Impact of metabolic syndrome on the progression of coronary calcium and of coronary artery disease assessed by repeated cardiac computed tomography scans

Common clinical laboratory features among women with polycystic ovary syndrome and metabolic syndrome

Women with polycystic ovary syndrome (PCOS) have a high prevalence of metabolic syndrome (MS), with rates up to 33%. This is associated with long-term consequences such as cardiovascular diseases, type 2 diabetes mellitus (T2DM), cancer, sleep apnea, and psychological issues. The prevalence of MS worldwide is often associated with obesity and T2DM, yet regional variations are reported. In this study, 122 women consulting general practice and family medicine physicians were evaluated, revealing a BMI exceeding 30 kg/m2. Among MS criteria, the most common diagnoses were T2DM in 29 patients, insulin resistance (IR) in 36, arterial hypertension (AH) in 51, reduced HDL levels in 53, and elevated triglycerides in 39. Further analysis revealed 16 unique combinations of MS components in these patients, with 75% of PCOS cases exhibiting three MS components and 25% having four. Additionally, research indicated that most women with PCOS face persistent, treatment-resistant obesity, with a notably higher BMI (ρ=0.87; r=0.76). These findings highlight the multifactorial nature of PCOS and MS etiology.

Association Between Premorbid Metabolic Syndrome and Coronary Arterial Stenosis: Results from One Medical Center in Taiwan

Background: Although the relationship between metabolic syndrome (MetS) and cardiovascular disease is already well-established, there is limited evidence as to whether individuals are at risk for cardiovascular disease during the premorbid state of MetS. The aim of this study is to explore the relationship between coronary arterial stenosis and MetS in a nonhypertensive and nondiabetic population. Methods: In this cross-sectional study, we analyzed the data of participants who underwent annual health checkups in a medical center. These data were collected from physical examination, blood tests, cardiac computed tomography examinations, and medical charts. We excluded those with established hypertension or diabetes and age of <50 or >75 years. Results: This study recruited 700 participants with a mean age of 59.5 years. More than 31% had MetS, and the overall prevalence of coronary arterial stenosis was 48.0% (grade 1, 2, 3, 4: 16.3%, 20.9%, 8.4%, 2.4%, respectively). In univariate analysis, older age, male sex, smoking, body mass index, elevated fasting plasma glucose (FPG), elevated triglyceride, lower level of high-density lipoprotein cholesterol, and presence of MetS were all positively correlated with coronary arterial stenosis. After adjustment for confounding factors, MetS still showed strong association with high grades of coronary arterial stenosis [odds ratio (OR) 2.86, confidence interval (95% CI) 1.30-4.01]. Specific components of MetS, such as elevated triglyceride [OR 2.02, 95% CI 1.14-3.57] and elevated FPG [OR 2.25, 95% CI 1.31-3.88], were also associated with coronary arterial stenosis. Conclusion: Our study concluded that premorbid MetS was significantly associated with coronary arterial stenosis. As for the individual components, elevated triglyceride and elevated FPG were both correlated with coronary arterial stenosis. Early preventive measures would be suggested at this stage of MetS to prevent future cardiovascular events.

Association between Non-alcoholic Fatty Liver Disease and the Severity of Coronary Artery Stenosis in Eastern Chinese Population

