Imaging Interstitial Fibrosis, Left Ventricular Remodeling, and Function in Stage A and B Heart Failure

Heart Failure With Preserved Ejection Fraction: Will Cardiac Magnetic Imaging Impact on Diagnosis, Treatment, and Outcomes?: Explaining the Need for Advanced Imaging to Clinical Stakeholders

Clinicians frequently equate symptoms of volume overload to heart failure (HF) but such generalization may preclude diagnostic or etiologic precision essential to optimizing outcomes. HF itself must be specified as the disparate types of cardiac pathology have been traditionally surmised by examination of left ventricular (LV) ejection fraction (EF) as either HF with preserved LVEF (HFpEF-LVEF >50%) or reduced LVEF of (HFrEF-LVEF <40%). More recent data support a third, potentially transitional HF subtype, but therapy, assessment, and prognosis have been historically dictated within the corresponding LV metrics determined by echocardiography. The present effort asks whether this historically dominant role of echocardiography is now shifting slightly, becoming instead a shared if not complimentary test. Will there be a gradual increasing profile for cardiac magnetic resonance as the attempt to further refine our understanding, diagnostic accuracy, and outcomes for HFpEF is attempted?

Chronic sleep fragmentation reduces left ventricular contractile function and alters gene expression related to innate immune response and circadian rhythm in the mouse heart

Sleep disorders have emerged as a widespread public health concern, primarily due to their association with an increased risk of developing cardiovascular diseases. Our previous research indicated a potential direct impact of insufficient sleep duration on cardiac remodeling in children and adolescents. Nevertheless, the underlying mechanisms behind the link between sleep fragmentation (SF) and cardiac abnormalities remain unclear. In this study, we aimed to investigate the effects of SF interventions at various life stages on cardiac structure and function, as well as to identify genes associated with SF-induced cardiac dysfunction. To achieve this, we established mouse models of chronic SF and two-week sleep recovery (SR). Our results revealed that chronic SF significantly compromised left ventricular contractile function across different life stages, leading to alterations in cardiac structure and ventricular remodeling, particularly during early life stages. Moreover, microarray analysis of mouse heart tissue identified two significant modules and nine hub genes (Ddx60, Irf9, Oasl2, Rnf213, Cmpk2, Stat2, Parp14, Gbp3, and Herc6) through protein-protein interaction analysis. Notably, the interactome predominantly involved innate immune responses. Importantly, all hub genes lost significance following SR. The second module primarily consisted of circadian clock genes, and real-time PCR validation demonstrated significant upregulation of Arntl, Dbp, and Cry1 after SF, while subsequent SR restored normal Arntl expression. Furthermore, the expression levels of four hub genes (Ddx60, Irf9, Oasl2, and Cmpk2) and three circadian clock genes (Arntl, Dbp, and Cry1) exhibited correlations with structural and functional echocardiographic parameters. Overall, our findings suggest that SF impairs left ventricular contractile function and ventricular remodeling during early life stages, and this may be mediated by modulation of the innate immune response and circadian rhythm. Importantly, our findings suggest that a short period of SR can alleviate the detrimental effects of SF on the cardiac immune response, while the influence of SF on circadian rhythm appears to be more persistent. These findings underscore the importance of good sleep for maintaining cardiac health, particularly during early life stages.

Baicalin alleviates angiotensin II-induced cardiomyocyte apoptosis and autophagy and modulates the AMPK/mTOR pathway

As a main extraction compound from Scutellaria baicalensis Georgi, Baicalin exhibits various biological activities. However, the underlying mechanism of Baicalin on hypertension-induced heart injury remains unclear. In vivo, mice were infused with angiotensin II (Ang II; 500 ng/kg/min) or saline using osmotic pumps, followed by intragastrically administrated with Baicalin (5 mg/kg/day) for 4 weeks. In vitro, H9C2 cells were stimulated with Ang II (1 μM) and treated with Baicalin (12.5, 25 and 50 μM). Baicalin treatment significantly attenuated the decrease in left ventricular ejection fraction and left ventricular fractional shortening, increase in left ventricular mass, left ventricular systolic volume and left ventricular diastolic volume of Ang II infused mice. Moreover, Baicalin treatment reversed 314 differentially expressed transcripts in the cardiac tissues of Ang II infused mice, and enriched multiple enriched signalling pathways (including apoptosis, autophagy, AMPK/mTOR signalling pathway). Consistently, Baicalin treatment significantly alleviated Ang II-induced cell apoptosis in vivo and in vitro. Baicalin treatment reversed the up-regulation of Bax, cleaved-caspase 3, cleaved-caspase 9, and the down-regulation of Bcl-2. Meanwhile, Baicalin treatment alleviated Ang II-induced increase of autophagosomes, restored autophagic flux, and down-regulated LC3II, Beclin 1, as well as up-regulated SQSTM1/p62 expression. Furthermore, autophagy inhibitor 3-methyladenine treatment alleviated the increase of autophagosomes and the up-regulation of Beclin 1, LC3II, Bax, cleaved-caspase 3, cleaved-caspase 9, down-regulation of SQSTM1/p62 and Bcl-2 expression after Ang II treated, which similar to co-treatment with Baicalin. Baicalin treatment reduced the ratio of p-AMPK/AMPK, while increased the ratio of p-mTOR/mTOR. Baicalin alleviated Ang II-induced cardiomyocyte apoptosis and autophagy, which might be related to the inhibition of the AMPK/mTOR pathway.

