Impact of obesity and epicardial fat on early left atrial dysfunction assessed by cardiac MRI strain analysis

Increased epicardial adipose tissue is associated with left atrial mechanical dysfunction in patients with heart failure with mildly reduced and preserved ejection fraction

INTRODUCTION

Heart failure (HF) with mildly reduced and preserved ejection fraction (HFmrEF/HFpEF) is often accompanied by atrial dysfunction. It has been suggested that specific ectopic fat depots, such as epicardial adipose tissue (EAT), may directly influence the myocardial cells and, therefore, be involved in the pathophysiology of atrial mechanical dysfunction. In this study, we aimed to investigate the association between EAT and left atrial (LA) mechanical dysfunction.

METHODS AND RESULTS

In total, 82 patients with symptomatic HF and left ventricular ejection fraction > 40% were prospectively enrolled. All patients underwent CMR while in sinus rhythm. LA mechanical dysfunction was defined as the presence of LA end-systolic volume index > 52 mL/m2 and LA reservoir strain < 23%. EAT volume was indexed for body surface area. Mean age was 69 ± 10 years, 42 (51%) were women and mean body mass index (BMI) was 29 ± 6 kg/m2. Mean LVEF was 55 ± 9% and 34 (41%) patients had LA mechanical dysfunction. In patients with LA mechanical dysfunction, the EAT volume was significantly higher than in patients without LA mechanical dysfunction (90 vs 105 mL/m2, p = 0.02) while BMI was similar. In multivariable logistic regression analyses, increased EAT remained significantly associated with LA mechanical dysfunction (OR 1.31, 95% CI 1.03-1.66, p = 0.03).

CONCLUSION

Increased EAT was associated with LA mechanical dysfunction in patients with HFmrEF and HFpEF. Further research is needed to elucidate the exact mechanisms that underlie this association.

Role of epicardial adipose tissue in diabetic cardiomyopathy through the lens of cardiovascular magnetic resonance imaging - a narrative review

Accumulating evidence suggests that ectopic/visceral adiposity may play a key role in the pathogenesis of nonischaemic cardiovascular diseases associated with type 2 diabetes. Epicardial adipose tissue (EAT) is a complex visceral fat depot, covering 80% of the cardiac surface with anatomical and functional contiguity to the myocardium and coronary arteries. EAT interacts with the biology of the underlying myocardium by secreting a wide range of adipokines. Magnetic resonance imaging (MRI) is the reference modality for structural and functional imaging of the heart. The technique is now also emerging as the reference imaging modality for EAT quantification. With this narrative review, we (a) surveyed contemporary clinical studies that utilized cardiovascular MRI to characterize EAT (studies published 2010-2023); (b) listed the clinical trials monitoring the response to treatment in EAT size as well as myocardial functional and structural parameters and (c) discussed the potential pathophysiological role of EAT in the development of diabetic cardiomyopathy. We concluded that increased EAT quantity and its inflammatory phenotype correlate with early signs of left ventricle dysfunction and may have a role in the pathogenesis of cardiac disease in diabetes with and without coronary artery disease.

Epicardial adipose tissue, metabolic disorders, and cardiovascular diseases: recent advances classified by research methodologies

Epicardial adipose tissue (EAT) is located between the myocardium and visceral pericardium. The unique anatomy and physiology of the EAT determines its great potential in locally influencing adjacent tissues such as the myocardium and coronary arteries. Classified by research methodologies, this study reviews the latest research progress on the role of EAT in cardiovascular diseases (CVDs), particularly in patients with metabolic disorders. Studies based on imaging techniques demonstrated that increased EAT amount in patients with metabolic disorders is associated with higher risk of CVDs and increased mortality. Then, in-depth profiling studies indicate that remodeled EAT may serve as a local mediator of the deleterious effects of cardiometabolic conditions and plays a crucial role in CVDs. Further, in vitro coculture studies provided preliminary evidence that the paracrine effect of remodeled EAT on adjacent cardiomyocytes can promote the occurrence and progression of CVDs. Considering the important role of EAT in CVDs, targeting EAT might be a potential strategy to reduce cardiovascular risks. Several interventions have been proved effective in reducing EAT amount. Our review provides valuable insights of the relationship between EAT, metabolic disorders, and CVDs, as well as an overview of the methodological constructs of EAT-related studies.

The correlation between epicardial fat thickness and longitudinal left atrial reservoir strain in patients with type 2 diabetes mellitus and controls

BACKGROUND

Diabetes mellitus (DM) has been documented among the strongest risk factors for developing heart failure with preserved ejection fraction (HFpEF). The earliest imaging changes in patients with DM are the left atrial (LA) functional and volumetric changes. The aim of this study was to determine the correlation between epicardial fat thickness (EFT) and longitudinal LA reservoir strain (LARS) in patients with type 2 DM (T2DM), as compared with non-diabetic controls.

RESULTS

The study samples in this case-control study comprised of consecutive patients with T2DM (n=64) and matched non-diabetic controls (n=30). An echocardiography was performed on all patients and EFT, volumetric and longitudinal LARS, left ventricular (LV) global longitudinal strain (LVGLS), pulsed-wave Doppler-derived transmitral early (E wave) and late (A wave) diastolic velocities, and tissue-Doppler-derived mitral annular early diastolic (e') and peak systolic (s') velocities were obtained. The study results demonstrated that the patients with T2DM had thicker EFT (5.96±2.13 vs. 4.10±3.11 mm) and increased LA volume index (LAVI) (43.05± 44.40 vs. 29.10±11.34 ml/m2) in comparison with the non-diabetic ones (p-value: 0.005 and 0.022, respectively). On the other hand, a direct association was observed between EFT and the E/e' ratio, and an inverse correlation was established between EFT and LARS in patients with T2DM (r=0.299, p-value=0.020 and r=- 0.256, p-value=0.043, respectively). However, regression analysis showed only LV mass index (LVMI) (β=0.012, 95% CI 0.006-0.019, p-value<0.001), LAVI (β=- 0.034, 95% CI - 0.05-0.017, p-value<0.001), and EFT (β=- 0.143, 95% CI - 0.264-- 0.021, p-value=0.021) were independently correlated with LARS.

