Boundary attention with multi-task consistency constraints for semi-supervised 2D echocardiography segmentation.

The 2D echocardiography semantic automatic segmentation technique is important in clinical applications for cardiac function assessment and diagnosis of cardiac diseases. However, automatic segmentation of 2D echocardiograms also faces the problems of loss of image boundary information, loss of image localization information, and limitations in data acquisition and annotation. To address these issues, this paper proposes a semi-supervised echocardiography segmentation method. It consists of two models: (1) a boundary attention transformer net (BATNet) and (2) a multi-task level semi-supervised model with consistency constraints on boundary features (semi-BATNet). BATNet is able to capture the location and spatial information of the input feature maps by using the self-attention mechanism. The multi-task level semi-supervised model with boundary feature consistency constraints (semi-BATNet) encourages consistent predictions of boundary features at different scales from the student and teacher networks to calculate the multi-scale consistency loss for unlabeled data. The proposed semi-BATNet was extensively evaluated on the dataset of cardiac acquisitions for multi-structure ultrasound segmentation (CAMUS) and self-collected echocardiography dataset from the First Affiliated Hospital of Chongqing Medical University. Experimental results on the CAMUS dataset showed that when only 25% of the images are labeled, the proposed method greatly improved the segmentation performance by utilizing unlabeled images, and it also outperformed five state-of-the-art semi-supervised segmentation methods. Moreover, when only 50% of the images labeled, semi-BATNet achieved the Dice coefficient values of 0.936, the Jaccard similarity of 0.881 on self-collected echocardiography dataset. Semi-BATNet can complete a more accurate segmentation of cardiac structures in 2D echocardiograms, indicating that it has the potential to accurately and efficiently assist cardiologists.

Severity of functional tricuspid regurgitation is associated with mortality in patients with pulmonary hypertension in long-term follow-up.

Pulmonary hypertension (PH) is a hemodynamic and pathophysiologic state present in many cardiovascular, respiratory, and systemic diseases. PH is considered to have a higher risk of cardiovascular events and mortality. The most common type of functional tricuspid regurgitation (FTR) is associated with PH. The aim of this study was to evaluate the association between FTR severity and mortality in PH in western China. This is a retrospective analysis in PH patients and all patients underwent right-heart catheterization (RHC) for hemodynamic measurements. The FTR severity was determined according to the guidelines. Uni- and multivariate analyses were used to identify risk factors for mortality. From 2015 to 2021, 136 patients with PH with a median age of 50 years (interquartile range [IQR]: 35-64 years). During 26-month median follow-up (mean 27.7 ± 15.1 months), 40 (29.2%) patients died (mean after 21.7 ± 14.1 months). In the univariate Cox regression analysis, World Health Organization functional class (WHO FC) III/IV, elevated B-type natriuretic peptide, pulmonary vascular resistance (≥16.2 Wood units), pulmonary artery oxygen saturation, severe FTR and right ventricular diameter/left ventricular diameter (≥0.62) were significantly associated with mortality. In the multivariate Cox regression analysis, severe FTR, WHO FC III/IV, and right ventricular end-diastolic pressure (RVEDP) were risk factors for mortality. Severe FTR at baseline was strongly associated with mortality in both precapillary and postcapillary PH patients, independent of the other risk factors as RVEDP, HO FC III/IV, optimal pulmonary arterial hypertension targeted therapy.

Phonocardiogram transfer learning-based CatBoost model for diastolic dysfunction identification using multiple domain-specific deep feature fusion.

