Epicardial adipose tissue density and volume are related to subclinical atherosclerosis, inflammation and major adverse cardiac events in asymptomatic subjects

COVID-19 cardiac injury: Implications for long-term surveillance and outcomes in survivors

Up to 20%-30% of patients hospitalized with coronavirus disease 2019 (COVID-19) have evidence of myocardial involvement. Acute cardiac injury in patients hospitalized with COVID-19 is associated with higher morbidity and mortality. There are no data on how acute treatment of COVID-19 may affect the convalescent phase or long-term cardiac recovery and function. Myocarditis from other viral pathogens can evolve into overt or subclinical myocardial dysfunction, and sudden death has been described in the convalescent phase of viral myocarditis. This raises concerns for patients recovering from COVID-19. Some patients will have subclinical and possibly overt cardiovascular abnormalities. Patients with ostensibly recovered cardiac function may still be at risk of cardiomyopathy and cardiac arrhythmias. Screening for residual cardiac involvement in the convalescent phase for patients recovered from COVID-19-associated cardiac injury is needed. The type of testing and therapies for post COVID-19 myocardial dysfunction will need to be determined. Therefore, now is the time to plan for appropriate registries and clinical trials to properly assess these issues and prepare for long-term sequelae of "post-COVID-19 cardiac syndrome."

Relationship between changes in pericoronary adipose tissue attenuation and coronary plaque burden quantified from coronary computed tomography angiography

AIMS

Increased attenuation of pericoronary adipose tissue (PCAT) around the proximal right coronary artery (RCA) from coronary computed tomography angiography (CTA) has been shown to be associated with coronary inflammation and improved prediction of cardiac death over plaque features. Our aim was to investigate whether PCAT CT attenuation is related to progression of coronary plaque burden.

METHODS AND RESULTS

We analysed CTA studies of 111 stable patients (age 59.2 ± 9.8 years, 77% male) who underwent sequential CTA (3.4 ± 1.6 years between scans) with identical acquisition protocols. Total plaque (TP), calcified plaque (CP), non-calcified plaque (NCP), and low-density non-calcified plaque (LD-NCP) volumes and corresponding burden (plaque volume × 100%/vessel volume) were quantified using semi-automated software. PCAT CT attenuation (HU) was measured around the proximal RCA, the most standardized method for PCAT analysis. Patients with an increase in NCP burden (n = 51) showed an increase in PCAT attenuation, whereas patients with a decrease in NCP burden (n = 60) showed a decrease {4.4 [95% confidence interval (CI) 2.6-6.2] vs. -2.78 (95% CI -4.6 to -1.0) HU, P < 0.0001}. Changes in PCAT attenuation correlated with changes in the burden of NCP (r = 0.55, P < 0.001) and LD-NCP (r = 0.24, P = 0.01); but not CP burden (P = 0.3). Increased baseline PCAT attenuation ≥-75 HU was independently associated with increase in NCP (odds ratio 3.07, 95% CI 1.4-7.0; P < 0.008) and TP burden on follow-up CTA.

CONCLUSION

PCAT attenuation measured from routine CTA is related to the progression of NCP and TP burden. This imaging biomarker may help to identify patients at increased risk of high-risk plaque progression and allow monitoring of beneficial changes from medical therapy.

Obesity as a Potential Predictor of Disease Severity in Young COVID-19 Patients: A Retrospective Study

OBJECTIVE

This study aims to explore the indicators for severity of coronavirus disease 2019 (COVID-19) in young patients between the ages of 18 and 40 years.

METHODS

This retrospective cohort study included 65 consecutively admitted patients with COVID-19 who were between 18 and 40 years old in Zhongnan Hospital of Wuhan University in Wuhan, China. Among them, 53 were moderate cases, and 12 were severe or critical cases. Epidemiological, clinical, and laboratory characteristics and treatment data were collected. A multivariate logistic regression analysis was implemented to explore risk factors.

RESULTS

The patients with severe/critical cases had obviously higher BMI (average 29.23 vs. 22.79 kg/m² ) and lower liver computed tomography value (average 50.00 vs. 65.00 mU) than the group of moderate cases. The patients with severe/critical cases had higher fasting glucose, alanine aminotransferase, aspartate aminotransferase, and creatinine compared with patients with moderate cases (all P < 0.01). More severe/critical cases (58.33% vs. 1.92%) had positive urine protein levels. The severe/critical cases also experienced a significant process of serum albumin decline. Logistic regression analysis showed that male sex, high BMI (especially obesity), elevated fasting blood glucose, and urinary protein positivity were all risk factors for young patients with severe COVID-19.

CONCLUSIONS

Obesity is an important predictor of COVID-19 severity in young patients. The main mechanism is related to damage of the liver and kidney.

COVID-19 and cardiac injury: clinical manifestations, biomarkers, mechanisms, diagnosis, treatment, and follow up

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has the characteristics of high transmission, diverse clinical manifestations, and a long incubation period. In addition to infecting the respiratory system, COVID-19 also has adverse effects on the cardiovascular system. COVID-19 causes acute myocardial injuries, as well as chronic damage to the cardiovascular system.

AREAS COVERED

The present review is aimed at providing current information on COVID-19 and the cardiovascular system. PubMed, Scopus, Science direct, and Google Scholar were searched.

EXPERT OPINION

It is suggested that heart injury caused by COVID-19 infection might be an important cause of severe clinical phenotypes or adverse events in affected patients. Myocardial damage is closely related to the severity of the disease and even the prognosis in patients with COVID-19. In addition to disorders that are caused by COVID-19 on the cardiovascular system, more protection should be employed for patients with preexisting cardiovascular disease (CVD). Hence, it is very important that once relevant symptoms appear, patients with COVID-19 be rapidly treated to reduce mortality. Thus, early measurements of cardiac damage via biomarkers following hospitalization for COVID-19 infections in a patient with preexisting CVD are recommended, together with careful monitoring of any myocardial injury that might be caused by the infection.Abbreviations: ICU: An intensive care unit; 2019-nCoV: 2019 novel coronavirus; ACEI: ACE inhibitor; ACS: Acute coronary syndrome; ARDS: Acute respiratory distress syndrome; AT₁R: Ang II type 1 receptor; ATP: Adenosine triphosphate; ACC: American College of Cardiology; ACE: Angiotensin converting enzyme; Ang II: Angiotensin II; ARB: Angiotensin II receptor blocker; AV block: Atrioventricular block; CAD: Coronary artery disease; CVD: Cardiovascular disease; CT: Computerized tomography; CHF: Congestive heart failure; CHD: Coronary heart disease; CK-MB: Creatine kinase isoenzyme-MB; CRP: C-reactive protein; cTnI: Cardiac troponin I; EAT: Epicardial adipose tissue; ECMO: Extracorporeal membrane oxygenation; FDA: Food and Drug Administration; G-CSF: Granulocyte colony-stimulating factor; HFrEF: HF with a reduced ejection fraction; synhACE2: Human isoform of ACE2; IL: Interleukin; IABP: Intra-aortic balloon counterpulsation; IP10: Interferon γ-induced protein 10 kDa; LPC: Lysophosphatidylcholine; Mas: Mitochondrial assembly receptor; MCP1: Monocyte chemoattractant protein-1; MERS: Middle East respiratory syndrome; MIP1a: macrophage inflammatory protein 1a: MOF: Multiple organ failure; MI: Myocardial infarction; MRI: Magnetic resonance imaging; MYO: Myohe-moglobin; NT-proBNP: N-terminal pro-brain natriuretic peptide; PCPS: Percutaneous cardiopulmonary assistance; rhACE2: Recombinant human ACE2; SARS: Severe acute respiratory syndrome; Th: T helper; RAS: Renin-angiotensin system; TNF-α: Tumor necrosis factor-α; WHO: World Health Organization.