LncRNA GAS5 restrains ISO-induced cardiac fibrosis by modulating mir-217 regulation of SIRT1

Considering the effect of SIRT1 on improving myocardial fibrosis and GAS5 inhibiting occurrence and development of myocardial fibrosis at the cellular level, the aim of the present study was to investigate whether LncRNA GAS5 could attenuate cardiac fibrosis through regulating mir-217/SIRT1, and whether the NLRP3 inflammasome activation was involved in this process. Isoprenaline (ISO) was given subcutaneously to the male C57BL/6 mice to induce myocardial fibrosis and the AAV9 vectors were randomly injected into the left ventricle of each mouse to overexpress GAS5. Primary myocardial fibroblasts (MCFs) derived from neonatal C57BL/6 mice and TGF-β1 were used to induce fibrosis. And the GAS5 overexpressed MCFs were treated with mir-217 mimics and mir-217 inhibitor respectively. Then the assays of expression levels of NLRP3, Caspase-1, IL-1β and SIRT1 were conducted. The findings indicated that the overexpression of GAS5 reduced the expression levels of collagen, NLRP3, Capase-1, IL-1β and SIRT1 in ISO treated mice and TGF-β1 treated MCFs. However, this effect was significantly weakened after mir-217 overexpression, but was further enhanced after knockdown of mir-217. mir-217 down-regulates the expression of SIRT1, leading to increased activation of the NLRP3 inflammasome and subsequent pyroptosis. LncRNA GAS5 alleviates cardiac fibrosis induced via regulating mir-217/SIRT1 pathway.

Renalase mediates macrophage-to-fibroblast crosstalk to attenuate pressure overload-induced pathological myocardial fibrosis

A potential antifibrotic mechanism in pathological myocardial remodeling is the recruitment of beneficial functional subpopulations of macrophages or the transformation of their phenotype. Macrophages are required to activate molecular cascades that regulate fibroblast behavior. Identifying mediators that activate the antifibrotic macrophage phenotype is tantamount to identifying the button that retards pathological remodeling of the myocardium; however, relevant studies are inadequate. Circulating renalase (RNLS) is mainly of renal origin, and cardiac myocytes also secrete it autonomously. Our previous studies revealed that RNLS delivers cell signaling to exert multiple cardiovascular protective effects, including the improvement of myocardial ischemia, and heart failure. Here, we further investigated the potential mechanism by which macrophage phenotypic transformation is targeted by RNLS to mediate stress load-induced myocardial fibrosis. Mice subjected to transverse aortic constriction (TAC) were used as a model of myocardial fibrosis. The co-incubation of macrophages and cardiac fibroblasts was used to study intercellular signaling. The results showed that RNLS co-localized with macrophages and reduced protein expression after cardiac pressure overload. TAC mice exhibited improved cardiac function and alleviated left ventricular fibrosis when exogenous RNLS was administered. Flow sorting showed that RNLS is essential for macrophage polarization towards a restorative phenotype (M2-like), thereby inhibiting myofibroblast activation, as proven by both mouse RAW264.7 and bone marrow-derived macrophage models. Mechanistically, we found that activated protein kinase B is a major pathway by which RNLS promotes M2 polarization in macrophages. RNLS may serve as a prognostic biomarker and a potential clinical candidate for the treatment of myocardial fibrosis.

HTRA1-driven detachment of type I collagen from endoplasmic reticulum contributes to myocardial fibrosis in dilated cardiomyopathy

BACKGROUND

The aberrant secretion and excessive deposition of type I collagen (Col1) are important factors in the pathogenesis of myocardial fibrosis in dilated cardiomyopathy (DCM). However, the precise molecular mechanisms underlying the synthesis and secretion of Col1 remain unclear.