CONCLUSIONS

LARS is considered as an important early marker of subclinical cardiac dysfunction. Thickened epicardial fat may be an independent risk factor for decreased LA reservoir strain. Diabetics are especially considered as a high risk group due to having an increased epicardial adipose tissue thickness.

Targeting epicardial adipose tissue: A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various comorbidities, multiple cardiac and extracardiac pathophysiologic abnormalities, and diverse phenotypic presentations. Since HFpEF is a heterogeneous disease with different phenotypes, individualized treatment is required. HFpEF with type 2 diabetes mellitus (T2DM) represents a specific phenotype of HFpEF, with about 45%-50% of HFpEF patients suffering from T2DM. Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM, which is intimately related to the expansion and dysfunction (inflammation and hypermetabolic activity) of epicardial adipose tissue (EAT). EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms. Therefore, suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM. Although there is no treatment specifically for EAT, lifestyle management, bariatric surgery, and some pharmaceutical interventions (anti-cytokine drugs, statins, proprotein convertase subtilisin/kexin type 9 inhibitors, metformin, glucagon-like peptide-1 receptor agonists, and especially sodium-glucose cotransporter-2 inhibitors) have been shown to attenuate the inflammatory response or expansion of EAT. Importantly, these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF. Accordingly, well-designed randomized controlled trials are needed to validate the efficacy of current therapies. In addition, more novel and effective therapies targeting EAT are needed in the future.

Association of sodium intake with adverse left atrial function and left atrioventricular coupling in Chinese

OBJECTIVES

High sodium intake is strongly associated with hypertension and obesity. This study aims to investigate the relationship between 24-h urinary sodium (a surrogate measure of sodium intake), ambulatory blood pressure parameters, left atrial function, and left atrioventricular coupling. Further, we intend to examine whether blood pressure and BMI might be mediators of the relationship between 24-h urinary sodium and subclinical cardiac function.

METHODS

Our study had 398 participants, all of whom were subjected to 24-h urine collection, 24-h ambulatory blood pressure measurement, and cardiac magnetic resonance imaging.

RESULTS

The average age of the participants was 55.70 ± 11.30 years old. The mean urinary sodium of the participants was 172.01 ± 80.24 mmol/24 h. After adjusting for age, sex, history of diabetes, smoking status, alcohol consumption, and use of diuretics, 24-h urinary sodium was correlated with multiple ambulatory blood pressure parameters, BMI, left atrial function, and the left atrioventricular coupling index (LACI) (P < 0.05). Mediation analysis showed that BMI explained 16% of the indirect effect of 24-h urinary sodium and left atrial function and 30% of the indirect effect of LACI. Independent of the mediator, 24-h urinary sodium had a significant direct effect on left atrial function and left atrioventricular coupling.

CONCLUSIONS

Higher 24-h urinary sodium was associated with a greater BMI as well as poor left atrial function and left atrioventricular coupling, and the BMI mediated the relationship between 24-h urinary sodium and subclinical left cardiac function. Furthermore, and more importantly, 24-h urinary sodium may have directly affected the left atrial function and left atrioventricular coupling independent of intermediary factors.

Adverse association of epicardial adipose tissue accumulation with cardiac function and atrioventricular coupling in postmenopausal women assessed by cardiac magnetic resonance imaging

Background

This study aims to investigate the association of epicardial adipose tissue (EAT) accumulation with cardiac function and atrioventricular coupling in a cohort of postmenopausal women assessed by cardiac magnetic resonance imaging (CMR).

Materials and methods

Overall, 283 postmenopausal women (mean age 61.5 ± 9.1 years) who underwent CMR examination were enrolled. Participants were classified into four groups by the quartile of EAT volume. EAT volume was quantified on short-axis cine stacks covering the entire epicardium. CMR-derived cardiac structure and function, including left atrial (LA)- volume, emptying fraction, deformation, and left ventricular (LV)- mass, volume, ejection fraction, and deformation, were compared among the four groups of graded EAT volume.

Results

Left ventricular mass (LVM) and LV remodeling index were both increased in the group with the highest EAT volume, compared to those in the lowest quartile (p = 0.016 and p = 0.003). The LV global longitudinal strain (LV-GLS), circumferential strain (LV-GCS), and LA- reservoir strain (LA-RS), conduit strain (LA-CS), and booster strain (LA-BS), were all progressively decreased from the lowest quartile of EAT volume to the highest (all p &lt; 0.05). Multivariable linear regression analyses showed that EAT was independently associated with LV-GLS, LA-RS, LA-CS, and LA-BS after adjusting for body mass index and other clinical factors.

Conclusion

Epicardial adipose tissue accumulation is independently associated with subclinical LV and LA function in postmenopausal women. These associations support the role of EAT in mediating deleterious effects on cardiac structure and function.