Epicardial fat attenuation, not volume, predicts obstructive coronary artery disease and high risk plaque features in patients with atypical chest pain

OBJECTIVE

This study sought to investigate the association between volume and attenuation of epicardial fat and presence of obstructive coronary artery disease (CAD) and high-risk plaque features (HRPF) on CT angiography (CTA) in patients with atypical chest pain and whether the association, if any, is independent of conventional cardiovascular risk factors and coronary artery calcium score (CACS).

METHODS

Patients referred for coronary CTA with atypical chest pain and clinical suspicion of CAD were included in the study. Quantification of CACS, epicardial fat volume (EFV) and epicardial fat attenuation (EFat) was performed on non-contrast images. CTA was evaluated for presence of obstructive CAD and presence of HRPF.

RESULTS

255 patients (median age [interquartile range; IQR]: 51[41-60] years, 51.8% males) were included. On CTA, CAD, obstructive CAD (≥50% stenosis) and CTA-derived HRPFs was present in 133 (52.2%), 37 (14.5%) and 82 (32.2%) patients respectively. A significantly lower EFat was seen in patients with obstructive CAD than in those without (-86HU [IQR:-88 to -82 HU] vs -84 [IQR:-87 HU to -82 HU]; p = 0.0486) and in patients with HRPF compared to those without (-86 HU [IQR:-88 to -83 HU] vs -83 HU [-86 HU to -81.750 HU]; p < 0.0001). EFat showed significant association with obstructive CAD (unadjusted Odd's ratio (OR) [95% CI]: 0.90 [0.81-0.99];p = 0.0248) and HRPF (unadjusted OR [95% CI]: 0.83 [0.76-0.90];p < 0.0001) in univariate analysis, which remained significant in multivariate analysis. However, EFV did not show any significant association with neither obstructive CAD nor HRPF in multivariate analysis. Adding EFat to conventional coronary risk factors and CACS in the pre-test probability models increased the area-under curve (AUC) for prediction of both obstructive CAD (AUC[95% CI]: 0.76 [0.70-0.81] vs 0.71 [0.65-0.77)) and HRPF (AUC [95% CI]: 0.92 [0.88-0.95] vs 0.89 [0.85-0.93]), although not reaching statistical significance.

CONCLUSION

EFat, but not EFV, is an independent predictor of obstructive CAD and HRPF. Addition of EFat to traditional cardiovascular risk factors and CACS improves estimation for pretest probability of obstructive CAD and HRPF.

ADVANCES IN KNOWLEDGE

EFat is an important attribute of epicardial fat as it reflects the "quality" of fat, taking into account the effects of brown-white fat transformation and fibrosis, as opposed to mere evaluation of "quantity" of fat by EFV. Our study shows that EFat is a better predictor of obstructive CAD and HRPF than EFV and can thus explain the inconsistent association of increased EFV alone with CAD.

Thickness of epicardial and pericoronary adipose tissue measured using 128-slice MSCT as predictors for risk of significant coronary artery diseases

Aim

Determination the relationship between the epicardial adipose tissue thickness (EATT) and pericoronary adipose tissue thickness (PATT) and the risk of significant coronary artery diseases (CAD) using the coronary artery calcium score (CACS).

Materials and methods

The study group consisted of 80 patients. The risk of significant CAD was estimated based on CACS. Adipose tissue thickness was measured based on multiplanar reformation (MPR), left ventricle short axis and mid-chamber level. EATT in the middle of the length of the right ventricular free wall, PATT around the left anterior descending (LAD), around the left circumflex (LCX) and around the right coronary artery in the posterior interventricular sulcus (RCA).

Results

The median (IQR) values of CACS and EATT were 12.00 (97.90) and 8.65 (3.90) mm. It was found that in the subgroup CACS = 0 statistically significantly lower than in the subgroup CACS > 0 were mean values EATT and PATT RCA. Based on the regression analysis, it was demonstrated that higher CACS is associated with higher EATT, independent of older age and higher BMI. On the basis the ROC curve analysis, the highest prediction sensitivity of 98.4% was demonstrated for EATT ≥ 16.7 mm as a predictor of high risk of significant CAD and the highest specificity of 61.5% for the criterion EATT ≤ 8.7 mm as a predictor of practically no risk of significant CAD.

Conclusion

There is a positive relationship between the risk of a significant CAD estimated based on the coronary artery calcium score and the epicardial adipose tissue thickness.

Towards reference values of pericoronary adipose tissue attenuation: impact of coronary artery and tube voltage in coronary computed tomography angiography

Objectives

To determine normal pericoronary adipose tissue mean attenuation (PCAT_MA) values for left the anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) in patients without plaques on coronary CT angiography (cCTA), taking into account tube voltage influence.

Methods

This retrospective study included 192 patients (76 (39.6%) men; median age 49 years (range, 19–79)) who underwent cCTA with third-generation dual-source CT for the suspicion of CAD between 2015 and 2017. We selected patients without plaque on cCTA. PCAT_MA was measured semi-automatically on cCTA images in the proximal segment of the three main coronary arteries with 10 mm length. Paired t-testing was used to compare PCAT_MA between combinations of two coronary arteries within each patient, and one-way ANOVA testing was used to compare PCAT_MA in different kV groups.

Results

The overall mean ± standard deviation (SD) PCAT_MA was − 90.3 ± 11.1 HU. PCAT_MA in men was higher than that in women: − 88.5 ± 10.5 HU versus − 91.5 ± 11.3 HU (p = 0.001). PCAT_MA of LAD, LCX, and RCA was − 92.4 ± 11.6 HU, − 88.4 ± 9.9 HU, and − 90.2 ± 11.4 HU, respectively. Pairwise comparison of the arteries showed significant difference in PCAT_MA: LAD and LCX (p < 0.001), LAD and RCA (p = 0.009), LCX and RCA (p = 0.033). PCAT_MA of the 70 kV, 80 kV, 90 kV, 100 kV, and 120 kV groups was − 95.6 ± 9.6 HU, − 90.2 ± 11.5 HU, − 87.3 ± 9.9 HU, − 82.7 ± 6.2 HU, and − 79.3 ± 6.8 HU, respectively (p < 0.001).

