Left ventricular global longitudinal strain using a novel fully automated method: A head-to-head comparison with a manual layer-specific strain and establishment of normal reference ranges.

BACKGROUND: A novel automated method for measuring left ventricular (LV) global longitudinal strain (GLS) along the endocardium has advantages in terms of its rapid application and excellent reproducibility. However, it remains unclear whether the available normal range for conventional GLS using the manual method is applicable to the automated GLS method. This study aimed to compare automated GLS head-to-head with manual layer-specific GLS, and to identify whether a specialized normal reference range for automated GLS is needed and explore the main determinants. METHODS: In total, 1683 healthy volunteers (men, 43%; age, 18-80 years) were prospectively enrolled from 55 collaborating laboratories. LV GLS was measured using both manual layer-specific and automated methods. RESULTS: Automated GLS was higher than endocardial, mid-myocardial, and epicardial GLS. Women had a higher automated GLS than men. GLS had no significant age dependency in men, but first increased and then decreased with age in women. Accordingly, sex- and age-specific normal ranges for automated GLS were proposed. Moreover, GLS appeared to have different burdens in relation to dominant determinants between the sexes. GLS in men showed no dominant determinants; however, GLS in women correlated with age, body mass index, and heart rate. CONCLUSIONS: Using the novel automated method, was LV GLS higher than when using the manual GLS method. The normal ranges of automated GLS stratified according to sex and age were provided, with dominant determinants showing sex disparities that require full consideration in clinical practice.

Incremental values of AOPP, IL-6, and GDF15 for identifying arteriosclerosis in patients with obstructive sleep apnea.

BACKGROUND: The objective of this study was to determine the independent and incremental values of advanced oxidative protein product (AOPP), interleukin 6 (IL-6), and growth differentiation factor 15 (GDF15) in identifying arteriosclerosis in patients with obstructive sleep apnea (OSA). METHODS: A total of 104 individuals diagnosed with OSA by polysomnography were recruited in our study. Arteriosclerosis was defined by measuring the ultrafast pulse wave velocity of the carotid artery. Peripheral venous blood samples were collected to analyze the levels of AOPP, IL-6, and GDF15 utilizing commercially available enzyme-linked immunosorbent assays. RESULTS: Compared to OSA patients without arteriosclerosis, those with arteriosclerosis exhibited significantly higher levels of AOPP, IL-6, and GDF15. GDF15 remained significantly associated with arteriosclerosis even after accounting for clinical factors such as age, gender, body mass index, systolic blood pressure, fasting blood glucose, smoking, and the apnea-hypoxia index (AHI). GDF15 demonstrated the largest area under the curve (AUC) for identifying arteriosclerosis in OSA patients (AUC, 0.85 [0.77-0.94]). The logistic regression model, combining clinical factors and AHI, was enhanced by the inclusion of AOPP and IL-6 (Chi-square = 25.06), and even further improved when GDF15 was added (Chi-square = 50.74). The integrated discrimination index increased by 0.06 to 0.16 when GDF15 was added to the models including clinical factors, AOPP, and IL-6. CONCLUSIONS: This study verified the independent and incremental value of GDF15 in identifying arteriosclerosis in OSA patients, surpassing clinical risk factors and other serum biomarkers such as AOPP and IL-6.

STGA-MS: AI diagnosis model of regional wall motion abnormality based on 2D transthoracic echocardiography.

Regional wall motion abnormality (RWMA) is a common manifestation of ischemic heart disease detected through echocardiography. Currently, RWMA diagnosis heavily relies on visual assessment by doctors, leading to limitations in experience-based dependence and suboptimal reproducibility among observers. Several RWMA diagnosis models were proposed, while RWMA diagnosis with more refined segments can provide more comprehensive wall motion information to better assist doctors in the diagnosis of ischemic heart disease. In this paper, we proposed the STGA-MS model which consists of three modules, the spatial-temporal grouping attention (STGA) module, the segment feature extraction module, and the multiscale downsampling module, for the diagnosis of RWMA for multiple myocardial segments. The STGA module captures global spatial and temporal information, enhancing the representation of myocardial motion characteristics. The segment feature extraction module focuses on specific segment regions, extracting relevant features. The multiscale downsampling module analyzes myocardial motion deformation across different receptive fields. Experimental results on a 2D transthoracic echocardiography dataset show that the proposed STGA-MS model achieves better performance compared to state-of-the-art models. It holds promise in improving the accuracy and reproducibility of RWMA diagnosis, assisting clinicians in diagnosing ischemic heart disease more reliably.

