Non-invasive and invasive imaging of vulnerable coronary plaque

A novel radiomics-based technique for identifying vulnerable coronary plaques: a follow-up study

BACKGROUND

Previous reports have suggested that coronary computed tomography angiography (CCTA)-based radiomics analysis is a potentially helpful tool for assessing vulnerable plaques. We aimed to investigate whether coronary radiomic analysis of CCTA images could identify vulnerable plaques in patients with stable angina pectoris.

METHODS

This retrospective study included patients initially diagnosed with stable angina pectoris. Patients were randomly divided into either the training or test dataset at an 8 : 2 ratio. Radiomics features were extracted from CCTA images. Radiomics models for predicting vulnerable plaques were developed using the support vector machine (SVM) algorithm. The model performance was assessed using the area under the curve (AUC); the accuracy, sensitivity, and specificity were calculated to compare the diagnostic performance using the two cohorts.

RESULTS

A total of 158 patients were included in the analysis. The SVM radiomics model performed well in predicting vulnerable plaques, with AUC values of 0.977 and 0.875 for the training and test cohorts, respectively. With optimal cutoff values, the radiomics model showed accuracies of 0.91 and 0.882 in the training and test cohorts, respectively.

CONCLUSION

Although further larger population studies are necessary, this novel CCTA radiomics model may identify vulnerable plaques in patients with stable angina pectoris.

Positron emission tomography and its role in the assessment of vulnerable plaques in comparison to other imaging modalities

The diagnosis and management of vulnerable plaques are topics of high interest in the cardiovascular field. Although imaging techniques like computed tomography angiography (MCTA) and ultrasonography (USG) can structurally evaluate atherosclerotic plaques, they are limited in examining internal cellular processes. Positron emission tomography (PET) molecular imaging, on the other hand, can highlight these cellular processes, including inflammation, angiogenesis, and lipid oxidation. Magnetic resonance imaging (MRI) is also a valuable non-invasive imaging technique that can provide detailed anatomical and functional information on the cardiovascular system. In this review, we compare the advantages and drawbacks of MCTA, USG and MRI imaging techniques with PET molecular imaging in evaluating vulnerable plaques. PET imaging allows physicians to measure different pathophysiological events within the plaque using intravenous radiotracers, of which 18F-fluorodeoxyglucose (18F-FDG) is the most validated one. By using 18F-FDG, physicians can understand the formation of the plaque, assess the accumulation of macrophages, and predict major cardiovascular events. However, some limitations exist in using 18F-FDG, including myocardial uptake and low sensitivity in imaging coronary arteries. We also mention other radiotracers that can help in evaluating vulnerable plaques, including 18F-NaF. Although PET imaging is still challenging, it has shown promise in evaluating vulnerable plaques and could be used to intervene in high-risk patients before major cardiovascular events occur.

Ultrasound technology assisted colloidal nanocrystal synthesis and biomedical applications

Non-invasive and high spatiotemporal resolution mythologies for the diagnosis and treatment of disease in clinical medicine promote the development of modern medicine. Ultrasound (US) technology provides a non-invasive, real-time, and cost-effective clinical imaging modality, which plays a significant role in chemical synthesis and clinical translation, especially in in vivo imaging and cancer therapy. On the one hand, the US treatment is usually accompanied by cavitation, leading to high temperature and pressure, so-called "hot spot", playing a significant role in sonochemical-based colloidal synthesis. Compared with the classical nucleation synthetic method, the sonochemical synthesis strategy presents high efficiency for the fabrication of colloidal nanocrystals due to its fast nucleation and growth procedure. On the other hand, the US is attractive for in vivo and medical treatment, with applications increasing with the development of novel contrast agents, such as the micro and nano bubbles, which are widely used in neuromodulation, with which the US can breach the blood-brain barrier temporarily and safely, opening a new door to neuromodulation and therapy. In terms of cancer treatment, sonodynamic therapy and US-assisted synergetic therapy show great effects against cancer and sonodynamic immunotherapy present unparalleled potentiality compared with other synergetic therapies. Further development of ultrasound technology can revolutionize both chemical synthesis and clinical translation by improving efficiency, precision, and accessibility while reducing environmental impact and enhancing patient care. In this paper, we review the US-assisted sonochemical synthesis and biological applications, to promote the next generation US technology-assisted applications.

