Development of Pericardial Fat Count Images Using a Combination of Three Different Deep-Learning Models: Image Translation Model From Chest Radiograph Image to Projection Image of Three-Dimensional Computed Tomography

RATIONALE AND OBJECTIVES

Pericardial fat (PF)-the thoracic visceral fat surrounding the heart-promotes the development of coronary artery disease by inducing inflammation of the coronary arteries. To evaluate PF, we generated pericardial fat count images (PFCIs) from chest radiographs (CXRs) using a dedicated deep-learning model.

MATERIALS AND METHODS

We reviewed data of 269 consecutive patients who underwent coronary computed tomography (CT). We excluded patients with metal implants, pleural effusion, history of thoracic surgery, or malignancy. Thus, the data of 191 patients were used. We generated PFCIs from the projection of three-dimensional CT images, wherein fat accumulation was represented by a high pixel value. Three different deep-learning models, including CycleGAN were combined in the proposed method to generate PFCIs from CXRs. A single CycleGAN-based model was used to generate PFCIs from CXRs for comparison with the proposed method. To evaluate the image quality of the generated PFCIs, structural similarity index measure (SSIM), mean squared error (MSE), and mean absolute error (MAE) of (i) the PFCI generated using the proposed method and (ii) the PFCI generated using the single model were compared.

RESULTS

The mean SSIM, MSE, and MAE were 8.56 × 10-1, 1.28 × 10-2, and 3.57 × 10-2, respectively, for the proposed model, and 7.62 × 10-1, 1.98 × 10-2, and 5.04 × 10-2, respectively, for the single CycleGAN-based model.

CONCLUSION

PFCIs generated from CXRs with the proposed model showed better performance than those generated with the single model. The evaluation of PF without CT may be possible using the proposed method.

Pericardial fat volume and coronary risk factors as predictors of non-calcified coronary plaque presence among patients with coronary calcium score = 0

INTRODUCTION

There is scarce data linking pericardial fat volume (PFV) and classical coronary risk factors with non-calcified plaque presence among patients with CAC = 0 in the literature.

MATERIAL AND METHOD

A total of 811 patients with chest pain suggestive of angina underwent CT coronary angiography for the assessment of coronary artery disease were collected. Of these, 417 with CAC = 0 were included in the analysis.

RESULT

Patients with non-calcified plaque were older (54 ± 9 versus 50 ± 10, P = 0.01) and had a higher prevalence of diabetes mellitus (31% versus 17%, P = 0.02), high BMI (29.9 versus 28.3, P = 0.04), and increased PFV (123 cm3 versus 99 cm3, P < 0.01) compared to patients without plaque. In multivariate regression analysis, high BMI[OR(CI) = 1.1(1-1.3), P = 0.02] was an independent predictor of non-calcified coronary plaque presence among patients with CAC = 0 after adjustment to variables with P < 0.05 in the univariate analysis.

CONCLUSION

In patients with a CAC score of 0, advanced age, diabetes mellitus, increased PFV, and high BMI were all associated with the presence of non-calcified plaque. After multivariate adjustment, increased BMI remained a significant independent predictor for non-calcified plaque presence.

Radical mediastinal lipectomy for tamponade-like cardiac physiology

BACKGROUND

Re-opening the chest is an unwanted and potentially morbid complication after open heart surgery, most commonly required for refractory bleeding or tamponade. In this report, we present a unique case of a postoperative coronary artery bypass patient, demonstrating clinical features of cardiac tamponade of the right atrium and ventricle with inconclusive findings on imaging.

CASE PRESENTATION

A 62 year-old male presented to hospital with exertional angina and a coronary angiogram found severe three-vessel coronary artery disease with preserved left ventricular function. He underwent an uncomplicated triple coronary artery bypass surgery. Over the following hours in the cardiac intensive care unit, the patient had a climbing serum lactate level and increasing vasopressor requirements. On investigations, there was evidence of compression of the right heart. The patient was taken back to the operating room where very little clot or bleeding was identified, rather there was significant amounts of mediastinal fat surrounding the heart which was subsequently resected with wide margins. The patient had complete resolution of their symptoms and an uncomplicated postoperative course thereafter.

CONCLUSIONS

To our knowledge, this case is the first reported occurrence of cardiac constriction from excessive mediastinal fat after open heart surgery. Identifying patients at high-risk for excessive pericardial fat, as well as considering alternative modalities of imaging appear to be the main stay in diagnosis at this point. Current treatment is a mediastinal lipectomy with wide margins, avoiding injury to surrounding structures such as the phrenic nerve and innominate vein. Future study might consider the value of prophylactic mediastinal lipectomy at time of surgery, and methods to improve detection with current and future imaging modalities.