Left ventricular diastolic dyfunction detection is particularly important in cardiac function screening. This paper proposed a phonocardiogram (PCG) transfer learning-based CatBoost model to detect diastolic dysfunction noninvasively. The Short-Time Fourier Transform (STFT), Mel Frequency Cepstral Coefficients (MFCCs), S-transform and gammatonegram were utilized to perform four different representations of spectrograms for learning the representative patterns of PCG signals in two-dimensional image modality. Then, four pre-trained convolutional neural networks (CNNs) such as VGG16, Xception, ResNet50 and InceptionResNetv2 were employed to extract multiple domain-specific deep features from PCG spectrograms using transfer learning, respectively. Further, principal component analysis and linear discriminant analysis (LDA) were applied to different feature subsets, respectively, and then these different selected features are fused and fed into CatBoost for classification and performance comparison. Finally, three typical machine learning classifiers such as multilayer perceptron, support vector machine and random forest were employed to compared with CatBoost. The hyperparameter optimization of the investigated models was determined through grid search. The visualized result of the global feature importance showed that deep features extracted from gammatonegram by ResNet50 contributed most to classification. Overall, the proposed multiple domain-specific feature fusion based CatBoost model with LDA achieved the best performance with an area under the curve of 0.911, accuracy of 0.882, sensitivity of 0.821, specificity of 0.927, F1-score of 0.892 on the testing set. The PCG transfer learning-based model developed in this study could aid in diastolic dysfunction detection and could contribute to non-invasive evaluation of diastolic function.

Impact of Brachial-Ankle Pulse Wave Velocity on Myocardial Work by Non-invasive Left Ventricular Pressure-Strain in Non-hypertensive and Hypertensive Patients With Preserved Left Ventricular Ejection Fraction.

OBJECTIVE: Data regarding the influence of arterial stiffness on myocardial work (MW) has been scarce. This study was performed to investigate the association between brachial-ankle pulse wave velocity (baPWV) and MW by non-invasive left ventricular pressure-strain in a population of non-hypertensive and hypertensive individuals. METHODS: Two hundred and eight participants (104 hypertensive and 104 non-hypertensive individuals) were prospectively enrolled into the study. All participants underwent conventional echocardiography, as well as 2D speckle-tracking echocardiography to assess MW by non-invasive left ventricular pressure-strain and global longitudinal strain (GLS). baPWV measurements were made at the same day as the echocardiography. Then, participants were categorized according to baPWV tertiles. Correlation between baPWV and MW were analyzed. Predicting ability of baPWV for abnormal WM was analyzed using receiver operating characteristic (ROC) curve. RESULTS: The median baPWV from the low to high tertile groups were 1286.5 (1197.5-1343.5), 1490.0 (1444.5-1544.0), and 1803.8(1708.3-1972.0) cm/s, respectively. In simple linear regression analysis, baPWV had a significant positive association with global work index (GWI), global constructed work (GCW), and global wasted work (GWW), and a negative association with global work efficiency (GWE). The association remained significant after adjusting for major confounding factors in multiple linear regression analysis. The areas under the ROC curve of baPWV for predicting abnormal GWI, GCW, GWW, and GWE were 0.653, 0.666, 0.725, and 0.688, respectively (all p < 0.05). CONCLUSIONS: BaPWV is significantly associated with all four components of MW using non-invasive left ventricular pressure-strain method in a mixed population of non-hypertensive and hypertensive individuals.

Non-invasive global myocardial work index as a new surrogate of ventricular-arterial coupling in hypertensive patients with preserved left ventricular ejection fraction.