Exosomal circSCMH1/miR-874 ratio in serum to predict carotid and coronary plaque stability

Background

To investigate the correlation between lg (circSCMH1/miR-874) and acute coronary syndrome (ACS), acute myocardial infarction (AMI), and carotid plaque stability.

Methods

701 patients were divided into stable coronary artery disease (SCAD), ACS, and control groups. Furthermore, 225 patients who underwent carotid ultrasound were selected from the above 701 patients and were divided into low-risk plaque, medium-to-high risk plaque, and control (without carotid plaques) groups. We collected their baseline characteristics and measured the contents of exosomal circSCMH1 and miR-874 in peripheral blood. Then lg(circSCMH1/miR-874) was calculated and statistical analysis was performed.

Results

The lg (circSCMH1/miR-874) values of ACS, SCAD, and the control group decreased successively (P < 0.05). Compared with the low-risk plaque and control groups, the lg (circSCMH1/miR-874) value of medium-high risk plaque group decreased (P < 0.05). Multivariate logistic regression analysis showed that with the decrease of lg (circSCMH1/miR-874), the risk of ACS, AMI, and medium-high risk plaques increased. ROC curve analysis demonstrated that lg (circSCMH1/miR-874) has a higher diagnostic value for ACS, AMI and medium-high risk plaques than previously used predictive ratios.

Conclusion

Lg (circSCMH1/miR-874) is closely associated with coronary and carotid plaque stability.

Cyclothymic affective temperament is independently associated with left ventricular hypertrophy in chronic hypertensive patients

OBJECTIVE

Affective temperaments (depressive, anxious, irritable, hyperthymic, and cyclothymic) are regarded as the stable core of personality and when present in their dominant form, are considered subclinical manifestations and high-risk states for various affective disorders. Furthermore, cumulating evidence supports their relationship with cardiovascular diseases. Our aim was to assess the association between affective temperaments and left ventricular hypertrophy (LVH) in chronic hypertensive patients.

METHODS

In the present cross-sectional study, 296 patients referred to coronary computed tomography angiography (CCTA) due to suspected coronary artery disease were analyzed. All patients completed the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A). Left ventricular mass was quantified by CCTA and indexed to the body surface area (LVMi). Logistic regression analysis was used to identify predictors of LVH (men: ≥67.2 g/m² and women: ≥54.7 g/m²).

RESULTS

Among our patient cohort (mean age: 59.4 ± 10.6, 44.9% female), the median LVM and LVMi were 115.5 [88.4-140.7] g and 58.4 [47.4-64.2] g/m², respectively. Elevated BMI (OR = 1.04 CI: 1.01-1.10, p = 0.04) and cyclothymic affective temperament scores (OR = 1.06 CI: 1.00-1.12, p = 0.04) significantly increased the odds of LVH in multivariate logistic regression analysis.

CONCLUSION

Assessment of affective temperaments may allow for the identification of chronic hypertensive patients with elevated risk for LVH as a potential target for earlier primary intervention.

Heart Rate-Dependent Degree of Motion Artifacts in Coronary CT Angiography Acquired by a Novel Purpose-Built Cardiac CT Scanner

Although reaching target heart rate (HR) before coronary CT angiography (CCTA) is still of importance, adequate HR control remains a challenge for many patients. Purpose-built cardiac scanners may provide optimal image quality at higher HRs by further improving temporal resolution. We aimed to compare the amount of motion artifacts on CCTA acquired using a dedicated cardiac CT (DCCT) compared to a conventional multidetector CT (MDCT) scanner. We compared 80 DCCT images to 80 MDCT scans matched by sex, age, HR, and coronary dominance. Image quality was graded on a per-patient, per-vessel and per-segment basis. Motion artifacts were assessed using Likert scores (1: non-diagnostic, 2: severe artifacts, 3: mild artifacts, 4: no artifacts). Patients were stratified into four groups according to HR (<60/min, 60−65/min, 66−70/min and >70/min). Overall, 2328 coronary segments were evaluated. DCCT demonstrated superior overall image quality compared to MDCT (3.7 ± 0.4 vs. 3.3 ± 0.7, p < 0.001). DCCT images yielded higher Likert scores in all HR ranges, which was statistically significant in the 60−65/min, 66−70/min and >70/min ranges (3.9 ± 0.2 vs. 3.7 ± 0.2, p = 0.008; 3.5 ± 0.5 vs. 3.1 ± 0.6, p = 0.048 and 3.5 ± 0.4 vs. 2.7 ± 0.7, p < 0.001, respectively). Using a dedicated cardiac scanner results in fewer motion artifacts, which may allow optimal image quality even in cases of high HRs.