Conclusions

In patients without plaque on cCTA, PCAT_MA varied by tube voltage, with minor differences in PCAT_MA between coronary arteries (LAD, LCX, RCA). PCAT_MA values need to be interpreted taking into account tube voltage setting.

Key Points

• In patients without plaque on cCTA, PCAT_MAdiffers slightly by coronary artery (LAD, LCX, RCA).

• Tube voltage of cCTA affects PCAT_MAmeasurement, with mean PCAT_MAincreasing linearly with increasing kV.

• For longitudinal cCTA analysis of PCAT_MA, the use of equal kV setting is strongly recommended.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07069-0) contains supplementary material, which is available to authorized users.

Association of plaque calcification pattern and attenuation with instability features and coronary stenosis and calcification grade

BACKGROUND AND AIMS

Coronary computed tomography (CT) allows calculating coronary artery calcium score (CACS). However, other CT features might be more strongly related to plaque vulnerability and risk of future coronary events. This study investigated the association of plaque calcification pattern and attenuation with plaque instability features, coronary artery disease (CAD) grade and CACS.

METHODS

One-hundred patients with coronary stenosis associated with calcified plaques were considered for this analysis. CACS, CAD grade, calcification pattern and attenuation, features of plaque instability, and epicardial adipose tissue (EAT) thickness and attenuation were assessed with non-contrast and contrast-enhanced CT angiography.

RESULTS

Of 373 calcified plaques, 131 were responsible for the highest degree of coronary stenosis (1.31 ± 0.53 per patient). Participants were stratified according to the features of the highest-grade lesion(s) into patients with large (35%), spotty (52%) or mixed (13%) calcification pattern and tertiles of plaque calcification attenuation (using the mean value for multiple lesions). Patients with large calcification pattern or higher plaque calcification attenuation had higher stenosis and CACS grade (and EAT attenuation), but lower plaque instability score, whereas those with spotty calcification pattern or lower plaque calcification attenuation had lower stenosis and CACS grade (and EAT attenuation), but higher plaque instability score. Among the instability features, low attenuation and napkin-ring sign, but not positive remodeling, were associated with a spotty pattern and a lower calcification attenuation.

CONCLUSIONS

Both the pattern and attenuation of calcification should be considered, in addition to CACS, for risk stratification of heavily calcified high-risk patients with non-critical coronary stenosis.

The Natural history of Epicardial Adipose Tissue Volume and Attenuation: A long-term prospective cohort follow-up study

Epicardial adipose tissue (EAT) is associated with cardiovascular risk. The longitudinal change in EAT volume (EATv) and density (EATd), and potential modulators of these parameters, has not been described. We prospectively recruited 90 patients with non-obstructive coronary atherosclerosis on baseline computed tomography coronary angiography (CTCA) performed for suspected coronary artery disease to undergo a repeat research CTCA. EATv in millilitres (mL) and EATd in Hounsfield units (HU) were analysed and multivariable regression analysis controlling for traditional cardiovascular risk factors (CVRF) performed to assess for any predictors of change. Secondary analysis was performed based on statin therapy. The median duration between CTCA was 4.3years. Mean EATv increased at follow-up (72 ± 33 mL to 89 ± 43 mL, p < 0.001) and mean EATd decreased (baseline −76 ± 6 HU vs. −86 ± 5 HU, p < 0.001). There were no associations between baseline variables of body mass index, age, sex, hypertension, hyperlipidaemia, diabetes or smoking on change in EATv or EATd. No difference in baseline, follow-up or delta EATv or EATd was seen in patients with (60%) or without baseline statin therapy. In this select group of patients, EATv consistently increased and EATd consistently decreased at long-term follow-up and these changes were independent of CVRF, age and statin use. Together with the knowledge of strong associations between EAT and cardiac disease, these findings may suggest that EAT is an independent parameter rather than a surrogate for cardiovascular risk.

Effects of epicardial adipose tissue volume and density on cardiac structure and function in patients free of coronary artery disease

PURPOSE

To determine the association of epicardial adipose tissue (EAT) volume and density with cardiac geometry and function.

METHODS

We included 178 consecutive patients who performed coronary computed tomography angiography but were not diagnosed with coronary artery disease (CAD). The EAT volume, density, and following cardiac structure and function parameters were measured: left ventricular ejection fraction, left ventricular mass (LVM), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSV), left ventricular end-diastolic diameter (LVEDD), interventricular septal thickness (IVST) and posterior wall thickness (PWT). All the parameters were standardized using the height^2.7.

RESULTS

A significant correlation was found between larger EAT volume and increased LVM, LVEDV, LVESV, LVSV, LVEDD, IVST and corresponding standardized indexes (P < 0.05 for all). Higher EAT density significantly correlated with increased LVM, LVEDV, LVESV, LVSV, LVEDD, IVST, PWT and corresponding standardized indexes (P < 0.05 for all). The largest cardiac structure and function parameters were observed in the population with above-median EAT volume and density.

CONCLUSION

Both large EAT volume and high EAT density were associated with cardiac structure and function in patients with no CAD. The EAT density may render complementary information to EAT volume regarding cardiac geometry changes.

Deep Learning-Based Quantification of Epicardial Adipose Tissue Volume and Attenuation Predicts Major Adverse Cardiovascular Events in Asymptomatic Subjects

BACKGROUND

Epicardial adipose tissue (EAT) volume (cm³) and attenuation (Hounsfield units) may predict major adverse cardiovascular events (MACE). We aimed to evaluate the prognostic value of fully automated deep learning-based EAT volume and attenuation measurements quantified from noncontrast cardiac computed tomography.

METHODS

Our study included 2068 asymptomatic subjects (56±9 years, 59% male) from the EISNER trial (Early Identification of Subclinical Atherosclerosis by Noninvasive Imaging Research) with long-term follow-up after coronary artery calcium measurement. EAT volume and mean attenuation were quantified using automated deep learning software from noncontrast cardiac computed tomography. MACE was defined as myocardial infarction, late (>180 days) revascularization, and cardiac death. EAT measures were compared to coronary artery calcium score and atherosclerotic cardiovascular disease risk score for MACE prediction.

