The effect of hyperlipidemia and body fat distribution on subclinical left ventricular function in obesity: a cardiovascular magnetic resonance study.

BACKGROUND: Obesity is often associated with multiple comorbidities. However, whether obese subjects with hyperlipidemia in the absence of other complications have worse cardiac indices than metabolically healthy obese subjects is unclear. Therefore, we aimed to determine the effect of hyperlipidemia on subclinical left ventricular (LV) function in obesity and to evaluate the association of cardiac parameters with body fat distribution. MATERIALS AND METHODS: Ninety-two adults were recruited and divided into 3 groups: obesity with hyperlipidemia (n = 24, 14 males), obesity without hyperlipidemia (n = 25, 13 males), and c ntrols (n = 43, 25 males). LV strain parameters (peak strain (PS), peak diastolic strain rate (PDSR), peak systolic strain rate) derived from cardiovascular magnetic resonance tissue tracking were measured and compared. Dual-energy X-ray absorptiometer was used to measure body fat distribution. Correlations of hyperlipidemia and body fat distribution with LV strain were assessed by multivariable linear regression. RESULTS: Obese individuals with preserved LV ejection fraction showed lower global LV longitudinal, circumferential, and radial PS and longitudinal and circumferential PDSR than controls (all P < 0.05). Among obese patients, those with hyperlipidemia had lower longitudinal PS and PDSR and circumferential PDSR than those without hyperlipidemia (- 12.8 ± 2.9% vs. - 14.2 ± 2.7%, 0.8 ± 0.1 s-1 vs. 0.9 ± 0.3 s-1, 1.2 ± 0.2 s-1 vs. 1.4 ± 0.2 s-1; all P < 0.05). Multivariable linear regression demonstrated that hyperlipidemia was independently associated with circumferential PDSR (ß = - 0.477, P < 0.05) in obesity after controlling for growth differences, other cardiovascular risk factors, and central fat distribution. In addition, android fat had an independently negative relationship with longitudinal and radial PS (ß = - 0.486 and ß = - 0.408, respectively; all P < 0.05); and visceral fat was negatively associated with longitudinal PDSR (ß = - 0.563, P < 0.05). Differently, gynoid fat was positively correlated with circumferential PS and PDSR and radial PDSR (ß = 0.490, ß = 0.481, and ß = 0.413, respectively; all P < 0.05). CONCLUSION: Hyperlipidemia is independently associated with subclinical LV diastolic dysfunction in obesity. Central fat distribution (android and visceral fat) has a negative association, while peripheral fat distribution (gynoid fat) has a positive association on subclinical LV function. These results suggest that appropriate management of hyperlipidemia may be beneficial for obese patients, and that the differentiation of fat distribution in different regions may facilitate the precise management of obese patients. Clinical trials registration Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476).

Myocardial tissue remodeling in early adult obesity and its association with regional adipose tissue distribution and ectopic fat deposits: a prospective study.

OBJECTIVES: To evaluate the left ventricular (LV) myocardial tissue characteristics in early adult obesity and its association with regional adipose tissue and ectopic fat deposition. METHODS: Forty-nine obese adults (mean body mass index: 29.9 ± 2.0 kg/m2) and 44 healthy controls were prospectively studied. LV native and post-contrast T1 values, extracellular volume fraction (ECV), regional adipose tissue (epicardial, visceral, and subcutaneous adipose tissue (EAT, VAT, and SAT)), and ectopic fat deposition (hepatic and pancreatic proton density fat fractions (H-PDFF and P-PDFF)) based on magnetic resonance imaging were compared. The association was assessed by multivariable linear regression. RESULTS: The obese participants showed reduced global ECV compared to the healthy controls (p < 0.05), but there was no significant difference in global native or post-contrast T1 values between the two groups. Additionally, the obese individuals exhibited higher EAT, VAT, SAT, H-PDFF, and P-PDFF than the controls (p < 0.05). ECV was associated with insulin resistance, dyslipidemia, and systolic blood pressure (SBP) (p < 0.05). Multiple linear regression demonstrated that H-PDFF and SAT were independently associated with ECV in entire population (ß = - 0.123 and - 0.012; p < 0.05). CONCLUSIONS: Reduced myocardial ECV in patients with mild-to-moderate obesity and its relationship to SBP may indicate that cardiomyocyte hypertrophy, rather than extracellular matrix expansion, is primarily responsible for myocardial tissue remodeling in early adult obesity. Our findings further imply that H-PDFF and SAT are linked with LV myocardial tissue remodeling in this cohort beyond the growth difference and cardiovascular risk factors. CLINICAL TRIALS REGISTRATION: Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476). CLINICAL RELEVANCE STATEMENT: Myocardial fibrosis in severe obesity predicts poor prognosis. We showed that cardiomyocyte hypertrophy, not myocardial fibrosis, is the main myocardial tissue characteristic of early obesity. This finding raises the possibility that medical interventions, like weight loss, may prevent cardiac fibrosis. KEY POINTS: • Myocardial tissue characteristics in early adult obesity are unclear. • Myocardial extracellular volume fraction (ECV) can be quantitatively evaluated using T1 mapping based on cardiac magnetic resonance imaging (MRI). • Cardiac MRI-derived ECV may noninvasively evaluate myocardial tissue remodeling in early adult obesity.

