Cap Thickness Research Articles

Red and White Thrombus Characteristics in Patients Undergoing Carotid Endarterectomy

ObjectiveThe study aimed to compare the characteristics of red and white thrombi in patients undergoing carotid endarterectomy. Material and MethodsThe study was conducted in 81 patients with ischemic stroke who underwent carotid endarterectomy for carotid artery stenosis. Carotid plaques were graded by two pathologists. Thrombus materials were divided into two groups: white and red. The parameters of assessment were plaque rupture, lipid core, fibrous cap thickness, inflammation, intraplaque hemorrhage, calcification, necrotic core, and neovascularization. Normally distributed data were evaluated using Mann–Whitney U and Chi-squared tests. ResultsThe ratio of white and red thrombus was 19.8% and 80.2%, respectively. Lipid core, plaque rupture, necrotic core, neovascularization, intraplaque hemorrhage, obstruction, and inflammation were observed more in red thrombus, which were statistically significant. Calcification and fibrous cap thickness were not statistically significant in the two groups. Moreover, intimal smooth muscle cells were present in all thrombus types. ConclusionIn our study, we found that red thrombi had more unstable characteristics than white thrombi. Thus, the risk for ischemic cerebrovascular events is more in red thrombi. However, this finding cannot be generalized due to the small number of patients in this study. Therefore, studies involving more patients are needed.

Genesis of the Yarikçi Hydrothermal Clay Deposit Within the Mesozoic Metamorphic Units, Mihaliççik, Eskişehir, Turkey

AbstractHydrothermal alteration led to development of the Yarıkçı clay deposit within the Mesozoic chlorite-, muscovite-, chlorite-muscovite-schist, and garnet-graphite phyllite units along NW–SE- and N–S-trending faults in Mihalıççık in western central Anatolia. The geological, mineralogical, and geochemical characteristics and genesis of this economically important clay deposit have not been examined in detail previously. The present study has attempted to fill this gap. Green smectitic and cream kaolinitic claystones are abundant with smaller amounts of gray illite, dark brown Fe oxides, and silica phases occurring as stockwork/fracture infill and stain/coating. These units are covered by a dark, hard, sharp-edged, and thick silica cap. Metamorphic units exhibit cataclastic texture due to tectonic activities. Muscovite is mostly degraded to kaolinite, and feldspars show sericitization and argillization. Kaolinite typically has a platy form with irregular margins and locally sub-rounded, book-like texture suggesting hydrolysis during the hydrothermal injections. The association of Fe oxides, cristobalite/tridymite/quartz, gypsum/anhydrite, and jarosite are indicative of intense hydrothermal activities and development of kaolinite under acidic geochemical conditions. The local enrichment of SiO2, Fe2O3, S, Cu, and Au also supports this suggestion. The leaching of Sr, Rb, Ba, and Zr, and the slight increase in LREE/MREE+HREE ratios together with the negative Eu and Ce anomalies suggest the selective dissolution of muscovite, garnet, feldspar, and pyroxene by the hydrothermal fluids. Thus, abundant claystones of smectite and kaolinite were formed via the increase in Al+Fe+Mg/Si and Al±Fe/Si ratios in the alkaline and acidic environment, respectively, under the tectonic control of hydrothermal activity as seen in the alteration of chlorite, muscovite, and feldspar in metamorphic units.

Macrophage ATP citrate lyase deficiency stabilizes atherosclerotic plaques

Macrophages represent a major immune cell population in atherosclerotic plaques and play central role in the progression of this lipid-driven chronic inflammatory disease. Targeting immunometabolism is proposed as a strategy to revert aberrant macrophage activation to improve disease outcome. Here, we show ATP citrate lyase (Acly) to be activated in inflammatory macrophages and human atherosclerotic plaques. We demonstrate that myeloid Acly deficiency induces a stable plaque phenotype characterized by increased collagen deposition and fibrous cap thickness, along with a smaller necrotic core. In-depth functional, lipidomic, and transcriptional characterization indicate deregulated fatty acid and cholesterol biosynthesis and reduced liver X receptor activation within the macrophages in vitro. This results in macrophages that are more prone to undergo apoptosis, whilst maintaining their capacity to phagocytose apoptotic cells. Together, our results indicate that targeting macrophage metabolism improves atherosclerosis outcome and we reveal Acly as a promising therapeutic target to stabilize atherosclerotic plaques.

