Electron Beam Computed Tomography Research Articles

Reversible Intrapore Redox Cycling of Platinum in Platinum-Ion-Exchanged HZSM-5 Catalysts.

Isolated platinum(II) ions anchored at acid sites in the pores of zeolite HZSM-5, initially introduced by aqueous ion exchange, were reduced to form platinum nanoparticles that are stably dispersed with a narrow size distribution (1.3 ± 0.4 nm in average diameter). The nanoparticles were confined in reservoirs within the porous zeolite particles, as shown by electron beam tomography and the shape-selective catalysis of alkene hydrogenation. When the nanoparticles were oxidatively fragmented in dry air at elevated temperature, platinum returned to its initial in-pore atomically dispersed state with a charge of +2, as shown previously by X-ray absorption spectroscopy. The results determine the conditions under which platinum is retained within the pores of HZSM-5 particles during redox cycles that are characteristic of the reductive conditions of catalyst operation and the oxidative conditions of catalyst regeneration.

Association of Anthropometric and CT-Based Obesity Indices with Subclinical Atherosclerosis.

Few studies have compared the strength in the associations of anthropometric and computed tomography (CT)-based obesity indices with coronary artery calcification (CAC), aortic artery calcification (AoAC), and aortic valve calcification (AVC). We assessed cross-sectcional associations of anthropometric and CT-based obesity indices with CAC, AoAC, and AVC. Anthropometric measures included body mass index (BMI), waist circumference, hip ircumference, waist-to-hip circumference ratio, and waist-to-height ratio in 931 men (mean age, 63.7 years) from a population-based cohort. CT images at the L4/5 level were obtained to calculate the areas of abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), total adipose tissue (TAT), VAT-to-SAT ratio (VSR), and VAT-to-TAT ratio (VTR). CAC, AoAC, and AVC were quantified using the Agatston score based on CT scanning. CAC, AVC, and AoAC were present in 348 (62.6%), 173 (18.6%), and 769 (82.6%) participants, respectively. In multivariable models adjusting for age, lifestyle factors, and CT types (electron beam CT and multidetector row CT), anthropometric and CT-based obesity indices were positively associated with CAC (p＜0.01). Conversely, VAT-to-SAT ratio and VAT-to-TAT ratio were positively associated with AoAC (p＜0.01). Any obesity indices were not associated with AVC. The strength of the associations of obesity indices with subclinical atherosclerosis varied according to the anatomically distinct atherosclerotic lesions, among men.

Differential effect of atorvastatin and pravastatin on thoracic spine attenuation: A sub-analysis of a randomized clinical trial

BackgroundStatins reduce cardiovascular events and may improve bone mineral density. MethodsWe conducted a sub-analysis of a randomized clinical trial that investigated the differential effect of moderate vs intensive low-density lipoprotein cholesterol (LDL-C) lowering therapies on coronary artery calcium (CAC) scores, and used the acquired images to assess the change in radiological attenuation of selected thoracic vertebrae. Baseline and 12-month unenhanced chest CT scans were performed in 420 hyperlipidemic, postmenopausal women randomized to atorvastatin (ATV) 80 mg/day or pravastatin (PRV) 40 mg/day in the Beyond Endorsed Lipid Lowering with Electron Beam Tomography Scanning (BELLES) trial. Bone attenuation was measured in three contiguous thoracic vertebrae at baseline and 12 months. ResultsThere were no differences in baseline demographic and clinical characteristics between treatment arms. The median percent lowering (interquartile range) in LDL-C was significantly greater with ATV than PRV [-53 (-69 to 20)% vs −28 (-55 to 74)%, p < 0.001], although the CAC score change was similar [12 (-63 to 208)% vs 13 (-75 to 358)%; p = 0.44]. At follow-up, the median bone attenuation loss was significantly greater with PRV than with ATV [-2.6 (-27 to 11)% vs 0 (-11 to 25)%; p < 0.001]. The attenuation loss in the PRV group was comparable to that of a historical untreated general population sample. In the entire cohort, the changes in LDL-C and total cholesterol were inversely correlated with bone attenuation change (p < 0.01). In adjusted multivariable linear regression analyses, race and percent change in LDL-C were independent predictors of bone attenuation change. Age, body mass index, history of smoking, diabetes mellitus, hypertension, peripheral vascular disease, or hormone replacement therapy did not affect percent change in BMD. ConclusionsThese findings support the hypothesis that there is an interaction between bone and cardiometabolic health and that intensive lipid lowering has a beneficial effect on bone health.