Left atrial evaluation by cardiovascular magnetic resonance: sensitive and unique biomarkers

Left atrial (LA) imaging is still not routinely used for diagnosis and risk stratification, although recent studies have emphasized its importance as an imaging biomarker. Cardiovascular magnetic resonance is able to evaluate LA structure and function, metrics that serve as early indicators of disease, and provide prognostic information, e.g. regarding diastolic dysfunction, and atrial fibrillation (AF). MR angiography defines atrial anatomy, useful for planning ablation procedures, and also for characterizing atrial shapes and sizes that might predict cardiovascular events, e.g. stroke. Long-axis cine images can be evaluated to define minimum, maximum, and pre-atrial contraction LA volumes, and ejection fractions (EFs). More modern feature tracking of these cine images provides longitudinal LA strain through the cardiac cycle, and strain rates. Strain may be a more sensitive marker than EF and can predict post-operative AF, AF recurrence after ablation, outcomes in hypertrophic cardiomyopathy, stratification of diastolic dysfunction, and strain correlates with atrial fibrosis. Using high-resolution late gadolinium enhancement (LGE), the extent of fibrosis in the LA can be estimated and post-ablation scar can be evaluated. The LA LGE method is widely available, its reproducibility is good, and validations with voltage-mapping exist, although further scan-rescan studies are needed, and consensus regarding atrial segmentation is lacking. Using LGE, scar patterns after ablation in AF subjects can be reproducibly defined. Evaluation of 'pre-existent' atrial fibrosis may have roles in predicting AF recurrence after ablation, predicting new-onset AF and diastolic dysfunction in patients without AF. LA imaging biomarkers are ready to enter into diagnostic clinical practice.

Impact of BMI on Left Atrial Strain and Abnormal Atrioventricular Interaction in Patients With Type 2 Diabetes Mellitus: A Cardiac Magnetic Resonance Feature Tracking Study

BACKGROUND

Type 2 diabetes mellitus (T2DM) and obesity often coexist and together contribute to left atrial (LA) functional abnormalities. However, little is known about the impact of body mass index (BMI) on LA strains measured using cardiac magnetic resonance feature tracking (MR-FT).

PURPOSE

To investigate the additive effect of BMI on LA functional remodeling using MR-FT as well as to explore abnormal atrioventricular interaction in T2DM patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and fifty-nine T2DM patients (53, 34, and 72 normal-weight, overweight, and obese individuals) and 105 non-diabetic controls (46, 32, and 27 normal-weight, overweight, and obese individuals).

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession.

ASSESSMENT

LA reservoir strain (ε_s ), conduit strain (ε_e ), and active strain (ε_a ) and their corresponding strain rates (SRs, SRe, SRa) were measured together with left ventricular (LV) radial, circumferential, and longitudinal peak strain, peak systolic strain rate, and peak diastolic strain rate.

STATISTICAL TESTS

Student's t-test or Mann-Whitney U test, one-way ANOVA, univariate and multivariate linear regression. A P value <0.05 was considered statistically significant.

RESULTS

Compared to controls in the same BMI category, T2DM patients had significantly decreased reservoir and conduit function, while pump function was not significantly different (ε_a and SRa: P = 0.757 and 0.583 for normal-weight, P = 0.171 and 0.426 for overweight, P = 0.067 and 0.330 for obese). LA strains were significantly correlated with BMI (r = -0.346 for ε_s , -0.345 for ε_e ) in T2DM patients. Multivariable linear regression analysis indicated that BMI was independently associated with LA ε_s and ε_e , LV global longitudinal strain was independently associated with LA ε_s and ε_a , and LV circumferential peak diastolic strain rate was independently associated with LA ε_e .

DATA CONCLUSION

These findings suggest that the coexistence of increased body weight and T2DM patients can exacerbate the impairment of LA strains and indicate abnormal atrioventricular interactions.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Left Ventricular Diastolic Function Studied with Magnetic Resonance Imaging: A Systematic Review of Techniques and Relation to Established Measures of Diastolic Function

Purpose: In recent years, cardiac magnetic resonance (CMR) has been used to assess LV diastolic function. In this systematic review, studies were identified where CMR parameters had been evaluated in healthy and/or patient groups with proven diastolic dysfunction or known to develop heart failure with preserved ejection fraction. We aimed at describing the parameters most often used, thresholds where possible, and correlation to echocardiographic and invasive measurements. Methods and results: A systematic literature review was performed using the databases of PubMed, Embase, and Cochrane. In total, 3808 articles were screened, and 102 studies were included. Four main CMR techniques were identified: tagging; time/volume curves; mitral inflow quantification with velocity-encoded phase-contrast sequences; and feature tracking. Techniques were described and estimates were presented in tables. From published studies, peak change of torsion shear angle versus volume changes in early diastole (−dφ′/dV′) (from tagging analysis), early peak filling rate indexed to LV end-diastolic volume <2.1 s⁻¹ (from LV time-volume curve analysis), enlarged LA maximal volume >52 mL/m², lowered LA total (<40%), and lowered LA passive emptying fractions (<16%) seem to be reliable measures of LV diastolic dysfunction. Feature tracking, especially of the atrium, shows promise but is still a novel technique. Conclusion: CMR techniques of LV untwisting and early filling and LA measures of poor emptying are promising for the diagnosis of LV filling impairment, but further research in long-term follow-up studies is needed to assess the ability for the parameters to predict patient related outcomes.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study

BACKGROUND

In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children.

PURPOSE

To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI.

STUDY TYPE

Prospective.

SUBJECTS

Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile).

FIELD STRENGTH

5 T.

SEQUENCE

Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views.

ASSESSMENT

Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated.

STATISTICAL TESTS

Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant.

RESULTS

As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m² ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%.

DATA CONCLUSION

MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3.