Topology-sensitive weighting model for myocardial segmentation.

Accurate myocardial segmentation is crucial for the diagnosis of various heart diseases. However, segmentation results often suffer from topology structural errors, such as broken connections and holes, especially in cases of poor image quality. These errors are unacceptable in clinical diagnosis. We proposed a Topology-Sensitive Weight (TSW) model to keep both pixel-wise accuracy and topological correctness. Specifically, the Position Weighting Update (PWU) strategy with the Boundary-Sensitive Topology (BST) module can guide the model to focus on positions where topological features are sensitive to pixel values. The Myocardial Integrity Topology (MIT) module can serve as a guide for maintaining myocardial integrity. We evaluate the TSW model on the CAMUS dataset and a private echocardiography myocardial segmentation dataset. The qualitative and quantitative experimental results show that the TSW model significantly enhances topological accuracy while maintaining pixel-wise precision.

Normal reference values for mitral annular plane systolic excursion by motion-mode and speckle tracking echocardiography: a prospective, multicentre, population-based study.

AIMS: Mitral annular plane systolic excursion (MAPSE) is a simple and reliable index for evaluating left ventricular (LV) systolic function, particularly in patients with poor image quality; however, the lack of reference values limits its widespread use. This study aimed to establish the normal ranges for MAPSE measured using motion-mode (M-mode) and two-dimensional speckle tracking echocardiography (2D-STE) and to explore its principal determinants. METHODS AND RESULTS: This multicentre, prospective, cross-sectional study included 1952 healthy participants [840 men (43%); age range, 18-80 years] from 55 centres. MAPSE was measured using M-mode echocardiography and 2D-STE. The results showed that women had a higher MAPSE than men and MAPSE decreased with age. The age- and sex-specific reference values for MAPSE were established for these two methods. Multiple linear regression analyses revealed that MAPSE on M-mode echocardiography correlated with age and MAPSE on 2D-STE with age, blood pressure (BP), heart rate, and LV volume. Moreover, MAPSE measured by 2D-STE correlated more strongly with global longitudinal strain compared with that measured using M-mode echocardiography. CONCLUSION: Normal MAPSE reference values were established based on age and sex. BP, heart rate, and LV volume are potential factors that influence MAPSE and should be considered in clinical practice. Normal values are useful for evaluating LV longitudinal systolic function, especially in patients with poor image quality, and may further facilitate the use of MAPSE in routine assessments.

Effects of obstructive sleep apnea on myocardial injury and dysfunction: a review focused on the molecular mechanisms of intermittent hypoxia.

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) and is strongly associated with adverse cardiovascular outcomes. Myocardial injury and dysfunction have been commonly observed in clinical practice, particularly in patients with severe OSA. However, the underlying mechanisms remain obscure. In this review, we summarized the molecular mechanisms by which IH impact on myocardial injury and dysfunction. In brief, IH-induced cardiomyocyte death proceeds through the regulation of multiple biological processes, including differentially expressed transcription factors, alternative epigenetic programs, and altered post-translational modification. Besides cell death, various cardiomyocyte injuries, such as endoplasmic reticulum stress, occurs with IH. In addition to the direct effects on cardiomyocytes, IH has been found to deteriorate myocardial blood and energy supply by affecting the microvascular structure and disrupting glucose and lipid metabolism. For better diagnosis and treatment of OSA, further studies on the molecular mechanisms of IH-induced myocardial injury and dysfunction are essential.

Evaluation of left ventricular function in patients with coronary slow flow: A systematic review and meta-analysis.

BACKGROUND: Coronary slow flow (CSF) is an angiographic finding defined as delayed distal vessel perfusion without severe stenosis of the epicardial coronary arteries. However, definite alterations in left ventricular (LV) function in patients with CSF remains inconsistent. This study aimed to clarify the changes in LV function in patients with CSF and explore the factors that may influence LV function. METHODS: PubMed, Embase, and Cochrane Library databases were systematically searched. Standardized mean differences and 95% confidence intervals (CI) for the LV function parameters were calculated. Subgroup analysis, meta-regression analysis, and correlation analysis were performed to explore the factors influencing LV function. RESULTS: Twenty-two studies (1101 patients with CSF) were included after searching three databases. In patients with CSF, LV ejection function in patients with CSF was marginally lower (61.8%; 95% CI: 61.0%, 62.7%), global longitudinal strain was decreased (-18.2%; 95% CI: -16.7%, -19.7%). Furthermore, left atrial diameter, left atrial volume index, and E/e' were significantly increased, while E/A and e' were significantly decreased. The mean thrombolysis in myocardial infarction frame count (TFC) was linearly associated with LV function; the larger the mean TFC, the greater the impairment of LV function. CONCLUSIONS: Left ventricular systolic and diastolic functions were impaired in patients with CSF, and this impairment was aggravated with increasing mean TFC.