Background: The present study aimed to investigate the relationship of non-alcoholic fatty liver disease (NAFLD) with the severity and extent of coronary stenotic lesions calculated by the Gensini score. In addition, the ability of Fibrosis-4 (FIB4) score to differentiate coronary artery calcification (CAC) and its severity is assessed. Methods: The current retrospective study was performed on a total of 342 patients examined between January and December 2016 in an affiliated hospital of Jiaxing University, Zhejiang, China. The study used liver ultrasonography for the assessment of NAFLD. Furthermore, the FIB4 and Gensini scores were used to predict hepatic fibrosis risk and the severity of coronary stenotic lesions. Results: The present study revealed that the serum levels of triglycerides, fasting glucose, alanine aminotransferase, and uric acid were significantly higher in patients with NAFLD than in participants without NAFLD (P < 0.001, P < 0.001, P = 0.032, and P = 0.002). Moreover, cases with NAFLD had a higher percentage of diabetes mellitus and hypertension (P < 0.001 and 0.001) than those without NAFLD. It was noted that the level of high-density lipoprotein was lower in patients with NAFLD than in participants without NAFLD (P = 0.006). In addition, we observed that the Gensini score was higher in patients with NAFLD than in participants without NAFLD (P = 0.033). It was found that 27.3%, 25.8%, 45.7%, and 56.3% of the participants had NAFLD in control, single, double, and multi lesion groups, respectively, and the difference was statistically significant (P = 0.008). The number of diseased vessels in patients with severe NAFLD was higher than in the control group (P < 0.001). It was also evident that the number of affected vessels significantly increased (P = 0.010 and P = 0.001) with the stages of NAFLD predicted by the FIB4 and Gensini scores. Furthermore, the Gensini score in patients with moderate and severe NAFLD was higher than in the control group (P = 0.013 and P = 0.019). We also conducted univariate logistic regression analyses to examine the relationship of CAC with FIB4 scores, and it was not significant (P = 0.191). Conclusions: The present study showed a positive relationship between NAFLD severity and coronary stenotic lesions in the eastern Chinese population. Furthermore, it was found that the higher the degree of FIB4 score, the higher the risk of CAC in patients with NAFLD. Therefore, assessing NAFLD severity using the FIB4 score may be useful for differentiating the patients at a higher risk of CAC. However, further prospective studies are required to establish the link between the FIB4 score and CAC.

Clinical Significance of Body Fat Distribution in Coronary Artery Calcification Progression in Korean Population

BACKGROUND

Although obesity differs according to ethnicity, it is globally established as a solid risk factor for cardiovascular disease. However, it is not fully understood how obesity parameters affect the progression of coronary artery calcification (CAC) in Korean population. We sought to evaluate the association of obesity-related parameters including visceral adipose tissue (VAT) measurement and CAC progression.

METHODS

This retrospective observational cohort study investigated 1,015 asymptomatic Korean subjects who underwent serial CAC scoring by computed tomography (CT) with at least 1-year interval and adipose tissue measurement using non-contrast CT at baseline for a routine checkup between 2003 and 2015. CAC progression, the main outcome, was defined as a difference of ≥2.5 between the square roots of the baseline and follow-up CAC scores using Agatston units.

RESULTS

During follow-up (median 39 months), 37.5% of subjects showed CAC progression of a total population (56.4 years, 80.6% male). Body mass index (BMI) ≥25 kg/m2, increasing waist circumferences (WC), and higher VAT/subcutaneous adipose tissue (SAT) area ratio were independently associated with CAC progression. Particularly, predominance of VAT over SAT at ≥30% showed the strongest prediction for CAC progression (adjusted hazard ratio, 2.20; P<0.001) and remained of prognostic value regardless of BMI or WC status. Further, it provided improved risk stratification of CAC progression beyond known prognosticators.

CONCLUSION

Predominant VAT area on CT is the strongest predictor of CAC progression regardless of BMI or WC in apparently healthy Korean population. Assessment of body fat distribution may be helpful to identify subjects at higher risk.

Influence of sex and menopausal status on the relationship between metabolic syndrome and coronary artery calcification: a Chinese community-based cross-sectional study

OBJECTIVE

To evaluate the association between metabolic syndrome and coronary artery calcification according to different sex and menopausal status.

METHODS

This cross-sectional study included 2,704 adults from the Jidong community (Tangshan, China) recruited from July 2013 to August 2014. Adults aged ≥40 years with no cardiovascular disease and with coronary artery calcification score data were included. Metabolic syndrome was defined according to the 2005 International Diabetes Federation standard. Coronary artery calcification score was determined using the Agatston method. The associations between metabolic syndrome and coronary artery calcification prevalence were evaluated using logistic regression.

RESULTS

In the multivariable regression analysis, metabolic syndrome was associated with coronary artery calcification (odds ratio: 1.34, 95% confidence interval: 1.04-1.71, P = 0.021). When stratified by sex, metabolic syndrome was positively associated with coronary artery calcification prevalence in female participants (odds ratio: 2.79, 95% confidence interval: 1.96-3.96, P < 0.001), whereas no association was observed in male participants. Furthermore, metabolic syndrome was associated with a higher prevalence of coronary artery calcification (P < 0.001) independent of adjustment for covariates in postmenopausal women than in premenopausal women, and coronary artery calcification prevalence increased with an increase in conditions related to metabolic syndrome.