Using optical coherence tomography and intravascular ultrasound imaging to quantify coronary plaque cap thickness and vulnerability: a pilot study

BackgroundDetecting coronary vulnerable plaques in vivo and assessing their vulnerability have been great challenges for clinicians and the research community. Intravascular ultrasound (IVUS) is commonly used in clinical practice for diagnosis and treatment decisions. However, due to IVUS limited resolution (about 150–200 µm), it is not sufficient to detect vulnerable plaques with a threshold cap thickness of 65 µm. Optical Coherence Tomography (OCT) has a resolution of 15–20 µm and can measure fibrous cap thickness more accurately. The aim of this study was to use OCT as the benchmark to obtain patient-specific coronary plaque cap thickness and evaluate the differences between OCT and IVUS fibrous cap quantifications. A cap index with integer values 0–4 was also introduced as a quantitative measure of plaque vulnerability to study plaque vulnerability.MethodsData from 10 patients (mean age: 70.4; m: 6; f: 4) with coronary heart disease who underwent IVUS, OCT, and angiography were collected at Cardiovascular Research Foundation (CRF) using approved protocol with informed consent obtained. 348 slices with lipid core and fibrous caps were selected for study. Convolutional Neural Network (CNN)-based and expert-based data segmentation were performed using established methods previously published. Cap thickness data were extracted to quantify differences between IVUS and OCT measurements.ResultsFor the 348 slices analyzed, the mean value difference between OCT and IVUS cap thickness measurements was 1.83% (p = 0.031). However, mean value of point-to-point differences was 35.76%. Comparing minimum cap thickness for each plaque, the mean value of the 20 plaque IVUS-OCT differences was 44.46%, ranging from 2.36% to 91.15%. For cap index values assigned to the 348 slices, the disagreement between OCT and IVUS assignments was 25%. However, for the OCT cap index = 2 and 3 groups, the disagreement rates were 91% and 80%, respectively. Furthermore, the observation of cap index changes from baseline to follow-up indicated that IVUS results differed from OCT by 80%.ConclusionsThese preliminary results demonstrated that there were significant differences between IVUS and OCT plaque cap thickness measurements. Large-scale patient studies are needed to confirm our findings.

Carotid Plaque Fibrous Cap Thickness Measurement by ARFI Variance of Acceleration: In Vivo Human Results

This study evaluates the performance of an acoustic radiation force impulse (ARFI)-based outcome parameter, the decadic logarithm of the variance of acceleration, or log(VoA), for measuring carotid fibrous cap thickness. Carotid plaque fibrous cap thickness measurement by log(VoA) was compared to that by ARFI peak displacement (PD) in patients undergoing clinically indicated carotid endarterectomy using a spatially-matched histological validation standard. Fibrous caps in parametric log(VoA) and PD images were automatically segmented using a custom clustering algorithm, and a pathologist with expertise in atherosclerosis hand-delineated fibrous caps in histology. Over 10 fibrous caps, log(VoA)-derived thickness was more strongly correlated to histological thickness than PD-derived thickness, with Pearson correlation values of 0.98 for log(VoA) compared to 0.89 for PD. The log(VoA)-derived cap thickness also had better agreement with histology-measured thickness, as assessed by the concordance correlation coefficient (0.95 versus 0.62), and, by Bland-Altman analysis, was more consistent than PD-derived fibrous cap thickness. These results suggest that ARFI log(VoA) enables improved discrimination of fibrous cap thickness relative to ARFI PD and further contributes to the growing body of evidence demonstrating ARFI's overall relevance to delineating the structure and composition of carotid atherosclerotic plaque for stroke risk prediction.

Magnetic Cloud and Sheath in the Ground-level Enhancement Event of 2000 July 14. I. Effects on the Solar Energetic Particles

Abstract Ground-level enhancements generally accompany fast interplanetary coronal mass ejections (ICMEs), and ICME-driven shocks are sources of solar energetic particles (SEPs). Observations of the GLE event of 2000 July 14 show that a very fast and strong magnetic cloud (MC) is behind the ICME shock and the proton intensity-time profiles observed at 1 au had a rapid two-step decrease near the sheath and MC. Therefore, we study the effect of sheath and MC on SEPs accelerated by an ICME shock by numerically solving the focused transport equation. The shock is regarded as a moving source of SEPs with an assumed particle distribution function. The sheath and MC are set to thick spherical caps with enhanced magnetic field, and the turbulence levels in the sheath and MC are set to be higher and lower than those of the ambient solar wind, respectively. The simulation results of proton intensity-time profiles agree well with the observations in energies ranging from ∼1 to ∼100 MeV, and the two-step decrease is reproduced when the sheath and MC arrived at the Earth. The simulation results show that the sheath-MC structure reduced the proton intensities for about 2 days after the shock passed through the Earth. It is found that the sheath contributed most of the decrease while the MC facilitated the formation of the second step decrease. The simulation also infers that the coordination of magnetic field and turbulence in sheath-MC structure can produce a stronger reduction of SEP intensities.