Radiomics Based on Single-Phase CTA for Distinguishing Left Atrial Appendage Thrombus from Circulatory Stasis in Patients with Atrial Fibrillation before Ablation.

Differentiation of left atrial appendage thrombus (LAAT) and left atrial appendage (LAA) circulatory stasis is difficult when based only on single-phase computed tomography angiography (CTA) in routine clinical practice. Radiomics provides a promising tool for their identification. We retrospectively enrolled 204 (training set: 144; test set: 60) atrial fibrillation patients before ablation, including 102 LAAT and 102 circulatory stasis patients. Radiomics software was used to segment whole LAA on single-phase CTA images and extract features. Models were built and compared via a multivariable logistic regression algorithm and area under of the receiver operating characteristic curves (AUCs), respectively. For the radiomics model, radiomics clinical model, radiomics radiological model, and combined model, the AUCs were 0.82, 0.86, 0.90, 0.93 and 0.82, 0.82, 0.84, 0.85 in the training set and the test set, respectively (p < 0.05). One clinical feature (rheumatic heart disease) and four radiological features (transverse diameter of left atrium, volume of left atrium, location of LAA, shape of LAA) were added to the combined model. The combined model exhibited excellent differential diagnostic performances between LAAT and circulatory stasis without increasing extra radiation exposure. The single-phase, CTA-based radiomics analysis shows potential as an effective tool for accurately detecting LAAT in patients with atrial fibrillation before ablation.

Computed Tomography-Based Radiomics for Differentiation of Thymic Epithelial Tumors and Lymphomas in Anterior Mediastinum.

Objective: To investigate the differential diagnostic performance of computed tomography (CT)-based radiomics in thymic epithelial tumors (TETs) and lymphomas in anterior mediastinum. Methods: There were 149 patients with TETs and 93 patients with lymphomas enrolled. These patients were assigned to a training set (n = 171) and an external validation set (n = 71). Dedicated radiomics prototype software was used to segment lesions on preoperative chest enhanced CT images and extract features. The multivariable logistic regression algorithm was used to construct three models according to clinico-radiologic features, radiomics features, and combined features, respectively. Performance of the three models was compared by using the area under the receiver operating characteristic curves (AUCs). Decision curve analysis was used to evaluate clinical utility of the three models. Results: For clinico-radiologic model, radiomics signature model, and combined model, the AUCs were 0.860, 0.965, 0.975 and 0.843, 0.961, 0.955 in the training cohort and the test cohort, respectively (all P<0.05). The accuracies of each model were 0.836, 0.895, 0.918 and 0.845, 0.901, 0.859 in the two cohorts, respectively (all P<0.05). Compared with the clinico-radiologic model, better diagnostic performances were found in the radiomics signature model and the combined model. Conclusions: Radiomics signature model and combined model exhibit outstanding and comparable differential diagnostic performances between TETs and lymphomas. The CT-based radiomics analysis might serve as an effective tool for accurately differentiating TETs from lymphomas before treatment.

The effect of community-acquired pneumonia on myocardial injury in systemic lupus erythematosus: Insights from cardiac magnetic resonance.