Association between affective temperaments and severe coronary artery disease

BACKGROUND

Affective temperaments are regarded as subclinical manifestations of major mood disorders and cumulating evidence suggest their role in cardiovascular (CV) pathology. We wished to analyze associations between affective temperaments and severe coronary artery disease (CAD), as assessed by coronary computed tomography angiography (CCTA).

METHODS

225 consecutive patients referred to CCTA due to suspected CAD were included. Medical history and demographic parameters were recorded and all patients completed the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A). The severity and extent of CAD was evaluated by CCTA. Logistic regression analysis was used to identify predictors of severe CAD (≥70% luminal stenosis in ≥1 major coronary artery).

RESULTS

According to multivariate logistic regression analysis, elevated hyperthymic affective temperament scores significantly decreased the odds of severe CAD (OR=0.92 CI: 0.84-1.00, p = 0.04), while independent positive associations were observed in case of dyslipidemia (OR=4.23 CI: 1.81-9.88, p = 0.001) and cyclothymic affective temperament scores (OR=1.12 CI: 1.02-1.23, p = 0.02). Furthermore, receiver operating curve (ROC) analysis was used to define ideal cutoff values. Hyperthymic temperament scores >11 (OR=0.41 CI: 0.19-0.90, p = 0.03), cyclothymic scores >7 (OR=3.23 CI: 1.35-7.76, p = 0.01) and irritable scores >6 (OR=2.79 CI: 1.17-6.69, p = 0.02) were also independently associated with severe CAD.

LIMITATIONS

Our study was limited by the cross-sectional design and the self-report nature of the questionnaires.

CONCLUSIONS

Evaluation of affective temperaments might help to identify patients with elevated risk for severe CAD and subsequent need for coronary intervention.

Model-based adaptive filter for a dedicated cardiovascular CT scanner: Assessment of image noise, sharpness and quality

BACKGROUND

Filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR) are ubiquitously applied in the reconstruction of coronary CT angiography (CCTA) datasets. However, currently no data is available on the impact of a model-based adaptive filter (MBAF2), recently developed for a dedicated cardiac scanner.

PURPOSE

Our aim was to determine the effect of MBAF2 on subjective and objective image quality parameters of coronary arteries on CCTA.

METHODS

Images of 102 consecutive patients referred for CCTA were evaluated. Four reconstructions of coronary images (FBP, ASIR, MBAF2, ASIR + MBAF2) were co-registered and cross-section were assessed for qualitative (graininess, sharpness, overall image quality) and quantitative [image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)] image quality parameters. Image noise and signal were measured in the aortic root and the left main coronary artery, respectively. Graininess, sharpness, and overall image quality was assessed on a 4-point Likert scale.

RESULTS

As compared to FBP, ASIR, and MBAF2, ASIR + MBAF2 resulted in reduced image noise [53.1 ± 12.3, 30.6 ± 8.5, 36.3 ± 4.2, 26.3 ± 4.0 Hounsfield units (HU), respectively; p < 0.001], improved SNR (8.4 ± 2.6, 14.1 ± 3.6, 11.8 ± 2.3, 16.3 ± 3.3 HU, respectively; p < 0.001) and CNR (9.4 ± 2.7, 15.9 ± 4.0, 13.3 ± 2.5, 18.3 ± 3.5 HU, respectively; p < 0.001). No difference in sharpness was observed amongst the reconstructions (p = 0.08). Although ASIR + MBAF2 was non-superior to ASIR regarding overall image quality (p = 0.99), it performed better than FBP (p < 0.001) and MBAF2 (p < 0.001) alone.

CONCLUSION

The combination of ASIR and MBAF2 resulted in reduced image noise and improved SNR and CNR. The implementation of MBAF2 in clinical practice may result in improved noise reduction performance and could potentiate radiation dose reduction.