CONCLUSIONS

Our findings indicate that metabolic syndrome in postmenopausal women is associated with a higher prevalence of coronary artery disease than in premenopausal women and men.

Metabolic Syndrome and Coronary Artery Disease Risk: A Meta-Analysis of Observational Studies

Although numerous studies have described the link between metabolic syndrome (MetS) and Coronary Artery Disease (CAD), no meta-analysis has been carried out on this relationship. Thus, the present study intended to address this limitation. A systematic search was carried out using electronic databases, such as PubMed, CINAHL Plus, Medline, and Web of Science. A sum of 10 studies (n = 9327) was incorporated in the meta-analysis. Compared with non-MetS, MetS was significantly associated with high CAD risk (OR = 4.03, 95% CI = 3.56–4.56). The MetS components were also significantly correlated with high CAD risk (OR = 3.72, 95% CI = 3.22–4.40). The presence of two (OR = 3.93, 95% CI = 2.81–5.49), three (OR = 4.09, 95% CI = 2.85–5.86), four (OR = 4.04, 95% CI = 2.83–5.78), or all five MetS components (OR = 3.92, 95% CI = 3.11–4.93), were significantly associated with a high risk of CAD. MetS and its individual or combined elements were linked with high CAD risk based on contemporary evidence. Thus, the assessment of MetS and its components might help identify people at a higher risk of advancing CAD in the future.

Prevalence of high-risk coronary plaques in patients with and without metabolic syndrome and the relationship with prognosis

BACKGROUND

Metabolic syndrome (MS) is a disorder, characterized by clusters of cardiovascular risk factors such as central obesity, insulin resistance, dyslipidemia and hypertension. Patients with MS may have a higher plaque burden that increases their risk of major adverse cardiovascular events (MACEs). This study aimed to analyze the prevalence of high-risk coronary plaques in patients with and without MS by coronary computed tomography angiography (CCTA) and to investigate the relationship between MS, high-risk coronary plaques, and their prognosis.

METHODS

This was a retrospective cohort study of 1136 patients who underwent CCTA due to chest pain without obstructive heart disease (≥50% coronary stenosis) between January 2014 and December 2015 in our hospital. The relationships between high risk coronary plaques, MS, and other clinical factors were assessed. Multicollinearity analysis was performed to identify the collinearity between the variables. The proportional hazard assumption was checked and using Schoenfeld residual test. Cox proportional hazards model and Kaplan-Meier survival analysis assessed the relationship between MS, high-risk coronary plaques and MACEs.

RESULTS

High-risk plaques were more frequent in the MS group than non-MS group (P = 0.004). MS (HR = 2.128, 95%CI: 1.524-2.970, P < 0.001), presence of high-risk plaques (HR = 11.059, 95%CI: 7.749-57.232, P < 0.001) and high sensitivity C-reactive protein (hsCRP) (HR = 1.629, 95%CI: 1.128-2.352, P = 0.009) were related with an increased risk of MACEs in patients with risk factors for coronary heart disease. In patients with high-risk plaques, MS (HR = 2.265, 95%CI: 1.629-3.150, P < 0.001) and hsCRP (HR = 1.267, 95%CI: 1.191-1.348, P = 0.004) were related with an increased risk of MACEs. Kaplan-Meier analysis showed differences in MACEs between the MS and non-MS groups in the whole population and those with high-risk plaques (both P < 0.0001).

CONCLUSIONS

High-risk plaques were more common in patients with MS. MS and the presence of high-risk plaques were independent risk factors for MACEs.

The impact of non-alcoholic fatty liver disease and metabolic syndrome on the progression of coronary artery calcification

It is unclear whether non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for cardiovascular disease. We examined the independent impact of NAFLD on the progression of the coronary artery calcification (CAC) score, a well-known marker of atherosclerosis progression. We examined 1,173 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. The subjects were categorised into four groups based on the presence (+) or absence (−) of NAFLD and metabolic syndrome (MetS). The progression of CAC score was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥2.5 units between the baseline and the final square roots of the CAC scores of participants with detectable CAC at baseline. CAC progression was seen in 18.6% (98/526), 28.3% (77/272), 29.1% (30/103) and 32.0% (87/272) of the subjects with NAFLD(−)/MetS(−), NAFLD(+)/MetS(−), NAFLD(−)/MetS(+) and NAFLD(+)/MetS(+), respectively. The subjects with NAFLD(+)/MetS(+) and NAFLD(+)/MetS(−) had a significantly higher risk of CAC progression than those with NAFLD(−)/MetS(−) (multivariate-adjusted odds ratio [OR]: 1.76; 95% confidence interval [CI]: 1.18–2.62 and multivariate-adjusted OR: 1.53, 95% CI: 1.05–2.23, respectively). NAFLD is an independent risk factor for CAC progression, irrespective of the presence of MetS.