Relationship of cardiovascular risk factors, pericardial fat, and carotid thickness with coronary plaque type in patients with diabetes mellitus

Background

There is paucity of data on the potential predictors of coronary plaque types among patients with diabetes mellitus(DM).

Aims

To assess the association of cardiovascular risk factors, pericardial fat volume (PFV) assessed by multi-detector CT(MDCT)angiography, and internal carotid intima media thickness with coronary atherosclerotic plaque types in patients with type 2 DM.

Patients and methods

Patients with suspected coronary artery disease who underwent 64-slice MDCT angiography were enrolled in this retrospective study.

Results

A total of 784 patients were enrolled in this study, 198 of whom had DM and 586 of whom did not. The prevalence of calcified and mixed plaques was significantly higher in the DM group than without DM group, while no significant difference was found in the distribution of non-calcified plaque between groups. There was significant association between smoking [OR(CI) = 4(2-10),P = 0.001] and increased age[OR(CI) = 1.1(1-1.3),P = 0.023] and calcified plaque presence. Regarding mixed and non-calcified plaque, increased PFV[OR(CI) = 1.1(1-1.3),P = 0.001] and positive family history[OR(CI) = 4(2-12),P = 0.049] showed a significant association with coronary mixed plaque presence while no significant association was observed between cardiovascular risk factors, PFV, and internal carotid intima media thickness and non-calcified plaque presence in patients with DM.

Conclusion

Increased PFV showed significant and independent association with mixed coronary plaques development, which suggests that PFV may be used as an imaging marker for early detection of increased risk for future coronary events in patients with DM.

Ventricular conduction improvement after pericardial fat reduction triggered by rapid weight loss in subjects with obesity undergoing bariatric surgery

BACKGROUND

Obesity is considered a major cardiovascular risk factor. The excess of pericardial fat (PF) in patients with obesity has been associated with a variety of electrocardiographic alterations. In previous studies, we demonstrated that rapid weight loss and bariatric interventions result in decreased PF.

OBJECTIVES

The aim of this study is to report the changes in PF after bariatric surgery and its effect on ventricular conduction.

SETTING

US hospital, academic institution.

METHODS

A linear measurement of PF thickness on computed tomography scans was obtained for 81 patients, as well as a retrospective review of electrocardiographic changes before and after bariatric surgery. We compared the changes in PF thickness and electrocardiographic components before and after procedures. Common demographics and co-morbidities were collected along with lipid profiles preoperative and postoperative.

RESULTS

A total of 81 patients had electrocardiograms done before and 1 year after bariatric surgery. Females comprised 67.9% (n = 55), and the average age for our population was 55.07 ± 14.17 years. Pericardial fat thickness before surgery was 5.6 ± 1.84 and 4.5 ± 1.62 mm after surgery (P = .0001). Ventricular conduction (QT and QT corrected [QTc] intervals) showed a significant improvement from 438.7 + 29 before to 426.8 + 25.3 after bariatric surgery (P = .006). We found a statistically significant association between the decrease in PF and the decrease in QTc intervals (P = .002).

CONCLUSION

Obesity is a risk factor for arrhythmias and sudden cardiac death. Bariatric surgery and its effect on PF produce an improvement in ventricular conduction, which may reduce the ventricular electrical instability in patients with obesity.

Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications

Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.

A prospective randomized study comparing effects of empagliflozin to sitagliptin on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes: the ASSET study

Background

While the cardioprotective benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors have been established in patients with cardiovascular disease (CVD), their advantages over other anti-diabetic drugs at earlier stages remain unclear. We compared the cardioprotective effects of empagliflozin, an SGLT2 inhibitor, with those of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, focusing on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes mellitus (T2DM) without CVD complications.

Methods

This was a prospective, randomized, open-label, blinded-endpoint, parallel-group trial that enrolled 44 Japanese patients with T2DM. The patients were randomized for 12-week administration of empagliflozin or sitagliptin. Pericardial fat accumulation and myocardial triglyceride content were evaluated by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. Echocardiography, ¹²³I-β-methyl-iodophenyl pentadecanoic acid myocardial scintigraphy, and laboratory tests were performed at baseline and after the 12-week treatment period.

Results

The patients were middle-aged (50.3 ± 10.7 years, mean ± standard deviation) and overweight (body mass index 29.3 ± 4.9 kg/m²). They had a short diabetes duration (3.5 ± 3.2 years), HbA1c levels of 7.1 ± 0.8%, and preserved cardiac function (ejection fraction 73.8 ± 5.0%) with no vascular complications, except for one baseline case each of diabetic nephropathy and peripheral arterial disease. After the 12-week treatment, no differences from baseline were observed between the two groups regarding changes in pericardial, epicardial, and paracardial fat content; myocardial triglyceride content; cardiac function and mass; and cardiac fatty acid metabolism. However, considering cardiometabolic biomarkers, high-density lipoprotein cholesterol and ketone bodies, including β-hydroxybutyric acid, were significantly increased, whereas uric acid, plasma glucose, plasma insulin, and homeostasis model assessment of insulin resistance were significantly lower in the empagliflozin group than in the sitagliptin group (p < 0.05).