Predictors of left atrial remodeling in newly diagnosed hypertensive patients: a speckle-tracking echocardiographic study

Endothelial dysfunction, oxidative stress, and increased inflammatory activity are the main pathophysiological mechanisms responsible for cardiac remodeling secondary to hypertension. Bilirubin has anti-oxidant, anti-inflammatory, and anti-fibrotic functions. This report's objectives are to determine whether Query identifiers of left atrial (LA) remodeling, total atrial conduction time (TACT) and LA reservoir strain (LARS), are associated with serum total bilirubin levels, and to identify the possible predictors of LA remodeling in newly diagnosed hypertensive subjects. One hundred thirty-four subjects were enrolled in this study. TACT was evaluated by tissue Doppler imaging, and LARS was calculated by speckle-tracking echocardiography. Laboratory parameters were recorded. The subjects were classified into two separate groups according to the median value of TACT and LARS. In patients with supramedian TACT, LA volume index (LAVI) and epicardial adipose tissue (EAT) thickness were higher, while LARS and LVGLS were lower. In subjects with inframedian LARS, TACT was longer, LAVI and EAT thickness were higher, and LVGLS was lower. Patients with supramedian TACT and inframedian LARS were older and had lower total bilirubin. Total bilirubin, EAT thickness, and age were predictors of TACT and LARS. Serum bilirubin levels may have a protective effect on the LA remodeling process in newly diagnosed hypertensive subjects.

Association of pericardial adipose tissue with left ventricular structure and function: a region-specific effect?

BACKGROUND

The independent role of pericardial adipose tissue (PAT) as an ectopic fat associated with cardiovascular disease (CVD) remains controversial. This study aimed to determine whether PAT is associated with left ventricular (LV) structure and function independent of other markers of general obesity.

METHODS

We studied 2471 participants (50.9 % women) without known CVD from the Korean Genome Epidemiology Study, who underwent 2D-echocardiography with tissue Doppler imaging (TDI) and computed tomography measurement for PAT.

RESULTS

Study participants with more PAT were more likely to be men and had higher cardiometabolic indices, including blood pressure, glucose, and cholesterol levels (all P < 0.001). Greater pericardial fat levels across quartiles of PAT were associated with increased LV mass index and left atrial volume index (all P < 0.001) and decreased systolic (P = 0.015) and early diastolic (P < 0.001) TDI velocities, except for LV ejection fraction. These associations remained after a multivariable-adjusted model for traditional CV risk factors and persisted even after additional adjustment for general adiposity measures, such as waist circumference and body mass index. PAT was also the only obesity index independently associated with systolic TDI velocity (P < 0.001).

CONCLUSIONS

PAT was associated with subclinical LV structural and functional deterioration, and these associations were independent of and stronger than with general and abdominal obesity measures.

Associations of region-specific visceral adiposity with subclinical atrial dysfunction and outcomes of heart failure

AIMS

Excessive visceral adiposity (VAT) plays an essential role in metabolic derangements with those close to heart further mediates myocardial homeostasis. The disparate biological links between region-specific VAT and cardiometabolic profiles as mediators influencing atrial kinetics remain unexplored.

METHODS AND RESULTS

Among 1326 asymptomatic individuals, region-specific VAT including peri-aortic root fat (PARF) and total pericardial fat (PCF) of cardiac region, together with thoracic peri-aortic adipose tissue (TAT), was assessed using multiple-detector computed tomography. VAT measures were related to functional left atrial (LA) metrics assessed by speckle-tracking algorithm and clinical outcomes of atrial fibrillation (AF) and heart failure (HF). Multivariate linear regression models incorporating body fat, metabolic syndrome, and E/TDI-e' consistently demonstrated independent associations of larger PARF/PCF with peak atrial longitudinal systolic strain (PALS) reduction, higher LA stiffness, and worsened strain rate components; instead, TAT was independently associated with cardiometabolic profiles. PARF rather than PCF or TAT conferred independent prognostic values for incident AF/HF by multivariate Cox regression (adjusted hazard ratio: 1.56, 95% confidence interval: 1.17-2.08, P = 0.002) during a median of 1790 days (interquartile range: 25th to 75th: 1440-1927 days) of follow-up, with subjects categorized into worst PALS and largest VAT tertiles demonstrating highest events (all log-rank P < 0.001). Mediation analysis showed that higher triglyceride and lower high-density lipoproteins may serve as intermediary factors for effects between VAT and LA functional metrics, with lesser role by glucose level.

CONCLUSIONS

Visceral adiposity surrounding atrial region was tightly associated with subclinical atrial dysfunction and incident AF or HF beyond metabolic factors. Instead, peri-aortic adiposity may mediate their toxic effects mainly through circulating cardiometabolic profiles.

Volumetric evaluation of renal sinus adipose tissue on computed tomography images in bilateral nephrolithiasis patients

Purpose

To compare renal sinus fat volume (RSFV) separately within the right and left kidneys between bilateral nephrolithiasis patients and healthy controls.

Methods

This cross-sectional study analyzed patients who underwent unenhanced abdominal computed tomography (CT) divided into nephrolithiasis (n = 102) and healthy control (n = 130) groups. Age, sex, blood pressure [systolic blood pressure (SBP) and diastolic blood pressure (DBP)], estimated glomerular filtration rate (eGFR), body weight, and height of each participant were extracted. Volumetric renal sinus adipose tissue was measured separately for both kidneys on CT images. Urea, serum creatinine (Scr), uric acid (UA), total serum cholesterol (TCH), serum triglyceride (TG), and serum high- and low-density lipoprotein (HDL and LDL, respectively) cholesterol levels were obtained.