Milestones in CT: Past, Present, and Future.

In 1971, the first patient CT examination by Ambrose and Hounsfield paved the way for not only volumetric imaging of the brain but of the entire body. From the initial 5-minute scan for a 180° rotation to today's 0.24-second scan for a 360° rotation, CT technology continues to reinvent itself. This article describes key historical milestones in CT technology from the earliest days of CT to the present, with a look toward the future of this essential imaging modality. After a review of the beginnings of CT and its early adoption, the technical steps taken to decrease scan times-both per image and per examination-are reviewed. Novel geometries such as electron-beam CT and dual-source CT have also been developed in the quest for ever-faster scans and better in-plane temporal resolution. The focus of the past 2 decades on radiation dose optimization and management led to changes in how exposure parameters such as tube current and tube potential are prescribed such that today, examinations are more customized to the specific patient and diagnostic task than ever before. In the mid-2000s, CT expanded its reach from gray-scale to color with the clinical introduction of dual-energy CT. Today's most recent technical innovation-photon-counting CT-offers greater capabilities in multienergy CT as well as spatial resolution as good as 125 μm. Finally, artificial intelligence is poised to impact both the creation and processing of CT images, as well as automating many tasks to provide greater accuracy and reproducibility in quantitative applications.

Vendor Independent Coronary Calcium Scoring Improves Individual Risk Assessment: MESA (Multi-Ethnic Study of Atherosclerosis)

BackgroundSubstantial variation in Agatston scores (AS) acquired with different computed tomography (CT) scanners may influence patient risk classification. ObjectivesThis study sought to develop a calibration tool for state-of-the-art CT systems resulting in vendor-neutral AS (vnAS), and to assess the impact of vnAS on coronary heart disease (CHD) event prediction. MethodsThe vnAS calibration tool was derived by imaging 2 anthropomorphic calcium containing phantoms on 7 different CT and 1 electron beam tomography system, which was used as the reference system. The effect of vnAS on CHD event prediction was analyzed with data from 3,181 participants from MESA (Multi-Ethnic Study on Atherosclerosis). Chi-square analysis was used to compare CHD event rates between low (vnAS <100) and high calcium groups (vnAS ≥100). Multivariable Cox proportional hazard regression models were used to assess the incremental value of vnAS. ResultsFor all CT systems, a strong correlation with electron beam tomography–AS was found (R2 >0.932). Of the MESA participants originally in the low calcium group (n = 781), 85 (11%) participants were reclassified to a higher risk category based on the recalculated vnAS. For reclassified participants, the CHD event rate of 15% was significantly higher compared with participants in the low calcium group (7%; P = 0.008) with a CHD HR of 3.39 (95% CI: 1.82-6.35; P = 0.001). ConclusionsThe authors developed a calibration tool that enables calculation of a vnAS. MESA participants who were reclassified to a higher calcium category by means of the vnAS experienced more CHD events, indicating improved risk categorization.

High- vs. low-intensity statin therapy and changes in coronary artery calcification density after one year

Abstract Introduction High-dose statin therapy (HIST) halts coronary plaque progression and reduces the risk of cardiovascular events by increasing atheroma calcification. The Agatston score is well established in the clinical routine for assessment of coronary artery calcification using non-contrast computed tomography. However, randomized controlled trials failed to detect an influence of HIST vs. low-to-intermediate statin therapy (LIST) on the Agatston and CAC volume score after one year. Coronary plaques with lower density including spotty calcifications may represent dynamic and early stages of atherosclerosis. We evaluated whether CAC density differentiates in HIST- vs. LIST-treated patients after one year. Methods The meta-analysis contains data from two prospective, randomized, double-blind studies (BELLES, EBEAT) that were designed to detect CAC changes after one year comparing HIST vs. LIST. In both studies, patient's coronary calcification burden was measured at baseline and one-year follow-up using electron beam computed tomography (EBCT). Patients data were pooled and stratified by intensity of statin therapy. Furthermore, the cohort was divided into several subgroup analyses, accounting for LDL-Cholesterol reduction, initial Agatston score and a consistent number of lesions. Results Data from 852 patients, 66% female were included. The amount of CAC overall increased after 1 year [Agatston score: 169.3 (80.0, 377.1) vs. 214.9 (95.4, 450.0); p&amp;lt;0.0001NP; volume score: 292.1±445.4 vs. 355.5±482.4; p&amp;lt;0.0001; number of lesions: 6 (3,10) vs. 7 (4,12); p&amp;lt;0.0001NP, at baseline and follow-up, respectively]. Likewise, the average CAC density was higher at follow-up [CAC density: 228.8±35.4 vs. 232.6±37.0; p&amp;lt;0.0001]. HIST vs. LIST more effectively reduced LDL-cholesterol (annualized change: −58.6±50.9 vs. −44.4±43.7 mg/dL, p=0.005). Comparing patients on HIST vs. LIST, CAC density at follow-up (231.9±36.1 HU vs. 233.3±37.7, p=0.59) and its change from baseline (4.0±19.1 HU vs. 3.6±19.6 HU, p=0.73) did not differ. Subgroup analyses, stratifying by LDL-reduction ( Conclusion HIST vs. LIST leads to a higher reduction in cholesterol levels, which does not translate into relevant differences in the change of CAC density at one-year follow-up. Funding Acknowledgement Type of funding sources: None.