RESULTS

At 14±3 years, 223 subjects suffered MACE. Increased EAT volume and decreased EAT attenuation were both independently associated with MACE. Atherosclerotic cardiovascular disease risk score, coronary artery calcium, and EAT volume were associated with increased risk of MACE (hazard ratio [95%CI]: 1.03 [1.01-1.04]; 1.25 [1.19-1.30]; and 1.35 [1.07-1.68], P<0.01 for all) and EAT attenuation was inversely associated with MACE (hazard ratio, 0.83 [95% CI, 0.72-0.96]; P=0.01), with corresponding Harrell C statistic of 0.76. MACE risk progressively increased with EAT volume ≥113 cm³ and coronary artery calcium ≥100 AU and was highest in subjects with both (P<0.02 for all). In 1317 subjects, EAT volume was correlated with inflammatory biomarkers C-reactive protein, myeloperoxidase, and adiponectin reduction; EAT attenuation was inversely related to these biomarkers.

CONCLUSIONS

Fully automated EAT volume and attenuation quantification by deep learning from noncontrast cardiac computed tomography can provide prognostic value for the asymptomatic patient, without additional imaging or physician interaction.

Pericoronary adipose tissue and quantitative global non-calcified plaque characteristics from CT angiography do not differ in matched South Asian, East Asian and European-origin Caucasian patients with stable chest pain

PURPOSE

South Asian (SA) have been observed to have higher cardiovascular mortality rates compared to East Asians (EA) and Caucasians. Pericoronary adipose tissue (PCAT) attenuation around the right coronary artery (RCA) from coronary CT angiography (CTA) has been associated with coronary inflammation and cardiac death. We aimed to investigate i) the relationship between plaque characteristics and PCAT attenuation and ii) to assess gender and ethnic differences in PCAT attenuation using a matched cohort of SA, EA and Caucasians.

METHOD

Three-hundred symptomatic patients who underwent CTA were matched for age, gender, BMI and diabetes (100 in each ethnic group). Semi-automated software was used to quantify the total volumes and burden of non-calcified plaque (NCP), low-density non-calcified plaque (LD-NCP) and calcified plaque (CP) in blinded core-lab analysis. PCAT CT attenuation was measured around the RCA (10-50 mm from RCA ostium), the most standardized model for PCAT analysis.

RESULTS

The total volumes and burden of NCP, LD-NCP and CP were comparable in the ethnic groups (each p > 0.05). PCAT attenuation was higher in patients with coronary plaque. PCAT attenuation correlated with the total volumes and burden of NCP, LD-NCP and CP (r>0.17; p < 0.003). Within the RCA this correlation persisted only for NCP features (r>0.39;p < 0.001). Males showed higher PCAT attenuation (p < 0.001). PCAT attenuation was similar between Caucasian, EA and SA (p = 0.32).

CONCLUSIONS

PCAT CT attenuation correlated most with its surrounded NCP features further highlighting its role as surrogate measure of coronary inflammation. As coronary plaque burden and RCA PCAT attenuation did not differ between ethnic groups, causes of increased cardiac mortality in South Asians needs further investigations.

Novel imaging biomarkers: epicardial adipose tissue evaluation

Epicardial adipose tissue (EAT) is a metabolically activated beige adipose tissue, non-homogeneously surrounding the myocardium. Physiologically, EAT regulates toxic fatty acids, protects the coronary arteries against mechanical strain, regulates proinflammatory cytokines, stimulates the production of nitric oxide, reduces oxidative stress, and works as a thermogenic source against hypothermia. Conversely, EAT has pathologic paracrine interactions with the surrounded vessels, and might favour the onset of atrial fibrillation. In addition, initial atherosclerotic lesions can promote inflammation and trigger the EAT production of cytokines increasing vascular inflammation, which, in turn, may help the development of collateral vessels but also of self-stimulating, dysregulated inflammatory process, increasing coronary artery disease severity. Variations in EAT were also linked to metabolic syndrome. Echocardiography first estimated EAT measuring its thickness on the free wall of the right ventricle but does not allow accurate volumetric EAT estimates. Cardiac CT (CCT) and cardiac MR (CMR) allow for three-dimensional EAT estimates, the former showing higher spatial resolution and reproducibility but being limited by radiation exposure and long segmentation times, the latter being radiation-free but limited by lower spatial resolution and reproducibility, higher cost, and difficulties for obese patients. EAT radiodensity at CCT could to be related to underlying metabolic processes. The correlation between EAT and response to certain pharmacological therapies has also been investigated, showing promising results. In the future, semi-automatic or fully automatic techniques, machine/deep-learning methods, if validated, will facilitate research for various EAT measures and may find a place in CCT/CMR reporting.

Fully Automated CT Quantification of Epicardial Adipose Tissue by Deep Learning: A Multicenter Study

Purpose

To evaluate the performance of deep learning for robust and fully automated quantification of epicardial adipose tissue (EAT) from multicenter cardiac CT data.

Materials and Methods

In this multicenter study, a convolutional neural network approach was trained to quantify EAT on non-contrast material-enhanced calcium-scoring CT scans from multiple cohorts, scanners, and protocols (n = 850). Deep learning performance was compared with the performance of three expert readers and with interobserver variability in a subset of 141 scans. The deep learning algorithm was incorporated into research software. Automated EAT progression was compared with expert measurements for 70 patients with baseline and follow-up scans.

Results

Automated quantification was performed in a mean (± standard deviation) time of 1.57 seconds ± 0.49, compared with 15 minutes for experts. Deep learning provided high agreement with expert manual quantification for all scans (R = 0.974; P < .001), with no significant bias (0.53 cm³; P = .13). Manual EAT volumes measured by two experienced readers were highly correlated (R = 0.984; P < .001) but with a bias of 4.35 cm³ (P < .001). Deep learning quantifications were highly correlated with the measurements of both experts (R = 0.973 and R = 0.979; P < .001), with significant bias for reader 1 (5.11 cm³; P < .001) but not for reader 2 (0.88 cm³; P = .26). EAT progression by deep learning correlated strongly with manual EAT progression (R = 0.905; P < .001) in 70 patients, with no significant bias (0.64 cm³; P = .43), and was related to an increased noncalcified plaque burden quantified from coronary CT angiography (5.7% vs 1.8%; P = .026).

Conclusion

Deep learning allows rapid, robust, and fully automated quantification of EAT from calcium scoring CT. It performs as well as an expert reader and can be implemented for routine cardiovascular risk assessment.© RSNA, 2019See also the commentary by Schoepf and Abadia in this issue.

Perivascular Adipose Tissue and Coronary Atherosclerosis: from Biology to Imaging Phenotyping

PURPOSE OF REVIEW

Perivascular adipose tissue (PVAT) has a complex, bidirectional relationship with the vascular wall. In disease states, PVAT secretes pro-inflammatory adipocytokines which may contribute to atherosclerosis. Recent evidence demonstrates that pericoronary adipose tissue (PCAT) may also function as a sensor of coronary inflammation. This review details PVAT biology and its clinical translation to current imaging phenotyping.