Objective: As a new method of left ventricular-arterial coupling (VAC), the non-invasive myocardial work index (MWI) may provide more useful information than the classical methods of arterial elastance/left ventricular (LV) elastance index (the ratio of effective arterial elastance (Ea) over end-systolic elastance [Ea/Ees]). This research aims to investigate if MWI might be better associated with hypertension-mediated organ damage (HMOD) and diastolic dysfunction than Ea/Ees in hypertension. Methods: We prospectively enrolled 104 hypertensives and 69 normotensives. All subjects had speckle-tracking echocardiography for myocardial work, conventional echocardiography, and brachial-ankle pulse wave velocity (baPWV) measurements. The global work index (GWI) is a myocardial work component. The correlation between GWI and HMOD, as well as diastolic dysfunction, was analyzed. The receiver operating characteristic (ROC) curve was utilized for evaluating the GWI predicting efficacy. Results: The global work index was significantly higher in hypertensives than in normotensives (2,021.69 ± 348.02 vs. 1,757.45 ± 225.86 mmHg%, respectively, p < 0.001). Higher GWI was a risk factor on its own for increased baPWV, pulse pressure (PP), echocardiographic LV hypertrophy (LVH), and left atrial volume index (LAVI) (p = 0.030, p < 0.001, p = 0.018 p = 0.031, respectively), taking into account the sex, age, mean arterial pressure (MAP), body mass index (BMI), and antihypertensive therapy. However, no considerable associations were found between Ea/Ees and HMOD parameters and the diastolic dysfunction markers. The GWI area under the ROC curve for increased PP and baPWV, echocardiographic LVH, and increased LAVI were 0.799, 0.770, 0.674, and 0.679, respectively (p < 0.05). Conclusions: The global work index but not traditionally echocardiographic-derived Ea/Ees of VAC is independently related to HMOD and diastolic impairment in hypertensives with preserved LV ejection fraction. The GWI may be a potential marker for evaluating the VAC in hypertension.

Study of the Correlation Between the Ratio of Diastolic to Systolic Durations and Echocardiography Measurements and Its Application to the Classification of Heart Failure Phenotypes.

BACKGROUND: This study aimed to investigate the correlation between the ratio of diastolic to systolic durations (D/S) and echocardiographic parameters of patients with chronic heart failure (CHF) and evaluate whether the D/S can be used as a supplementary biomarker for the classification of heart failure (HF) phenotypes. METHODS: In total, 122 CHF patients with a left ventricular ejection fraction (LVEF) <40%, 40%≤LVEF<50%, or ≥50% were categorized as having HF with a reduced ejection fraction (HFrEF) (N=32), HF with a mid-range ejection fraction (HFmrEF) (N=21) or HF with a preserved ejection fraction (HFpEF) (N=69), respectively. All patients underwent echocardiography for assessment of nineteen structural and functional echocardiographic parameters and digital phonocardiography for the measurement of D/S. Spearman correlation was used to analyse the associations between the D/S and echocardiographic parameters. Multivariate logistic regression analysis was performed to examine the associations between the D/S and HF phenotypes, and receiver operating characteristic (ROC) curve analysis was employed to evaluate the predictive value of the D/S in the classification of HF phenotypes. RESULTS: The D/S values of patients with HFrEF, HFmrEF and HFpEF were 1.32±0.06, 1.44±0.11 and 1.54±0.08, respectively, which were significantly different (All P<0.05). A close correlation between the D/S and LVEF was found (r=0.777, P<0.001). The multivariate analysis indicated that the D/S was an independent risk factor for CHF phenotypes (OR=4.927, 95% CI 2.532-9.587; P<0.001). The area under the ROC curve for distinguishing between HFmrEF and HFpEF using the D/S was 0.764 (95% CI 0.707-0.845; P < 0.001) and that for distinguishing between HFmrEF and HFrEF using the D/S was 0.821 (95% CI 0.755-0.882; P < 0.001). CONCLUSION: The D/S was significantly associated with LVEF, and as LVEF decreased, the D/S tended to decrease, which could also serve as a noninvasive supplementary indicator for detecting systolic and diastolic dysfunction.

Cardiovascular events and all-cause mortality in surgically or medically treated primary aldosteronism: A Meta-analysis.

OBJECTIVES: To compare the effect of surgical or medical treatment on the risk of cardiovascular diseases (CVD) and all-cause mortality in patients with established primary aldosteronism (PA). METHODS: We searched PUBMED, MEDLINE and Cochrane Library for the meta-analysis. We included patients who were diagnosed with PA following guideline-supported protocols and received surgery or mineralocorticoid receptor antagonist (MRA)-based medical treatment, and age-sex matched patients with treated essential hypertension (EH). Primary endpoints were CVD incidence and all-cause mortality. RESULTS: Compared with EH, patients with treated PA had a higher risk of CVD [odds ratio (OR) 1.79; 95% confidence interval (CI) 1.39-2.31]. This elevated risk was only observed in patients with medically treated PA [OR 2.11; 95%CI 1.88-2.38] but not in those with surgically treated PA. The risk of all-cause mortality was significantly lower in patients with treated PA [OR 0.86; 95% CI 0.77-0.95] compared to EH. The reduced risk was only observed in patients with surgically treated PA [OR 0.47; 95% CI 0.34-0.66], but not in those with medically treated PA. CONCLUSIONS: Patients with medically treated PA have a higher risk of CVD compared to patients with EH. Surgical treatment of PA reduces the risk of CVD and all-cause mortality in patients with PA.

