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

Recent advances in artificial intelligence for cardiac CT: Enhancing diagnosis and prognosis prediction

Recent advances in artificial intelligence (AI) for cardiac computed tomography (CT) have shown great potential in enhancing diagnosis and prognosis prediction in patients with cardiovascular disease. Deep learning, a type of machine learning, has revolutionized radiology by enabling automatic feature extraction and learning from large datasets, particularly in image-based applications. Thus, AI-driven techniques have enabled a faster analysis of cardiac CT examinations than when they are analyzed by humans, while maintaining reproducibility. However, further research and validation are required to fully assess the diagnostic performance, radiation dose-reduction capabilities, and clinical correctness of these AI-driven techniques in cardiac CT. This review article presents recent advances of AI in the field of cardiac CT, including deep-learning-based image reconstruction, coronary artery motion correction, automatic calcium scoring, automatic epicardial fat measurement, coronary artery stenosis diagnosis, fractional flow reserve prediction, and prognosis prediction, analyzes current limitations of these techniques and discusses future challenges.

Adiposity-associated atrial fibrillation: molecular determinants, mechanisms, and clinical significance

Obesity is an important contributing factor to the pathophysiology of atrial fibrillation (AF) and its complications by causing systemic changes, such as altered haemodynamic, increased sympathetic tone, and low-grade chronic inflammatory state. In addition, adipose tissue is a metabolically active organ that comprises various types of fat deposits with discrete composition and localization that show distinct functions. Fatty tissue differentially affects the evolution of AF, with highly secretory active visceral fat surrounding the heart generally having a more potent influence than the rather inert subcutaneous fat. A variety of proinflammatory, profibrotic, and vasoconstrictive mediators are secreted by adipose tissue, particularly originating from cardiac fat, that promote atrial remodelling and increase the susceptibility to AF. In this review, we address the role of obesity-related factors and in particular specific adipose tissue depots in driving AF risk. We discuss the distinct effects of key secreted adipokines from different adipose tissue depots and their participation in cardiac remodelling. The possible mechanistic basis and molecular determinants of adiposity-related AF are discussed, and finally, we highlight important gaps in current knowledge, areas requiring future investigation, and implications for clinical management.

Relationship between epicardial adipose tissue attenuation and coronary artery disease in type 2 diabetes mellitus patients

BACKGROUND AND AIMS

High epicardial adipose tissue (EAT) attenuation is a key characteristic of adipose tissue dysfunction and associated with coronary artery disease (CAD). As little is known about the modulation of EAT attenuation by metabolic disorders, we investigated the association between EAT attenuation and CAD risk factors, CAD presence and CAD severity in type 2 diabetes mellitus (T2DM) patients.

METHODS

We included 276 inpatients with T2DM and 305 control patients with normal glucose metabolism (NGM), who underwent cardiac computed tomography angiography (CCTA) and coronary artery calcium (CAC) scoring. EAT attenuation and volume were evaluated by contrast-enhanced CCTA image analysis. Furthermore, segment stenosis scores (SSSs) of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCX), right coronary artery (RCA), diagonal/intermediate branch (D/I) and obtuse marginal branch (OM) were calculated to assess CAD severity.

RESULTS

T2DM patients showed higher significant CAC scores, coronary plaque prevalence, total SSSs and LMCA-SSSs, LAD-SSSs, LCX-SSSs, RCA-SSSs and D/I-SSSs compared with NGM controls. In contrast to NGM controls, EAT volume was significantly increased in T2DM patients, whereas EAT attenuation was similar. In T2DM patients, EAT attenuation was associated with discrete CAD risk factors, the presence of coronary and triple-vessel plaques, as well as LAD-SSSs, LCX-SSSs, RCA-SSSs and total SSSs. In addition, EAT attenuation was only associated with the total SSS of calcified plaques, but not with noncalcified plaques.

CONCLUSION

In T2DM patients, high EAT attenuation is associated with the presence and severity of CAD in general and with coronary stenosis caused by calcified plaques in particular.

Epicardial Adipose Tissue in Patients with Coronary Artery Disease: A Meta-Analysis

Objective: The aim of this study is to assess the association between epicardial adipose tissue (EAT) and coronary artery disease (CAD) via meta−analysis. Methods: Specific searches of online databases from January 2000 to May 2022 were conducted. All observational studies evaluating the association between EAT and CAD in PubMed, Web of Science, and the Cochrane Library databases were screened. A meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta−Analyses guidelines (PRISMA). In total, 21 studies encompassing 4975 subjects met the inclusion criteria, including 2377 diagnosed and assigned as the CAD group, while the other 2598 were assigned as the non−CAD group. Subjects in the CAD group were further divided into the severe stenosis group (stenosis ≥ 50%, n = 846) and the mild/moderate stenosis group (stenosis < 50%, n = 577). Results: Both the volume and thickness of EAT in the CAD group were larger compared to the non−CAD group (p < 0.00001). In a subgroup analysis within the CAD group, the severe stenosis group had a larger volume and thickness with respect to EAT when compared to the mild/moderate group (p < 0.001). Conclusions: The enlargement of EAT presented in CAD patients with an association with CAD severity. Although limited by different CAD types and measuring methods for EAT, as well as a smaller sample size, our results suggest that EAT is a novel predictor and a potential therapeutic target for CAD.