RECENT FINDINGS

PCAT attenuation derived from routine coronary computed tomography (CT) angiography is a novel noninvasive imaging biomarker of coronary inflammation. Pro-inflammatory cytokines released from the arterial wall diffuse directly into the surrounding PCAT and inhibit adipocyte lipid accumulation in a paracrine manner. This can be detected as an increased PCAT CT attenuation, a metric which associates with high-risk plaque features and independently predicts cardiac mortality. There is also evidence that PCAT attenuation relates to coronary plaque progression and is modified by systemic anti-inflammatory therapies. Due to its proximity to the coronary arteries, PCAT has emerged as an important fat depot in cardiovascular research. PCAT CT attenuation has the potential to improve cardiovascular risk stratification, and future clinical studies should examine its role in guiding targeted medical therapy.

Future Directions in Coronary CT Angiography: CT-Fractional Flow Reserve, Plaque Vulnerability, and Quantitative Plaque Assessment

Coronary computed tomography angiography (CCTA) is a well-validated and noninvasive imaging modality for the assessment of coronary artery disease (CAD) in patients with stable ischemic heart disease and acute coronary syndromes (ACSs). CCTA not only delineates the anatomy of the heart and coronary arteries in detail, but also allows for intra- and extraluminal imaging of coronary arteries. Emerging technologies have promoted new CCTA applications, resulting in a comprehensive assessment of coronary plaques and their clinical significance. The application of computational fluid dynamics to CCTA resulted in a robust tool for noninvasive assessment of coronary blood flow hemodynamics and determination of hemodynamically significant stenosis. Detailed evaluation of plaque morphology and identification of high-risk plaque features by CCTA have been confirmed as predictors of future outcomes, identifying patients at risk for ACSs. With quantitative coronary plaque assessment, the progression of the CAD or the response to therapy could be monitored by CCTA. The aim of this article is to review the future directions of emerging applications in CCTA, such as computed tomography (CT)-fractional flow reserve, imaging of vulnerable plaque features, and quantitative plaque imaging. We will also briefly discuss novel methods appearing in the coronary imaging scenario, such as machine learning, radiomics, and spectral CT.

Proteomics of epicardial adipose tissue in patients with heart failure

Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot closely linked to the pathogenesis of heart failure (HF). But the molecular signatures related to the mechanism of HF have not been systematically explored. Here, we present comprehensive proteomic analysis of EAT in HF patients and non‐HF patients as controls. A total of 771 proteins were identified in liquid chromatography‐tandem mass spectrometry experiments. Amongst them, 17 increased in abundance in HF and seven decreased. They were involved in HF‐related processes including inflammation and oxidative stress response and lipid metabolism. Of these proteins, serine proteinase inhibitor A3 (Serpina3) levels in EAT were highly up‐regulated in HF, with HF/non‐HF ratio of 4.63 (P = .0047). Gene expression of Serpina3 via quantitative polymerase chain reaction was significantly increased in the HF group. ELISA analysis confirmed a significant increase in circulating plasma Serpina3 levels in the HF group (P = .004). In summary, for the first time, we describe that parts of EAT proteome may be reactive and work as modulators of HF. Our profiling provides a comprehensive basis for linking EAT with pathogenesis of HF. Understanding the role of EAT may offer new insights into the treatment of HF.

Epicardial adipose tissue predicts incident cardiovascular disease and mortality in patients with type 2 diabetes

Background

Cardiac fat is a cardiovascular biomarker but its importance in patients with type 2 diabetes is not clear. The aim was to evaluate the predictive potential of epicardial (EAT), pericardial (PAT) and total cardiac (CAT) fat in type 2 diabetes and elucidate sex differences.

Methods

EAT and PAT were measured by echocardiography in 1030 patients with type 2 diabetes. Follow-up was performed through national registries. The end-point was the composite of incident cardiovascular disease (CVD) and all-cause mortality. Analyses were unadjusted (model 1), adjusted for age and sex (model 2), plus systolic blood pressure, body mass index (BMI), low-density lipoprotein (LDL), smoking, diabetes duration and glycated hemoglobin (HbA_1c) (model 3).

Results

Median follow-up was 4.7 years and 248 patients (191 men vs. 57 women) experienced the composite end-point. Patients with high EAT (> median level) had increased risk of the composite end-point in model 1 [Hazard ratio (HR): 1.46 (1.13; 1.88), p = 0.004], model 2 [HR: 1.31 (1.01; 1.69), p = 0.038], and borderline in model 3 [HR: 1.32 (0.99; 1.77), p = 0.058]. For men, but not women, high EAT was associated with a 41% increased risk of CVD and mortality in model 3 (p = 0.041). Net reclassification index improved when high EAT was added to model 3 (19.6%, p = 0.035). PAT or CAT were not associated with the end-point.

Conclusion

High levels of EAT were associated with the composite of incident CVD and mortality in patients with type 2 diabetes, particularly in men, after adjusting for CVD risk factors. EAT modestly improved risk prediction over CVD risk factors.

Osteocalcin and epicardial adipose tissue in obesity: new hints for epicardial adipose tissue-bone crosstalk

Objectives: Osteocalcin (OC) appears to be involved in the regulation of glucose and fat metabolism. We aimed to determine the association between OC and epicardial adipose tissue (EAT) in premenopausal obese women. Design: The study included 73 premenopausal obese women and 55 non-obese women. Echocardiographic examination was performed to measure EAT. Serum OC levels were measured by chemiluminescence immunoassay. Results: OC levels were significantly lower in obese women than controls (18.26 ± 5.27 vs. 22.53 ± 6.84 ng/ml, p < .001). EAT thickness was higher in obese women than controls (5.19 ± 0.73 vs. 3.25 ± 1.35 mm, p < .001). In obese women, OC was positively correlated with EAT thickness (p = .043; r = 0.326). There was no correlation in controls. Conclusions: Premenopausal obese women had lower OC levels and thicker EAT than controls. There was a weak positive correlation between OC and EAT in premenopausal obese women. This potential cross talk between bone metabolism and EAT could play a role in the development of atherosclerosis in obesity.