Studying the Factors of Human Carotid Atherosclerotic Plaque Rupture, by Calculating Stress/Strain in the Plaque, Based on CEUS Images: A Numerical Study.

Carotid plaque neovascularization is one of the major factors for the classification of vulnerable plaque, but the axial force effects of the pulsatile blood flow on the plaque with neovessel and intraplaque hemorrhage was unclear. Together with the severity of stenosis, the fibrous cap thickness, large lipid core, and the neovascularization followed by intraplaque hemorrhage (IPH) have been regarded as high-risk features of plaque rupture. In this work, the effects of these factors were evaluated on the progression and rupture of the carotid atherosclerotic plaques. Five geometries of carotid artery plaque were developed based on contrast-enhanced ultrasound (CEUS) images, which contain two types of neovessel and IPH, and geometry without neovessel and IPH. A one-way fluid-structure interaction model was applied to compute the maximum principal stress and strain in the plaque. For that hyper-elastic and non-linear material, Yeoh 3rd Order strain energy density function was used for components of the plaque. The simulation results indicated that the maximum principal stress of plaque in the carotid artery was higher when the degree of the luminal stenosis increased and the thickness of the fibrous cap decreased. The neovessels within the plaque could introduce a 2.5% increments of deformation in the plaque under the pulsatile blood flow pressure. The IPH also contributed to the increased risk of plaque rupture that a gain of stress was 8.983, 14.526, and 34.47 kPa for the plaque with 50, 65, and 75%, respectively, when comparing stress in the plaque with IPH distributed at the middle to the shoulder of the plaque. In conclusion, neovascularization in the plaque could reduce the stability of the plaque by increasing the stress within the plaque. Also, the risk of plaque rupture increased when large luminal stenosis, thin fibrous cap, and IPH were observed.

Abstract 15389: Effect of Icosapent Ethyl on Changes in Coronary Plaque Characteristics at 9 Months in Patients With Elevated Triglycerides on Statin Therapy: Insights From EVAPORATE

Background: Residual cardiovascular (CV) risk persists despite statin therapy. In REDUCE-IT, icosapent ethyl (IPE) reduced total CV events by 30%, but the mechanisms of benefit are not fully understood. The EVAPORATE trial evaluated the effects of IPE as adjunct to statins on adverse atherosclerotic plaque characteristics by CCTA. Here we use a novel software validated using histology to evaluate the effect of IPE on vulnerable plaque features. Methods: The EVAPORATE trial randomized statin-treated patients, with high TG (135-499 mg/dL), and known atherosclerosis to IPE 4 g/d or placebo. Plaque characteristics including lipid rich necrotic core (LRNC), fibrous cap thickness, and intraplaque hemorrhage (IPH) were assessed using vascuCAP ® (Elucid Bioimaging Inc., Boston, MA). Per-patient multivariable models robust with respect to physiological variation were used to evaluate plaque progression. Results: A total of 60 patients had interpretable images. Relative to placebo, patients on IPE demonstrated decreased wall volume (-7.2 vs. +28.4 mm 3 ), LRNC (-1.4 vs. +9.7 mm 3 ), and IPH (-0.02 vs. +0.3 mm 3 ), as well as increased cap thickness (+100 vs. -290 microns), indicating a migration to more stable phenotypes (p>0.05).Statistical significance was achieved when incorporated into an optimized neural network model of lipid-rich phenotype (p = 0.04), AUROC=0.7[0.63,0.77], sensitivity=0.66[0.59,0.74], specificity=0.64 [0.56,0.72], and Cohen’s kappa=0.3 [0.19,0.41]. Operating points when used as a per-patient measure of response are presented in Figure 1. Conclusions: This study demonstrated that IPE, when added to statin therapy, is associated with reduction in vulnerable plaque, moving patients to a more stable plaque phenotype.