Results

Overall, 232 participants (mean age 47 years, 50% women) were enrolled. There were no differences in sex, DBP, urea, and LDL-cholesterol between the two groups (all p > 0.05). However, nephrolithiasis patients had higher age, BMI, SBP, and RSFV; higher Scr, UA, TCH, and TG serum levels; and lower HDL-cholesterol level and eGFR. Average left RSFV was significantly higher than right RSFV in healthy controls (4.56 ± 2.29 versus 3.34 ± 1.90 cm³, p < 0.001). A significant relationship between bilateral RSFV, age, BMI, SBP, and eGFR was noted in bilateral nephrolithiasis patients. Multivariate linear regression analysis showed age, BMI, and LDL-cholesterol to be independent predictors of left RSFV, and only BMI was an independent predictor of right RSFV.

Conclusions

Our data showed renal sinus adipose tissue accumulation and the relationship among RSFV, age, BMI, and LDL-cholesterol in bilateral nephrolithiasis patients.

Effect of Obesity on Left Atrial Strain in Persons Aged 35-55 Years (The Asklepios Study)

Obesity increases the risk of heart failure and atrial fibrillation. Left atrial (LA) dysfunction is increasingly recognized as a mediator of cardiovascular disease. Early effects of obesity on LA function have not been examined in large population samples. We quantified LA strain and strain rate (SR) through speckle tracking echocardiography in 1,531 middle-aged community-based participants enrolled in the Asklepios study. We compared LA function between individuals with body mass index (BMI) < 25 kg/m² (n = 779), 25 to 29.9 kg/m² (n = 618) and ≥ 30 kg/m² (n = 134). Significant differences in reservoir longitudinal LA strain (BMI < 25 kg/m² = 35.3%, BMI 25-29.9 kg/m² = 33.1%, and BMI ≥ 30 kg/m² = 30.9%; p < 0.00001) strain rate ([SR] BMI < 25 kg/m² = 151; BMI 25 to 29.9 kg/m² = 141; and BMI ≥ 30 kg/m² = 135 %/s; p <0.00001) and expansion index (BMI < 25 kg/m² = 1.6, BMI 25 to 29.9 kg/m² = 1.4, and BMI ≥ 30 kg/m² = 1.4; p <0.00001) were seen, indicating reduced reservoir function with increasing BMI. Obesity was also associated with impaired LA conduit function, including conduit longitudinal LA strain (BMI < 25 kg/m² = 21.6%, BMI 25 to 29.9 kg/m² = 18.9%, and BMI ≥ 30 kg/m² = 16.7%; p <0.00001), SR (BMI < 25 kg/m² = -189, BMI 25 to 29.9 kg/m² = 166, and BMI ≥ 30 kg/m² = 150 %/s; p <0.0001) and passive LA emptying fraction (BMI < 25 kg/m² = 40.5, BMI 25 to 29.9 kg/m² = 36.5, and BMI ≥ 30 kg/m² = 36%, p <0.00001). These differences persisted after adjustment for age, gender and other potential confounders. In contrast to reservoir and conduit function, obesity was associated with increased booster pump function (active LA emptying fraction: BMI < 25 kg/m² = 19.4%, BMI 25 to 29.9 kg/m² = 20.5%, and BMI ≥ 30 kg/m² = 21.5%; p <0.00001). In middle-aged adults, obesity is associated with impaired reservoir and conduit LA function and higher booster function, which may be compensatory. Loss of booster LA function, either because of more advanced LA dysfunction or atrial fibrillation, may play an important role in precipitating heart failure in obese individuals.

The Association Between Diabetes Mellitus and Atrial Fibrillation: Clinical and Mechanistic Insights

A number of clinical studies have reported that diabetes mellitus (DM) is an independent risk factor for Atrial fibrillation (AF). After adjustment for other known risk factors including age, sex, and cardiovascular risk factors, DM remains a significant if modest risk factor for development of AF. The mechanisms underlying the increased susceptibility to AF in DM are incompletely understood, but are thought to involve electrical, structural, and autonomic remodeling in the atria. Electrical remodeling in DM may involve alterations in gap junction function that affect atrial conduction velocity due to changes in expression or localization of connexins. Electrical remodeling can also occur due to changes in atrial action potential morphology in association with changes in ionic currents, such as sodium or potassium currents, that can affect conduction velocity or susceptibility to triggered activity. Structural remodeling in DM results in atrial fibrosis, which can alter conduction patterns and susceptibility to re-entry in the atria. In addition, increases in atrial adipose tissue, especially in Type II DM, can lead to disruptions in atrial conduction velocity or conduction patterns that may affect arrhythmogenesis. Whether the insulin resistance in type II DM activates unique intracellular signaling pathways independent of obesity requires further investigation. In addition, the relationship between incident AF and glycemic control requires further study.

Usefulness of Epicardial Adipose Tissue Volume to Predict Recurrent Atrial Fibrillation After Radiofrequency Catheter Ablation

Although increasing evidence suggests that epicardial adipose tissue volume (EATV) is associated with post-ablation atrial fibrillation (AF), ranges of EATV predictive of post-ablation recurrence of AF remain unclear. In this study, we evaluated: (1) relationships between EATV and characteristics of AF, (2) impact of EATV on recurrent AF after radiofrequency ablation; , and (3) cut-off point for recurrent AF using a receiver operating characteristic curve. In 218 consecutive symptomatic patients undergoing who underwent ablation for AF (143 paroxysmal AF; 78 persistent AF), the EATV index (EATVI: EATV/body surface area, mL/m²) was measured using 320-row multidetector computed tomography. The high EATV group showed specific cardiometabolic derangements as well as left atrial dilatation and left ventricular dysfunction. Multivariate regression analysis showed that the EATVI was an independent predictor of recurrent AF after catheter ablation. High EATV (EATVI ≥ 85 mL/m²) or EATVI cutoff ≥116 mL/m² can predict recurrent AF after catheter ablation, independent of other risk factors. In conclusion, EATVI was an independent predictor of recurrent AF after catheter ablation; a high EATV tertile or EATVI cutoff may be useful for prediction of recurrent AF after catheter ablation. Future studies should determine the utility of the EATVI in the clinical setting of AF ablation.