Associations of the Mediterranean-Style Dietary Pattern Score with Coronary Artery Calcification and Pericardial Adiposity in a Sample of US Adults.

Several studies have identified improvements in the risks of cardiovascular disease in adults following a Mediterranean dietary pattern. However, data are scarce on its association with coronary artery calcification (CAC) and pericardial adiposity (PAT) in US adults with and without diabetes. To address this gap, we conducted a case-control study using baseline data from the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study [n = 1255; Type 1 Diabetes (T1D): n = 563; non-Diabetes Mellitus (non-DM): n = 692]. Participants completed a validated food frequency questionnaire, fasting (12 h overnight fast) biochemical analyses, and a physical examination including anthropometric measures. CAC and PAT were measured using electron beam-computed tomography. Logistic regression models were used to examine the associations of the Mediterranean-Style Dietary Pattern Score (MSDPS) with CAC (presence or absence), and linear regression models were applied to PAT analyses. In all of the adjusted models, no significant associations with CAC were found. For PAT, an increasing MSDPS was consistently associated with its lower volume in models adjusted for age, sex, diabetes status, total calories, and body mass index (all p < 0.05). The association between MSDPS and PAT was attenuated after adjusting for serum lipids and physical activity. In conclusion, the baseline data from the CACTI study show that a greater adherence to MSDPS is associated with a lower PAT volume and provide evidence that the Mediterranean dietary pattern is associated with lower cardiovascular risk markers.

Coronary artery calcium and cardiovascular disease prediction by scanner type: the multi-ethnic study of atherosclerosis

To evaluate the predictive value of coronary artery calcium (CAC) scoring methods across cardiac computed tomography (CT) scanner types. CAC was measured in participants from the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of participants free of baseline cardiovascular disease (CVD), using either EBCT (electron beam CT) or MDCT (multidetector CT). The risks for incident coronary heart disease (CHD) and CVD events were compared for CAC scores per SD using Cox proportional hazards models with multivariable adjustment in 3,362 MESA participants with detectable CAC. Using the Agatston score, the hazard ratio (HR) and 95% confidence interval (CI) for CHD was 1.50 (1.27,1.78) for EBCT and 1.60 (1.37,1.87) for MDCT. Using volume and density scores, the HR for CHD was 2.14 (1.71,2.68) for volume and 0.61 (0.48,0.76) for density on EBCT and 1.73 (1.42,2.11) for volume and 0.88 (0.71,1.10) for density on MDCT. Similar results were seen for CVD risk and in analyses stratified by sex, body mass index (BMI), and age. The volume and density score model demonstrated higher areas under the curve (AUC) for CHD than the Agatston score with EBCT (0.702, 95% CI: 0.666,0.738 versus 0.677, 95% CI: 0.638,0.715, p<0.001) and MDCT (0.669, 95% CI: 0.632,0.705 versus 0.660, 95% CI: 0.622,0.697, p=0.216). The CAC volume and density scores provide better risk prediction than the Agatston score for CHD and CVD events, regardless of CT scanner type. CAC density was strongly and inversely associated with CHD risk. Both density and volume score prediction were stronger for EBCT than MDCT.