Non-culprit plaque characteristics in acute coronary syndrome patients with raised hemoglobinA1c: an intravascular optical coherence tomography study

Background

Raised hemoglobinA1c (HbA1c) is an indicator of pre-diabetes, which is associated with increased risk of coronary artery disease. However, the detailed morphological characteristics of non-culprit plaques in acute coronary syndrome (ACS) patients remain largely unknown.

Methods

A total of 305 non-culprit plaques from 216 ACS patients were analyzed by intravascular optical coherence tomography. These patients were divided into three groups according to the serum glycosylated hemoglobin level: normal HbA1c (< 5.7%), pre-diabetes with raised HbA1c (5.7–6.4%) and diabetes mellitus (DM).

Results

Plaques in patients with raised HbA1c had a longer lipid length (17.0 ± 8.3 mm vs. 13.9 ± 7.2 mm, P = 0.004) and greater lipid index (2775.0 ± 1694.0 mm° vs. 1592.1 ± 981.2 mm°, P = 0.001) than those with normal HbA1c but were similar to DM. The prevalence of calcification in patients with raised HbA1c was significantly higher (38.7% vs. 26.3%, P = 0.048) than normal HbA1c but was similar to DM. The percentage of macrophage infiltration in the DM group was higher than that in the normal HbA1c group (20.5% vs. 7.4%, P = 0.005).

Conclusions

Compared to patients with normal HbA1c, the non-culprit plaques in ACS patients with raised HbA1c had more typical vulnerable features but were similar to DM.

Evaluation of the impact of glycemic status on the progression of coronary artery calcification in asymptomatic individuals

BACKGROUND

Data on the influence of glycemic status on the progression of coronary calcification, an important marker for future adverse cardiovascular events, are limited.

METHODS

Data from the Korea Initiatives on Coronary Artery Calcification (KOICA) registry on 12,441 asymptomatic Korean adults (52 ± 9 years, 84.2% males) without previous history of coronary artery disease and stroke, who underwent serial coronary artery calcification (CAC) screening examinations, were included in this study. The median inter-scan period was 3.0 (2.0-4.8) years. All participants were categorized into three groups based on their glycemic status: normal (n = 6578), pre-diabetes (n = 4146), and diabetes (n = 1717). CAC progression was defined as a difference ≥ 2.5 between the square roots (√) of the baseline and follow-up CAC scores.

RESULTS

The incidence of CAC progression was significantly different between the three groups (normal, 26.3%; pre-diabetes, 30.9%; and diabetes, 46.9%; p < 0.001). In the univariate logistic analysis, the risk of CAC progression was higher in the pre-diabetes (odds ratio [OR] 1.253; 95% confidential interval [CI] 1.150-1.366) and diabetes (OR 2.471; 95% CI 2.215-2.758) groups than in the normal group (p < 0.001, both). In the multivariate logistic analysis, the risk of CAC progression was not significantly different between the normal and pre-diabetes groups but was significantly higher in the diabetes group than in the normal group.

CONCLUSIONS

In asymptomatic subjects, diabetes had an incremental impact on CAC progression; however, pre-diabetes did not increase the risk of CAC progression after adjusting for confounding factors.

Type 2 diabetes mellitus is associated with a lower fibrous cap thickness but has no impact on calcification morphology: an intracoronary optical coherence tomography study

Background

Patients with type 2 diabetes (T2DM) are at high risk for cardiovascular events, which usually arise from the rupture of a vulnerable coronary plaque. The minimal fibrous cap thickness (FCT) overlying a necrotic lipid core is an established predictor for plaque rupture. Recently, coronary calcification has emerged as a relevant feature of plaque vulnerability. However, the impact of T2DM on these morphological plaque parameters is largely unexplored. Therefore, this study aimed to compare differences of coronary plaque morphology in patients with and without T2DM with a particular focus on coronary calcification.