The Napkin-Ring Sign – the Story Behind Invasive Coronary Angiography

Coronary artery disease (CAD) represents one of the leading causes of morbidity and mortality across Europe. Most of the patients do not experience any warning sign before the coronary event develops, therefore screening this group of patients is essential to prevent major cardiac events. Coronary computed tomography angiography (CCTA) offers a noninvasive approach of the coronary arteries, providing information not only on the presence and severity of the coronary stenosis, but is also able to characterize the structure of the coronary wall. CCTA allows complex evaluation of the extension of CAD, and by assessing the structure of the atherosclerotic plaque, it can identify its degree of vulnerability. The napkin-ring sign (NRS) represents a ring-like attenuation of the non-calcified portion of the coronary lesion and has a high specificity (96–100%) for the identification of thin cap fibroatheroma (TCFA) or culprit lesion in acute coronary syndromes (ACS). It is also an independent predictor for ACS events and the strongest predictor for future ACS. Modern CCTA can provide submillimeter isotropic spatial resolution. Thus, CT attenuation-based tissue interpretation enables the assessment of total coronary plaque burden and individual plaque components, with a similar accuracy as intravascular ultrasoud-based investigations. This review aims to present the important role of CCTA as a potent screening tool for patients with CAD, and the current evidences in the detection and quantification of vulnerable plaques.

[Computed Tomography Coronary Angiography Possibilities in "High Risk" Plaque Identification in Patients with non-ST-Elevation Acute Coronary Syndrome: Comparison with Intravascular Ultrasound]

Aim      To evaluate structural characteristics of atherosclerotic plaques (ASP) by coronary computed tomography arteriography (CCTA) and intravascular ultrasound (IVUS).Material and methods  This study included 37 patients with acute coronary syndrome (ACS). 64-detector-row CCTA, coronarography, and grayscale IVUS were performed prior to coronary stenting. The ASP length and burden, remodeling index (RI), and known CT signs of unstable ASP (presence of dot calcification, positive remodeling of the artery in the ASP area, irregular plaque contour, presence of a peripheral high-density ring and a low-density patch in the ASP). The ASP type and signs of rupture or thrombosis were determined by IVUS.Results The IVUS study revealed 45 unstable ASP (UASP), including 25 UASP with rupture and 20 thin-cap fibroatheromas (TCFA), and 13 stable ASP (SASP). No significant differences were found between distribution of TCFA and ASP with rupture among symptom-associated plaques (SAP, n=28) and non-symptom-associated plaques (NSAP, n=30). They were found in 82.1 and 73.3 % of cases, respectively (p&gt;0.05), which indicated generalization of the ASP destabilization process in the coronary circulation. However, the incidence of mural thrombus was higher for SAP (53.5 and 16.6 % of ASP, respectively; p&lt;0.001). There was no difference between UASP and SASP in the incidence of qualitative ASP characteristics or in values of quantitative ASP characteristics, including known signs of instability, except for the irregular contour, which was observed in 92.9 % of UASP and 46.1 % of SASP (p=0.0007), and patches with X-ray density ≤46 HU, which were detected in 83.3 % of UASP and 46.1 % of SASP (р=0.01). The presence of these CT criteria 11- and 7-fold increased the likelihood of unstable ASP (odd ratio (OR), 11.1 at 95 % confidence interval (CI), from 2.24 to 55.33 and OR, 7.0 at 95 % CI, from 5.63 to 8.37 for the former and the latter criterion, respectively).Conclusion      According to IVUS data, two X-ray signs are most characteristic for UASP, the irregular contour and a patch with X-ray density ≤46 HU. The presence of these signs 11- and 7-fold, respectively, increases the likelihood of unstable ASP.

Identification of hub genes in unstable atherosclerotic plaque by conjoint analysis of bioinformatics

AIMS

Unstable atherosclerotic plaque is the main pathological basis of acute coronary syndrome, which is the leading cause of death and disability worldwide. Therefore, we combined multiple bioinformatics tools to identify key genes related to unstable plaque.

MAIN METHODS

GSE94605 contained 7 plasma sample pools of 175 healthy and 6 sample pools of 150 unstable angina pectoris (UAP) patients, and detected with miRNA array while GSE60993 collected peripheral blood from 7 normal and 9 UAP, and detected with mRNA array. GSE120521 collected carotid plaques from 4 patients and dissected in stable and unstable regions, then detected with RNA-seq. Differentially expressed miRNAs (DEMs) and genes (DEGs) in UAP were re-analyzed. Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein-protein interaction (PPI) network were applied on top 10 up-regulated or down-regulated DEMs targets, and whole DEGs. MiRNAs-mRNAs network was constructed with these DEMs and DEGs, and the expression profile of genes within the network was finally validated in GSE120521.