Diagnostic and prognostic value of echocardiography in pulmonary hypertension: an umbrella review of systematic reviews and meta-analyses.

BACKGROUND: The role of echocardiography in the diagnostic and prognostic assessment of pulmonary hypertension (PH) has been widely studied recently. However, these findings have not undergone normative evaluation and may provide confusing evidence for clinicians. To evaluate and summarize existing evidence, we performed an umbrella review. METHODS: Systematic reviews and meta-analyses were searched in PubMed, Embase, Web of Science, and Cochrane Library from inception to September 4, 2022. The methodological quality of the included studies was assessed using Assessment of Multiple Systematic Reviews (AMSTAR), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the quality of evidence. RESULTS: Thirteen meta-analyses (nine diagnostic and four prognostic studies) were included after searching four databases. The methodological quality of the included studies was rated as high (62%) or moderate (38%) by AMSTAR. The thirteen included meta-analyses involved a total of 28 outcome measures. The quality of evidence for these outcomes were high (7%), moderate (29%), low (39%), and very low (25%) using GRADE methodology. In the detection of PH, the sensitivity of systolic pulmonary arterial pressure is 0.85-0.88, and the sensitivity and specificity of right ventricular outflow tract acceleration time are 0.84. Pericardial effusion, right atrial area, and tricuspid annulus systolic displacement provide prognostic value in patients with pulmonary arterial hypertension with hazard ratios between 1.45 and 1.70. Meanwhile, right ventricular longitudinal strain has independent prognostic value in patients with PH, with a hazard ratio of 2.96-3.67. CONCLUSION: The umbrella review recommends echocardiography for PH detection and prognosis. Systolic pulmonary arterial pressure and right ventricular outflow tract acceleration time can be utilized for detection, while several factors including pericardial effusion, right atrial area, tricuspid annular systolic displacement, and right ventricular longitudinal strain have demonstrated prognostic significance. TRIAL REGISTRATION: PROSPERO (CRD42022356091), https://www.crd.york.ac.uk/prospero/ .

Learning what and where to segment: A new perspective on medical image few-shot segmentation.

Traditional medical image segmentation methods based on deep learning require experts to provide extensive manual delineations for model training. Few-shot learning aims to reduce the dependence on the scale of training data but usually shows poor generalizability to the new target. The trained model tends to favor the training classes rather than being absolutely class-agnostic. In this work, we propose a novel two-branch segmentation network based on unique medical prior knowledge to alleviate the above problem. Specifically, we explicitly introduce a spatial branch to provide the spatial information of the target. In addition, we build a segmentation branch based on the classical encoder-decoder structure in supervised learning and integrate prototype similarity and spatial information as prior knowledge. To achieve effective information integration, we propose an attention-based fusion module (AF) that enables the content interaction of decoder features and prior knowledge. Experiments on an echocardiography dataset and an abdominal MRI dataset show that the proposed model achieves substantial improvements over state-of-the-art methods. Moreover, some results are comparable to those of the fully supervised model. The source code is available at github.com/warmestwind/RAPNet.

EchoEFNet: Multi-task deep learning network for automatic calculation of left ventricular ejection fraction in 2D echocardiography.

Left ventricular ejection fraction (LVEF) is essential for evaluating left ventricular systolic function. However, its clinical calculation requires the physician to interactively segment the left ventricle and obtain the mitral annulus and apical landmarks. This process is poorly reproducible and error prone. In this study, we propose a multi-task deep learning network EchoEFNet. The network use ResNet50 with dilated convolution as the backbone to extract high-dimensional features while maintaining spatial features. The branching network used our designed multi-scale feature fusion decoder to segment the left ventricle and detect landmarks simultaneously. The LVEF was then calculated automatically and accurately using the biplane Simpson's method. The model was tested for performance on the public dataset CAMUS and private dataset CMUEcho. The experimental results showed that the geometrical metrics and percentage of correct keypoints of EchoEFNet outperformed other deep learning methods. The correlation between the predicted LVEF and true values on the CAMUS and CMUEcho datasets was 0.854 and 0.916, respectively.