Conclusions

Although the effects on cardiac fat and function were not statistically different between the two groups, empagliflozin exhibited superior effects on cardiometabolic biomarkers, such as uric acid, high-density lipoprotein cholesterol, ketone bodies, and insulin sensitivity. Therefore, when considering the primary preventive strategies for CVD, early supplementation with SGLT2 inhibitors may be more beneficial than DPP-4 inhibitors, even in patients with early-stage T2DM without current CVD complications.

Clinical Trial Registration: UMIN000026340; registered on February 28, 2017. https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000030257

Pericardial fat and its influence on cardiac diastolic function

Background

Pericardial fat (PF) has been suggested to directly act on cardiomyocytes, leading to diastolic dysfunction. The aim of this study was to investigate whether a higher PF volume is associated with a lower diastolic function in healthy subjects.

Methods

254 adults (40–70 years, BMI 18–35 kg/m², normal left ventricular ejection fraction), with (a)typical chest pain (otherwise healthy) from the cardiology outpatient clinic were retrospectively included in this study. All patients underwent a coronary computed tomographic angiography for the measurement of pericardial fat volume, as well as a transthoracic echocardiography for the assessment of diastolic function parameters. To assess the independent association of PF and diastolic function parameters, multivariable linear regression analysis was performed. To maximize differences in PF volume, the group was divided in low (lowest quartile of both sexes) and high (highest quartile of both sexes) PF volume. Multivariable binary logistic analysis was used to study the associations within the groups between PF and diastolic function, adjusted for age, BMI, and sex.

Results

Significant associations for all four diastolic parameters with the PF volume were found after adjusting for BMI, age, and sex. In addition, subjects with high pericardial fat had a reduced left atrial volume index (p = 0.02), lower E/e (p < 0.01) and E/A (p = 0.01), reduced e′ lateral (p < 0.01), reduced e′ septal p = 0.03), compared to subjects with low pericardial fat.

Conclusion

These findings confirm that pericardial fat volume, even in healthy subjects with normal cardiac function, is associated with diastolic function. Our results suggest that the mechanical effects of PF may limit the distensibility of the heart and thereby directly contribute to diastolic dysfunction.

Trial registration NCT01671930

Pericardial fat versus BMI in the assessment of coronary atherosclerotic burden in patients with diabetes mellitus

AIMS

To investigate the association of obesity measured by body mass index (BMI) versus pericardial fat volume (PFV) measured by multi-detector computed tomography (MDCT) with coronary atherosclerotic markers (coronary artery calcium score (CAC), coronary stenosis severity and coronary plaque presence) in patients with type 2 diabetes mellitus (DM).

METHODS

Among 496 patients with suspected coronary artery disease who underwent 64-slice MDCT angiography to exclude occlusive coronary artery disease, 102 patients with DM were enrolled in the present study.

RESULTS

PFV showed a significant association with CAC (r = 0.2, P = 0.01) and significant coronary artery stenosis [PFV median (IQR) = 75 (51-136) in patients with coronary stenosis < 50% versus PFV median (IQR) = 113 (68-140) in patients with coronary stenosis ≥ 50%, P = 0.01] while there was no significant association of PFV with coronary plaque presence (PFV median (IQR) = 84 (56-140) in patients without plaque versus PFV median (IQR) = 109 (70-136) in patients with plaque presence, P = 0.4). The association between PFV with CAC persisted after adjustment for conventional cardiac risk factors. BMI showed no significant association with CAC, coronary stenosis severity and coronary plaque presence (P > 0.05).

CONCLUSIONS

PFV was independently associated with CAC in diabetic patients. PFV, rather than obesity measured by BMI, could be used as an imaging biomarker for assessing coronary atherosclerotic burden in patients with DM.

Rationale, Design for the ASSET Study: A Prospective Randomized Study Comparing Empagliflozin's Effect to Sitagliptin on Cardiac Fat Accumulation/Function in Patients with Type 2 Diabetes

INTRODUCTION

Ectopic fat accumulation has been found to play a pathophysiological role in insulin resistance, type 2 diabetes (T2DM), and coronary artery diseases. Findings from a number of previous studies suggest that sodium glucose cotransporter 2 (SGLT2) inhibitors reduce lipid accumulation, including myocardial and pericardial fat, while dipeptidyl peptidase 4 (DPP4) inhibitors suppress ectopic lipid accumulation and improve cardiac function. However, a clinical study that precisely explains and compares the efficacy of SGLT2 inhibitors and DPP4 inhibitors on cardiac fat accumulation has not been performed. Moreover, the association between cardiac fat accumulation and cardiac function or metabolic changes, such as tissue-specific insulin resistance, remains unclear. It is our intention to conduct the first study to assess the effects of empagliflozin compared to sitagliptin in reducing ectopic fat accumulation, specifically pericardial fat, and its association with improvement in cardiac function and tissue-specific insulin sensitivity.