METHODS AND RESULTS

RNA-sequencing analysis revealed an increased HtrA serine peptidase 1 (HTRA1) expression in patients with DCM, which is strongly correlated with myocardial fibrosis. Consistent findings were observed in both human and mouse tissues by immunoblotting, quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry, and immunofluorescence analyses. Pearson's analysis showed a markedly positive correlation between HTRA1 level and myocardial fibrosis indicators, including extracellular volume fraction (ECV), native T1, and late gadolinium enhancement (LGE), in patients with DCM. In vitro experiments showed that the suppression of HTRA1 inhibited the conversion of cardiac fibroblasts into myofibroblasts and decreased Col1 secretion. Further investigations identified the role of HTRA1 in promoting the formation of endoplasmic reticulum (ER) exit sites, which facilitated the transportation of Col1 from the ER to the Golgi apparatus, thereby increasing its secretion. Conversely, HTRA1 knockdown impeded the retention of Col1 in the ER, triggering ER stress and subsequent induction of ER autophagy to degrade misfolded Col1 and maintain ER homeostasis. In vivo experiments using adeno-associated virus-serotype 9-shHTRA1-green fluorescent protein (AAV9-shHTRA1-GFP) showed that HTRA1 knockdown effectively suppressed myocardial fibrosis and improved left ventricular function in mice with DCM.

CONCLUSIONS

The findings of this study provide valuable insights regarding the treatment of DCM-associated myocardial fibrosis and highlight the therapeutic potential of targeting HTRA1-mediated collagen secretion.

Imaging of Cardiac Fibrosis: How Far Have We Moved From Extracellular to Cellular?

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Myocardial fibrosis plays an important role in adverse outcomes such as heart failure and arrhythmias. As the pathological response and degree of scarring, and therefore clinical presentation varies from patient to patient, early detection of fibrosis is crucial for identifying the appropriate treatment approach and forecasting the progression of a disease along with the likelihood of disease-related mortality. Current imaging modalities provides information about either decreased function or extracellular signs of fibrosis. Targeting activated fibroblasts represents a burgeoning approach that could offer insights prior to observable functional alterations, presenting a promising focus for potential anti-fibrotic therapeutic interventions at cellular level. In this article, we provide an overview of imaging cardiac fibrosis and discuss the role of different advanced imaging modalities with the focus on novel non-invasive imaging of activated fibroblasts.

The influence of left bundle branch block on myocardial T1 mapping

Tissue characterisation using T1 mapping has become an established magnetic resonance imaging (MRI) technique to detect myocardial diseases. This retrospective study aimed to determine the influence of left bundle branch block (LBBB) on T1 mapping at 1.5 T. Datasets of 36 patients with LBBB and 27 healthy controls with T1 mapping (Modified Look-Locker inversion-recovery (MOLLI), 5(3)3 sampling) were included. T1 relaxation times were determined on mid-cavity short-axis images. R2 maps were generated as a pixel-wise indicator for the goodness of the fit of T1 maps. R2 values were significantly lower in patients with LBBB than in healthy controls (whole myocardium/septum, 0.997, IQR, 0.00 vs. 0.998, IQR, 0.00; p = 0.008/0.998, IQR, 0.00 vs. 0.999, IQR, 0.00; p = 0.027). Manual correction of semi-automated evaluation tended to improve R2 values but not significantly. Strain analysis was performed and the systolic dyssynchrony index (SDIglobal) was calculated as a measure for left ventricular dyssynchrony. While MRI is generally prone to artefacts, lower goodness of the fit in LBBB may be mainly attributable to asynchronous contraction. Therefore, careful checking of the source data and, if necessary, manual post-processing is important. New techniques might improve the goodness of the fit of T1 mapping by reducing sampling in the motion prone diastole of LBBB patients.

Left ventricular concentric hypertrophy with cardiac magnetic resonance imaging improves risk stratification in patients with Duchenne muscular dystrophy: a prospective cohort study

BACKGROUND

The development of left ventricular (LV) remodeling has been associated with an increased cardiovascular risk and cardiogenic death, and different patterns of remodeling result in varying levels of prognosis.

OBJECTIVE

To investigate the association between different patterns of LV remodeling and clinical outcomes in the preclinical stage of patients with Duchenne muscular dystrophy (DMD).