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

BACKGROUND

Abnormal left atrial (LA) function is a marker of cardiac dysfunction and adverse cardiovascular outcome, but is difficult to assess, and hence not, routinely quantified. We aimed to determine the feasibility and effectiveness of a fast method to measure long-axis LA strain and strain rate (SR) with standard cardiovascular magnetic resonance (CMR) compared to conventional feature tracking (FT) derived longitudinal strain.

METHODS

We studied 50 normal controls, 30 patients with hypertrophic cardiomyopathy, and 100 heart failure (HF) patients, including 40 with reduced ejection fraction (HFrEF), 30 mid-range ejection fraction (HFmrEF) and 30 preserved ejection fraction (HFpEF). LA longitudinal strain and SR parameters were derived by tracking the distance between the left atrioventricular junction and a user-defined point at the mid posterior LA wall on standard cine CMR two- and four-chamber views. LA performance was analyzed at three distinct cardiac phases: reservoir function (reservoir strain εs and strain rate SRs), conduit function (conduit strain εe and strain rate SRe) and booster pump function (booster strain εa and strain rate SRa).

RESULTS

There was good agreement between LA longitudinal strain and SR assessed using the fast and conventional FT-CMR approaches (r = 0.89 to 0.99, p < 0.001). The fast strain and SRs showed a better intra- and inter-observer reproducibility and a 55% reduction in evaluation time (85 ± 10 vs. 190 ± 12 s, p < 0.001) compared to FT-CMR. Fast LA measurements in normal controls were 35.3 ± 5.2% for εs, 18.1 ± 4.3% for εe, 17.2 ± 3.5% for εa, and 1.8 ± 0.4, - 2.0 ± 0.5, - 2.3 ± 0.6 s- 1 for the respective phasic SRs. Significantly reduced LA strains and SRs were observed in all patient groups compared to normal controls. Patients with HFpEF and HFmrEF had significantly smaller εs, SRs, εe and SRe than hypertrophic cardiomyopathy, and HFmrEF had significantly impaired LA reservoir and booster function compared to HFpEF. The fast LA strains and SRs were similar to FT-CMR for discriminating patients from controls (area under the curve (AUC) = 0.79 to 0.96 vs. 0.76 to 0.93, p = NS).

CONCLUSIONS

Novel quantitative LA strain and SR derived from conventional cine CMR images are fast assessable parameters for LA phasic function analysis.

Left ventricular subclinical myocardial dysfunction in uncomplicated type 2 diabetes mellitus is associated with impaired myocardial perfusion: a contrast-enhanced cardiovascular magnetic resonance study

BACKGROUND

Early detection of subclinical myocardial dysfunction in patients with diabetes mellitus (DM) is essential for recommending therapeutic interventions that can prevent or reverse heart failure, thereby improving the prognosis in such patients. This study aims to quantitatively evaluate left ventricular (LV) myocardial deformation and perfusion using cardiovascular magnetic resonance (CMR) imaging in patients with type 2 diabetes mellitus (T2DM), and to investigate the association between LV subclinical myocardial dysfunction and coronary microvascular perfusion.

METHODS

We recruited 71 T2DM patients and 30 healthy individuals as controls who underwent CMR examination. The T2DM patients were subdivided into two groups, namely the newly diagnosed DM group (n = 31, patients with diabetes for ≤ 5 years) and longer-term DM group (n = 40, patients with diabetes > 5 years). LV deformation parameters, including global peak strain (PS), peak systolic strain rate, and peak diastolic strain rate (PSDR), and myocardial perfusion parameters such as upslope, time to maximum signal intensity (TTM), and max signal intensity (Max SI, were measured and compared among the three groups. Pearson's correlation was used to evaluate the correlation between LV deformation and perfusion parameters.

RESULTS

Pooled data from T2DM patients showed a decrease in global longitudinal, circumferential, and radial PDSR compared to healthy individuals, apart from lower upslope. In addition, increased TTM and reduced Max SI were found in the longer-term diabetics compared to the normal subjects (p < 0.017 for all). Multivariable linear regression analysis showed that T2DM was independently associated with statistically significant CMR parameters, except for TTM (β = 0.137, p = 0.195). Further, longitudinal PDSR was significantly associated with upslope (r = - 0.346, p = 0.003) and TTM (r = 0.515, p < 0.001).

CONCLUSIONS

Our results imply that a contrast-enhanced 3.0T CMR can detect subclinical myocardial dysfunction and impaired myocardial microvascular perfusion in the early stages of T2DM, and that the myocardial dysfunction is associated with impaired coronary microvascular perfusion.