Dietary patterns influence epicardial adipose tissue fatty acid composition and inflammatory gene expression in the Ossabaw pig

Epicardial adipose tissue (EAT) inflammation is implicated in the development and progression of coronary atherosclerosis. Dietary saturated and polyunsaturated fatty acids (SFAs and PUFA) can influence adipose tissue inflammation. We investigated the influence of dietary patterns, with emphasis on dietary fat type, and statin therapy, on EAT fatty acid (FA) composition and inflammatory gene expression. Thirty-two Ossabaw pigs were fed isocaloric amounts of a Heart Healthy (high in unsaturated fat) or Western (high in saturated fat) diets +/- atorvastatin for 6 months. EAT FA composition reflected dietary fat composition. There was no significant effect of atorvastatin on EAT FA composition. Total and long-chain SFAs were positively associated with inflammatory signaling (TLR2) and a gene involved in lipid mediator biosynthesis (PTGS2) (P<.0003). Medium-chain SFAs capric and lauric acids were negatively associated with IL-6 (all P<.0003). N-6 and n-3 PUFAs were positively associated with anti-inflammatory signaling genes (PPARG, FFAR4 and ADIPOQ) and long-chain n-3 PUFAs were positively associated with a gene involved in lipid mediator biosynthesis (ALOX5) (all P<.0003). These data indicate that dietary patterns, differing in fat type, influence EAT FA composition. Associations between EAT SFAs, PUFAs, and expression of genes related to inflammation provide a link between dietary quality and EAT inflammation.

Relationship between epicardial adipose tissue and coronary vascular function in patients with suspected coronary artery disease and normal myocardial perfusion imaging

Aims

We evaluated the relationship between epicardial adipose tissue (EAT) and coronary vascular function assessed by rubidium-82 (82Rb) positron emission tomography/computed tomography (PET/CT) in patients with suspected coronary artery disease (CAD).

Methods and results

The study population included 270 patients with suspected CAD and normal myocardial perfusion at stress–rest 82Rb PET/CT. Coronary artery calcium (CAC) score and EAT volume were measured. Absolute myocardial blood flow (MBF) was computed in mL/min/ from the dynamic rest and stress imaging. Myocardial perfusion reserve (MPR) was defined as the ratio of hyperaemic to baseline MBF and it was considered reduced when <2. MPR was normal in 177 (65%) patients and reduced in 93 (35%). Patients with impaired MPR were older (P < 0.001) and had higher CAC score values (P = 0.033), EAT thickness (P = 0.009), and EAT volume (P < 0.001). At univariable logistic regression analysis, age, heart rate reserve (HRR), CAC score, EAT thickness, and EAT volume resulted significant predictors of reduced MPR, but only age (P = 0.002), HRR (P = 0.021), and EAT volume (P = 0.043) were independently associated with reduced MPR, at multivariable analysis. In patients with CAC score 0 (n = 114), a significant relation between EAT volume and MPR (P = 0.014) was observed, while the relationship was not significant (P = 0.21) in patients with CAC score >0 (n = 156).

Conclusion

In patients with suspected CAD and normal myocardial perfusion, EAT volume predicts hyperaemic MBF and reduced MPR, confirming that visceral pericardium fat may influence coronary vascular function. Thus, EAT evaluation has a potential role in the early identification of coronary vascular dysfunction.

Adherence to a healthy plant diet may reduce inflammatory factors in obese and overweight women-a cross-sectional study

OBJECTIVE

Obesity and overweight which are consequence of some interaction factor such as genetics and behavioral habit. Obesity as a metabolic disorder and chronic inflammation is a trigger to countless disease. The main goal of this study is to investigate the interaction of herbal diet on the levels of liver enzymes, inflammatory factors and adipocytes profile.

MATERIALS AND METHODS

A total of 240 adult women range of 18-48 years were included in the current comparative cross-sectional study. Body composition and dietary intake (using a validated semi-quantitative food frequency questionnaire (FFQ)) were assessed in all participants. In determining a plant based diet index (PDI), vegetarian foods were taken positive score and reverse points for animal foods. For determining a healthful plant based diet index (hPDI), healthy plant foods received positive scores, while less healthy plant foods and animal foods received reverse scores. To create an unhealthful plant-based diet index (uPDI), positive scores were assigned to less healthy plant foods and reverse scores to healthy plant foods and animal foods. For the measurement of serum liver enzymes and inflammatory factors, an enzyme-linked immunosorbent assay (ELISA) method was used.

RESULTS

Healthy diet like whole grains, fruits, vegetables, cereals, and beverages such as tea and coffee, based on dietary guidelines, significantly reduced the amount of hs-CRP and TGF-β (P < 0.0001). Higher adhering to hPDI may as a result in higher intake of fiber intake, antioxidants, unsaturated fats, micronutrients, could reduce saturated fats and iron content, and finally weight loss, and reduce inflammation in the body.

CONCLUSION

Base on our finding, in those people who intake higher amounts of healthy plant foods, (vegetable types), instead of unhealthy herbal foods (sweets and desserts), might be useful to reduce inflammation factor like TGF-β and hs-CRP. Women with a higher compliance score in uPDI group (juices, refined grains, starches sweetened with sugar, sweets, and desserts) did not have significantly increase in inflammatory factors levels.

Statins Reduce Epicardial Adipose Tissue Attenuation Independent of Lipid Lowering: A Potential Pleiotropic Effect

Background

High epicardial adipose tissue (EAT) attenuation (Hounsfield units [HUs]) on computed tomography is considered a marker of inflammation and is associated with an increased risk of cardiovascular events. Statins reduce the volume of EAT, but it is unknown whether they affect EAT HUs.

Methods and Results

We reviewed the chest computed tomographic scans of 420 postmenopausal women randomized to either 80 mg of atorvastatin or 40 mg of pravastatin daily and rescanned after 1 year to measure change in coronary artery calcium score. EAT HUs were measured near the proximal right coronary artery and remote from any area of coronary artery calcium. Computed tomographic images were also queried for subcutaneous adipose tissue (SubQ) attenuation (HUs) change over time. The mean patients’ age was 65±6 years. The baseline EAT HU value was higher than the SubQ HU value (−89.4±24.0 HU versus −123.3±30.4 HU; P<0.001). The EAT HU value decreased significantly in the entire cohort (−5.4±29.7 HU [−6% change]; P<0.001), but equally in the patients given atorvastatin and pravastatin (−6.35+31 HU and −4.55+28 HU; P=0.55). EAT HU change was not associated with change in total cholesterol, low‐density lipoprotein cholesterol, coronary artery calcium, and EAT volume (all P=not significant). Change in high‐density lipoprotein cholesterol was marginally associated with EAT HU change (P=0.07). Statin treatment did not induce a change in SubQ HUs.

Conclusions

Statins induced a decrease in EAT HUs over time, independent of intensity of low‐density lipoprotein cholesterol lowering. The positive effect on EAT and the neutral effect on SubQ suggest that statins induced a decrease in metabolic activity in EAT by reduction in cellularity, vascularity, or inflammation. The clinical significance of the observed change in EAT HUs remains to be demonstrated.