MATERIALS AND METHODS

A total of 148 patients with DMD and 43 sex- and age-matched healthy participants were enrolled. We used the four-quadrant analysis method to investigate LV remodeling based on cardiac magnetic resonance (MR) imaging. Kaplan-Meier curves were generated to illustrate the event-free survival probability stratified by the LV remodeling pattern. Cox regression models were constructed and compared to evaluate the incremental predictive value of the LV remodeling pattern.

RESULTS

During the median follow-up period of 2.2 years, all-cause death, cardiomyopathy, and ventricular arrhythmia occurred in 5, 35, and 7 patients, respectively. LV concentric hypertrophy (hazard ratio 2.91, 95% confidence interval 1.47-5.75, P=0.002) was an independent predictor of composite endpoint events. Compared to the model without LV concentric hypertrophy, the model with LV concentric hypertrophy had significant incremental predictive value (chi-square value 33.5 vs. 25.2, P=0.004).

CONCLUSION

Age and late gadolinium enhancement positivity were positively correlated with clinical outcomes according to the prediction models. LV concentric hypertrophy was also an independent predictor for risk stratification and provided incremental value for predicting clinical outcomes in the preclinical stage of patients with DMD.

HSPA12A acts as a scaffolding protein to inhibit cardiac fibroblast activation and cardiac fibrosis

INTRODUCTION

Cardiac fibrosis is the main driver for adverse remodeling and progressive functional decline in nearly all types of heart disease including myocardial infarction (MI). The activation of cardiac fibroblasts (CF) into myofibroblasts is responsible for cardiac fibrosis. Unfortunately, no ideal approach for controlling CF activation currently exists.

OBJECTIVES

This study investigated the role of Heat shock protein A12A (HSPA12A), an atypical member of the HSP70 family, in CF activation and MI-induced cardiac fibrosis.

METHODS

Primary CF and Hspa12a knockout mice were used in the experiments. CF activation was indicated by the upregulation of myofibroblast characters including alpha-Smooth muscle actin (αSMA), Collagen, and Fibronectin. Cardiac fibrosis was illustrated by Masson's trichrome and picrosirius staining. Cardiac function was examined using echocardiography. Glycolytic activity was indicated by levels of extracellular lactate and the related protein expression. Protein stability was examined following cycloheximide and MG132 treatment. Protein-protein interaction was examined by immunoprecipitation-immunoblotting analysis.

RESULTS

HSPA12A displayed a high expression level in quiescent CF but showed a decreased expression in activated CF, while ablation of HSPA12A in mice promoted CF activation and cardiac fibrosis following MI. HSPA12A overexpression inhibited the activation of primary CF through inhibiting glycolysis, while HSPA12A knockdown showed the opposite effects. Moreover, HSPA12A upregulated the protein expression of transcription factor p53, by which mediated the HSPA12A-induced inhibition of glycolysis and CF activation. Mechanistically, this action of HSPA12A was achieved by acting as a scaffolding protein to bind p53 and ubiquitin specific protease 10 (USP10), thereby promoting the USP10-mediated p53 protein stability and the p53-medicated glycolysis inhibition.

CONCLUSION

The present study provided clear evidence that HSPA12A is a novel endogenous inhibitor of CF activation and cardiac fibrosis. Targeting HSPA12A in CF could represent a promising strategy for the management of cardiac fibrosis in patients.

Effect of Astragalus membranaceus on left ventricular remodeling in HFrEF: a systematic review and meta-analysis