Methods

In 91 patients (T2DM = 56, non-T2DM = 35) with 105 coronary de novo lesions (T2DM = 56, non-T2DM = 49) plaque morphology and calcification were analyzed using optical coherence tomography (OCT) prior to coronary intervention.

Results

Patients with T2DM had a lower minimal FCT (80.4 ± 27.0 µm vs. 106.8 ± 27.8 µm, p < 0.001) and a higher percent area stenosis (77.9 ± 8.1% vs. 71.7 ± 11.2%, p = 0.001) compared to non-diabetic subjects. However, patients with and without T2DM had a similar total number of calcifications (4.0 ± 2.6 vs. 4.2 ± 3.1, p = ns) and no significant difference was detected in the number of micro- (0.34 ± 0.79 vs. 0.31 ± 0.71), spotty (2.11 ± 1.77 vs. 2.37 ± 1.89) or macro-calcifications (1.55 ± 1.13 vs. 1.53 ± 0.71, all p = ns). The mean calcium arc (82.3 ± 44.8° vs. 73.7 ± 31.6), the mean thickness of calcification (0.54 ± 0.13 mm vs. 0.51 ± 0.15 mm), the mean calcified area (0.99 ± 0.72 mm² vs. 0.78 ± 0.49 mm²), the mean depth of calcification (172 ± 192 μm vs. 160 ± 76 μm) and the cap thickness overlying the calcification (50 ± 71 μm vs. 62 ± 61 μm) did not differ between the diabetic and non-diabetic groups (all p = ns).

Conclusion

T2DM has an impact on the minimal FCT of the coronary target lesion, but not on localization, size, shape or extent of calcification. Thus, the minimal FCT overlying the necrotic lipid core but not calcification is likely to contribute to the increased plaque vulnerability observed in patients with T2DM.

Fitness attenuates the prevalence of increased coronary artery calcium in individuals with metabolic syndrome

Background

The association between cardiorespiratory fitness, physical activity and coronary artery calcium (CAC) is unclear, and whether higher levels of fitness attenuate CAC prevalence in subjects with metabolic syndrome is not fully elucidated. The present study aims to: a) investigate the independent association of fitness on the prevalence of CAC, after adjustment for moderate-to-vigorous physical activity and sedentary time, and b) study the possible attenuation of increased CAC by higher fitness, in participants with metabolic syndrome.

Design

Cross-sectional.

Methods

In total 678 participants (52% women), 50–65 years old, from the SCAPIS pilot study were included. Fitness (VO2max) was estimated by submaximal cycle ergometer test and moderate-to-vigorous physical activity and sedentary time were assessed using hip-worn accelerometers. CAC score (CACS) was quantified using the Agatston score.

Results

The odds of having a significant CACS (≥100) was half in participants with moderate/high fitness compared with their low fitness counterparts. Further consideration of moderate-to-vigorous physical activity, sedentary time and number of components of the metabolic syndrome did only slightly alter the effect size. Those with metabolic syndrome had 47% higher odds for significant CAC compared with those without metabolic syndrome. However, moderate/high fitness seems to partially attenuate this risk, as further joint analysis indicated an increased odds for having significant CAC only in the unfit metabolic syndrome participants.

Conclusions

Being fit is associated with a reduced risk of having significant CAC in individuals with metabolic syndrome. While still very much underutilized, fitness should be taken into consideration in everyday clinical risk prediction in addition to the traditional risk factors of the metabolic syndrome.

Associations between reflux esophagitis and the progression of coronary artery calcification: A cohort study

BACKGROUND

Reflux esophagitis (RE) and coronary heart disease (CHD) have common risk factors, including obesity and metabolic syndrome. This study aimed to evaluate the associations between RE and the future CHD risk.

METHODS

This retrospective cohort study included 8,221 participants who were ≥20 years old, and who underwent esophagogastroduodenoscopy and coronary computed tomography (CT) scans during the same visit and subsequent CT scans between 2003 and 2013. RE was defined as the presence of at least Los Angeles classification grade A mucosal break. CT scan was used to determine the coronary artery calcium (CAC) scores. CAC progression was defined as an increase in the CAC score on a subsequent CT scan.