ANALYSIS OF OBTAINING AN IMAGE WITH THE TOMOGRAPH

CT scans vary from manufacturer to manufacturer. There are several generations of CT. The concept of CT generation is not so much related to the time of its birth, but to the use in the scanner of the type of motion of the emitter-detector system. The generation number (first, second, third, fourth, etc.) is related to the type of tube-detector system design. Three types of scanners are now available: third, fourth and fifth generation. The life of the first generation of CT was fleeting: the duration of the scan did not suit – about 20 minutes. and the computer reconstruction of the image took too long. Only the brain could be examined on such devices. As for the human body, the image turned out blurry, blurred. But the process of improvement continues. Today, research is being conducted on fourth- and fifth-generation devices. They have not one, but many X-ray emitters, up to 200. It uses a very powerful processor with high-speed information processing – up to 10 million operations per second. As a result, the scan time was reduced to 40-50 milliseconds. It is now possible (here is a scientific idea!) To see on the telemonitor the reduction of certain transverse layers of the heart 1-2 millimeters thick. At spiral CT in the course of research with simultaneous constant rotation of system “tube – detectors” the table constantly moves and thus there is a spiral movement of a fan-shaped beam through a patient’s body. Spiral CT makes it possible to examine the anatomical region in one period of respiratory arrest, and the thickness of the reconstructed layer is not related to the original width of the tomogram. Obtaining thin conjunctival sections, which are tightly arranged in a spiral, allows you to get three-dimensional reconstructions. In combination with intravenous bolus contrast and subtraction data processing, CT angiograms can be obtained, which reproduce images of large vessels. In recent years, multispiral (multislice) CT has been used, which is based on the principles of imaging as in spiral CT, but due to multi-row detectors for full rotation of the system “tube detectors” can display more than one slice (currently from 2 to 16 images). This has made it possible to perform studies of the heart, study a large anatomical area, such as the lungs, thin sections in one breath hold, and significantly improve the quality of multiplanar and three-dimensional reconstructions. In electron beam tomography, the source of X-rays is a large electron gun with several massive parallel anode targets located in semiconductor rings around the patient. The intense anode beam is directed along the tungsten anode rings. The electron beam thus obtained passes through the patient’s body and is received by a fixed array of detectors. This achieves a high tomography rate, which is sufficient for the study of a moving heart: clearly delineated images can be obtained without the use of synchronization with the ECG. With the help of electron-beam tomography it is also possible to perform CT angiography and construction of high-quality three-dimensional reconstructions. Thus, modern medicine is impossible without CT. For example, in neurology, computed tomography, in addition to skull bones, well identifies the ventricles of the brain, venous sinuses, subarachnoid cisterns, interhemispheric fissure, cortex, basal nodes, inner capsule, trunk, cerebellum and other structures. The radiation load does not exceed the level usual for X-ray examination. At the same time, CT scans provide 100 times more information about the brain than conventional skull x-rays. But its importance is not limited to use only for the diagnosis of various diseases. Under the control of CT perform punctures and directed biopsy of various organs and pathological foci. The role of CT in the control of conservative and surgical treatment of patients is extremely important. CT is a valuable method of accurate localization of tumors and directing the radiation source to the focus when planning radiation treatment of malignant tumors.

Psychosocial Well-Being and Progression of Coronary Artery Calcification in Midlife Women.

BackgroundPrevention of cardiovascular disease (CVD) is a public health priority. The combination of physical activity, a healthy diet, and abstaining from tobacco plays an important role in prevention whereas aspects of psychosocial well‐being have largely been examined separately with conflicting results. This study evaluated whether the combination of indices of psychosocial well‐being was associated with less progression of coronary artery calcium (CAC).Methods and ResultsParticipants were 312 women (mean age 50.8) from the SWAN (Study of Women’s Health Across the Nation) ancillary Heart Study, free of clinical CVD at baseline. A composite psychosocial well‐being score was created from 6 validated psychosocial questionnaires assessing optimism, vitality, life engagement, life satisfaction, rewarding multiple roles, and positive affect. Subclinical CAC progression was defined as an increase of ≥10 Agatston units over 2.3 years measured using electron beam tomography. Relative risk (RR) regression models examined the effect of well‐being on CAC progression, progressively adjusting for sociodemographic factors, depression, healthy lifestyle behaviors, and standard CVD risk factors. At baseline, 42.9% had a CAC score >0, and progression was observed in 17.6%. Well‐being was associated with less progression (RR, 0.909; 95% CI, 0.843−0.979; P=0.012), which remained significant with adjustment for potential confounders, depression, and health behaviors. Further adjustment for standard CVD risk factors weakened the association for the total sample (RR, 0.943; 95% CI, 0.871−1.020; P=0.142) but remained significant for the 134 women with baseline CAC>0 (RR, 0.921; 95% CI, 0.852−0.995; P=0.037).ConclusionsOptimum early prevention of CVD in women may result from including the mind side of the mind‐heart‐body continuum.