Effects of anti-osteoporosis therapy on plasma aldosterone and renin.

OBJECTIVE: This study aimed to investigate the effect of anti-osteoporosis therapy on plasma aldosterone concentration (PAC), plasma renin concentration (PRC) and the aldosterone/renin ratio (ARR) in patients with postmenopausal osteoporosis. METHODS: In 60 patients with postmenopausal osteoporosis, bone mineral density (BMD), PAC and PRC were measured before and after treatment with alendronate (70 mg/week, n=22) or recombinant human parathyroid hormone (20 µg/day, n=35) for 48 weeks. RESULTS: PAC was negatively correlated with the T-score of lumbar spine BMD and femoral neck BMD (lumbar r=-0.386, p<0.01; femoral neck r=-0.262, p<0.05). With the improvement in lumbar BMD after anti-osteoporosis treatment (T-score -3.4±0.5 vs. -3.1 ±0.4, p<0.0001), PAC decreased from 182.8±53.2 to 143.7±68.6 pg/mL (p<0.0001), PRC increased from 7.8±11.6 to 39.2±50.0 µIU/mL (p<0.0001) and the ARR decreased from 74.8±75.2 to 13.1±17.1 pg/µIU (p<0.0001). At baseline, 58% (35/60) of the patients had an ARR >37 pg/µIU, and the proportion decreased to 8% (5/57) after treatment. CONCLUSION: Treatment with alendronate or parathyroid hormone causes decreased PAC and increased PRC, resulting in a decreased ARR in postmenopausal women with osteoporosis.

[Effect of electrical stimulation on the differentiation of induced pluripotent stem cells into cardiomyocytes induced by vitamin C in vitro].

OBJECTIVE: To investigate the effect of electrical stimulation on the differentiation of induced pluripotent stem cells (iPSCs) into cardiomyocytes in vitro. METHODS: Classical hanging-drop method was used to induce iPSCs from mice to form embryoid bodies (EBs) and vitamin C was contained in the medium through the induction period. According to whether or not electrical stimulation was used in the whole induction period, iPSCs were divided to electrical stimulation group and non-stimulation group. During the induction, dynamic morphological changes of the EBs were observed and photographed, the time point when beating EBs in each group appeared was recorded and the number of them was counted. The percentage of beating ones in all EBs was calculated as the differentiation rate of cardiomyocytes induced from iPSCs. Furthermore, expression of cardiac troponin T (cTnT) was observed by immunofluorescent staining under a confocal laser scanning microscope (CLSM), and mRNA expression levels of the related genes Oct-4, GATA-4 and α-MHC were analyzed by RT-PCR. RESULTS: Compared with the non-stimulation group, beating cells in electrical stimulation group appeared in a shorter time, and the differentiation rate of cardiomyocytes was higher [(68.89 ± 5.09)% vs (52.22 ± 3.85)%, P<0.05]. c-TnT was expressed in the beating area of both groups, but the cells in the electrical stimulation group showed a more clear cytoskeleton. The mRNA level of Oct-4 decreased in a time-dependent manner in the whole period of induction and in the electrical stimulated group it decreased faster than the non-stimulation group (P<0.05). In addition, more GATA4 and α-MHC mRNA in electrical stimulation group were expressed than the non-stimulated group at the same point-in-time (P<0.05). CONCLUSION: The electrical stimulation which simulates cardiac electrical microenvironment to some extent improved the differentiation of iPSCs into functional cardiomyocytes induced by vitamin C in vitro.