METHODS

We have designed a prospective, randomized open-label, and blinded-endpoint study with the intention to enroll 44 Japanese patients with T2DM. The patients are to be divided them into two groups, an empagliflozin group and an sitagliptin group, with the former to be supplemented with empagliflozin 10 mg and the latter to be supplemented with sitagliptin 100 mg, both groups for 12 weeks. The primary endpoint of the study is the change in the amount of pericardial fat. The secondary endpoints are the changes in the amount of intracellular fat in the myocardium, cardiac function, tissue-specific insulin sensitivity, fatty acid metabolism in myocardial tissue, assessed by parameters of iodine-123-β-methyl-iodophenyl pentadecanoic acid myocardial scintigraphy, blood and urine biomarkers, and lifestyle evaluation.

PLANNED OUTCOMES

The results of this study will be available in 2020. The aim of this study is to provide an effective treatment strategy for patients with T2DM by considering cardiac fat accumulation, cardiac function, and insulin resistance.

FUNDING

Boehringer Ingelheim & Eli Lilly and Company Diabetes Alliance.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trial Registry: UMIN000026340.

Characterization of mouse pericardial fat: regulation by PAPP-A

Although implicated in cardiovascular disease, little is known about the fat surrounding the heart. In humans, epicardial fat is the visceral fat depot of the heart, which directly contacts the myocardium. This strategically placed fat depot is thought to produce bioactive molecules that could affect cardiac function. A major limitation in understanding the biology of epicardial fat is its restricted access in humans and its seeming absence in commonly-used experimental animal models. Although laboratory mice do not have epicardial fat per se, they do have a fat depot around the heart. In this study, we found that mouse pericardial fat has the molecular signature, small adipocyte size, and resistance to differentiation consistent with visceral fat. In addition, we show that mouse pericardial fat is regulated by pregnancy-associated plasma protein-A (PAPP-A), a key modulator of local insulin-like growth factor bioavailability. PAPP-A is highly expressed in mouse pericardial fat at levels equivalent to those in mesenteric visceral fat and 10-fold higher than in subcutaneous inguinal fat (P = .0003). Cultured pre-adipocytes isolated from pericardial fat show 2-fold increased PAPP-A secretion compared to pre-adipocytes isolated from inguinal fat. Furthermore, PAPP-A knock-out mice fed a high fat diet for 20 weeks have significantly reduced pericardial fat (by 60%; P < .0001) compared to wild-type littermates. There was no significant difference in inguinal fat between wild-type and PAPP-A knock-out mice. These data characterize a new mouse model of visceral-like pericardial fat and lay a foundation for understanding its role in human heart disease.

Change in Pericardial Fat Volume and Cardiovascular Risk Factors in a General Population of Japanese Men

BACKGROUND

Pericardial fat volume (PFV), defined as the volume of ectopic fat in and around the heart, is associated with the atherosclerotic process in coronary arteries. The magnitude of change in PFV over time and the factors affecting this change in a general population, however, have not been investigated. Methods and Results: Cardiac computed tomography (CT) was carried out at baseline and at follow-up in 623 Japanese men aged 40-79 years without a history of cardiovascular disease who were selected randomly in Kusatsu (Shiga, Japan). PFV was measured on cardiac CT in a qualified laboratory. Age, heart rate, triglycerides, and obesity measurements (weight, body mass index, and waist circumference) were significantly and positively associated with PFV at baseline. Over an average interval of 4.7 years, median PFV increased significantly from 64.1 cm³ (IQR, 47.2-90.0 cm³) to 73.6 cm³ (IQR, 53.3-98.1 cm³; P<0.001). Current smoking and heart rate were significantly and independently associated with changes in PFV (B=3.336, P<0.001 and B=6.409, P=0.003, respectively).

CONCLUSIONS

PFV increased significantly over time in a population-based observational study of Japanese men. PFV change was significantly and independently associated with smoking status and heart rate, suggesting that quitting smoking might help reduce PFV, which could be expected to decrease the risk of coronary artery disease.