Background: Left ventricular remodeling (LVR) is a key factor leading to the onset and progression of heart failure with reduced ejection fraction (HFrEF). Improving LVR can delay the progression of HFrEF and improve quality of life. Objective: To evaluate the improvement effect of Astragalus membranaceus (A. membranaceus) on LVR in patients with HFrEF. Method: We retrieved randomized controlled trials (RCTs) of A. membranaceus in treating HFrEF from eight Chinese and English databases, up until 31 October 2023. To assess the quality of the literature, we utilized the bias risk tool from the Cochrane Handbook. For meta-analysis, we employed Review Manager 5.4.1 software. Additionally, we performed sensitivity analysis and publication bias assessment using Stata 17.0 software. Result: Totally 1,565 patients were included in 19 RCTs. Compared to conventional treatment (CT), the combination therapy of A. membranaceus with CT demonstrated significant improvements in LVR, specifically increasing left ventricular ejection fraction (LVEF, MD = 5.82, 95% CI: 4.61 to 7.03, p < 0.00001), decreasing left ventricular end-diastolic diameter (LVEDD, MD = -4.05, 95% CI: -6.09 to -2.01, p = 0.0001), and left ventricular end-systolic diameter (LVESD, MD = -12.24, 95% CI: -15.24 to -9.24, p < 0.00001). The combination therapy of A. membranaceus with CT also improved clinical efficacy (RR = 4.81, 95% CI: 3.31 to 7.00, p < 0.00001), reduced brain natriuretic peptide (BNP, MD = -113.57, 95% CI: -146.91 to -81.22, p < 0.00001) level, and increased 6-min walking distance (6-MWD, MD = 67.62, 95% CI: 41.63 to 93.60, p < 0.00001). In addition, the combination therapy of A. membranaceus with CT mitigated inflammatory responses by reducing tumor necrosis factor-alpha (TNF-α, MD = -16.83, 95% CI: -22.96 to -10.71, p < 0.00001), interleukin-6 (IL-6, MD = -29.19, 95% CI: -36.08 to -22.30, p < 0.00001), and high-sensitivity C-reactive protein (hs-CRP, MD = -0.98, 95% CI: -1.43 to -0.52, p < 0.0001). Notably, the combination therapy of A. membranaceus with CT did not increase the incidence of adverse reactions (RR = 0.86, 95% CI: 0.25 to 2.96, p = 0.81). Conclusion: This systematic review and meta-analysis revealed that the combination therapy of A. membranaceus with CT has more advantages than CT alone in improving LVR and clinical efficacy in HFrEF patients, without increasing the incidence of adverse reactions. However, due to the limited quality of included studies, more high-quality investigations are required to provide reliable evidence for clinical use. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=397571, Identifier: CRD42023397571.

ITRI Biofilm Prevented Thoracic Adhesion in Pigs That Received Myocardial Ischemic Induction Treated by Myocardial Implantation of EPCs and ECSW Treatment

This study tested the hypothesis that ITRI Biofilm prevents adhesion of the chest cavity. Combined extracorporeal shock wave (ECSW) + bone marrow-derived autologous endothelial progenitor cell (EPC) therapy was superior to monotherapy for improving heart function (left ventricular ejection fraction [LVEF]) in minipigs with ischemic cardiomyopathy (IC) induced by an ameroid constrictor applied to the mid-left anterior descending artery. The minipigs (n = 30) were equally designed into group 1 (sham-operated control), group 2 (IC), group 3 (IC + EPCs/by directly implanted into the left ventricular [LV] myocardium; 3 [+]/3[-] ITRI Biofilm), group 4 (IC + ECSW; 3 [+]/[3] - ITRI Biofilm), and group 5 (IC + EPCs-ECSW; 3 [+]/[3] - ITRI Biofilm). EPC/ECSW therapy was administered by day 90, and the animals were euthanized, followed by heart harvesting by day 180. In vitro studies demonstrated that cell viability/angiogenesis/cell migratory abilities/mitochondrial concentrations were upregulated in EPCs treated with ECSW compared with those in EPCs only (all Ps < 0.001). The LVEF was highest in group 1/lowest in group 2/significantly higher in group 5 than in groups 3/4 (all Ps < 0.0001) by day 180, but there was no difference in groups 3/4. The adhesion score was remarkably lower in patients who received ITRI Biofilm treatment than in those who did not (all Ps <0.01). The protein expressions of oxidative stress (NOX-1/NOX-2/oxidized protein)/apoptotic (mitochondrial-Bax/caspase3/PARP)/fibrotic (TGF-β/Smad3)/DNA/mitochondria-damaged (γ-H2AX/cytosolic-cytochrome-C/p-DRP1), and heart failure/pressure-overload (BNP [brain natriuretic peptide]/β-MHC [beta myosin heavy chain]) biomarkers displayed a contradictory manner of LVEF among the groups (all Ps < 0.0001). The protein expression of endothelial biomarkers (CD31/vWF)/small-vessel density revealed a similar LVEF within the groups (all Ps < 0.0001). ITRI Biofilm treatment prevented chest cavity adhesion and was superior in restoring IC-related LV dysfunction when combined with EPC/ECSW therapy compared with EPC/ECSW therapy alone.

Left atrioventricular coupling index assessed using cardiac CT as a prognostic marker of cardiovascular death

PURPOSE

The purpose of this study was to investigate the prognostic value of left atrioventricular coupling index (LACI) assessed by cardiac computed tomography (CT), to predict cardiovascular death in consecutive patients referred for cardiac CT with coronary analysis.