RESULTS

RE was present in 984 (12.0%) participants. RE at baseline was associated with CAC progression (odds ratio [OR], 1.253; 95% confidence interval [CI], 1.088-1.444; P = 0.002), and this association persisted after adjusting the model for age, sex, smoking status, and alcohol consumption (OR, 1.175; 95% CI, 1.001-1.378; P = 0.048). This association disappeared when the model was further adjusted for body mass index, diastolic blood pressure, the presence of hypertension, glycated hemoglobin, low-density lipoprotein cholesterol, and triglycerides (OR, 1.088; 95% CI, 0.924-1.281; P = 0.311) which were selected using a stepwise selection procedure from several metabolic variables.

CONCLUSIONS

Our results suggest that the presence of RE is closely associated with CHD, even though RE is not a direct risk factor for CHD. Metabolic factors may play roles in CAC progression in individuals with RE.

Nonalcoholic Fatty Liver Disease and Coronary Artery Calcification in a Northern Chinese Population: a Cross Sectional Study

Nonalcoholic fatty liver disease (NAFLD) has become an emerging health issue with a high prevalence in general population. The cross-sectional study was performed to investigate the association between NAFLD and coronary artery calcification (CAC) in individuals from northern city of China. A total of 2345 participants aged ≥40 (1035 men and 1310 women) were selected from the Jidong community of Tangshan city. Liver ultrasonography was used to the diagnosis of NAFLD. A 64-slice CT scanner was used to determine coronary artery calcification score (CACS), with CACS > 0 defined to be the presence of CAC. The risk level of coronary heart disease (CHD) was graded by CACS according to the 4 commonly used thresholds in clinical practice (0, 10, 100, and 400 Agatston units). NAFLD was significantly associated with CAC (crude OR: 1.631, 95% CI: 1.295–2.053, adjusted OR: 1.348, 95% CI: 1.030–1.765). The association between NAFLD and increased risk level of CHD (Crude OR: 1.639 95% CI: 1.303–2.063; adjusted OR: 1.359 95% CI: 1.043–1.770) was observed. The associations between NAFLD and CAC or increased risk level of CHD were significant in female but not in male. Our finding further confirmed the association between NAFLD and CAC, especially in Asian population.

Relationship between the triglyceride glucose index and coronary artery calcification in Korean adults

BACKGROUND

The triglyceride glucose (TyG) index has been considered a simple surrogate marker of insulin resistance. However, few studies have investigated the relationship between the TyG index and coronary artery calcification (CAC). Thus, we investigated the relationship between the TyG index and CAC in healthy Korean adults.

METHODS

In total, 4319 participants who underwent cardiac computed tomography (CT) in a health promotion center were enrolled. Anthropometric profiles and multiple cardiovascular risk factors were measured. The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2], and the insulin resistance index of homeostasis model assessment (HOMA-IR) was estimated. The CAC was measured using multidetector CT, and CAC presence was defined as an Agatston score of >0.

RESULTS

All subjects were stratified into four groups based on their TyG indices. Significant differences were observed in cardiovascular parameters among the groups, and the prevalence of CAC significantly increased with increasing TyG index. In the logistic regression analysis after adjustment for multiple risk factors, the odds ratio for the prevalence of CAC, when comparing the highest and lowest quartiles of the TyG index was 1.95 (95% CI 1.23-3.11; P for trend = 0.01); the odds ratio for the prevalence of CAC, when comparing the highest and lowest quartiles of HOMA-IR was 1.64 (95% CI 1.12-2.40; P for trend = 0.04). In the receiver operating characteristics analysis, the TyG index was superior to HOMA-IR in predicting CAC.

CONCLUSION

The TyG index is more independently associated with the presence of coronary artery atherosclerosis than is HOMA-IR in healthy Korean adults.

Detection and quantification of coronary calcium from dual energy chest x-rays: Phantom feasibility study

PURPOSE

We have demonstrated the ability to identify coronary calcium, a reliable biomarker of coronary artery disease, using nongated, 2-shot, dual energy (DE) chest x-ray imaging. Here we will use digital simulations, backed up by measurements, to characterize DE calcium signals and the role of potential confounds such as beam hardening, x-ray scatter, cardiac motion, and pulmonary artery pulsation. For the DE calcium signal, we will consider quantification, as compared to CT calcium score, and visualization.