Epicardial fat and atrial fibrillation: current evidence, potential mechanisms, clinical implications, and future directions

Obesity is increasingly recognized as a major modifiable determinant of atrial fibrillation (AF). Although body mass index and other clinical measures are useful indications of general adiposity, much recent interest has focused on epicardial fat, a distinct adipose tissue depot that can be readily assessed using non-invasive imaging techniques. A growing body of data from epidemiological and clinical studies has demonstrated that epicardial fat is consistently associated with the presence, severity, and recurrence of AF across a range of clinical settings. Evidence from basic science and translational studies has also suggested that arrhythmogenic mechanisms may involve adipocyte infiltration, pro-fibrotic, and pro-inflammatory paracrine effects, oxidative stress, and other pathways. Despite these advances, however, significant uncertainty exists and many questions remain unanswered. In this article, we review our present understanding of epicardial fat, including its classification and quantification, existing evidence implicating its role in AF, potential mechanisms, implications for clinicians, and future directions for research.

Relationships between left atrial pericardial fat and permanent atrial fibrillation: Results of a case-control study

PURPOSE

The goal of this study was to retrospectively investigate the relationships between pericardial fat, left atrium volume (LAV) as measured on multidetector row computed tomography (MDCT) and persistent atrial fibrillation (AF) using a case-control study.

MATERIALS AND METHODS

The study population consisted of 58 patients (19 men, 39 women; mean age, 67.8±10 [SD] years) with persistent AF and 74 control subjects (30 men, 44 women; mean age, 67.8±10.9 [SD] years). The associations between the presence of persistent AF and periatrial pericardial fat volume (PAFV), periatrial pericardial fat thickness (PAFT), and LAV as measured on MDCT were searched for using univariate and multiple linear regression analysis.

RESULTS

On univariate analysis, significant differences were found between patients with AF and control subjects for mean PAFV (54.33cm(3)±23.43 [SD]; range: 12.2-111.1cm(3) vs 42.99cm(3)±20.76 [SD]; range: 7.4-103.9cm(3), respectively) (P=0.01), PAFT at the esophagus (1.87mm±1.65 [SD]; range: 0.1-9.5mm vs 1.12mm±0.77 [SD]; range: 0.1-3.6mm, respectively) (P<0.001) and normalized LAV (78.3cm(3)/m(2)±48.84 [SD]; range: 32.1-319.6cm(3)/m(2) vs 42.1cm(3)/m(2)±25.43 [SD]; range: 15.7-191.4cm(3)/m(2), respectively) (P<0.001). Multiple linear regression analysis revealed that only LAV was an independent predictor (P<0.001) of persistent AF. Also PAFV was significantly associated with LAV (P=0.01).

CONCLUSION

LAV is greater in patients with AF than in control subjects and PAFV is strongly associated with LAV. PAFV and PAFT are not independently associated with AF.

Insights into the Genetic Susceptibility to Type 2 Diabetes from Genome-Wide Association Studies of Obesity-Related Traits

Obesity and type 2 diabetes (T2D) are common and complex metabolic diseases, which are caused by an interchange between environmental and genetic factors. Recently, a number of large-scale genome-wide association studies (GWAS) have improved our knowledge of the genetic architecture and biological mechanisms of these diseases. Currently, more than ~250 genetic loci have been found for monogenic, syndromic, or common forms of T2D and/or obesity-related traits. In this review, we discuss the implications of these GWAS for obesity and T2D, and investigate the overlap of loci for obesity-related traits and T2D, highlighting potential mechanisms that affect T2D susceptibility.

Relationship of pericardial fat with lipoprotein distribution: The Multi-Ethnic study of atherosclerosis

OBJECTIVE

Pericardial fat and lipoprotein abnormalities contribute to increased risk of cardiovascular disease (CVD). We investigated the relationship between pericardial fat volume and lipoprotein distribution, and whether the association of pericardial fat volume with subclinical atherosclerosis and incident CVD events differs according to lipoprotein distribution.

METHODS

We analyzed data from 5407 participants from the Multi-Ethnic Study of Atherosclerosis who had measurements of pericardial fat volume, lipoprotein distribution, carotid intima-media thickness (IMT), and coronary artery calcium (CAC). All participants were free of clinically apparent CVD at baseline. Incident CVD was defined as any adjudicated CVD event.

RESULTS

After adjusting for demographic factors, traditional risk factors, and biomarkers of inflammation and hemostasis, a larger pericardial fat volume was associated with higher large VLDL particle (VLDL-P) concentration and small HDL particle (HDL-P) concentration, and smaller HDL-P size (regression coefficients = 0.585 nmol/L, 0.366 μmol/L, and -0.025 nm per SD increase in pericardial fat volume respectively, all P < 0.05). The association of pericardial fat volume with large VLDL-P concentration and HDL-P size, but not small HDL-P concentration, remained significant after further adjusting for each other as well as LDL cholesterol, HDL cholesterol, and triglycerides. The relationship of pericardial fat volume with incident CVD events, carotid IMT, and prevalence and severity of CAC did not differ by quartiles of large VLDL-P concentration, small HDL-P concentration, or HDL-P size (P for interaction>0.05).

CONCLUSION

Pericardial fat is associated with atherogenic lipoprotein abnormalities. However, its relationship with subclinical atherosclerosis and incident CVD events does not differ according to lipoprotein distribution.