The correlation between hepatic fat fraction evaluated by dual-energy computed tomography and high-risk coronary plaques in patients with non-alcoholic fatty liver disease

PURPOSE

To determine the relationship between non-alcoholic fatty liver disease (NAFLD) evaluated by a hepatic fat fraction (HFF) using dual-energy computed tomography (DECT) and high-risk coronary plaques (HRP) in NAFLD patients.

METHODS

We conducted a matched case-control study involving 172 NAFLD individuals recruited from August 2019 to September 2020. They underwent dual-energy coronary computed tomographic angiography and were classified as no-plaque, HRP negative and HRP positive groups. HFF values were measured using multimaterial decomposition algorithm of DECT, and the differences among three groups were compared. Multiple logistic regression analysis was performed to determine the independent correlation between HFF and HRP. Spearman rank correlation was used to assess the correlations between HFF and multiple variables.

RESULTS

HRP positive group (15.3%) had higher HFF values than no-plaque (6.9%) and HRP negative groups (8.9%) (P < 0.001). After adjusting for confounding variables, the results indicated that HFF was an independent risk factor for HRP (OR 1.93, P < 0.001). Additionally, HFF significantly correlated with coronary artery calcium score, hepatic CT attenuation, epicardial and pericoronary adipose tissue volume, and CT attenuation (all P < 0.001).

CONCLUSIONS

As a new imaging marker for the quantification of liver fat, HFF was independently associated with HRP.

Latest Insights into Mechanisms behind Atrial Cardiomyopathy: It Is Not always about Ventricular Function

Atrial cardiomyopathy (ACM) represents a constantly evolving concept, with increasing importance in contemporary research and clinical practice. A better understanding of the mechanisms involved in atrial remodeling and its clinical correlations especially with atrial fibrillation (AF) and other cardiometabolic comorbidities may induce a significant impact on the diagnosis, prognosis, and therapeutic approach of ACM-related comorbidities. Although initially described several decades ago, investigators have only recently highlighted that several renal, metabolic, and cardiovascular diseases are determining factors for atrial remodeling and subsequent ACM. Based on data from multiple recent studies, our research emphasizes the correlations between ACM and other coexisting pathologies including cardiovascular, respiratory, or metabolic diseases, with fibrosis being the most incriminated pathophysiological mechanism. In addition to the usual tests, the paraclinical assessment of ACM is increasingly based on the use of various cardiac biomarkers, while the cardiac magnetic resonance (CMR) has become an increasingly tempting diagnostic too for describing morphofunctional aspects of the heart chambers, with the gadolinium contrast enhanced CMR (LGE-CMR) emerging as a commonly used technique aiming to identify and quantify the precise extent of atrial fibrosis. Further research should be conducted in order to clarify our knowledge regarding atrial remodeling and, therefore, to develop new and improved therapeutic approaches in these patients.

Environmental Tobacco Smoke Exposure Estimated Using the SHSES Scale and Epicardial Adipose Tissue Thickness in Hypertensive Patients

The aim of the study was to assess the relationship between environmental tobacco smoke exposure (ETS) and epicardial adipose tissue thickness (EATT) in hypertensive patients. A total of 96 patients with essential hypertension were recruited for this study. The group consisted of 48 females and 48 males with the mean age of 69.32 ± 9.54 years. ETS was assessed with The Secondhand Smoke Exposure Scale (SHSES). EATT was assessed in 128-slice dual source coronary computed tomography angiography. In accordance to SHSES scale patients were divided into subgroups: subgroup A-no ETS exposure (SHSES = 0 points, n = 48), subgroup B-low ETS exposure (SHSES = 1-3 points, n = 11), subgroup C-medium ETS exposure (SHSES = 4-7 points, n = 20) and subgroup D-high ETS exposure (SHSES = 8-11 points, n = 17). Within the study group the mean EATT was 5.75 ± 1.85 mm and the mean SHSES score was 3.05 ± 3.74. EATT was statistically significantly higher in subgroup D than in subgroups A and B (A: 5.28 ± 1.64 mm, B: 5.04 ± 2.64 mm, D: 7.04 ± 2.64 mm, p_A-D and p_B-D < 0.05). There was a positive linear correlation between the exposure to ETS expressed by the SHSES scale and EATT (r = 0.44, p < 0.05). Regression analysis showed that higher SHSES score, higher BMI, and higher systolic and diastolic blood pressure are independent risk factors for higher EATT values. Contrary, the use of ACE inhibitors and β-blockers appeared to be independent protecting factor against higher EATT values. There is an unfavorable positive relationship between ETS exposure estimated using the SHSES scale and EATT in hypertensive patients.