METHODS

We created stylized and anatomical digital 3D phantoms including heart, lung, coronary calcium, spine, ribs, pulmonary artery, and adipose. We simulated high and low kVp x-ray acquisitions with x-ray spectra, energy dependent attenuation, scatter, ideal detector, and automatic exposure control (AEC). Phantoms allowed us to vary adipose thickness, cardiac motion, etc. We used specialized dual energy coronary calcium (DECC) processing that includes corrections for scatter and beam hardening.

RESULTS

Beam hardening over a wide range of adipose thickness (0-30 cm) reduced the change in intensity of a coronary artery calcification (ΔI_CAC ) by < 3% in DECC images. Scatter correction errors of ±50% affected the calcium signal (ΔI_CAC ) in DECC images ±9%. If a simulated pulmonary artery fills with blood between exposures, it can give rise to a residual signal in DECC images, explaining pulmonary artery visibility in some clinical images. Residual misregistration can be mostly compensated by integrating signals in an enlarged region encompassing registration artifacts. DECC calcium score compared favorably to CT mass and volume scores over a number of phantom perturbations.

CONCLUSION

Simulations indicate that proper DECC processing can faithfully recover coronary calcium signals. Beam hardening, errors in scatter estimation, cardiac motion, calcium residual misregistration etc., are all manageable. Simulations are valuable as we continue to optimize DE coronary calcium image processing and quantitative analysis.

Extracellular Vesicles in Metabolic Syndrome

Metabolic syndrome defines a cluster of interrelated risk factors for cardiovascular disease and diabetes mellitus. These factors include metabolic abnormalities, such as hyperglycemia, elevated triglyceride levels, low high-density lipoprotein cholesterol levels, high blood pressure, and obesity, mainly central adiposity. In this context, extracellular vesicles (EVs) may represent novel effectors that might help to elucidate disease-specific pathways in metabolic disease. Indeed, EVs (a terminology that encompasses microparticles, exosomes, and apoptotic bodies) are emerging as a novel mean of cell-to-cell communication in physiology and pathology because they represent a new way to convey fundamental information between cells. These microstructures contain proteins, lipids, and genetic information able to modify the phenotype and function of the target cells. EVs carry specific markers of the cell of origin that make possible monitoring their fluctuations in the circulation as potential biomarkers inasmuch their circulating levels are increased in metabolic syndrome patients. Because of the mixed components of EVs, the content or the number of EVs derived from distinct cells of origin, the mode of cell stimulation, and the ensuing mechanisms for their production, it is difficult to attribute specific functions as drivers or biomarkers of diseases. This review reports recent data of EVs from different origins, including endothelial, smooth muscle cells, macrophages, hepatocytes, adipocytes, skeletal muscle, and finally, those from microbiota as bioeffectors of message, leading to metabolic syndrome. Depicting the complexity of the mechanisms involved in their functions reinforce the hypothesis that EVs are valid biomarkers, and they represent targets that can be harnessed for innovative therapeutic approaches.

Obesity, metabolic syndrome and cardiovascular prognosis: from the Partners coronary computed tomography angiography registry

Objective

To investigate the relationship among body mass index (BMI), cardiometabolic risk and coronary artery disease (CAD) among patients undergoing coronary computed tomography angiography (CTA).

Methods

Retrospective cohort study of 1118 patients, who underwent coronary CTA at two centers from September 2004 to October 2011. Coronary CTA were categorized as normal, nonobstructive CAD (<50%), or obstructive CAD (≥50%) in addition to segment involvement (SIS) and stenosis scores. Extensive CAD was defined as SIS > 4. Association of BMI with cardiovascular prognosis was evaluated using multivariable fractional polynomial models.

Results

Mean age of the cohort was 57 ± 13 years with median follow-up of 3.2 years. Increasing BMI was associated with MetS (OR 1.28 per 1 kg/m², p < 0.001) and burden of CAD on a univariable basis, but not after multivariable adjustment. Prognosis demonstrated a J-shaped relationship with BMI. For BMI from 20–39.9 kg/m², after adjustment for age, gender, and smoking, MetS (HR 2.23, p = 0.009) was more strongly associated with adverse events.

Conclusions

Compared to normal BMI, there was an increased burden of CAD for BMI > 25 kg/m². Within each BMI category, metabolically unhealthy patients had greater extent of CAD, as measured by CCTA, compared to metabolically healthy patients.