Pericardial fat is associated with all-cause mortality but not incident CVD: the Rancho Bernardo Study

OBJECTIVE

Pericardial and intra-thoracic fat are associated with prevalent cardiovascular disease (CVD) and CVD risk factors. However, it is unclear if these fat depots predict incident CVD events and/or all-cause mortality. We examined prospective associations between areas of pericardial and intra-thoracic fat and incident CVD and mortality over a 12-year follow-up in a subset of participants without baseline clinical CVD from the Rancho Bernardo Study (RBS).

METHODS

Participants were 343 community-dwelling older adults (mean baseline age = 67) who completed a clinic visit in 2001-02, including a computed tomography scan of the chest. Incident CVD and mortality were recorded through January 2013.

RESULTS

Over a 12.6-year median follow-up, there were 60 incident CVD events and 49 deaths. Pericardial fat was associated with all-cause mortality, such that each standard deviation increment predicted a 34% higher chance of death after adjusting for demographics, lifestyle factors, comorbidities, and visceral fat (95% CI = 1.01-1.78). When categorized by tertile, those in the middle tertile of pericardial fat showed no increased risk of mortality, while those in the highest tertile had 2.6 times the risk (95% CI = 1.10-5.97) compared to the lowest tertile. There was a marginal association between intra-thoracic fat and mortality (p = 0.06). Neither pericardial nor intra-thoracic fat was significantly associated with incident CVD. There were no significant interactions by sex.

CONCLUSIONS

Higher pericardial, but not intra-thoracic, fat was associated with earlier all-cause mortality in older adults over a 12-year follow-up. This association was primarily driven by a higher mortality rate in those in the highest tertile of pericardial fat.

Relationship of pericardial fat with biomarkers of inflammation and hemostasis, and cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Pericardial fat may increase the risk of cardiovascular disease (CVD) by increasing circulating levels of inflammation and hemostasis biomarkers. We investigated the associations of pericardial fat with inflammation and hemostasis biomarkers, as well as incident CVD events, and whether there are any ethnic differences in these associations.

METHODS

We analyzed results from 6415 participants from the Multi-Ethnic Study of Atherosclerosis who had measurements of pericardial fat volume and circulating levels of C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, factor VIII, D-dimer and plasmin-antiplasmin complex (PAP), and had a mean follow-up period of 9.5 years. Incident CVD event was defined as any adjudicated CVD event.

RESULTS

After adjusting for confounding factors, pericardial fat volume was positively associated with natural log (ln) of IL-6 levels, but inversely associated with ln D-dimer and ln PAP levels (β = 0.067, -0.032, and -0.105 respectively, all P < 0.05). Although a larger pericardial fat volume was associated with a higher risk of incident CVD, the association was attenuated to borderline significance after adjusting for traditional cardiovascular risk factors (P = 0.050). There was a borderline significant ethnicity interaction (P = 0.080), whereby the association between pericardial fat volume and incident CVD was significant in Hispanic Americans, even after further adjusting for biomarkers of inflammation and hemostasis (hazard ratio = 1.31 per SD increase, 95% confidence interval 1.09-1.57, P = 0.004).

CONCLUSION

Pericardial fat was associated with several inflammation and hemostasis biomarkers. The association of pericardial fat with incident CVD events was independent of these biomarkers only among Hispanic Americans.

Epicardial adipose tissue volume as a marker of coronary artery disease severity in patients with diabetes independent of coronary artery calcium: findings from the CTRAD study

AIMS

The association between epicardial adipose tissue (EAT) volume and coronary artery disease (CAD) severity was evaluated, independent of traditional risk factors and coronary artery calcium (CAC) scores, in patients with diabetes type 2 (DM-2) using cardiac computed tomography angiography (CTA).

METHODS

A multivariate analysis was utilized to assess for an independent association after calculating EAT volume, CAD severity, and calcium scores in 92 patients with DM-II from the CTRAD study. We graded CAD severity as none (normal coronaries), mild-moderate (<70% stenosis), and severe (70% or greater stenosis).

RESULTS

A total of 39 (42.3%) asymptomatic patients with diabetes did not have CAD; 30.4% had mild/moderate CAD; and 27.1% had severe CAD. Mean EAT volume was highest in patients with severe CAD (143.14 cm(3)) as compared to mild/moderate CAD (112.7 cm(3)), and no CAD (107.5 cm(3)) (p = 0.003). After adjustment of clinical risk factors, notably, CAC score, multivariate regression analysis showed EAT volume was an independent predictor of CAD severity in this sample (odds ratio 11.2, 95% confidence interval 1.7-73.8, p = 0.01).

CONCLUSIONS

Increasing EAT volume in asymptomatic patients with DM-II is associated with presence of severe CAD, independent of BMI and CAC, as well as traditional risk factors.

