risk factors ( p =0.011). Only 8.6% of men and none of the women were classified at high risk (presence of LRNC) by the Framingham Risk Score while 35.4% of men and 14.0% of women were classified at high risk by the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) risk score (risk of advanced atherosclerosis). Elevated TC/HDL-C (≥3) and/or WHR (≥0.8 in women, ≥0.9 in men) were superior to the PDAY risk score, identifying 62.2% of women (Net Reclassification Improvement [NRI]=1.85, p &lt;0.001) and 79.3% of men (NRI=0.26, p &lt;0.001) with LRNC. Conclusions: Women had less visceral adiposity, carotid atherosclerosis burden and LRNC volume, independently of age and risk profile. Carotid LRNC volume varied with sex, VAT, and atherogenic lipoproteins. WHR and TC/HDL-C improved the identification of high-risk carotid atherosclerosis features in women as well as men. This evidence supports the clinical potential of the atherogenic lipoprotein profile and of adiposity distribution in atherosclerosis risk evaluation of both women and men.

Association of Progression of Carotid Artery Wall Volume and Recurrent Transient Ischemic Attack or Stroke: A Magnetic Resonance Imaging Study.

This study aimed to investigate the association between carotid plaque progression and subsequent recurrent events using magnetic resonance imaging. Sixty-three symptomatic patients with ipsilateral carotid atherosclerotic stenosis (30%-69% stenosis) determined by ultrasound underwent first and second carotid artery magnetic resonance imaging for carotid artery at baseline and ≥6 months after the first scan, respectively. All the patients had clinical follow-up after the second magnetic resonance scan for ≤5 years until the onset of recurrent transient ischemic attack or stroke. Presence/absence of carotid plaque compositional features, particularly intraplaque hemorrhage and fibrous cap rupture was identified. The annual progression of carotid wall volume between 2 magnetic resonance scans was measured. Univariate and multivariate Cox regression was used to calculate the hazard ratio and corresponding 95% confidence interval of carotid plaque features in discriminating recurrent events. Receiver-operating-characteristic-curve analysis was conducted to determine the area-under-the-curve of carotid plaque features in predicting recurrent events. Sixty-three patients (mean age: 66.5±10.0 years old; 54 males) were eligible for final statistics analysis. During a mean follow-up duration of 55.1±13.6 months, 14.3% of patients (n=9) experienced ipsilateral recurrent transient ischemic attack/stroke. The annual progression of carotid wall volume was significantly associated with recurrent events before (hazard ratio, 1.14 per 10 mm3; 95% confidence interval, 1.02-1.27; P=0.019) and after (hazard ratio, 1.19 per 10 mm3; 95% confidence interval, 1.03-1.37; P=0.022) adjusted for confounding factors. In discriminating the recurrence of transient ischemia attack/stroke, receiver-operator curve analysis indicated that combined with annual progression of wall volume, there was a significant incremental improvement in the area-under-the-curve of intraplaque hemorrhage (area-under-the-curve: 0.69-0.81) and fibrous cap rupture (area-under-the-curve: 0.73-0.84). The annual progression of carotid wall volume is independently associated with recurrent ischemic cerebrovascular events, and this measurement has added value for intraplaque hemorrhage and fibrous cap rupture in predicting future events.

Apheresis as novel treatment for refractory angina with raised lipoprotein(a): a randomized controlled cross-over trial

To determine the clinical impact of lipoprotein apheresis in patients with refractory angina and raised lipoprotein(a) > 500 mg/L on the primary end point of quantitative myocardial perfusion, as well as secondary end points including atheroma burden, exercise capacity, symptoms, and quality of life. We conducted a single-blinded randomized controlled trial in 20 patients with refractory angina and raised lipoprotein(a) > 500 mg/L, with 3 months of blinded weekly lipoprotein apheresis or sham, followed by crossover. The primary endpoint was change in quantitative myocardial perfusion reserve (MPR) assessed by cardiovascular magnetic resonance. Secondary endpoints included measures of atheroma burden, exercise capacity, symptoms and quality of life. The primary endpoint, namely MPR, increased following apheresis (0.47; 95% CI 0.31-0.63) compared with sham (-0.16; 95% CI - 0.33-0.02) yielding a net treatment increase of 0.63 (95% CI 0.37-0.89; P < 0.001 between groups). Improvements with apheresis compared with sham also occurred in atherosclerotic burden as assessed by total carotid wall volume (P < 0.001), exercise capacity by the 6 min walk test (P = 0.001), 4 of 5 domains of the Seattle angina questionnaire (all P < 0.02) and quality of life physical component summary by the short form 36 survey (P = 0.001). Lipoprotein apheresis may represent an effective novel treatment for patients with refractory angina and raised lipoprotein(a) improving myocardial perfusion, atheroma burden, exercise capacity and symptoms.