Prognostic irrelevance of plaque vulnerability following plaque sealing in high-risk patients with type 2 diabetes: an optical coherence tomography study

BackgroundType 2 diabetes mellitus (T2DM) is associated with an increased cardiovascular risk related at least in part to a more vulnerable plaque phenotype. However, patients with T2DM exhibit also an increased risk following percutaneous coronary intervention (PCI). It is unknown if plaque vulnerability of a treated lesion influences cardiovascular outcomes in patients with T2DM. In this study, we aimed to assess the association of plaque morphology as determined by optical coherence tomography (OCT) with cardiovascular outcome following PCI in high-risk patients with T2DM.Methods81 patients with T2DM and OCT-guided PCI were recruited. Pre-interventional OCT and systematic follow-up of median 66.0 (IQR = 8.0) months were performed.ResultsDuring follow-up, 24 patients (29.6%) died. The clinical parameters age (HR 1.16 per year, 95% CI 1.07–1.26, p < 0.001), diabetic polyneuropathy (HR 3.58, 95% CI 1.44–8.93, p = 0.006) and insulin therapy (HR 3.25, 95% CI 1.21–8.70, p = 0.019) predicted mortality in T2DM patients independently. Among OCT parameters only calcium-volume-index (HR 1.71 per 1000°*mm, 95% CI 1.21–2.41, p = 0.002) and lesion length (HR 1.93 per 10 mm, 95% CI 1.02–3.67, p = 0.044) as parameters describing atherosclerosis extent were significant independent predictors of mortality. However, classical features of plaque vulnerability, such as thickness of the fibrous cap, the extent of the necrotic lipid core and the presence of macrophages had no significant predictive value (all p = ns).ConclusionClinical parameters including those describing diabetes severity as well as OCT-parameters characterizing atherosclerotic extent but not classical features of plaque vulnerability predict mortality in T2DM patients following PCI. These data suggest that PCI may provide effective plaque sealing resulting in limited importance of local target lesion vulnerability for future cardiovascular events in high-risk patients with T2DM.

Evaluating the efficiency of using different variants of background models for inversion calculations

The use of the method of seismic data acoustic inversion, in the presence of thick gas cap, can lead to difficulties when building background models of elastic parameters. In this regard, in the conditions of acoustically contrast thin environments within the perimeter of the Russkoye oil and gas condensate field, in addition to the standard version based on the well data, the authors considered a number of modified techniques ("block", "flat", and background models). The use of these background models provided the best results and made it possible to significantly improve the quality of predicting rock properties; based on the drilling results, effective penetration was ensured at 66 %, which was 102 % of the plan. Also, based on the inversion results, it became possible to predict reservoir properties using the Bayesian lithotype classification method.

Results of thin-cap small-incision lenticule extraction.

To evaluate the influence of a thin cap in small-incision lenticule extraction (SMILE) for the correction of myopia or myopic astigmatism. Tertiary care private practice. A chart review of 102 eyes of 51 patients was performed. The effect of 120 µm vs 100 μm cap thickness on postoperative spherical equivalent refraction (SEQ), cylinder, corrected and uncorrected visual acuities, and ease of lenticule separation was assessed in a contralateral manner, whereas all other parameters were identical between eyes (including optical zone, minimum lenticule thickness, incision size, and energy and spot settings) using paired t test. At 3 months postoperatively, SMILE with 120 μm cap thickness was undercorrected in SEQ relative to SMILE with 100 μm cap thickness in a cohort of 102 eyes of 51 consecutive patients. The difference of 0.06 ± 0.39 diopter (or 0.7% ± 5.7%) did not reach statistical significance. Postoperative cylinder was not statistically different in both groups. Visual acuity was similar in both groups. Ease of lenticule separation was identical in both groups. Suction time was shorter with a 100 μm cap (P < .005). Postoperative central residual stromal thickness was 20 ± 15 μm thicker with a 100 μm cap (P < .0001). Adverse events were comparable. Postoperative refraction, visual acuity, ease of lenticule separation, and incidence of adverse events were not significantly affected by cap thickness. Surgeons might safely use 100 μm instead of 120 μm caps without nomogram adjustment. Alternatively, after suction loss during the lenticule cut, a second docking with a programmed cap thickness of 100 μm (and a larger optical zone) might be a rescue technique enabling surgeons to still perform the intended SMILE procedure.

Potential relationship between high wall shear stress and plaque rupture that cause acute coronary syndrome: insights from optical coherence tomography based computational fluid dynamic simulation