KEY FINDINGS

Totally, 263 up-regulated and 201 down-regulated DEMs were identified in GSE94605, and 78 up-regulated and 29 down-regulated DEGs were identified in GSE60993. Subsequently, a miRNAs-mRNAs network was constructed with 6 up-regulated miRNAs targeted to 12 down-regulated genes, and 4 down-regulated miRNAs targeted to 8 up-regulated genes. Finally, MORF4L2, RAB3IL1 and MMP9 within the network were considered as hub genes in unstable plaque progression after being validated in GSE120521.

SIGNIFICANCE

These 3 genes may provide new targets for diagnosis and therapy of unstable atherosclerotic plaque.

Two-hour postload plasma glucose and pigment epithelium-derived factor levels are markers of coronary artery inflammation in type 2 diabetic patients

BACKGROUND

We have previously found that pioglitazone attenuates inflammation in the left main trunk of coronary artery (LMT), evaluated as target-to-background ratio (TBR) by 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with impaired glucose tolerance or type 2 diabetes.

OBJECTIVES

We assessed which clinical variables could predict the change in TBR in the LMT after 4-month add-on therapy with oral hypoglycemic agents (OHAs).

METHODS

A total of 38 type 2 diabetic patients with carotid atherosclerosis who had already received OHAs except for pioglitazone was enrolled. At baseline and 4 months after add-on therapy with pioglitazone or glimepiride, all patients underwent 75 g oral glucose tolerance test, blood chemistry analysis, and FDG-PET/CT.

RESULTS

Fasting plasma glucose, 30-, 60-, 90-, 120-minutes postload plasma glucose, HbA1c, and LMT-TBR values were significantly decreased by add-on therapy, whereas high-density lipoprotein-cholesterol and adiponectin levels were increased. Increased serum levels of pigment epithelium-derived factor (PEDF), a marker of insulin resistance and non-use of aspirin at baseline could predict the favorable response of LMT-TBR to add-on therapy. Moreover, Δ120-minutes postload plasma glucose and ΔPEDF were independent correlates of ΔLMT-TBR.

CONCLUSIONS

Our present study suggests that 120-minutes postload plasma glucose and PEDF values may be markers and potential therapeutic targets of coronary artery inflammation in type 2 diabetic patients.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov . Unique identifier: NCT00722631. New markers for diabetes and CAD is on the horizon! Two-hour postload plasma glucose and pigment epithelium derived factor are markers of coronary artery inflammation in type 2 diabetic patients.

IL-6-targeted ultrasmall superparamagnetic iron oxide nanoparticles for optimized MRI detection of atherosclerotic vulnerable plaques in rabbits

Vulnerable plaques of atherosclerosis (AS) are the main culprit lesion for the serious risk of acute cardiovascular disease (CVD). Therefore, developing new non-invasive methods to detect vulnerable plaques and to evaluate their stability effectively is of great value in the early diagnosis of CVD. IL-6 plays a vital role in the development and rupture of AS. In this study, IL-6-targeted superparamagnetic iron oxide nanoparticles (Anti-IL-6-USPIO) are synthesized by a chemical condensation reaction. An AS model was established by damaging rabbit abdominal aortic intima with Foley's tube in combination with a high cholesterol diet. The results confirm that Anti-IL-6-USPIO have excellent IL-6-targeting ability and usefulness in detecting vulnerable plaques in vitro and in vivo, which may provide a novel, non-invasive strategy for evaluating acute cardiovascular risk or exploiting anti-atherosclerotic drugs.

Herein, we report Anti-IL-6-USPIO for detecting IL-6 in inflammatory macrophages and MR imaging vulnerable plaques of atherosclerosis in rabbit, which would provide a novel non-invasive strategy for evaluating acute cardiovascular risk or exploiting anti-atherosclerotic drugs.