Abstract 9425: Coronary Artery Calcium Measurement and Prediction of Cardiovascular Disease by Different Ct Scanner Types: The Multi-Ethnic Study of Atherosclerosis

Introduction: Coronary artery calcium (CAC) scoring is a powerful tool for cardiovascular disease (CVD) risk prediction. The Agatston score weighs lesion area upward for density, and is consistent across computed tomography (CT) scanner type. Considering volume and density separately improves risk prediction, but has not been evaluated by CT scanner type. Hypothesis: Our hypothesis was that the predictive value of volume and density scoring would be superior to the Agatston score across CT scanner types. Methods: We used data from MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of participants free of baseline clinical cardiovascular disease. CAC was measured using either EBCT (electron beam CT) or MDCT (multi-detector CT). We compared risk prediction for coronary heart disease (CHD) and CVD events using the Agatston method and the volume and density scores by scanner type using Cox proportional hazards models with multivariable adjustment among those with baseline CAC &gt; 0. HRs are presented as per standard deviation. Results: The 3,362 MESA participants with CAC &gt;0 were studied. Using the Agatston method, the HR [95% CI] for CHD was 1.28 [1.16-1.42] for EBCT and 1.22 [1.12-1.34] for MDCT. Using the volume score adjusted for density, the HR for CHD was 2.11 [1.70-2.63] for EBCT and 1.71 [1.41-2.07] for MDCT. Density was strongly and inversely associated with CHD. Similar results were seen for CVD risk and in analyses stratified by sex, BMI, age, and baseline statin use. The volume score demonstrated higher areas under the curve (AUC) than the Agatston score with EBCT (0.702, 95% CI 0.665-0.738 vs 0.677, 95% CI 0.638-0.715, p=0.013) and MDCT (0.669, 95% CI 0.632-0.705 vs 0.653, 95% CI 0.616-0.690, p=0.107). Conclusions: Compared with the Agatston score, the CAC volume score, adjusted for density, provides better risk prediction for CHD and CVD events, regardless of CT scanner type. CAC density was strongly and inversely associated with CVD risk.

Abstract 9731: Improved Risk Stratification with Vendor Independent Coronary Calcium Scores: Data from the Multi-Ethnic Study of Atherosclerosis (mesa)

Introduction: Coronary calcium score (CCS) plays a role in cardiovascular disease (CVD) risk calculators, but also reclassifies patients when considering statin therapy. However, CCS is still calculated following the Agatston methodology as developed on electron beam tomography (EBT) in the early 1990s. EBT has been replaced by multidetector computed tomography (MDCT). It is known that CCS differs substantially between MDCT-systems from different manufacturers, which can lead to risk reclassifications for 6.5% of examined individuals Aims: Our first aim was to identify CT system specific conversion factors to calculate a vendor-neutral Agatston score (rCCS). Second, we aimed to validate rCCS risk stratification for participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Methods: As a first step, we calculated conversion factors between six state-of the-art CT systems and the reference EBT system used in the MESA study. For this purpose, we scanned two calcium-containing inserts, which were placed in a small and large anthropomorphic thorax phantom. Linear regression was used to find a model which converts vendor-specific CCS to vendor-independent rCCS. As a second step, we recalculated the non-zero Agatston scores of 550 MESA participants. Following the Youden method, we calculated an optimal cut-off point for rCCS. Results: The linear model for each CT system allowed for prediction of Agatston scores as measured on the EBT system (p=0.001). rCCS for GE LightSpeed, used in MESA, was calculated as rCCS=0.049+1.97xMESA Agatston score and rCCS=1.903+1.37xMESA Agatston score for small and large size, respectively. The median MESA Agatston score was 100.5 (26.3-379.5), and the median rCCS was 135.8 (35.6-508.6). Participants were assigned to a high Agatston category with Agatston scores exceeding 100 (50.2%) and 187 (43.1%) for CCS and rCCS, respectively. The hazard ratio for CVD of individuals with high Agatston scores increased from 1.88 (95%CI: 1.31-2.68, p=0.001) with MESA scores to 2.15 (95%CI: 1.52-3.05, p=0.001) with rCCS. rCCS reclassified 39 participants into the lower risk group, without statin therapy. Conclusions: In conclusion, based on these preliminary results, rCCS may improve patient classification for statin therapy.