Behind Traditional Semi-quantitative Scores of Myocardial Perfusion Imaging: An Eye on Niche Parameters

The evaluation of stress-induced myocardial perfusion defects by non-invasive myocardial perfusion imaging (MPI) modalities has a leading role in the identification of coronary artery disease, and has excellent diagnostic and prognostic value. Non-invasive MPI can be performed using conventional and novel gamma cameras or by PET/CT. New software has allowed novel parameters that may have a role in the identification of early marks of cardiac impairment to be evaluated. We aim to give an overview of niche parameters obtainable by single photon emission CT (SPECT) and PET/CT MPI that may help practitioners to detect initial signs of cardiac damage and identify new therapy targets. In particular, we summarise the role of left ventricular geometry indices for remodelling, phase analysis parameters to evaluate mechanical dyssynchrony, the concept of relative flow reserve in the evaluation of flow-limiting epicardial stenosis, vascular age and epicardial adipose tissue as early markers of atherosclerotic burden, and emerging parameters for the evaluation of myocardial innervation, such as the total defect score.

Emerging measurements of atherosclerosis: extra-media thickness, epicardial adipose tissue, and periarterial adipose tissue intima media adventitia index in morbidly obese patients undergoing bariatric surgery

Introduction

Increased values of emerging fat indices are correlated with increased cardiovascular risk.

Aim

To examine the novel non-invasive predictors of coronary disease, namely the carotid extra-media thickness (EMT), PATIMA, and epicardial adipose tissue (EAT), in a group of patients with morbid obesity.

Material and methods

We examined a group of 40 morbidly obese (OB) patients and a control group (CG). All patients were subjected to anthropometric measurements, as well as laboratory and ultrasound examinations.

Results

EATmean and EMTmean differed significantly between groups (OB vs. CG): 5.09 vs. 3.50 and 808.50 vs. 737.00, p < 0.0001, respectively.

Conclusions

Strong correlations were found between novel non-invasive predictors of coronary disease, namely the carotid extra-media thickness, PATIMA, and epicardial adipose tissue. The above-mentioned fat indices were not found to correlate significantly with BMI or other body weight-related parameters used to assess the adipose tissue content. Further studies are required.

Coronary plaque characteristics and epicardial fat tissue in long term survivors of type 1 diabetes identified by coronary computed tomography angiography

OBJECTIVES

The aim was to assess coronary atherosclerosis, plaque morphology and associations to cardiovascular risk factors and epicardial adipose tissue (EAT) in patients with long duration of type 1 diabetes mellitus (T1DM).

MATERIALS AND METHODS

Eighty-eight patients with ≥ 45 year T1DM duration and 60 controls underwent coronary CT angiography (CCTA) for evaluation of coronary artery plaque volume (total, calcified or mixed/soft), coronary artery calcification score (CAC) and EAT.

RESULTS

Plaques were detected in 75 (85%) T1DM patients and 28 (47%) controls, p < 0.01. Median (interquartile range) plaque volume (mm³) in T1DM vs. controls was: 21.0 (1.0-66.0) vs. 0.2 (0.0-7.1), p < 0.01 for calcified, 0.0 (0.0-8.7) vs. 0.0 (0.0-0.0), p < 0.01 for soft/mixed and 29.5 (3.9-95.8) vs. 0.4 (0.0-7.4), p < 0.01 for total plaque volume. Median CAC was 128 (13-671) vs. 1 (0.0-39.0), p < 0.01 in T1DM vs. controls. Median EAT volume did not differ between the groups; 52.3 (36.1-65.5) cm³ vs. 55 (38.3-79.6), p = 0.20. No association between CAC or plaque volumes and EAT were observed. Low time-weighted LDL-cholesterol and HbA1c for 30 years were associated with having plaque volume < 25th percentile, OR (95% CI) 0.18 (0.05-0.70), p = 0.01 and 0.45 (0.20-1.00), p < 0.05, respectively. Time-weighted LDL-c was linearly associated with CAC (beta 0.82 (95% CI 0.03-1.62), p = 0.04) and total plaque volume (beta 0.77 (95% CI 0.19-1.36), p = 0.01).

CONCLUSION

Long-term survivors of T1DM have a higher prevalence of coronary atherosclerosis compared to controls. Low LDL-cholesterol and HbA1c over time have a protective effect on coronary atherosclerosis. EAT volume was not associated with coronary atherosclerosis in T1DM patients.

Non-contrast cardiac CT-based quantitative evaluation of epicardial and intra-thoracic fat in healthy, recently menopausal women: Reproducibility data from the Kronos Early Estrogen Prevention Study

BACKGROUND

Cardiac fat is emerging as an important parameter for cardiovascular risk stratification. Accurate and reproducible volumetric measurements can facilitate in the serial assessment of cardiac fat by computed tomography (CT). We assessed the intra- and inter-observer variability of cardiac fat volumetric measurements using a semi-automated CT software.

METHODS

We used non-contrast coronary calcium CT scans to quantify epicardial and intra-thoracic fat volumes. Two expert readers analyzed baseline and follow up CT scans of 45 subjects by using a semi-automated CT software (QFAT 2.0, Cedars Sinai-Medical Center). Correlation and Bland-Altman analysis was performed for both intra- and inter-observer comparisons for each cardiac fat type.

RESULTS

The intra-observer correlation coefficients ranged between 0.86 to 0.99 and 0.87 to 0.99 for epicardial (median fat per reader (cm³) 20.9 to 25.7) and intra-thoracic (median fat per reader (cm³) 27.1 to 31.6) fat volumes respectively, with no significant differences between individual data points (all p > 0.38). The inter-observer correlation coefficient was 0.99 (p < 0.0001 for correlation) for both epicardial and intra-thoracic fat. By Bland-Altman analysis for epicardial fat measurements, mean difference of intra-observer was 0.90 cm³ with 95% confidence intervals (0.22,1.7) and -1.8 cm³ for inter-observer, with 95% CI (-2.9, -0.69). Bland-Altman plots for intra-thoracic fat measurements were similarly impressive for both inter- and intra-observer reads.

CONCLUSIONS

Our data showed that measuring epicardial and intra-thoracic fat volumes by CT using a semi-automated software has excellent intra-observer and inter-observer reliability. Cardiac fat volumes can be obtained easily and reproducibly from routine calcium scoring scans and may help in assessing cardiovascular risk.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00154180; Keywords: Epicardial fat volume; intra-thoracic fat volume; computed tomography; intra-observer; inter-observer.

State-of-the-art review article. Atherosclerosis affecting fat: What can we learn by imaging perivascular adipose tissue?