Association between triglyceride-glucose index and arterial stiffness reflected by carotid pulse-wave velocity in stage 1 hypertension and individuals with normal/elevated blood pressure.

Evidence of the triglyceride-glucose (TyG) index as an independent predictor of arterial stiffness in stage 1 hypertension patients is scarce. This study aimed to explore the association between TyG index and arterial stiffness in this population. A total of 1041 individuals from 32 centers with normal/elevated blood pressure (BP, <130/80 mmHg; 345 men (33%); median age, 37 years) and 585 stage 1 hypertension patients (BP ≥130/80 and <140/90 mmHg; 305 men (52%); median age, 47 years) were prospectively enrolled. Arterial stiffness was determined by measuring carotid ultrafast pulse-wave velocity (ufPWV). TyG index was calculated as ln (fasting triglyceride (TG) × fasting blood glucose/2). Patients with a higher TyG index tended to have higher ufPWV. The TyG index was positively associated with ufPWV at the end of systole in stage 1 hypertension patients after adjusting for confounding factors (ß for per unit .48), and restricted cubic spline analysis confirmed a linear association. Subgroup analyses in terms of age, sex, and body mass index yielded similar results. However, no significant relationship was observed between the TyG index and ufPWV in the population with normal/elevated BP. The fully adjusted ß between ufPWV and the TyG index was higher than the TG/high-density lipoprotein cholesterol ratio, TG, and pulse pressure. In conclusion, patients with a higher TyG index had greater arterial stiffness, and the TyG index independently and positively correlated with arterial stiffness in stage 1 hypertension patients. The TyG index may provide a simple and reliable marker to monitor arterial stiffness in hypertensive patients.

Soluble Vascular Cell Adhesion Molecule-1 as an Inflammation-Related Biomarker of Coronary Slow Flow.

Background: Coronary slow flow (CSF) is an angiographic entity characterized by delayed coronary opacification with no evident obstructive lesion in the epicardial coronary artery. Several studies have shown that the occurrence and development of CSF may be closely related to inflammation. Soluble vascular cell adhesion molecule-1 (sVCAM-1) is a biomarker related to inflammation. The aim of this study was to evaluate the correlation between plasma soluble VCAM-1 level and CSF occurrence and thus the predictive value of VCAM-1 for CSF. Methods: Forty-six CSF patients and thirty control subjects were enrolled. Corrected thrombolysis in myocardial infarction frame count (cTFC) was used to diagnose CSF. Functional status and quality of life were determined by the Seattle Angina Questionnaire (SAQ). Echocardiography was used to evaluate the systolic and diastolic function of the left ventricle (LV) and right ventricle (RV). The plasma levels of sVCAM-1, IL-6, and TNF-α were quantified by enzyme-linked immunosorbent assay. Results: Compared with the control group, the physical limitation score by the SAQ, the LV global longitudinal strain (GLS), mitral E, and mitral E/A decreased in patients with CSF, while the plasma IL-6 and TNF-α levels increased. The plasma sVCAM-1 level in the CSF group was significantly higher than that in the control group (186.03 ± 83.21 vs. 82.43 ± 42.12 ng/mL, p < 0.001), positively correlated with mean cTFC (r = 0.57, p < 0.001), and negatively correlated with the physical limitation score (r = −0.32, p = 0.004). Logistic regression analyses confirmed that plasma sVCAM-1 level (OR = 1.07, 95%CI: 1.03−1.11) is an independent predictor of CSF, and the receiver operating characteristic curve analysis showed that plasma sVCAM-1 levels had statistical significance in predicting CSF (area under curve = 0.88, p < 0.001). When the sVCAM-1 level was higher than 111.57 ng/mL, the sensitivity for predicting CSF was 87% and the specificity was 73%. Conclusions: Plasma sVCAM-1 level can be used to predict CSF and was associated with the clinical symptoms of patients. It may serve as a potential biomarker for CSF in the future.

Understanding the pathogenesis of coronary slow flow: Recent advances.