Correlation between pericardial, mediastinal, and intrathoracic fat volumes with the presence and severity of coronary artery disease, metabolic syndrome, and cardiac risk factors

AIMS

To investigate the association of pericardial, mediastinal, and intrathoracic fat volumes with the presence and severity of coronary artery disease (CAD), metabolic syndrome (MS), and cardiac risk factors (CRFs).

METHODS AND RESULTS

Two hundred and sixteen consecutive patients who underwent cardiac magnetic resonance (CMR) imaging and had a coronary angiogram within 12 months of the CMR were studied. Fat volume was measured by drawing region of interest curves, from short-axis cine views from base to apex and from a four-chamber cine view. Pericardial fat, mediastinal fat, intrathoracic fat (addition of pericardial and mediastinal fat volumes), and fat ratio (pericardial fat/mediastinal fat) were analysed for their association with the presence and severity of CAD (determined based on the Duke CAD Jeopardy Score), MS, CRFs, and death or myocardial infarction on follow-up. Pericardial fat volume was significantly greater in patients with CAD when compared with those without CAD [38.3 ± 25.1 vs. 31.9 ± 21.4 cm(3) (P = 0.04)]. A correlation between the severity of CAD and fat volume was found for pericardial fat (β = 1, P < 0.01), mediastinal fat (β = 1, P = 0.03), intrathoracic fat (β = 2, P = 0.01), and fat ratio (β = 0.005, P = 0.01). These correlations persisted for all four thoracic fat measurements even after performing a stepwise linear regression analysis for relevant risk factors. Patients with MS had significantly greater mediastinal and intrathoracic fat volumes when compared with those without MS [126 ± 33.5 vs. 106 ± 30.1 cm(3) (P < 0.01) and 165 ± 54.9 vs. 140 ± 52 cm(3) (P < 0.01), respectively]. However, there was no significant difference in pericardial fat, mediastinal fat, intrathoracic fat, or fat ratio between patients with or without myocardial infarction during the follow-up [33.6 ± 22.1 vs. 35.7 ± 23.8 cm(3) (P = 0.67); 115 ± 26.2 vs. 114 ± 33.8 cm(3) (P = 0.84); 149 ± 44.7 vs. 150 ± 55.7 cm(3) (P = 0.95); and 0.27 ± 0.15 vs. 0.28 ± 0.14 (P = 0.70), respectively]. There was no significant difference in pericardial fat, mediastinal fat, intrathoracic fat, or fat ratio between patients who were alive compared with those who died during follow-up [36.6 ± 26.6 vs. 35.3 ± 23.2 cm(3) (P = 0.76); 114 ± 40.2 vs. 114 ± 31.4 cm(3) (P = 0.95); 150 ± 64.7 vs. 149 ± 52.5 cm(3) (P = 0.92); and 0.29 ± 0.15 vs. 0.28 ± 0.14 (P = 0.85), respectively].

CONCLUSION

Our study confirms an association between pericardial fat volume with the presence and severity of CAD. Furthermore, an association between mediastinal and intrathoracic fat volumes with MS was found.

Pericardial fat volume is associated with clinical recurrence after catheter ablation for persistent atrial fibrillation, but not paroxysmal atrial fibrillation: an analysis of over 600-patients

BACKGROUND

Although pericardial fat volume (PFV) has been suggested to be associated with atrial fibrillation (AF), only a few studies have reported the association between pericardial fat and clinical outcome after radiofrequency catheter ablation (RFCA). The purpose of this study was to explore the factors associated with PFV and its prognostic significance after catheter ablation for AF, depending on the types of AF.

METHODS

We included 665 patients (76.7% male, 57.3±11.1 years of age, 67.7% with paroxysmal AF [PAF] and 32.3% with persistent AF [PeAF]) who underwent RFCA for AF, and compared PFV with clinical variables. The factors associated with clinical recurrence of AF were evaluated.

RESULTS

1. PFV (10 cm3) was independently correlated with age (B=0.09, 95% CI 0.06-0.13, p<0.001), body mass index (BMI) (B=0.25, 95% CI 0.12-0.38, p<0.001), body surface area (BSA) (B=10.51, 95% CI 7.64-13.39, p<0.001), and left atrial (LA) dimension (B=0.09, 95% CI 0.03-0.14, p=0.003). 2. During the 19.3±8.5 month follow-up period, the clinical recurrence rate was 26.5%. PFV (HR 1.06; 95% CI 1.02-1.10, p= 0.004) and PeAF (HR 1.86; 95% CI 1.31-2.62, p<0.001) were independent predictors of clinical recurrence after RFCA. 3. PFV was significantly greater in PeAF patients with recurrence compared to those without (p=0.001), but, not in the PAF group (p=0.212). 4. PFV was independently associated with post-ablation recurrence only in PeAF (HR 1.10; 95% CI 1.05-1.16, p<0.001).