Abstract 11985: Association of GlycA and Progression of Coronary Artery Calcification: The Multi-Ethnic Study of Atherosclerosis

Background: GlycA, a composite biomarker of systemic inflammation, predicts cardiovascular morbidity and mortality. Despite growing evidence regarding the association of GlycA and CVD, there are no data about the association of GlycA with coronary artery calcium (CAC), a marker of subclinical atherosclerosis. Objective: To investigate the relationship between GlycA levels and progression of CAC. Methods: MESA is a multiethnic cohort study of 6814 men and women aged 45-84 years, free of clinical CVD at baseline. Serum level of GlycA was measured by nuclear magnetic resonance (NMR) spectroscopy at baseline. CAC score was assessed by CT at baseline and follow up using either a cardiac gated electron beam CT scanner or 4-16 detector CT systems. Progression of CAC from baseline was defined as average yearly change in Agatston score &gt;= 3 for CAC 0 to 100 and &gt;=10% for CAC &gt;100. Mean follow up period was 9.6±0.6 years. Multivariate regression analysis was performed adjusting for atherosclerotic risk factors. Results: Cross-sectional mean GlycA level, stratified by race/ethnicity, was higher in those with CAC &gt; 0 compared to no CAC across all race/ethnicity groups and in both men and women (Fig1A). In regression analysis, the progression of annualized CAC was associated with higher baseline GlycA levels (Fig1B). Analysis was stratified due to interaction between GlycA and BMI (Fig2). In multivariable adjusted models, a one unit increase in GlycA was related to 0.23% higher average annual CAC change in normal BMI (p=0.002). In those who were excess weight (BMI &gt;25) one unit increase in GlycA was associated with a 0.04% yearly average CAC change, after adjusting for covariates(p=0.07). Conclusion: Participants with higher baseline GlycA levels have CAC &gt;0 as compared to lower baseline GlycA levels. The annualized progression of CAC is also higher in participants with baseline elevated GlycA levels. This association was statistically significant in participants with normal BMI.

Dual-Energy Heart CT: Beyond Better Angiography-Review.

Heart CT has undergone substantial development from the use of calcium scores performed on electron beam CT to modern 256+-row CT scanners. The latest big step in its evolution was the invention of dual-energy scanners with much greater capabilities than just performing better ECG-gated angio-CT. In this review, we present the unique features of dual-energy CT in heart diagnostics.

Ethnicity and coronary artery calcification

Abstract Funding Acknowledgements Type of funding sources: None. Background Although individuals of South Asian (S. Asian) origin represent 20% of the world population, they are under-represented in studies investigating the presence of coronary artery calcification (CAC). Aim We compared the prevalence of CAC in Caucasians and Asians who underwent electron beam computed tomography (EBCT). CAC score (CACS) was performed on an Imatron C300 Ultrafast EBCT scanner (GE Healthcare), using a standard method with calcium deposition scored according to Agatston method. Demographic information and the presence of risk factors were abstracted from referral letters and questionnaires completed by the patients prior to their test. Results CACS was assessed in 935 S. Asians (739 males and 196 females) and 13,501 Caucasians (10,232 males and 3269 females). Gender distribution between Caucasians and S. Asians was similar (p = 0.1); conversely, the Caucasians group was older to its S. Asians counterpart (52.8 ± 9.6 vs. 50.6 ± 10.3; p &amp;lt; 0.001); while on the other hand, S. Asians appeared to have a higher prevalence of diabetes mellitus (17.5% vs. 4.3%; p &amp;lt;0.0001). There was no difference in the prevalence of smoking between the 2 groups (15% vs. 12.1%; p = 0.06), of hypertension (31.3% vs. 25.3%; p =0.4), family history of CHD (22.8% vs. 16.1%; p = 0.3), and hyperlipidemia (24.5% vs. 17.3%; p = 0.3). The prevalence of CAC (CACS &amp;gt;0) was similar between Caucasians and S. Asians (50.9% vs. 50.8%; p = 0.9), although a statistically significant difference in the prevalence of CAC in South Asians &amp;gt;50 years was noted (p = 0.01). S. Asian males showed a higher mean CACS as compared to Caucasians (179.6 ± 545.1 vs. 144.1 ± 420.1; p = 0.03). In males &amp;lt;50 years, there was no statistically significantly difference in mean CACS between S. Asians and Caucasians (36.1 ± 277.8 vs. 23.8 ± 104.2; p = 0.06), but in males &amp;gt;50 years old the difference in mean CACS was significant (S. Asians, 339.1 ± 702.9 vs. Caucasians 232.3 ± 528.7; p &amp;lt; 0.0001). On the other hand, no difference was observed in the mean CACS between South Asian and Caucasian females (59.2 ± 224.9 vs. 56.6 ± 219.2; p = 0.86). S. Asian females &amp;lt;50 years and S. Asian females &amp;gt;50 years had similar mean CACS compared to Caucasians. Conclusion S. Asians seem more prone to extensive calcification. Age seems to play an important role as the prevalence of CAC was similar in S. Asians and Caucasians &amp;lt;50 years but there was a difference in prevalence of CAC after the age of 50, but this deference was statistically significant only in males. Our results support current evidence in showing that the pattern of CAC is influenced by ethnicity. If this reflects a difference in traditional risk factors or has genetic origin it has to be clarified.