OBJECTIVES: Myocardial injury (MInj) in systemic lupus erythematosus (SLE) has been observed in several studies. However, clinical predictors of MInj remain unclear. We aim to explore the effects of community-acquired pneumonia (CAP) on MInj in SLE patients according to cardiac magnetic resonance (CMR) T1 mapping. METHODS: SLE patients with or without CAP and healthy controls underwent CMR screening. The CMR protocol included: cines, T1- and T2 mapping, and late gadolinium enhancement (LGE). Clinical characteristics, CMR findings, and T1 mapping measuremments were compared between subgroups. Clinical assessment was performed on the subjects. RESULTS: Thirty-eight SLE patients were screened, including 18 patients with CAP (CAP group) and 20 age- and gender-matched patients without CAP (non-CAP group) as well as 26 healthy controls. The platelet count of CAP group was higher than the non-CAP group (p = 0.015). Compared with the health control group, native T1 was higher in the CAP group (p < 0.001) and the non-CAP group (p = 0.002). ECV was higher in the CAP group (p < 0.001) and the non-CAP group (p = 0.002). The LV ejection fraction (p = 0.049) and RV ejection fraction (p = 0.026) of the CAP group was lower than that of the healthy control group, whereas no significant difference was observed between non-CAP and healthy control groups. CONCLUSIONS: This is the first study that assesses the effects of CAP on MInj of SLE patients by CMRI T1 mapping. We highlight SLE patients with CAP who are at increased risk of MInj, manifesting as myocardial inflammation, diffuse myocardial fibrosis, and decreased ventricular function.

Regional Fat Distributions Are Associated With Subclinical Right Ventricular Dysfunction in Adults With Uncomplicated Obesity.

Objective: Obesity is a prominent public health problem that has increased cardiovascular mortality risks. However, the specific effects of obesity, independent of comorbidities, on cardiac structure and function have not been well clarified, especially those effects on the right ventricle (RV). Cardiovascular magnetic resonance (CMR) tissue tracking can assess detailed RV mechanical features. This study aimed to evaluate RV strain using CMR in uncomplicated obese adults and assess its association with fat distributions. Methods: A total of 49 obese patients and 30 healthy controls were included. The RV global systolic function and strain parameters based on CMR were assessed. Body fat distributions were measured with dual X-ray absorptiometry. RV function indices of obese patients were compared with those of healthy controls. Correlations among related body fat distribution parameters and RV function indices were conducted with multivariable linear regression. Results: Compared with healthy controls, the obese group had impaired RV strain with lower global longitudinal peak strain (PS), longitudinal peak systolic strain rate (PSSR), circumferential and longitudinal peak diastolic strain rates (PDSR) (all P < 0.05), while LV and RV ejection fractions were not significantly different between the two groups (P > 0.05). Multivariable linear regression analysis demonstrated that android fat% was independently associated with longitudinal PS (ß = -0.468, model R2 = 0.219), longitudinal PDSR (ß = -0.487, model R2 = 0.237), and circumferential PSSR (ß = -0.293, model R2 = 0.086). Trunk fat% was independently associated with longitudinal PSSR (ß = -0.457, model R2 = 0.209). In addition, the strongest correlations of circumferential PDSR were BMI and gynoid fat% (ß = -0.278, ß = 0.369, model R2 = 0.324). Conclusions: Extensive subclinical RV dysfunction is found in uncomplicated obese adults. BMI, as an index of overall obesity, is independently associated with subclinical RV dysfunction. In addition, central obesity (android fat and trunk fat distributions) has a negative effect on subclinical RV function, while peripheral obesity (gynoid fat distribution) may have a positive effect on it. Clinical Trials Registration: Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476).

Cardiac remodeling and subclinical left ventricular dysfunction in adults with uncomplicated obesity: a cardiovascular magnetic resonance study.

Background: Obesity often exists alongside comorbidities and increases the risk of heart failure and cardiovascular mortality. However, the specific effects of obesity on cardiac structure and function have not been clarified. This study set out to evaluate left ventricular (LV) geometric and functional changes using cardiovascular magnetic resonance imaging (CMR) in adults with uncomplicated obesity. Methods: Forty-eight patients with uncomplicated obesity [body mass index (BMI) mean ± SD: 29.8±2.1 kg/m2] and 25 healthy controls were included in this study. CMR was used to assess LV geometry, global systolic function, and strains, and to quantify epicardial adipose tissue (EAT). Body composition was measured by dual X-ray absorptiometry. Results: Compared with healthy controls, patients with obesity had increased LV size, mass, and myocardial thickness, and impaired myocardial contractility, with lower global radial, circumferential, and longitudinal peak strains (PS), and circumferential and longitudinal peak diastolic strain rates (PDSR; all P<0.05). Multivariable linear regression showed that BMI was independently associated with LV maximum myocardial thickness (LVMMT) (ß=0.197, P=0.016). Visceral adipose tissue (VAT) was independently associated with LV global longitudinal PS (ß=-2.684, P=0.001), and both longitudinal (ß=-0.192, P=0.002) and circumferential (ß=-0.165, P=0.014) PDSR. Homeostasis model assessment of insulin resistance (HOMA-IR) was mildly correlated with BMI (r=0.327) and body fat percentage (BF%) (r=0.295) in patients with obesity (all P<0.05). HOMA-IR was independently associated with LV global circumferential PS (ß=-0.276, P=0.04) and PDSR (ß=-0.036, P=0.026). Conclusions: Extensive LV geometric remodeling and marked changes in cardiac strains were observed in adults with obesity. Tissue tracking with CMR can reveal subclinical impaired ventricular function with preserved LV ejection fraction in such patients. BMI was independently related to LV remodeling in obesity. HOMA-IR and VAT are potentially superior to BMI as predictors of subclinical dysfunction, assessed by strain, in obesity. Trial Registry: This study has been registered with the Chinese Clinical Trial Registry (ID: ChiCTR1900026476; Effect of lifestyle intervention on metabolism of obese patients based on smart phone software).