The effects of statin therapy on carotid plaque composition and volume: A systematic review and meta-analysis

Background and purposePrior studies have demonstrated that statin use stabilizes and diminishes atherosclerotic lesions. The main objective of this systematic review and meta-analysis was to study the effects of statin therapy on carotid plaque composition as seen on serial high-resolution carotid plaque MRI. We hypothesized that statin therapy would result in significant improvements in lipid-rich-necrotic-core (LRNC) volumes, wall volumes and lumen volumes. Materials and methodsProspective studies using serial high-resolution carotid plaque MRI (1.5 or 3T only) in patients on statin therapy to document changes in carotid plaque composition were included. All studies had a minimum of 10 patients and minimum follow-up duration of 3 months. Outcomes included change in LRNC volume, wall volume, and lumen volume at: (1) 1–6 months; (2) 7–12 months; (3) >12 months following initiation of statin therapy; and (4) at last follow-up. Meta-analysis was performed using the random effects model. Results were reported as weighted mean differences (WMD) and 95% confidence interval (CI). ResultSeven studies including 361 patients were included. There was no significant change in carotid wall volume or lumen volume at any time points. While there was no significant difference in LRNC at 1–6 months and at 7–12 months following initiation of statin therapy; at >12 months, there was significant decrease in LRNC volume (WMD=−9.9mm3, 95% CI=−8.9, −2.3). ConclusionsOur study suggests statin therapy is associated with significant reductions in LRNC at 1-year of statin therapy on serial carotid MRI. However, no significant reduction in carotid wall volume was seen.

Obesity Is Associated With Progression of Atherosclerosis During Statin Treatment.

BackgroundThis study aimed to determine the relationship of statin therapy and cardiovascular risk factors to changes in atherosclerosis in the carotid artery.Methods and ResultsCarotid magnetic resonance imaging was used to evaluate 106 hyperlipidemic participants at baseline and after 12 months of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitor (statin) treatment. Multivariable logistic regression was used to determine factors associated with progression (change in carotid wall volume >0) or regression (change ≤0) of carotid atherosclerosis. Computed tomography coronary calcium scores were obtained at baseline for all participants. The median age was 65 years (interquartile range 60–69 years), and 63% of the participants were male. Body mass index >30, elevated C‐reactive protein, and hypertension were associated with increased carotid wall volume (obesity: odds ratio for progression 4.6, 95% CI 1.8–12.4, P<0.01; C‐reactive protein: odds ratio for progression 2.56, 95% CI 1.17–5.73, P=0.02; hypertension: odds ratio 2.4, 95% CI 1.1–5.3, P<0.05). Higher statin dose was associated with regression of carotid wall volume (P<0.05). In multivariable analysis, obesity remained associated with progression (P<0.01), whereas statin use remained associated with regression (P<0.05). Change in atheroma volume in obese participants was +4.8% versus −4.2% in nonobese participants (P<0.05) despite greater low‐density lipoprotein cholesterol reduction in obese participants.ConclusionsIn a population with hyperlipidemia, obese patients showed atheroma progression despite optimized statin therapy.Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01212900.

Abstract 17973: Clinical Markers Associated With Subclinical Atherosclerosis in Otherwise Apparently Healthy Young Adults