MATERIALS AND METHODS

Between 2010 and 2020, we conducted a single-centre study with all consecutive patients without known cardiovascular disease referred for cardiac CT. LACI was defined as the ratio of left atrial to left ventricle end-diastolic volumes. The primary outcome was cardiovascular death. Cox regressions were used to evaluate the association between LACI and primary outcome after adjustment for traditional risk factors and cardiac CT angiography findings.

RESULTS

In 1,444 patients (mean age, 70 ± 12 [standard deviation] years; 43% men), 67 (4.3%) patients experienced cardiovascular death after a median follow-up of 6.8 (Q1, Q3: 5.9, 9.1) years. After adjustment, LACI was positively associated with the occurrence of cardiovascular death (adjusted hazard ratio [HR], 1.07 [95% CI: 1.05-1.09] per 1% increment; P < 0.001), and all-cause death (adjusted HR, 1.05 [95% CI: 1.03-1.07] per 1% increment; P <0.001). After adjustment, a LACI ≥ 25% showed the best improvement in model discrimination and reclassification for predicting cardiovascular death above traditional risk factors and cardiac CT findings (C-statistic improvement: 0.27; Nnet reclassification improvement = 0.826; Integrative discrimination index =0.209, all P < 0.001; likelihood-ratio-test, P < 0.001).

CONCLUSION

LACI measured by cardiac CT is independently associated with cardiovascular death and all-cause death in patients without known cardiovascular disease referred for cardiac CT, with an incremental prognostic value over traditional risk factors and cardiac CT findings.

A deep learning method for the automated assessment of paradoxical pulsation after myocardial infarction using multicenter cardiac MRI data

OBJECTIVE

The current study aimed to explore a deep convolutional neural network (DCNN) model that integrates multidimensional CMR data to accurately identify LV paradoxical pulsation after reperfusion by primary percutaneous coronary intervention with isolated anterior infarction.

METHODS

A total of 401 participants (311 patients and 90 age-matched volunteers) were recruited for this prospective study. The two-dimensional UNet segmentation model of the LV and classification model for identifying paradoxical pulsation were established using the DCNN model. Features of 2- and 3-chamber images were extracted with 2-dimensional (2D) and 3D ResNets with masks generated by a segmentation model. Next, the accuracy of the segmentation model was evaluated using the Dice score and classification model by receiver operating characteristic (ROC) curve and confusion matrix. The areas under the ROC curve (AUCs) of the physicians in training and DCNN models were compared using the DeLong method.

RESULTS

The DCNN model showed that the AUCs for the detection of paradoxical pulsation were 0.97, 0.91, and 0.83 in the training, internal, and external testing cohorts, respectively (p < 0.001). The 2.5-dimensional model established using the end-systolic and end-diastolic images combined with 2-chamber and 3-chamber images was more efficient than the 3D model. The discrimination performance of the DCNN model was better than that of physicians in training (p < 0.05).

CONCLUSIONS

Compared to the model trained by 2-chamber or 3-chamber images alone or 3D multiview, our 2.5D multiview model can combine the information of 2-chamber and 3-chamber more efficiently and obtain the highest diagnostic sensitivity.

CLINICAL RELEVANCE STATEMENT

A deep convolutional neural network model that integrates 2-chamber and 3-chamber CMR images can identify LV paradoxical pulsation which correlates with LV thrombosis, heart failure, ventricular tachycardia after reperfusion by primary percutaneous coronary intervention with isolated anterior infarction.

KEY POINTS

• The epicardial segmentation model was established using the 2D UNet based on end-diastole 2- and 3-chamber cine images. • The DCNN model proposed in this study had better performance for discriminating LV paradoxical pulsation accurately and objectively using CMR cine images after anterior AMI compared to the diagnosis of physicians in training. • The 2.5-dimensional multiview model combined the information of 2- and 3-chamber efficiently and obtained the highest diagnostic sensitivity.

Assessment of left atrioventricular coupling and left atrial function impairment in diabetes with and without hypertension using CMR feature tracking

PURPOSE

The study was designed to assess the effect of co-occurrence of diabetes mellitus (DM) and hypertension on the deterioration of left atrioventricular coupling index (LACI) and left atrial (LA) function in comparison to individuals suffering from DM only.

METHODS

From December 2015 to June 2022, we consecutively recruited patients with clinically diagnosed DM who underwent cardiac magnetic resonance (CMR) at our hospital. The study comprised a total of 176 patients with DM, who were divided into two groups based on their blood pressure status: 103 with hypertension (DM + HP) and 73 without hypertension (DM-HP). LA reservoir function (reservoir strain (εs), total LA ejection fraction (LAEF)), conduit function (conduit strain (εe), passive LAEF), booster-pump function (booster strain (εa) and active LAEF), LA volume index (LAVI), LV global longitudinal strain (LVGLS), and LACI were evaluated and compared between the two groups.