Left atrial function in obese and non-obese patients undergoing percutaneous pulmonary vein isolation

Obesity constitutes a risk factor for atrial fibrillation (AF) and modifies the efficacy of invasive AF treatment. Left atrial (LA) global longitudinal strain (GLS), which is measured using speckle-tracking echocardiography (STE), is one of the new methods that are helpful in evaluating the function of LA. The aim of the study was to evaluate LA function in obese and non-obese patients that were undergoing percutaneous pulmonary vein isolation (PVI) before and 6 months after the procedure. 89 patients (F/M: 31/58; mean age: 55.8 ± 9.8 years) with paroxysmal or persistent symptomatic AF that had been qualified for percutaneous PVI were prospectively enrolled in the study. Body mass index (BMI) constituted as a discriminating factor for the study groups: obese group: BMI ≥ 30 kg/m² (29 patients, F/M: 13/16, mean age: 55.13 ± 10.1 years) and non-obese group BMI < 30 kg/m² (60 patients, F/M: 18/42, mean age: 57.17 ± 9.0 years). Transthoracic echocardiography (TTE) with LA GLS and segmental longitudinal strain were analysed 1 day before and 6 months after PVI. PVI efficacy was evaluated 6 months after PVI via a seven-day Holter monitoring. Baseline analysis revealed significantly lower two-chamber (2-Ch) LA GLS in the obese patients compared to the non-obese subjects (− 10.55 ± 3.7 vs − 13.11 ± 5.1, p = 0.004). Segmental strain analysis showed no significant differences between the groups. The data that was obtained 6 months after PVI showed a significantly lower 4-Ch LA GLS in the obese patients compared to the non-obese subjects (− 11.04 ± 5.0 vs − 13.91 ± 4.2, p = 0.02), which was accompanied by a significantly lower segmental 4-Ch LA function in the obese patients (med-sept: − 11.66 ± 11.2 vs − 15.97 ± 5.3, p = 0.04; api-sept: − 9.04 ± 6.3 vs − 13.62 ± 6.5, p < 0.001; api-lat: − 7.62 ± 4.0 vs − 13.62 ± 6.5, p < 0.001; med-lat: −9.31 + − 7.9 vs − 15.04 + −  6.3, p = 0.003, global: − 11.04 + − 5.0 vs − 13.91 + − 4.2, p = 0.02). PVI efficacy was confirmed in 52 (58.4%) patients and was similar in both groups. Comparison of the baseline and 6-month strain revealed no differences in LA GLS in either group. Differences in LA GLS before and after the procedure (delta LA GLS) were not obesity dependent. Apical-septal and apical-lateral strain in the obese group, which were measured in 4-Ch view, were significantly lower after the procedure compared to the baseline (p < 0.001). Obese patients with paroxysmal AF were characterised by impaired LA GLS, which is persistent and was accompanied by segmental dysfunction after PVI at the 6-month follow-up. PVI efficacy was comparable between the obese and non-obese patients.

Association between epicardial adipose tissue, high-sensitivity C-reactive protein and myocardial dysfunction in middle-aged men with suspected metabolic syndrome

BACKGROUND

As body fat composition and metabolism differ between men and women, we evaluated sex-related differences in the association among epicardial adipose tissue (EAT), secretome profile, and myocardial function of subjects with suspected metabolic syndrome.

METHODS

We evaluated 277 participants (men, n = 140; 56.1 ± 4.7 years) who underwent conventional echocardiography and two-dimensional speckle tracking from the Seoul Metabolic Syndrome cohort. EAT was measured from the right ventricular free wall perpendicular to the aortic annulus at end systole. Global longitudinal strain (GLS) was obtained from 18 apical segments. Apolipoprotein A1, apolipoprotein B, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) levels were measured using immunoturbidimetry assay.

RESULTS

Mean age, body mass index, and hs-CRP level did not differ by sex. Waist circumference, fasting blood glucose level, and triglyceride/high-density lipoprotein cholesterol ratio were higher, and apolipoprotein AI and adiponectin levels were lower in men. No significant difference in mean EAT thickness was found (7.02 ± 1.81 vs. 7.13 ± 1.70 mm, p = 0.613). Men had a higher left ventricular (LV) mass index and lower GLS. EAT thickness was associated with hs-CRP level in men alone (ß = 0.206, p = 0.015). LV mass index (ß = 2.311, p = 0.037) and function represented by e' (ß = - 0.279, p = 0.001) and GLS (ß = - 0.332, p < 0.001) were independently associated with EAT thickness in men alone.

CONCLUSIONS

In middle-aged subjects with suspected metabolic syndrome, EAT was associated with inflammation represented by hs-CRP level, LV mass, and subclinical myocardial dysfunction only in men, suggesting that the inflammatory activity of EAT induced myocardial remodeling and dysfunction in middle-aged subjects but was attenuated in women. Trial registration NCT02077530 (date of registration: November 1, 2013).

Effect of the Epicardial Adipose Tissue Volume on the Prevalence of Paroxysmal and Persistent Atrial Fibrillation

BACKGROUND

Although increasing evidence suggests that epicardial adipose tissue volume (EATV) is associated with atrial fibrillation (AF), it is controversial whether there is a dose-response relationship of increasing EATV along the continuum of AF. We evaluated the effect of the EATV on the prevalence of paroxysmal AF (PAF) and persistent AF (PeAF) and the relationships with cardiac structure and functional remodeling.Methods and Results:Subjects who underwent multidetector computed tomography (MDCT) coronary angiography because of symptoms suggestive of coronary artery disease were divided into sinus rhythm (SR) (n=112), PAF (n=133), and PeAF (n=71) groups. The EATV index (EATV/body surface area, mL/m²) was strongly associated with the prevalence of PAF and PeAF on the model adjusted for known AF risk factors. The effect of the EATV index on the prevalence of PeAF, but not on that of PAF, was modified by the left atrial (LA) dimension, suggesting that extension of the LA dimension is related to EATV expansion in PeAF. The cutoff value of the EATV index for the prevalence was higher in PeAF than in PAF (64 vs. 55 mL/m², P<0.01).