Prevalence of coronary artery calcification in young adults in UK

Abstract Funding Acknowledgements Type of funding sources: None. Background Coronary atherosclerosis is a continuous process beginning early in life, with a long and clinically asymptomatic phase, before manifestations appear in middle and/or late adulthood. Coronary artery calcification (CAC) is a well-established marker of atherosclerosis; but the clinical validity of CAC in young adults (traditionally considered as a population group of low cardiovascular risk) remains unclear. Aim We aimed to assess the prevalence of CAC in a population of young individuals without previous history of coronary artery disease (CAD) in the UK and its association with conventional cardiovascular risk factors. Methods This analysis includes 4186 asymptomatic young individuals who underwent electron beam computed tomography (EBCT). Demographic information and the presence of cardiovascular risk factors were abstracted from referral letters and/or questionnaires completed by the patients prior to their tests. Individuals with previously documented CAD or chronic kidney disease were excluded. All EBCT CAC studies were performed using the same scanner (Imatron C300 Ultrafast computed tomography scanner, GE Healthcare, London, UK) and the same scanning protocol. Results The age (mean SD) of the study cohort was 40.5 ±3.6 years (range 26–45 years, 83.8% males). Hypertension, dyslipidemia, and diabetes mellitus (DM) were present in 15.5, 7.9, and 2.8% of individuals, respectively. Family history of premature CAD was present in 17% and 17.4% were smokers. CAC was present in 21.8% of the cohort, while individuals with CAC comparing with those with CAC score 0 were males (95.2 vs. 80%, p &amp;lt; 0.002), older in age (41.4 3.2 vs. 40.3 3.7 years, p &amp;lt; 0.0001), with DM (5.5 vs. 25%, p &amp;lt; 0.0001), hypertension (22 vs. 13.7%, p &amp;lt; 0.0001), and dyslipidemia (14.8 vs. 6%, p &amp;lt; 0.0001). The prevalence of CAC score 0, 1–100, 101–400, 401–1000, &amp;gt;1000 were 78.2, 19, 2.1, 0.5, and 0.2%, respectively. The prevalence and distribution of CAC among various age groups are shown in Table 1. CAC was found in 24.8% of males (CAC score 1–100, 101–400, 400–1000, &amp;gt;1000 in 21.6, 2.5, 0.5, and 0.1%, respectively) and 6.6% of females (CAC score 1–100, 101–400, 400–1000, &amp;gt;1000 in 5.4, 0.6, 0.15 and 0.4%, respectively) (p &amp;lt; 0.0001). There was no statistical difference of mean CAC score between genders (males 13.8 72.7; females 11.8 142.4; p = 0.6). In multivariate analysis, the presence of CAC was associated with age (p&amp;lt; 0.0001), male gender (p&amp;lt; 0.0001), DM (p&amp;lt; 0.0001), hypertension (p&amp;lt; 0.0001), and dyslipidemia (p&amp;lt; 0.0001). Conclusion In a large cohort of asymptomatic young individuals, subclinical atherosclerosis (CAC score &amp;gt;0) was identified in approximately 20%. Assessment of CAC score is a useful clinical tool in young individuals, as it can confirm the presence of subclinical atherosclerosis.

Periodically structured stretchable bundles of carbon nanofibers

Two to four carbon nanofibers repeatedly converge and diverge to form a periodically structured bundle. The detailed structure of the bundles was determined by transmission and scanning electron microscopy (SEM) including electron-beam tomography. Carbon fibers that form a bundle were grown from the same nickel sulfide catalytic nanoparticle, mostly on the {111} facets. The stretchability of a bundle was determined using a micro-manipulator via in situ SEM observation, by which a tensile elongation of 6% at break was determined.

Electron Beam CT: A Historical Review.