Coronary slow flow is taken to be indicative of delayed filling of terminal vessels of the coronary arteries in the absence of coronary stenosis, as detected using coronary angiography. Patients suffering from coronary slow flow typically experience recurrent chest pain, thereby markedly affecting their quality of life. The etiology and pathogenesis of coronary slow flow, which is gradually attracting clinical attention, have yet to be sufficiently established, although it is currently believed that they may be associated with endothelial dysfunction in the coronary arteries, inflammatory response, abnormalities in microvascular reserve function, subclinical atherosclerosis, blood cell and platelet abnormalities, and genetic factors. In this review, we provide a brief overview of recent progress in research on the pathogenesis of coronary slow flow with a view toward elucidating the possible underlying pathogenesis and identify targets and directions for the treatment of this condition.

Reference values of the carotid elastic modulus using shear wave elastography and arterial stiffness change in coronary slow flow.

PURPOSE: Shear wave elastography (SWE) accurately and sensitively evaluates arterial wall stiffness by quantifying the elastic modulus (EM); however, the absence of reference values has precluded its widespread clinical application. This prospective cohort study aimed to establish reference values for the carotid EM using SWE; investigate the main determinants of the EM; and evaluate EM changes in coronary slow flow (CSF), which is characterized by delayed coronary opacification without evident obstructive lesion in epicardial coronary artery on angiography. METHOD: This study enrolled 169 healthy volunteers and 30 patients with CSF. The carotid maximum EM (EMmax), mean EM, and minimum EM were measured using SWE. CSF was diagnosed by thrombolysis in the myocardial infarction frame count during coronary angiography. RESULTS: No differences were found in the EM between the left and right carotid arteries and between men and women. Multiple linear regression analysis revealed that age was independently correlated with the EMmax, which progressively increased with age. Moreover, smoking had an independent influence on the EM after adjusting for age; smokers had higher EM than non-smokers. Age-specific reference values for the carotid EM were established. The EM was higher in patients with CSF than in controls after adjusting for age and smoking status. CONCLUSIONS: This study first established the reference values for the carotid EM using SWE. Age and smoking status were the main determinants of the EM. Patients with CSF had high EM. SWE can effectively and noninvasively evaluate arterial stiffness in patients with CSF.

Automatic identification of septal flash phenomenon in patients with complete left bundle branch block.

Complete left bundle branch block (cLBBB) is an electrical conduction disorder associated with cardiac disease. Septal flash (SF) involves septal leftward contraction during early systole followed by a lengthening motion toward the right ventricle and affects several patients with cLBBB. It has been revealed that cLBBB patients with SF may be at risk of cardiac function reduction and poor prognosis. Therefore, accurate identification of SF may play a vital role in counseling patients about their prognosis. Generally, Septal flash is identified by echocardiography using visual "eyeballing". However, this conventional method is subjective as it depends on operator experience. In this study, we build a linear attention cascaded net (LACNet) capable of processing echocardiography to identify SF automatically. The proposed method consists of a cascaded CNN-based encoder and an LSTM-based decoder, which extract spatial and temporal features simultaneously. A spatial transformer network (STN) module is employed to avoid image inconsistency and linear attention layers are implemented to reduce data complexity. Moreover, the left ventricle (LV) area-time curve calculated from segmentation results can be considered as a new independent disease predictor as SF phenomenon leads to transient left ventricle area enlargement. Therefore, we added the left ventricle area-time curve to LACNet to enrich input data diversity. The result shows the possibility of using echocardiography to diagnose cLBBB with SF automatically.

Predictive value of HMGB1 for atrial fibrillation recurrence after cryoballoon ablation in paroxysmal atrial fibrillation patients.

BACKGROUND: Cryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow-up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients. HYPOTHESIS: To evaluate the clinical efficacy of high-mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1-year follow-up. METHODS: We included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year. RESULTS: A total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p = .03). However, no differences were noted in the levels of other biomarkers such as preoperative high-sensitivity C-reactive protein (hs-CRP), postoperativehs-CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17-23.92], p = .04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1-year AF-free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49-9.75], p = .005). CONCLUSION: In pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence.

Incremental Value of Three-dimensional Speckle-tracking Echocardiography for Evaluating Left Ventricular Systolic Function in Patients with Coronary Slow Flow.