Introduction: Traditional risk factors are poor predictors of cardiovascular events in younger adults. Considering the long silent evolution of atherosclerosis beginning in younger adulthood before the appearance of clinical events at a more advanced age, a simple tool to predict early atherosclerosis in young adults would be desirable to guide primordial prevention. An altered cardiometabolic profile is associated with increased cardiovascular disease in older adults independent from traditional risk factors, but the value of this profile in an otherwise healthy young adult population is unknown. Hypothesis: Cardiometabolic risk markers would be associated with early atherosclerosis in young adults despite the absence of traditional risk factors. Methods: Healthy young adults (18-35 years) devoid of cardiovascular risk factors (diabetes, smoking, hypertension, dyslipidemia) and obesity were prospectively enrolled. Anthropometric measurements, ECG, lipid profile, fasting blood glucose, blood pressure and high-resolution carotid artery MRI were realized. Results: Although the 240 participants (25.8 years, SEM=0.29, 48% women) were at low risk for atherosclerosis, we identified atherosclerosis in 72.6% of men and 64.7% of women (p=0.19). Males had greater atherosclerosis burden vs. females (carotid wall volume [CWV]: 1817 mm3/48mm, SEM=29.7 vs. 1579 mm3/48mm, SEM=21.2; p&lt;0.0001). By multivariate analysis, atherosclerosis burden was associated with fasting blood glucose (p=0.01), BMI (p=0.01), and waist circumference (p&lt;0.001), the latter having the strongest correlation with atherosclerosis burden (r=0.41, p&lt;0.0001). ROC analyses established cutoffs for waist circumference identifying greater atherosclerosis burden in apparently healthy young adults. Conclusion: A simple low-cost office-based tool, waist circumference measurement improves prediction of early atherosclerosis in otherwise apparently healthy young adults.

CARDIOMETABOLIC RISK FACTORS ASSOCIATED WITH SUBCLINICAL ATHEROSCLEROSIS IN APPARENTLY HEALTHY YOUNG ADULTS

Atherosclerosis is a leading cause of morbidity and mortality in developed and developing regions, resulting to overt vascular disease in the later decades of life. Nonetheless, the first signs of atherosclerosis have been identified in up to 78% of healthy young adults at autopsy, indicating that the needed conditions for disease development are present long before the appearance of traditional risk factors. We sought to determine whether and to what degree atherosclerosis is present in apparently healthy young adults devoid of traditional cardiovascular risk factors and obesity, and we investigated the associations of cardiometabolic risk markers with early atherosclerosis burden in this population. Young Caucasian adults (18-36 years) devoid of traditional cardiovascular risk factors and obesity, and no history of chronic medication use or disease were assessed for cardiometabolic risk markers. Subcutaneous abdominal adipose tissue (SAT), ectopic fat depots (visceral abdominal adipose tissue [VAT], epicardial adipose tissue [EAT], and hepatic fat fraction [HFF]), as well as carotid artery wall volumes (CAWV) were measured by magnetic resonance imaging. According to cardiometabolic profile, the 240 participants (25.8 ± 4.5 years; 48% women) had a low-risk for atherosclerosis. However, premature atherosclerosis was present in 68.8% of the population with no difference between prevalence in both sexes although the burden was significantly greater in men vs. women (CAWV: 1817 ± 330 vs. 1579 ± 228 mm3/48mm, p<0.0001). Men possessed lesser SAT volume than women, while they presented higher EAT and VAT volumes compared to women. HFF was similar between men and women. CAWV increased progressively with the accumulation of VAT and EAT. Early atherosclerosis was associated with apolipoprotein B/apolipoprotein A-1 ratio, fasting blood glucose, waist circumference and EAT volume, but waist circumference was the strongest marker independently associated with atherosclerosis burden. In addition, “high-normal” levels of risk factors commonly used (≥50th percentile), especially when clustering, are associated with greater atherosclerosis burden in this population. Subclinical atherosclerosis is present in more than half of all apparently healthy young adults despite the absence of traditional cardiovascular risk factors and obesity. Waist circumference is the strongest predictor of atherosclerosis burden in both males and females of our cohort. Our findings suggest routine waist circumference measurement may help identify risk of premature atherosclerosis in apparently healthy young men and women in the absence of traditional risk factors.

Demographics of carotid atherosclerotic plaque features imaged by computed tomography

This was a prospective, cross-sectional study to evaluate the risk factors and symptoms associated with specific carotid wall and atherosclerotic plaque features as seen on computed tomography-angiography (CTA) studies. A total of 120 consecutive consenting patients admitted to the emergency department with suspected cerebrovascular ischemia, and receiving standard-of-care CTA of the brain and neck on a 64-slice CT scanner, were prospectively enrolled in the study. The carotid wall features observed on CT were quantitatively analyzed with customized software using different radiodensities for contrast-phase acquisition of the carotids. Clinical datasets, including a complete medical history and examination, were obtained by research physicians or specially trained associates blinded to any findings on CT. Univariate and multivariate analyses were performed to assess the degree of association between clinical indicators and quantitative CT features of carotid atherosclerotic plaques. Men tended to have increased carotid lumen (coefficient: 608.7; 95% CI: 356.9-860.6; P<0.001) and wall volumes (209.2; 54.5-364.0; P=0.008), and hypertension was associated with increased wall volume (260.6; 88.7-432.6; P=0.003). Advanced age was associated with increases in maximum wall thickness (0.02; 0.003-0.05; P=0.029), fibrous cap thickness (0.005; 0.001-0.008; P=0.016) and number of calcium voxels (2.7; 1.25-4.2; P<0.001), and the presence of a carotid bruit was associated with carotid stenosis length (21.0; 5.38-37.8; P=0.009). Exercise was inversely related to the number of calcium (-37.1; -71.5 - -2.7; P=0.035) and lipid (-7.9; -15.1 - -0.7; P=0.032) voxels. ACE inhibitor use was associated with fibrous cap thickness (0.1; 0.04-0.23; P=0.005). Significant associations were found between clinical descriptors and carotid atherosclerotic plaque features as revealed by CT. Future studies are needed to validate our findings, and to continue investigations into whether CT features of carotid plaques can be used as biomarkers to quantify the impact of strategies aiming to correct vascular risk factors.