CONCLUSIONS

The EATV index is associated with the prevalence of PAF and PeAF, and its cutoff values are predictive for PAF and PeAF development independently of other AF risk factors.

Relationships between epicardial adipose tissue thickness and adipo-fibrokine indicator profiles post-myocardial infarction

BACKGROUND

Determination of the impact of visceral obesity and epicardial adipose tissue thickness on stimulating growth factor levels during hospitalization for myocardial infarction is of potential importance for predicting outcomes and assessing the development of cardiofibrotic changes associated with maladaptive myocardial remodeling. In this study, we aimed to investigate the relationships between epicardial adipose tissue thickness, adipokine profiles, and the stimulating growth factor 2/interleukin-33 signaling system during hospitalization for myocardial infarction, and with the cardiac fibrosis extent 1-year post-MI in patients with visceral obesity.

METHODS

Eighty-eight patients with myocardial infarction were grouped based on their visceral obesity. Serum leptin, adiponectin, stimulating growth factor 2, and interleukin-33 levels were measured on days 1 and 12 and at 1 year. The epicardial adipose tissue widths and the cardiac fibrosis areas were measured on day 12 and at 1 year.

RESULTS

Visceral obesity was associated with epicardial adipose tissue thickness increases, adipokine imbalances, elevated leptin levels, and lower adiponectin levels during early hospitalization, and cardiac fibrosis development. Patients without visceral obesity had higher interleukin-33 and stimulating growth factor 2 levels during early hospitalization and lower cardiac fibrosis rates. Epicardial adipose tissue thickness was positively associated with cardiac fibrosis prevalence and interleukin-33 levels and negatively associated with stimulating growth factor 2 levels. The cardiac fibrosis extent was negatively associated with interleukin-33 levels and positively associated with stimulating growth factor 2 levels.

CONCLUSIONS

Increases in epicardial adipose tissue thickness are associated with cardiac fibrosis development 1-year post-myocardial infarction and are higher in patients with visceral obesity. The metabolic activity of the epicardial adipose tissue is associated with elevated interleukin-33 and reduced stimulating growth factor 2 levels.

Impact of overweight on left ventricular function in type 2 diabetes mellitus

Background

Coexistence of left ventricular (LV) longitudinal myocardial systolic dysfunction with LV diastolic dysfunction could lead to heart failure with preserved ejection fraction (HFpEF). Diabetes mellitus (DM) is known as a significant factor associated with HFpEF. Although the mechanisms of DM-related LV myocardial injury are complex, it has been postulated that overweight contributes to the development of LV myocardial injury in type 2 diabetes mellitus (T2DM) patients. However, the precise impact of overweight on LV longitudinal myocardial systolic function in T2DM patients remains unclear.

Methods

We studied 145 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease. LV longitudinal myocardial systolic function was assessed by global longitudinal strain (GLS), which was defined as the average peak strain of 18-segments obtained from standard apical views. Overweight was defined as body mass index (BMI) ≥ 25 kg/m². Ninety age-, gender- and LVEF-matched healthy volunteers served as controls.

Results

GLS of overweight T2DM patients was significantly lower than that of non-overweight patients (17.9 ± 2.4% vs. 18.9 ± 2.6%, p < 0.05), whereas GLS of both overweight and non-overweight controls was similar (19.8 ± 1.3% vs. 20.4 ± 2.1%, p = 0.38). Furthermore, multiple regression analysis revealed that for T2DM patients, BMI was the independent determinant parameters for GLS as well as LV mass index.

Conclusions

Overweight has a greater effect on LV longitudinal myocardial systolic function in T2DM patients than on that in non-DM healthy subjects. Our finding further suggests that the strict control of overweight in T2DM patients may be associated with prevention of the development of HFpEF.

Anatomic fat depots and cardiovascular risk: a focus on the leg fat using nationwide surveys (KNHANES 2008-2011)

BACKGROUND

Although central fat is a well-known risk factor for cardiovascular disease (CVD) and cardiometabolic disorders, the effect of other regional fats or muscle distribution on CVD risk has not been fully investigated.

METHODS

This was a cross-sectional study using nationally representative samples of 15,686 subjects from the 2008-2011 Korea National Health and Nutrition Examination Survey. Individual CVD risk was evaluated in adults aged ≥20 without prior CVD, using atherosclerotic cardiovascular disease (ASCVD) risk equations according to the 2013 ACC/AHA guidelines. Body composition was assessed by dual X-ray absorptiometry.

RESULTS

Ratio of leg fat to total fat (LF/TF ratio) was the most predictive for CVD among body fat or muscle distribution parameters (AUC = 0.748, 95% CI 0.741-0.755). ASCVD risk score was gradually increased with decreased LF/TF ratio (P < 0.001), and individuals whose LF/TF ratio in lowest tertile tended to belong to the high-risk (10-year risk >10%) group compared to those in the highest tertile (OR = 6.25, 95% CI 5.60-6.98). Subjects in the lowest tertile showed increased risk of cardiometabolic risk factor components including obesity, hypertension, diabetes, dyslipidemia, chronic kidney disease, and albuminuria (OR range 2.57-11.24, all P < 0.001). In addition, a higher LF/TF ratio was associated with decreased ASCVD risk, even in subjects with multiple CVD risk factors. Multiple logistic regression analyses also demonstrated this association (OR = 1.85, 95% CI 1.36-2.52).

CONCLUSIONS

Among various body composition parameters, LF/TF ratio was superior in predicting higher CVD risk and a higher LF/TF ratio was independently associated with decreased risk of CVD and each cardiometabolic risk factor.