Abstract Background The direct relationship between plaque rupture (PR) that cause acute coronary syndrome (ACS) and wall shear stress (WSS) remains uncertain. Methods From the Kobe University ACS-OCT registry, one hundred ACS patients whose culprit lesions had PR documented by optical coherence tomography (OCT) were enrolled. Lesion-specific 3D coronary artery models were created using OCT data. Specifically, at the ruptured portion, the tracing of the luminal edge of the residual fibrous cap was smoothly extrapolated to reconstruct the luminal contour before PR. Then, WSS was computed from computational fluid dynamics (CFD) analysis by a single core laboratory. Relationships between WSS and the location of PR were assessed with 1) longitudinal 3-mm segmental analysis and 2) circumferential analysis. In the longitudinal segmental analysis, each culprit lesion was subdivided into five 3-mm segments with respect to the minimum lumen area (MLA) location at the centered segment (Figure. 1). In the circumferential analysis, we measured WSS values at five points from PR site and non-PR site on the cross-sections with PR. Also, each ruptured plaque was categorized into the lateral type PR (L-PR), central type PR (C-PR), and others according to the relation between the site of tearing and the cavity (Figure. 2). Results In the longitudinal 3-mm segmental analysis, the incidences of PR at upstream (UP1 and 2), MLA, and downstream (DN1 and 2) were 45%, 40%, and 15%, respectively. The highest average WSS was located in UP1 in the upstream PR (UP1: 15.5 (10.4–26.3) vs. others: 6.8 (3.3–14.7) Pa, p&amp;lt;0.001) and MLA segment in the MLA PR (MLA: 18.8 (6.0–34.3) vs. others: 6.5 (3.1–11.8) Pa, p&amp;lt;0.001), and the second highest WSS was located at DN1 in the downstream PR (DN1: 5.8 (3.7–11.5) vs. others: 5.5 (3.7–16.5) Pa, p=0.035). In the circumferential analysis, the average WSS at PR site was significantly higher than that of non-PR site (18.7 (7.2–35.1) vs. 13.9 (5.2–30.3) Pa, p&amp;lt;0.001). The incidence of L-PR, C-PR, and others were 51%, 42%, and 7%, respectively. In the L-PR, the peak WSS was most frequently observed in the lateral site (66.7%), whereas that in the C-PR was most frequently observed in the center site (70%) (Figure. 3). In the L-PR, the peak WSS value was significantly lower (44.6 (19.6–65.2) vs. 84.7 (36.6–177.5) Pa, p&amp;lt;0.001), and the thickness of broken fibrous cap was significantly thinner (40 (30–50) vs. 80 (67.5–100) μm, p&amp;lt;0.001), and the lumen area at peak WSS site was significantly larger than those of C-PR (1.5 (1.3–2.0) vs. 1.4 (1.1–1.6) mm2, p=0.008). Multivariate analysis demonstrated that the presence of peak WSS at lateral site, thinner broken fibrous cap thickness, and larger lumen area at peak WSS site were independently associated with the development of the L-PR. Conclusions A combined approach with CFD simulation and morphological plaque evaluation by using OCT might be helpful to predict future ACS events induced by PR. Funding Acknowledgement Type of funding source: None

Predictors of plaque erosion in current smokers and non-current smokers presented with ST-segment elevation myocardial infarction: an optical coherence tomography study

Abstract Background Plaque erosion with subsequent coronary thrombosis is considered as an important cause of ST-segment elevation myocardial infarction (STEMI). Smoking is a major risk factor for acute coronary thrombosis. However, the relationship between current smoking status and plaque erosion has not been systematically investigated. Purpose The present study aimed to investigate predictors of plaque erosion in current smokers and non-current smokers with STEMI by using optical coherence tomography (OCT). Methods Between January 2015 to December 2017, a total of 1313 STEMI patients underwent pre-intervention OCT of culprit lesion were enrolled and divided into two groups based on current smoking status: current smoking group (n=713) and non-current smoking group (n=600). Using established criteria, quantitative and qualitative underlying plaque characteristics were assessed by OCT. Clinical, angiographic and OCT characteristics of all enrolled patients were recorded. Univariable and multivariable logistic regression analyses were used to identify predictors of plaque erosion in two groups. Results Plaque erosion were found in 30.9% (220/713) culprit lesions in current smoking group and 20.8% (125/600) of those in non-current smoking group detected by OCT. In multivariate regression analysis, the predictors that strongly related to plaque erosion in the current smoking group were nearby bifurcation (OR: 4.84; 95% CI:2.38–9.87; p&amp;lt;0.001); the minimum fiber cap thickness (FCT, OR:1.05; 95% CI:1.03–1.08; p&amp;lt;0.001); thin-cap fibroatheroma (TCFA, OR: 0.22; 95% CI: 0.07–0.67; p=0.007) and lipid core length (OR: 0.91; 95% CI: 0.84–0.97; p=0.007). The predictors in the non-current smoking group were nearby bifurcation (OR: 4.84; 95% CI: 2.38–9.87; p=0.006); the minimal FCT (OR: 1.09; 95% CI: 1.06–1.13; p&amp;lt;0.001); multi-vessel disease (MVD, OR: 0.43; 95% CI: 0.19–0.97; p=0.042) and dyslipidemia (OR: 0.34; 95% CI: 0.14–0.84; p=0.020). Conclusions Predictors of plaque erosion causing STEMI onset are different between current smokers and non-current smoker, with nearby bifurcation and thicker minimal FCT both predicting plaque erosion in two groups of patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Key Research and Development Program of China, National Natural Science Foundation of China.