Characterization and clinical significance of biventricular mechanics in patients with systemic lupus erythematosus by 3T cardiovascular magnetic resonance tissue tracking.

BACKGROUND: Detecting impaired left ventricle (LV) or right ventricle (RV) mechanics could aid in fully understanding the process of cardiac involvement in patients with systemic lupus erythematosus (SLE). This study aimed to evaluate biventricular strain parameters derived from cardiac magnetic resonance (CMR) tissue tracking in SLE patients and their association with other clinical variables. METHODS: A group of 47 SLE patients and 27 healthy controls were enrolled and underwent CMR examination, including cine and late gadolinium enhancement (LGE) imaging. Aside from RV strain parameters in the radial direction, biventricular global peak strain and peak systolic/diastolic global strain rate in radial, circumferential, and longitudinal directions were assessed for each participant. Multivariate linear regression analysis was used to analyze the factors related to the biventricular strain parameters. Receiver operating characteristic (ROC) analysis was used to identify RV dysfunction. RESULTS: Compared with the controls, part of the biventricular strain parameters in the SLE subgroup with preserved ejection fraction (EF) were impaired, which was more significant in the SLE subgroup with reduced EF (all P<0.05). The SLE patients with RV dysfunction (15/47) included patients with LV dysfunction (8/47). The RVEF was associated with impaired LV global peak strain and peak diastolic strain rate in the SLE patients (absolute value of ß=0.406-0.715, all P<0.05). The LV LGE in SLE patients (12/47) was associated with LV global longitudinal peak strain and peak diastolic global longitudinal strain rate (ß=0.378 and -0.342; all P<0.05). There were independent correlations between pulmonary arterial hypertension and RV global longitudinal peak strain, anti-ribonucleoprotein (RNP) antibody and RV global circumferential peak strain, and pericardial effusion and RV peak diastolic global circumferential strain rate, respectively (ß=0.319, 0.359, and -0.285, respectively; all P<0.05). The LV global longitudinal peak strain had greater diagnostic accuracy for RV dysfunction RV dysfunction [area under curve (AUC): 0.933, cut-off value: -13.38%). CONCLUSIONS: Biventricular strain parameters derived from CMR are sensitive markers of subclinical ventricular function impairment before EF reduction at an early stage of SLE. Biventricular strain analysis could be considered for inclusion in early cardiac functional assessment in SLE patients, particularly LV global longitudinal peak strain, which might assist in therapeutic decision-making and disease monitoring.

Erdheim-Chester disease with multisystem involvement evaluated by multimodal imaging: A case report.

Erdheim-Chester disease is a rare, idiopathic, multisystemic non-Langerhans cell histiocytosis. Little is known about the imaging features. Herein, we report a very uncommon case of Erdheim-Chester disease in a 54-year-old woman with multisystem involvement including cardiovascular system, skeleton, retroperitoneum (renal and adrenal infiltration), orbit and pituitary. Multimodal imaging modalities, including computed tomography, magnetic resonance imaging, echocardiography, and bone scintigraphy were used to comprehensively evaluate different organs involvement. Finally, myocardial biopsy results indicated Erdheim-Chester disease. Electrocardiography showed sick sinus syndrome and slowest heart rate of 20 beats/min. The patient underwent permanent pacemaker implantation and had initial treatment with interferon. There were no remarkable changes in right atrial lesion during 9-month follow-up period. Erdheim-Chester disease was a rare entity with a dismal prognosis, especially when there were cardiac and neurological involvement. The present case report aimed to described and analyzed radiological findings of multiple organs involvement of Erdheim-Chester disease with multimodal imaging retrospectively, and being familiar with the imaging features of Erdheim-Chester disease might help prompt and correct diagnosis of this disease in the future.