Vulnerable Plaque, Characteristics, Detection, and Potential Therapies

Plaque development and rupture are hallmarks of atherosclerotic vascular disease. Despite current therapeutic developments, there is an unmet necessity in the prevention of atherosclerotic vascular disease. It remains a challenge to determine at an early stage if atherosclerotic plaque will become unstable and vulnerable. The arrival of molecular imaging is receiving more attention, considering it allows for a better understanding of the biology of human plaque and vulnerabilities. Various plaque therapies with common goals have been tested in high-risk patients with cardiovascular disease. In this work, the process of plaque instability, along with current technologies for sensing and predicting high-risk plaques, is debated. Updates on potential novel therapeutic approaches are also summarized.

Age-related diseases as vicious cycles

The mortality rates of age-related diseases (ARDs) increase exponentially with age. Processes described by the exponential growth function typically involve a branching chain reaction or, more generally, a positive feedback loop. Here I propose that each ARD is mediated by one or several positive feedback loops (vicious cycles). I then identify critical vicious cycles in five major ARDs: atherosclerosis, hypertension, diabetes, Alzheimer's and Parkinson's. I also propose that the progression of ARDs can be halted by selectively interrupting the vicious cycles and suggest the most promising targets.

Associations of 26 Circulating Inflammatory and Renal Biomarkers with Near-Infrared Spectroscopy and Long-term Cardiovascular Outcome in Patients Undergoing Coronary Angiography (ATHEROREMO-NIRS Substudy)

Purpose of Review

The purpose of this study was to investigate the association of 26 inflammatory biomarkers (acute phase proteins, cytokines, chemokines) and renal markers with coronary lipid core burden index (LCBI) assessed by near-infrared spectroscopy (NIRS) imaging, as well as the association of these biomarkers with long-term cardiovascular outcome.

Recent Findings

NIRS-derived LCBI has recently been shown to be an independent predictor of major adverse cardiac events (MACE). However, studies on the association between circulating biomarkers and NIRS-derived characteristics have not yet been performed.

Summary

Between 2008 and 2011, 581 patients underwent diagnostic coronary angiography or percutaneous coronary intervention for stable angina pectoris or acute coronary syndrome (ACS). NIRS of a non-culprit vessel was performed in a subset of 203 patients. In multivariable analyses, TNF-α tended to be associated with higher LCBI (beta 0.088 ln (pg/ml) increase per unit LCBI; 95% CI 0.000–0.177, p = 0.05) after adjustment for clinical characteristics. However, this association did not persist after Bonferroni correction (statistical threshold 0.0019). Major adverse cardiac events (MACE) were registered in 581 patients during a median follow-up time of 4.7 years (IQR: [4.2–5.6] years). After adjustment for clinical characteristics and Bonferroni correction, IL-8 (HR 1.60; 95% CI [1.18–2.17] per ln (pg/ml), p = 0.002) was borderline associated with MACE and significantly associated with all-cause mortality or ACS (HR 1.75; 95% CI [1.24–2.48] per ln (pg/ml), p = 0.0015). In conclusion, we found that IL-8 was independently associated with clinical outcome, but altogether, the multiplex panel we investigated here did not render a useful blood biomarker of high LCBI.

Electronic supplementary material

The online version of this article (10.1007/s11883-018-0752-8) contains supplementary material, which is available to authorized users.

Use of cardiovascular age for assessing risks and benefits of menopausal hormone therapy

The Women's Health Initiative studies and others have suggested that menopausal hormone therapy may enhance the risk of new cardiovascular (CV) events in older women and diminish the development of coronary atherosclerosis in younger women. The underlying mechanisms to explain these findings are encapsulated in the term "Timing Hypothesis." Extensive pathophysiologic studies have provided mechanistic evidence for the dichotomous effects of estrogen on coronary artery vasculature. Early in the atherosclerotic disease process, estrogen exerts protective effects on the endothelium and retards plaque formation. Late in the process, estrogen causes plaque erosion or rupture with subsequent thrombosis and acute coronary events. Analysis of the Timing Hypothesis in women examined in the Women's Health Initiative primarily used chronologic age to assess divergent effects of estrogen. The complexity of the data underlying coronary pathophysiology has resulted in controversy whether MHT can be used in older women or those with prior CV disease. In a debate of this issue at a recent International Menopause Society meeting, the concept of using CV age rather than chronologic age was discussed as a practical method of resolving this issue and facilitating therapeutic decisions in older women. This "Personal Perspective" will review the concepts underlying CV age, describe how it is determined, provide support for its utility, and propose future studies using this parameter.