Intracoronary polarimetry for characterizing coronary plaque vulnerability in patients with coronary artery disease

Abstract Background Intracoronary polarimetry with polarization-sensitive (PS-) optical frequency domain imaging (OFDI) measures polarization properties, including birefringence and depolarization, in parallel with structural features of conventional OFDI (Figure 1A). Collagen, which imparts mechanical integrity to fibrous caps, and collagen-synthesizing smooth muscle cells exhibit elevated birefringence. Depolarization is increased by the presence of macrophages and lipid/necrotic cores. Purpose This study aimed to compare conventional OFDI and polarimetric signatures of coronary lesions between patients with acute coronary syndrome (ACS) and chronic coronary syndrome (CCS). Furthermore, we aimed to determine a birefringence cut-off value for identifying which fibrous caps belong to ACS culprit lesions. Methods This study consisted of 37 patients with ACS (n=23) or CCS (n=14). ACS culprit lesions (ACS-lesions) and CCS stenotic lesions (CCS-lesions) were included in the analysis (820 mm). Qualitative and quantitative conventional OFDI analysis included the presence of plaque rupture, macrophage infiltration, micro-vessels, thrombus, stenosis severity, fibrous cap thickness (FCT), lipid arc, lipid-burden and calcium-burden index. Birefringence and depolarization of the coronary lesions and fibrous caps were measured in the cross-sectional images showing the minimum FCT or minimum luminal area. Predictors of ACS-lesions were investigated by multivariate regression analysis. Receiver operating characteristic (ROC) analysis was used to determine the birefringence cut-off value identifying ACS fibrous caps (ACS-caps). Results There were no significant differences in clinical characteristics between the two groups, except for previous history of coronary artery disease. Compared to CCS-lesions, ACS-lesions featured higher lipid-burden index and maximum lipid arc (both p&amp;lt;0.05). ACS-lesions featured lower birefringence and higher depolarization than CCS-lesions (p&amp;lt;0.05). Multivariable regression demonstrated an independent association of birefringence with ACS-lesions (p&amp;lt;0.05), even after adjusting for the conventional OFDI findings. Limiting the analysis to the fibrous caps, ACS-caps exhibited significantly lower birefringence (p&amp;lt;0.05) and higher depolarization (p&amp;lt;0.05) that CCS-caps. ROC analysis for differentiating ACS-caps from CCS-caps found that a birefringence value of 0.0004 results in a sensitivity and specificity of 88% and 82%, respectively (Figure 1B, AUC = 0.82). Conclusions Intracoronary polarimetry provides quantitative assessment of coronary lesions related to their composition. Birefringence was an independent robust predictor of ACS-lesions. Decreased birefringence and pronounced depolarization within the ACS-caps may indicate increased collagenolytic activity and macrophage infiltration, respectively. These results suggest that polarization properties may serve as quantitative imaging markers for assessing plaque vulnerability. Figure 1 Funding Acknowledgement Type of funding source: Other. Main funding source(s): This work was supported by the National Institutes of Health and by Terumo Corporation.

Adipokine omentin-1 enhances atherosclerotic plaque stability by binding to macrophage integrin receptor

Abstract Background Omentin-1 is a novel cytokine which is primarily released by epicardial adipose tissues, and the molecule structure analysis revealed that it contained a fibrinogen-like domain. Clinical studies considered that the expression of omentin-1 is tightly associated with the development of cardiovascular diseases. In this research, we sought to investigate the effect of omentin-1 on already-established atherosclerotic lesion in ApoE−/− mouse and find out the cellular receptor of omentin-1 in macrophages. Methods We investigated the effect of omentin-1 on the plaque phenotype by implanting the ALZET minipump (which can continuously inject omentin-1 solution into mice's jugular vein) in western diet-treated ApoE−/− mice. To validate the conjugation of omentin-1 to integrin receptor αvβ3 and αvβ5, we performed immunoprecipitation experiment. Confocal microscopy was used to verify the spatial co-localization of omentin-1 and integrin receptors. Results In vivo studies showed that the administration of omentin-1 increased the collagen content and the average fibrous cap thickness of atherosclerotic plaque in ApoE−/− mice. Omentin-1 mitigated the formation of necrotic cores within the plaque, and reduced the foam cell infiltration concomitantly. Immunohistochemistry analysis of the atherosclerotic lesion from the aorta of mice revealed that the intravenous infusion of omentin-1 can suppress expression of inflammatory cytokines in vivo. Immunoprecipitation experiment and confocal microscopy analysis confirmed the binding of omentin-1 to integrin receptor αvβ3 and αvβ5. To further study the mechanism by which omentin-1 had exerted its protective function, we used human myeloid leukemia mononuclear cell line (THP1) and oxidized low density lipoprotein (ox-LDL) to establish macrophage-derived foam cell model in vitro. Cell studies demonstrated that omentin-1 can attenuated the apoptosis and inflammatory cytokines secretion in ox-LDL-induced macrophages. Besides, omentin-1 can promote the phosphorylation of integrin-relevant signaling pathway in macrophage. After adding the cilengitide (inhibitor of integrin receptor αvβ3 and αvβ5) or intervening the expression of integrin subunit αv, the phenomenon induced by omentin-1 were potently suppressed. Moreover, flowcytometry analysis provided the evidence that omentin-1 had a negative effect on macrophage efferocytosis ability. Conclusions The administration of adipokine omentin-1 can inhibit the necrotic cores formation and pro-inflammatory cytokines expression within the atherosclerotic lesion. The mechanism might be the inhibition of apoptosis and the secretion of pro-inflammatory cytokines in macrophage by binding to integrin receptor αvβ3 and αvβ5. Effect of omentin-1 on AS plaques. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National natural science foundation of China