The purpose was to evaluate left ventricular (LV) systolic function in patients with coronary slow flow (CSF), and compared the incremental values of 3-dimensional (3D) speckle-tracking echocardiography (STE). Seventy-three patients with CSF and 60 control subjects were enrolled. CSF was diagnosed during coronary angiography. Two-dimensional (2D) and 3D global strain were measured using STE. Sex, mitral E, 2D GLS, and all 3D strain parameters were independent predictors of CSF. Combination of sex, mitral E, and 3D GTS had the highest area under the curve (AUC) for identifying CSF (AUC, 0.81; P < 0.001). Integrated discrimination index (IDI) improved adding 3D GTS to the combined sex and mitral E model (IDI = 0.12, P = 0.01) or 2D GLS model (IDI = 0.14, P < 0.001). LV systolic function was impaired in CSF patients. 3D GTS had an independent and incremental value for predicting CSF compared with 2D echocardiography.

Usefulness of soluble endothelial protein C receptor combined with left ventricular global longitudinal strain for predicting slow coronary flow: A case-control study.

BACKGROUND: Slow coronary flow (SCF) is an angiographic entity characterized by delayed coronary opacification without an evident obstructive lesion in the epicardial coronary artery. However, patients with SCF have decreased left ventricular (LV) global longitudinal strain (GLS). SCF is associated with inflammation, and soluble endothelial protein C receptor (sEPCR) is a potential biomarker of inflammation. Therefore, under evaluation herein, was the relationship between SCF and sEPCR and the predictive value of sEPCR and LV GLS for SCF was investigated. METHODS: Twenty-eight patients with SCF and 34 controls were enrolled. SCF was diagnosed by the thrombolysis in myocardial infarction frame count (TFC). The plasma level of sEPCR was quantified using enzyme-linked immunosorbent assay. LV GLS was measured by two-dimensional speckle-tracking echocardiography. RESULTS: Plasma sEPCR was significantly higher in patients with SCF than in controls and was positively correlated with the mean TFC (r = 0.67, p < 0.001) and number of involved vessels (r = 0.61, p < 0.001). LV GLS was decreased in patients with SCF compared to that in controls. sEPCR level (OR = 3.14, 95% CI 1.55-6.36, p = 0.001) and LV GLS (OR = 1.44, 95% CI 1.02-2.04, p = 0.04) were independent predictors of SCF. sEPCR predicted SCF (area under curve [AUC]: 0.83); however, sEPCR > 9.63 ng/mL combined with LV GLS > -14.36% demonstrated better predictive power (AUC: 0.89; sensitivity: 75%; specificity: 91%). CONCLUSIONS: Patients with SCF have increased plasma sEPCR and decreased LV GLS. sEPCR may be a useful potential biomarker for SCF, and sEPCR combined with LV GLS can better predict SCF.

Reference Values of Right Ventricular Volumes and Ejection Fraction by Three-Dimensional Echocardiography in Adults: A Systematic Review and Meta-Analysis.

Objective: This study was conducted in order to determine the reference values for right ventricular (RV) volumes and ejection fraction (EF) using three-dimensional echocardiography (3DE) and to identify sources of variance through a systematic review and meta-analysis. Methods: This systematic review was preregistered with the International Prospective Register of Systematic Reviews (https://www.crd.york.ac.uk/PROSPERO/) (CRD42020211002). Relevant studies were identified by searches of the PubMed, Embase, and Cochrane Library databases through October 12, 2020. Pooled reference values were calculated using the random-effects model weighted by inverse variance. Meta-regression analysis and Egger's test were used to determine the source of heterogeneity. A subgroup analysis was performed to evaluate the reference values across different conditions. Results: The search identified 25 studies of 2,165 subjects. The mean reference values were as follows: RV end-diastolic volume, 100.71 ml [95% confidence interval (CI), 90.92-110.51 ml); RV end-systolic volume, 44.19 ml (95% CI, 39.05-49.33 ml); RV end-diastolic volume indexed, 57.01 ml/m2 (95% CI, 51.93-62.08 ml/m2); RV end-systolic volume indexed, 25.41 ml/m2 (95% CI, 22.58-28.24 ml/m2); and RVEF, 56.20% (95% CI, 54.59-57.82%). The sex- and age-specific reference values were assessed according to the studies reporting the values of different sexes and age distributions, respectively. In addition, the vendor- and software-specific reference values were analyzed. The meta-regression analysis revealed that sex, frame rate, pulmonary artery systolic pressure, and software packages were associated with variations in RV volumes (P < 0.05). Inter-vendor and inter-software discrepancies may explain the variability of RVEF. Conclusions: The reference values for RV volumes and RVEF using 3DE were assessed. The confounders that impacted the variability in RV volumes or RVEF contained the sex, frame rate, pulmonary artery systolic pressure, inter-vendor discrepancies, and inter-software discrepancies.