Perivascular adipose tissue (PVAT) surrounding the human coronary arteries, secretes a wide range of adipocytokines affecting the biology of the adjacent vascular wall in a paracrine way. However, we have recently found that PVAT also behaves as a sensor of signals coming from the vascular wall, to which it reacts by changing its morphology and secretory profile. Indeed, vascular inflammation, a key feature of vascular disease pathogenesis, leads to the release of inflammatory signals that disseminate into local fat, inducing local lipolysis and inhibiting adipogenesis. This ability of PVAT to sense inflammatory signals from the vascular wall, can be used as a "thermometer" of the vascular wall, allowing for non-invasive detection of coronary inflammation. Vascular inflammation induces a shift of PVAT's composition from lipid to aqueous phase, resulting into increased computed tomography (CT) attenuation around the inflamed artery, forming a gradient with increasing attenuation closer to the inflamed coronary artery wall. These spatial changes in PVAT's attenuation are easily detected around culprit lesions during acute coronary syndromes. A new biomarker designed to captured these spatial changes in PVAT's attenuation around the human coronary arteries, the Fat Attenuation Index (FAI), has additional predictive value in stable patients for cardiac mortality and non-fatal heart attacks, above the prediction provided by the current state of the art that includes risk factors, calcium score and presence of high risk plaque features. The use of perivascular FAI in clinical practice may change the way we interpret cardiovascular CT angiography, as it is applicable to any coronary CT angiogram, and it offers dynamic information about the inflammatory burden of the coronary arteries, providing potential guidance for preventive measures and invasive treatments.

A Western-type dietary pattern and atorvastatin induce epicardial adipose tissue interferon signaling in the Ossabaw pig

Epicardial adipose tissue (EAT) inflammation is thought to potentiate the development of coronary artery disease (CAD). Overall diet quality and statin therapy are important modulators of inflammation and CAD progression. Our objective was to examine the effects and interaction of dietary patterns and statin therapy on EAT gene expression in the Ossabaw pig. Pigs were randomized to 1 of 4 groups; Heart Healthy diet (high in unsaturated fat, unrefined grain, fruits/vegetables [HHD]) or Western diet (high in saturated fat, cholesterol, refined grain [WD]), with or without atorvastatin. Diets were fed in isocaloric amounts for 6 months. A two-factor edge R analysis identified the differential expression of 21 genes. Relative to the HHD, the WD resulted in a significant 12-fold increase of radical s-adenosyl methionine domain containing 2 (RSAD2), a gene induced by interferon signaling. Atorvastatin led to the significant differential expression of 17 genes predominately involved in interferon signaling. Results were similar using the Porcine Translational Research Database. Pathway analysis confirmed the up-regulation of interferon signaling in response to the WD and atorvastatin independently. An expression signature of the largely interferon related differentially expressed genes had no predictive capability on a histological assessment of atherosclerosis in the underlying coronary artery. These results suggest that a WD and atorvastatin evoke an interferon mediated immune response in EAT of the Ossabaw pig, which is not associated with the presence of atherosclerosis.

Association of epicardial adipose tissue attenuation with coronary atherosclerosis in patients with a high risk of coronary artery disease

BACKGROUND AND AIMS

Density may indicate some tissue characteristics and help reveal the role of epicardial adipose tissue (EAT) in coronary artery disease (CAD). Therefore, we assessed the association of EAT density with the coronary artery plaque burden in patients presenting with chest pain.

METHODS

This retrospective cohort study comprised 614 patients (mean age 61 ± 9 years, 61% males) with a high cardiovascular disease risk, who underwent cardiac computed tomography angiography. Density was reflected as attenuation.

RESULTS

EAT attenuation was significantly associated with EAT volume with a negative Pearson's correlation coefficient and gradually increased across coronary artery calcium (CAC) scores of 0, 1-100, 101-400 and > 400. EAT attenuation was tightly associated with CAD risk factors, including age, sex, BMI, total cholesterol, neutrophil to lymphocyte ratios and CAC score. The association between EAT attenuation and CAC score was strengthened after adjusting for multivariable indices (OR 1.21, 95% CI 1.05-1.40, p = 0.01) and further adjusting for EAT volume (OR 1.26 95% CI 1.06-1.51, p<0.01). However, EAT attenuation was associated only with CAD presence (OR 1.32, 95% CI 1.02-1.69, p<0.05), CAC presence (OR 1.28, 95% CI 1.02-1.60, p<0.05), segment involvement score (OR 1.19, 95% CI 1.01-1.40, p<0.05) and segment stenosis score (OR 1.19, 95% CI 1.01-1.40, p<0.05) in the EAT volume- and multivariable-adjusted model. Additionally, EAT attenuation was not associated with significant coronary artery lesions and triple-vessel plaques.

CONCLUSIONS

Higher EAT attenuation is associated with a higher risk of CAD.

Epicardial adipose tissue and cardiovascular diseases

Obesity is a heterogeneous disease with different degrees of cardiovascular (CV) and metabolic manifestations. Certain ectopic fat depots may contribute to obesity-related CV risk and may explain part of the risk differential observed in metabolically healthy obese and the so called "obesity paradox". The growing interest towards the potential impact of epicardial adipose tissue (EAT) in cardiovascular (CV) risk has led to deepen its biological function. Genetic, epigenetic and environmental factors may drive the shift towards a dysfunctional EAT characterized by a pro-inflammatory and pro-fibrotic phenotype. Due to the close anatomic proximity to coronary arteries, a thicker and dysfunctional EAT actively contribute to development and progression of coronary atherosclerosis. Beside classical paracrine transmission, EAT may directly release mediators into the vasa vasorum of the coronary arterial wall, a mechanism referred to as "vasocrine". Similarly, the pro-inflammatory and pro-fibrotic secretome characterizing dysfunctional EAT may impair cardiac structure and function, thus being implicated in the pathogenesis of diastolic heart failure and atrial fibrillation. The development of 3D imaging techniques have paved the way for clarifying the causative role of EAT in CV pathophysiology, the use of EAT volume/thickness in CV risk stratification and potential cardio-protective effects of EAT reduction. The aim of this narrative review is to update current knowledge on the pathophysiological functions of EAT, focusing on basic mechanisms and potential clinical implications.

Cardiac CT: Technological Advances in Hardware, Software, and Machine Learning Applications

Purpose of Review

Multidetector row computed tomography (CT) allows noninvasive imaging of the heart and coronary arteries. The purpose of this review is to briefly summarize recent advances in CT hardware and software technology, and machine learning applications for cardiovascular imaging.

Recent Findings

In the last decades, there have been significant improvements in CT hardware focusing on faster gantry rotation resulting in improved temporal resolution. Concurrent hardware improvements include improved spatial resolution and higher coverage of the patient, enabling faster acquisition. Advances in cardiac CT software include methods for measurement of noninvasive FFR, coronary plaque characterization, and adipose tissue characteristics around the heart. Machine learning approaches using cardiac CT have been shown to improve both risk of prognosis and lesion-specific ischemia.

Summary

Recent advances in CT hardware and software have expanded the clinical utility of CT for cardiovascular imaging. In the next decades, continued advances can be anticipated in these areas, and in machine learning applications in cardiac CT, as they are incorporated into clinical routine for image acquisition, image analysis, and prediction of patient outcomes.