Dynamic Response of Machine Foundation Resting on End Bearing Piles

Herein, a finite element software (ANSYS. 11) is adopted which provides an effective tool for dynamic analysis and structural design of machine-foundations. As a case study, machine foundation on piles in sandy soil is investigated. Machine foundations supported by end-bearing piles are introduced. Sinusoidal dynamic load is applied. A study of parameters is conducted to investigate the influence of a number of parameters that include: geometry of the piles below the foundation, the dynamic load amplitude, damping ratio and frequency of the load. Linear elastic model is adopted for modeling the piles and their cap for machine foundation using eight node isoparametric (solid 65) element, while elastic model is adopted to model the soil behavior and eight node isoparametric elements are used to model the soil through (solid 45) element. It is concluded that the frequency ratio decreases with increase of spacing between piles values due to increase in natural frequency, except in the case of 3 m spacing where it increases due to decrease in natural frequency as the mass was increased obviously. The increase in spacing caused the increase of natural frequency by about 6% in the model having 1.5 m spacing more than the 1.25 m case and by about 3% for the 1.75 m spacing more than the 1.5 m reference case. The increase in pile cap length caused the natural frequency to decrease by about 18% for the 3.75 m pile cap length as compared with the reference case and by 29% in the case of 5 m less than the reference case. In the case of increasing pile cap thickness, there was only a slight difference in the values of natural frequency.

Association between pre-infarction angina and culprit-lesion morphology in patients with ST-segment elevation myocardial infarction: an optical coherence tomography study

Abstract Background Previous studies reported the cardiac protection effect of pre-infarction angina (PIA) in patients with acute myocardial infarction (AMI). However, the association between PIA and culprit plaques characteristics in AMI patients through optical coherence tomography (OCT)assessment remains unclear. Purpose We sought to identify culprit-plaque morphology associated with PIA in patients with ST-segment elevation myocardial infarction (STEMI) using OCT. Methods A total of 279 STEMI patients who underwent intravascular OCT of culprit-lesion were included. Baseline clinical data and culprit-plaque characteristics were compared between the PIA group the non-PIA group. Results Patients with PIA represented 54.8% of the study population (153 patients). No differences were observed in clinical and angiographic data between two groups, except STEMI onset with exertion was significantly less common in PIA group (24.2% versus 40.5%, P=0.004). Patients with PIA exhibited a significantly lower incidence of plaque rupture (40.5% versus 61.9%, P&amp;lt;0.001) and lipid-rich plaques (48.4% versus 69.0%, P=0.001). The thin-cap fibroatheroma (TCFA) prevalence was lower in PIA group, presenting a thicker fibrous cap thickness, although statistically significant differences were not observed (20.3% versus 30.2%, P=0.070; 129.1±92.0μm versus 111.4±78.1μm, P=0.088; respectively). Multivariate logistic regression analysis indicated that PIA was an independent negative predictor for plaque rupture (odds ratio: 0.44, 95% confidence interval: 0.268–0.725, P=0.001). Conclusion STEMI patients with PIA showed a significantly lower prevalence of plaque rupture and lipid-rich plaques in culprit-lesion than non-PIA group, implying different mechanisms of STEMI attack. Flow chart + Bar graphs of OCT findings Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Association between pre-infarction angina and culprit-lesion morphology in patients with ST-segment elevation myocardial infarction: An optical coherence tomography study