Inverse association between hyperthymic affective temperament and coronary atherosclerosis: A coronary computed tomography angiography study

OBJECTIVE

A bidirectional relationship exists between psychiatric disorders and cardiovascular diseases, however less is known with regards to personality traits. Accumulating data suggest that affective temperaments are both associated with psychiatric and somatic diseases. The aim of our study was to evaluate the associations between different affective temperaments and the presence of coronary atherosclerosis.

METHODS

200 consecutive patients referred to coronary computed tomography angiography (CCTA) due to suspected coronary artery disease (CAD) were included in our study. Medical history and demographic parameters were recorded and all patients completed the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A) and the Beck Depression Inventory (BDI). The presence of coronary artery disease was evaluated based on the CCTA images.

RESULTS

39 patients were free of any coronary atherosclerosis (CCTA-) and 161 had coronary atherosclerosis (CCTA+). Hyperthymic affective temperament score was higher in CCTA- subjects as compared to CCTA+ (13.1±3.0 vs 11.5±4.6, p=0.010, respectively). Hyperthymic affective temperament score showed a significant independent, inverse relationship with coronary atherosclerosis (OR: 0.91 CI: 0.82-0.99, p=0.04).

CONCLUSION

Our results suggest that hyperthymic affective temperament is independently associated with the absence of CAD. It requires further research to delineate the mechanism mediating the effect of hyperthymia on better coronary artery health and establishing potential biochemical or behavioral factors, both of which could be exploited for prevention and treatment purposes. But it is plausible, that the evaluation of affective temperaments have importance both in relation with psychiatric and cardiovascular disorders.

Relationship between monocyte-to-lymphocyte ratio and coronary plaque vulnerability in patients with stable angina

Aim: To investigate the relationship between monocyte-to-lymphocyte ratio (MLR) and plaque vulnerability assessed by virtual histology intravascular ultrasound in patients with stable angina. Methods: 133 patients with stable angina were enrolled. Results: MLR was found to be an independent risk factor of thin cap fibrous atheroma (OR: 2.61; p = 0.025). MLR could differentiate thin cap fibrous atheroma with a sensitivity of 73.7% and a specificity of 61.8%. MLR level was positively correlated with the percentage of necrotic core (NC) area at the sites of minimum lumen area and the largest NC area, and positively related to the percentage of NC volume. Conclusion: Circulating MLR level has potential in identifying the vulnerable plaques in the setting of stable angina.

Analysis of Cardiovascular Tissue Components for the Diagnosis of Coronary Vulnerable Plaque from Intravascular Ultrasound Images

The purpose of this study was to characterize cardiovascular tissue components and analyze the different tissue properties for predicting coronary vulnerable plaque from intravascular ultrasound (IVUS) images. For this purpose, sequential IVUS image frames were obtained from human coronary arteries using 20 MHz catheters. The plaque regions between the intima and media-adventitial borders were manually segmented in all IVUS images. Tissue components of the plaque regions were classified into having fibrous tissue (FT), fibrofatty tissue (FFT), necrotic core (NC), or dense calcium (DC). The media area and lumen diameter were also estimated simultaneously. In addition, the external elastic membrane (EEM) was computed to predict the vulnerable plaque after the tissue characterization. The reliability of manual segmentation was validated in terms of inter- and intraobserver agreements. The quantitative results found that the FT and the media as well as the NC would be good indicators for predicting vulnerable plaques in IVUS images. In addition, the lumen was not suitable for early diagnosis of vulnerable plaque because of the low significance compared to the other vessel parameters. To predict vulnerable plaque rupture, future study should have additional experiments using various tissue components, such as the EEM, FT, NC, and media.

Safety Evaluation and Imaging Properties of Gadolinium-Based Nanoparticles in nonhuman primates

In this article, we report the safety evaluation of gadolinium-based nanoparticles in nonhuman primates (NHP) in the context of magnetic resonance imaging (MRI) studies in atherosclerosis bearing animals and healthy controls. In healthy NHP, the pharmacokinetics and toxicity profiles demonstrated the absence of dose, time, and sex-effects, as well as a suitable tolerance of intravenous administration of the nanoparticles. We investigated their imaging properties for arterial plaque imaging in a standard diet or a high cholesterol diet NHP, and compared their characteristics with clinically applied Gd-chelate. This preliminary investigation reports the efficient and safe imaging of atherosclerotic plaques.