OBJECTIVE. At its advent, CT was too slow to image the heart. Temporal resolution improved with electron beam CT (EBCT); subsequently, the heart could be imaged, eventually leading to the discovery of prognostic information obtained from the coronary calcium score. In the early 2000s, EBCT was replaced by MDCT. In this review, we discuss the rise and fall of EBCT and explore its legacy in cardiac imaging. CONCLUSION. Although MDCT rendered EBCT obsolete, EBCT leaves a legacy in cardiac imaging regarding both diagnosis and prognosis. The creators of MDCT emulated the strengths of EBCT and learned from its weaknesses. Moreover, EBCT showed that imaging surrogates can predict outcomes, and the origins of substrate-guided treatment can be traced to EBCT.

Prevalence of Vascular Calcification in Chronic Kidney Disease Stage 4 and 5 Patients and its Correlation with Inflammatory Markers of Atherosclerosis.

Vascular calcification is one of the independent risk factors associated with cardiovascular disease (CVD) in chronic kidney disease (CKD) patients. This study evaluated the prevalence of vascular calcification in Indian patients with CKD stages 4 and 5. This was a prospective study conducted between January 2011 and June 2012. CKD stage 4 and 5 patients of either sex aged >18 years were screened for aortic vascular calcification using digital X-ray lumbar spine and multislice computed tomography (CT) scan. In addition, details of inflammatory markers [high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL-6)] were also collected. A total of 150 patients (stage 4, n = 98; stage 5, n = 56) were screened for vascular calcification, and the mean age was 56.56 years. Patients with CKD stage 5 had significantly higher (P ≤0.05) serum creatinine and lower estimated glomerular filtration rate, total cholesterol, and low-density lipoprotein than CKD stage 4. Significantly, more patients with CKD stage 5 had a history of CVD. A total of 113 (75.3%) patients had vascular calcification [aortic calcification index (ACI) >0] with significantly higher prevalence in CKD stage 5 (85.72%) as compared to CKD stage 4 (69.15%). Patients having high aortic calcification (ACI >20%) were older (P = 0.0013); had a higher frequency of diabetes, and CVD; and had significantly (P <0.05) higher blood urea, serum creatinine, phosphorus, Ca × PO4 product, intact parathyroid hormone, hs-CRP, and IL-6. The higher CKD stage was associated with a higher prevalence of vascular calcification and higher aortic calcification index (ACI). CT techniques (electron beam CT and multislice CT) are the gold standards for detection and quantification of progression of vascular calcification.

Abstract 13422: Long Term Association of Low Density Lipoprotein Patterns With Coronary Artery Calcium and Atherosclerotic Cardiovascular Disease Events: Insights From HeartSCORE Study

Introduction: Low-density lipoprotein (LDL) cholesterol, a factor in progression of atherosclerotic cardiovascular disease (CVD), consists of sub-fractions with different sizes and densities in three patterns (A (large buoyant), B (small dense), AB (intermediate pattern). We examined the associations of LDL patterns with subclinical ASCVD and future events. Methods: Participants from the Heart Strategies Concentrating on Risk Evaluation (HeartSCORE) study were assessed for baseline lipid levels and LDL sub-fraction types by an ultracentrifugation method (vertical auto profile). Electron beam CT scans were obtained in a subset of individuals and coronary artery calcium (CAC) scores were calculated (Agatston method). Adjusted odds ratios and hazard ratios (95% CI) were calculated using logistic regression and Cox regression, respectively, to estimate the independent association between LDL sub-fractions and both; CAC and ASCVD events (MI, ischemic stroke, death), respectively. Results: Among 1884 eligible participants (mean [SD] age; 59[7.5]y, 65.8% women, 37.9% black), mean HDL-c, LDL-c and Triglycerides were 142.2[36.0]mg/dL, 58.2[14.9]mg/dL and 111.2[47.7]mmHg, respectively. Sub-fractions of LDL pattern A, B and AB were observed in 761(40%), 507(26.9%) and 616(32.7%) individuals. Over a follow up of ~16y, patterns B(1.98[1.22-3.21) and AB (1.54[1.00-2.38)] were independently associated with incident risk of CVD events (vs pattern A). When stratified by race and gender, pattern AB showed independent risk of incident CVD events and CAC presence among blacks and males (Table) . Conclusions: In this biracial cohort of middle-aged adults, LDL sub-fraction patterns B and AB showed a significantly higher risk of long-term CVD events. Pattern AB was also associated with positive CAC in blacks and males. Further studies are needed to investigate LDL patterns in CVD risk profiling based on race and gender.