RESULTS

After adjusting for age, sex, body surface area (BSA), and history of current smoking, total LAEF (61.16 ± 14.04 vs. 56.05 ± 12.72, p = 0.013) and active LAEF (43.98 ± 14.33 vs. 38.72 ± 13.51, p = 0.017) were lower, while passive LAEF (33.22 ± 14.11 vs. 31.28 ± 15.01, p = 0.807) remained unchanged in the DM + HP group compared to the DM-HP group. The DM + HP group had decreased εs (41.27 ± 18.89 vs. 33.41 ± 13.94, p = 0.006), εe (23.69 ± 12.96 vs. 18.90 ± 9.90, p = 0.037), εa (17.83 ± 8.09 vs. 14.93 ± 6.63, p = 0.019), and increased LACI (17.40±10.28 vs. 22.72±15.01, p = 0.049) when compared to the DM-HP group. In patients with DM, multivariate analysis revealed significant independent associations between LV GLS and εs (β=-1.286, p < 0.001), εe (β=-0.919, p < 0.001), and εa (β=-0.324, p = 0.036). However, there was no significant association observed between LV GLS and LACI (β=-0.003, p = 0.075). Additionally, hypertension was found to independently contribute to decreased εa (β=-2.508, p = 0.027) and increased LACI in individuals with DM (β = 0.05, p = 0.011).

CONCLUSIONS

In DM patients, LV GLS showed a significant association with LA phasic strain. Hypertension was found to exacerbate the decline in LA booster strain and increase LACI in DM patients, indicating potential atrioventricular coupling index alterations.

AI-Based Fully Automated Left Atrioventricular Coupling Index as a Prognostic Marker in Patients Undergoing Stress CMR

BACKGROUND

The left atrioventricular coupling index (LACI) is a strong and independent predictor of heart failure (HF) in individuals without clinical cardiovascular disease. Its prognostic value is not established in patients with cardiovascular disease.

OBJECTIVES

This study sought to determine in patients undergoing stress cardiac magnetic resonance (CMR) whether fully automated artificial intelligence-based LACI can provide incremental prognostic value to predict HF.

METHODS

Between 2016 and 2018, the authors conducted a longitudinal study including all consecutive patients with abnormal (inducible ischemia or late gadolinium enhancement) vasodilator stress CMR. Control subjects with normal stress CMR were selected using propensity score matching. LACI was defined as the ratio of left atrial to left ventricular end-diastolic volumes. The primary outcome included hospitalization for acute HF or cardiovascular death. Cox regression was used to evaluate the association of LACI with the primary outcome after adjustment for traditional risk factors.

RESULTS

In 2,134 patients (65 ± 12 years, 77% men, 1:1 matched patients [1,067 with normal and 1,067 with abnormal CMR]), LACI was positively associated with the primary outcome (median follow-up: 5.2 years [IQR: 4.8-5.5 years]) before and after adjustment for risk factors in the overall propensity-matched population (adjusted HR: 1.18 [95% CI: 1.13-1.24]), in patients with abnormal CMR (adjusted HR per 0.1% increment: 1.22 [95% CI: 1.14-1.30]), and in patients with normal CMR (adjusted HR per 0.1% increment: 1.12 [95% CI: 1.05-1.20]) (all P < 0.001). After adjustment, a higher LACI of ≥25% showed the greatest improvement in model discrimination and reclassification over and above traditional risk factors and stress CMR findings (C-index improvement: 0.16; net reclassification improvement = 0.388; integrative discrimination index = 0.153, all P < 0.001; likelihood ratio test P < 0.001).

CONCLUSIONS

LACI is independently associated with hospitalization for HF and cardiovascular death in patients undergoing stress CMR, with an incremental prognostic value over traditional risk factors including inducible ischemia and late gadolinium enhancement.