Radiomic analysis of enhanced CMR cine images predicts left ventricular remodeling after TAVR in patients with symptomatic severe aortic stenosis.

Objective: This study aimed to develop enhanced cine image-based radiomic models for non-invasive prediction of left ventricular adverse remodeling following transcatheter aortic valve replacement (TAVR) in symptomatic severe aortic stenosis. Methods: A total of 69 patients (male:female = 37:32, median age: 66 years, range: 47-83 years) were retrospectively recruited, and severe aortic stenosis was confirmed via transthoracic echocardiography detection. The enhanced cine images and clinical variables were collected, and three types of regions of interest (ROIs) containing the left ventricular (LV) myocardium from the short-axis view at the basal, middle, and apical LV levels were manually labeled, respectively. The radiomic features were extracted and further selected by using the least absolute shrinkage and selection operator (LASSO) regression analysis. Clinical variables were also selected through univariate regression analysis. The predictive models using logistic regression classifier were developed and validated through leave-one-out cross-validation. The model performance was evaluated with respect to discrimination, calibration, and clinical usefulness. Results: Five basal levels, seven middle levels, eight apical level radiomic features, and three clinical factors were finally selected for model development. The radiomic models using features from basal level (Rad I), middle level (Rad II), and apical level (Rad III) had achieved areas under the curve (AUCs) of 0.761, 0.909, and 0.913 in the training dataset and 0.718, 0.836, and 0.845 in the validation dataset, respectively. The performance of these radiomic models was improved after integrating clinical factors, with AUCs of the Combined I, Combined II, and Combined III models increasing to 0.906, 0.956, and 0.959 in the training dataset and 0.784, 0.873, and 0.891 in the validation dataset, respectively. All models showed good calibration, and the decision curve analysis indicated that the Combined III model had a higher net benefit than other models across the majority of threshold probabilities. Conclusion: Radiomic models and combined models at the mid and apical slices showed outstanding and comparable predictive effectiveness of adverse remodeling for patients with symptomatic severe aortic stenosis after TAVR, and both models were significantly better than the models of basal slice. The cardiac magnetic resonance radiomic analysis might serve as an effective tool for accurately predicting left ventricular adverse remodeling following TAVR in patients with symptomatic severe aortic stenosis.

Amino Acid Principal Component Analysis (AAPCA) and its applications in protein structural class prediction.

The extremely complicated nature of many biological problems makes them bear the features of fuzzy sets, such as with vague, imprecise, noisy, ambiguous, or input-missing information For instance, the current data in classifying protein structural classes are typically a fuzzy set To deal with this kind of problem, the AAPCA (Amino Acid Principal Component Analysis) approach was introduced. In the AAPCA approach the 20-dimensional amino acid composition space is reduced to an orthogonal space with fewer dimensions, and the original base functions are converted into a set of orthogonal and normalized base functions The advantage of such an approach is that it can minimize the random errors and redundant information in protein dataset through a principal component selection, remarkably improving the success rates in predicting protein structural classes It is anticipated that the AAPCA approach can be used to deal with many other classification problems in proteins as well.

Heuristic molecular lipophilicity potential (HMLP): lipophilicity and hydrophilicity of amino acid side chains.

Heuristic molecular lipophilicity potential (HMLP) is applied in the study of lipophilicity and hydrophilicity of 20 natural amino acids side chains. The HMLP parameters, surface area S(i), lipophilic indices L(i), and hydrophilic indices H(i) of amino acid side chains are derived from lipophilicity potential L(r). The parameters are correlated with the experimental data of phase-transferring free energies of vapor-to-water, vapor-to-cyclohexane, vapor-to-octanol, cyclohexane-to-water, octanol-to-water, and cyclohexane-to-octanol through a linear free energy equation DeltaG(0)(tr,i) = b(0) + b(1)S(i) (+) + b(2)S(i) (-) + b(3)L(i) + b(4)H(i). For all above six phase-transfer free energies, the HMLP parameters of 20 amino acid side chains give good calculation results using linear free energy equation. HMLP is an ab initio quantum chemical approach and a structure-based technique. Except for atomic van der Waals radii, there are no other empirical parameters used. The HMLP has clear physical and chemical meaning and provides useful lipophilic and hydrophilic parameters for the studies of proteins and peptides.