CONCLUSIONS

PFV was independently associated with old age, greater LA dimension, and high BMI and BSA, and a significant predictor for AF recurrence after catheter ablation for PeAF.

Epicardial fat, rather than pericardial fat, is independently associated with diastolic filling in subjects without apparent heart disease

BACKGROUND AND AIM

Epicardial and pericardial fat are separate fat depots surrounding the heart. Previous studies found epicardial fat to be associated with diastolic dysfunction, but they had some limitations. Pericardial fat association with diastolic dysfunction was not examined. Our aim was to assess the relation of epicardial and pericardial fat with diastolic filling.

METHODS AND RESULTS

In 73 volunteers without known heart disease or complaints, using echocardiography, we measured epicardial and pericardial fat thickness from long(LAX) and short(SAX) axis views and assessed diastolic filling: mitral inflow (E/A ratio, E wave deceleration time[DT]), pulmonary vein flow (systolic/diastolic ratio [S/D], systolic filling fraction[SFR], late retrograde velocity[Ar]), color M-mode flow propagation velocity [Vp], and tissue Doppler derived mitral early annular velocities at the septum [e' sep] and lateral wall [e'-lat]. By Spearman's correlation, epicardial fat from LAX had a weak, but statistically significant correlations with several diastolic filling indices (SFR{rs = 0.29, P = 0.02}, Ar{rs = 0.3, P = 0.01}, Vp{rs = -0.3, P = 0.01}, e' sep{rs = -0.23, P = 0.04}, e' lat{rs = -0.26, P = 0.03}). In multivariate logistic regression model adjusting for age, gender, diabetes, systolic blood pressure and left ventricle mass index, epicardial fat thickness from LAX (and not from SAX) was the only independent predictor of e' [e' sep < 8: OR = 1.8, 95%CI = 1.1-2.9; e' lat<10: OR = 1.6, 95%CI = 1.01-2.6]. After adjustment, Pericardial fat measured from LAX was independent predictor of e' lat only[e' lat < 10:OR = 1.3, 95% CI 1.03-1.6).

CONCLUSIONS

Epicardial fat measured from LAX is an independent predictor of myocardial relaxation. Pericardial fat independent association with diastolic filling is uncertain.

Pericardial fat, insulin resistance, and left ventricular structure and function in morbid obesity

BACKGROUND AND AIM

Morbid obesity is often accompanied by insulin resistance and increased ectopic fat surrounding the heart. We evaluated the relation of epicardial and pericardial fat with insulin resistance and left ventricular (LV) structure and function.

METHODS AND RESULTS

Epicardial and pericardial fat thicknesses were determined at 2-dimensional echocardiography in 80 morbid obese subjects [age 42 ± 12 years, 31% men, body mass index (BMI) 44.4 ± 7 kg/m(2)]. LV hypertrophy (LV mass ≥51 g/m(2.7)), inappropriately high LV mass for a given cardiac workload (observed vs predicted LV mass >128%), and stress-adjusted LV mid-wall fractional shortening were determined. Pericardial and epicardial fat thicknesses had direct associations with BMI (r = 0.40 and 0.45, both p < 0.01) and waist circumference (r = 0.37 and 0.45, both p < 0.01). Pericardial (partial r = 0.35, p < 0.01), but not epicardial fat thickness (partial r = 0.05, p = n.s.), was correlated with homeostasis model assessment-insulin resistance after adjustment for BMI. Pericardial fat also had a strong negative correlation with mid-wall fractional shortening (p = 0.01) and a positive one with inappropriately high LV mass (p < 0.01), while no such relation was found for epicardial fat (both p = n.s.). Independently of age, male sex, BMI, and anti-hypertensive treatment, pericardial fat thickness had an independent positive association with inappropriately high LV mass (β = 0.29, p = 0.02), and a negative one with stress-adjusted mid-wall fractional shortening (β = -0.26, p = 0.04).

CONCLUSIONS

Pericardial fat thickness is associated with insulin resistance, inappropriately high LV mass, and LV systolic dysfunction in obese individuals. Findings from this study confirm the existence of a connection between insulin resistance, cardiac ectopic fat deposition and cardiac dysfunction in morbid obesity.

MRI findings of pericardial fat necrosis: case report

Pericardial fat necrosis is an infrequent cause of acute chest pain and this can mimic acute myocardial infarction and acute pericarditis. We describe here a patient with the magnetic resonance imaging (MRI) findings of pericardial fat necrosis and this was correlated with the computed tomography (CT) findings. The MRI findings may be helpful for distinguishing pericardial fat necrosis from other causes of acute chest pain and from the fat-containing tumors in the cardiophrenic space of the anterior mediastinum.