Carotid wall volume quantification from magnetic resonance images using deformable model fitting and learning-based correction of systematic errors

We present a method for carotid vessel wall volume quantification from magnetic resonance imaging (MRI). The method combines lumen and outer wall segmentation based on deformable model fitting with a learning-based segmentation correction step. After selecting two initialization points, the vessel wall volume in a region around the bifurcation is automatically determined. The method was trained on eight datasets (16 carotids) from a population-based study in the elderly for which one observer manually annotated both the lumen and outer wall. An evaluation was carried out on a separate set of 19 datasets (38 carotids) from the same study for which two observers made annotations. Wall volume and normalized wall index measurements resulting from the manual annotations were compared to the automatic measurements. Our experiments show that the automatic method performs comparably to the manual measurements. All image data and annotations used in this study together with the measurements are made available through the website http://ergocar.bigr.nl.

Longitudinal MRI Study on the Natural History of Carotid Artery Plaques in Symptomatic Patients

PurposeTo investigate the natural history of carotid atherosclerosis in patients who experienced a TIA or ischemic stroke.Patients and MethodsNinety-two TIA/stroke patients (57 men, mean age 67.7±9.8 years) with ipsilateral <70% carotid stenosis underwent multisequence MRI of the plaque ipsilateral to the symptomatic side at baseline and after one year. For each plaque, several parameters were assessed at both time points.ResultsCarotid lumen, wall and total vessel ( = carotid lumen and wall) volume did not significantly change. Forty-four patients had a plaque with a lipid-rich necrotic core (LRNC) at baseline, of which 34 also had a LRNC after one year. In three patients a LRNC appeared after one year. Thirty patients had a plaque with a thin and/or ruptured fibrous cap (FC) at both time points. In seven patients, FC status changed from thin and/or ruptured into thick and intact. In three patients, FC status changed from thick and intact into thin and/or ruptured. Twenty patients had intraplaque hemorrhage (IPH) at both time points. In four patients, IPH disappeared, whereas in three patients, new IPH appeared at follow-up.ConclusionIn TIA/stroke patients, carotid plaque morphology does not significantly change over a one-year period. IPH and FC status change in a minority of patients.

The Relationship of Carotid Three-Dimensional Ultrasound Vessel Wall Volume with Age and Sex: Comparison to Carotid Intima-Media Thickness

The relationship of three-dimensional ultrasound (3DUS)-derived carotid vessel wall volume (VWV) was evaluated with respect to age and sex. B-mode and 3DUS images were acquired for 316 subjects from diverse groups including obese primary prevention, diabetic nephropathy, renal transplant and rheumatoid arthritis populations. The relationship for intima-media thickness (IMT) and VWV with age and sex were determined using Pearson-product-moment correlations. Mean IMT (r = 0.18, p = 0.001) and VWV (r = 0.24, p < 0.01) correlated modestly with age. There were modest correlations in males (IMT, r = 0.19, p = 0.003; VWV, r = 0.34, p < 0.001) and in females for IMT and age (r = 0.30, p = 0.007) but not between 3DUS VWV and age in females (r = 0.10, p = 0.4). Significant associations between plaque and VWV (r = 0.36, p = 0.001) but not IMT suggest different correlations in females that may be attributed to plaque.

54 Interferon-α reduces early atherosclerosis in patients with Behcet's Syndrome

IntroductionInterferon-α is an immunoregulatory cytokine with several biological functions that may influence atherosclerosis. We took the opportunity to analyse atherosclerosis-related outcomes in patients entering a randomised controlled clinical trial testing...