Gap‐Plasmon Coupled Nanopillar Array to Promote Upconversion Luminescence

This work theoretically explored the well-defined nanogap arranged as an upconversion (UC)/gold capping layer photonic nanopillar array on a back-reflecting film-coated Si substrate. The gap-plasmon (GP)-coupled periodic nanopillar array with encapsulating the upconversion layer (denoted as GPNA) is suggested to promote the upconversion luminescence (UCL) intensity at excitation and emission wavelengths. The optical localized-plasmon properties of the GPNA platform were probed by finite-difference time-domain (FDTD) method. With tweaking the geometric design parameters such as a cap thickness and gap distance, the GPNA platform can induce a prominent GP mode between the UC cap layer, thus leading to the significant plasmon-driven optical electromagnetic field amplification within the UC layer followed by substantial light absorption and UCL promotion. This proposed GP-coupled nanopillar array would pave the alternative way for a broad range of plasmon-sensitized applications which are able to absorb the incident excitation and resultant emission light.

Pancoronary Plaque Characteristics in STEMI Caused by Culprit Plaque Erosion Versus Rupture: 3-Vessel OCT Study

ObjectivesThis study sought to investigate nonculprit plaque characteristics in patients with ST-segment elevation myocardial infarction (STEMI) presenting with plaque erosion (PE) and plaque rupture (PR). Pancoronary vulnerability was considered at nonculprit sites: 1) the CLIMA (Relationship Between OCT Coronary Plaque Morphology and Clinical Outcome) study (NCT02883088) defined high-risk plaques with simultaneous presence of 4 optical coherence tomography (OCT) features (minimum lumen area <3.5 mm2; fibrous cap thickness [FCT] <75 μm; maximum lipid arc >180º; and macrophage accumulation); and 2) the presence of plaque ruptures or thin-cap fibroatheromas (TCFA). BackgroundPE is a unique clinical entity associated with better outcomes than PR. There is limited evidence regarding pancoronary plaque characteristics of patients with culprit PE versus culprit PR. MethodsBetween October 2016 and September 2018, 523 patients treated by 3-vessel OCT at the time of primary percutaneous intervention were included with 152 patients excluded from final analysis. ResultsOverall, 458 nonculprit plaques were identified in 202 STEMI patients with culprit PE; and 1,027 nonculprit plaques were identified in 321 STEMI patients with culprit PR. At least 1 CLIMA-defined OCT nonculprit high-risk plaque was seen in 11.4% of patients with culprit PE, but twice as many patients were seen with culprit PR (25.2%; p < 0.001). This proportion was also seen when individual high-risk features were analyzed separately. When patients with PE were divided by a heterogeneous substrate (fibrous or lipid-rich plaque) underlying the culprit site, the prevalence of nonculprits with FCT <75 μm, macrophages, and TCFA showed a significant gradient from PE(Fibrous) to PElipid-rich plaque (LRP) to PR. Interestingly, nonculprit rupture was rarely found in patients with culprit PE(Fibrous) (1.9%), although it was exhibited with comparable prevalence in patients with culprit PE(LRP) (16.3%) versus PR (17.8%). Culprit PE predicted decreased pancoronary vulnerability independent of conventional risk factors. ConclusionsSTEMI patients with culprit PE have a limited pancoronary vulnerability that may explain better outcomes in these patients than in STEMI patients with culprit PR.

Analytical solutions for contaminant diffusion in four-layer sediment-cap system for subaqueous in-situ capping

This paper presents analytical solutions for predicting one-dimensional contaminant diffusion in a four-layer sediment-cap system, which is typically encountered in subaqueous in-situ capping of contaminated sediments. The sediment-cap system is comprised of, from top to bottom, a layer of capping material (e.g., clean sand), a layer of reactive core mat (RCM), a layer of contaminated sediment and a layer of uncontaminated sediment. Two different bottom boundary conditions are considered, i.e., zero-concentration-gradient bottom boundary condition and zero-concentration bottom boundary condition, for which the method of separation of variables is used to obtain the analytical solutions. The extensively verified CST3 (Consolidation and Solute Transport 3) model is used to verify the proposed analytical solutions. Using the verified analytical solutions, parametric studies are conducted to investigate the effect of several important parameters on contaminant transport in the four-layer sediment-cap system. The results indicate that the cap thickness, the contaminated sediment thickness, the uncontaminated sediment thickness, the effect of RCM, and the RCM distribution coefficient have significant impact on contaminant diffusion in the four-layer sediment-cap system. The analytical solutions presented herein can be used to assist the design of subaqueous in-situ capping of contaminated sediments and to verify other numerical models.