Differentiating the Prognostic Determinants of Myocardial Steatosis for Heart Failure With Preserved Ejection Fraction by Cardiac Magnetic Resonance Imaging

Background Myocardial steatosis and fibrosis may play a role in the pathophysiology of heart failure with preserved ejection fraction. We therefore investigated the prognostic significance of epicardial fat (epicardial adipose tissue [EAT]) and myocardial diffuse fibrosis. Methods and Results Myocardial fibrosis, estimated as extracellular volume (ECV), and EAT were measured using cardiac magnetic resonance imaging in 163 subjects with heart failure with preserved ejection fraction. We also evaluated cardiac structure and diastolic and systolic function by echocardiography and cardiac magnetic resonance imaging. After 24 months' follow-up, 39 (24%) subjects had experienced cardiovascular events, including hospitalization for heart failure, acute coronary syndrome, and cardiovascular death. Median EAT and mean ECV were significantly higher in subjects with cardiovascular events than survivors (EAT, 35 [25-45] versus 31 [21-38], P=0.006 and ECV, 28.9±3.16% versus 27.2±3.56%, P=0.04). Subjects with high EAT (≥42 g) had increased risk of cardiovascular events (hazard ratio [HR], 2.528 [95% CI, 1.704-4.981]; P=0.032). High ECV (>29%) was also significantly associated with poorer outcomes (HR, 1.647 [95% CI, 1.263-2.548]; P=0.013). With respect to secondary end points, high EAT and high ECV were associated with increased risk of the incident acute coronary syndrome (HR, 1.982 [95% CI, 1.008-4.123]; P=0.049) and hospitalization for heart failure (HR, 1.789 [95% CI, 1.102-6.987]; P=0.033), respectively. Conclusions Our study suggested that increased epicardial fat and ECV detected by cardiac magnetic resonance imaging have an impact on cardiovascular prognosis, in particular acute coronary syndrome and hospitalization for heart failure, respectively.

Accuracy of Devereaux and Teichholz formulas for left ventricular mass calculation in different geometric patterns: comparison with cardiac magnetic resonance imaging

Left ventricular (LV) myocardial mass is important in the evaluation of cardiac remodeling and requires accurate assessment when performed on linear measurements in two-dimensional echocardiography (Echo). We aimed to compare the accuracy of the Devereaux formula (DEV) and the Teichholz formula (TEICH) in calculating LV myocardial mass in Echo using cardiac magnetic resonance (CMR) as the reference method. Based on preceding mathematical calculations, we identified primarily LV size rather than wall thickness as the main source of bias between DEV and TEICH in a retrospective derivation cohort (n = 1276). Although LV mass from DEV and TEICH were correlated with CMR, TEICH did not show a proportional bias as did DEV (- 2 g/m2 vs. + 22 g/m2). This could be validated in an independent prospective cohort (n = 226) with symptomatic non-ischemic heart failure. DEV systematically overestimated LV mass in all tiers of LV remodeling as compared to TEICH. In conclusion, the TEICH method accounts for the changes in LV geometry with increasing LV mass and thus better reflects the different pattern of LV remodeling than the DEV method. This has important clinical implications, as TEICH may be more appropriate for use in clinical practice, rather than DEV, currently recommended.

Is increased myocardial triglyceride content associated with early changes in left ventricular function? A 1H-MRS and MRI strain study

Background

Type 2 diabetes (T2D) and obesity induce left ventricular (LV) dysfunction. The underlying pathophysiological mechanisms remain unclear, but myocardial triglyceride content (MTGC) could be involved.

Objectives

This study aimed to determine which clinical and biological factors are associated with increased MTGC and to establish whether MTGC is associated with early changes in LV function.

Methods

A retrospective study was conducted using five previous prospective cohorts, leading to 338 subjects studied, including 208 well-phenotyped healthy volunteers and 130 subjects living with T2D and/or obesity. All the subjects underwent proton magnetic resonance spectroscopy and feature tracking cardiac magnetic resonance imaging to measure myocardial strain.

Results

MTGC content increased with age, body mass index (BMI), waist circumference, T2D, obesity, hypertension, and dyslipidemia, but the only independent correlate found in multivariate analysis was BMI (p=0.01; R²=0.20). MTGC was correlated to LV diastolic dysfunction, notably with the global peak early diastolic circumferential strain rate (r=-0.17, p=0.003), the global peak late diastolic circumferential strain rate (r=0.40, p<0.0001) and global peak late diastolic longitudinal strain rate (r=0.24, p<0.0001). MTGC was also correlated to systolic dysfunction via end-systolic volume index (r=-0.34, p<0.0001) and stroke volume index (r=-0.31, p<0.0001), but not with longitudinal strain (r=0.009, p=0.88). Interestingly, the associations between MTGC and strain measures did not persist in multivariate analysis. Furthermore, MTGC was independently associated with LV end-systolic volume index (p=0.01, R²=0.29), LV end-diastolic volume index (p=0.04, R²=0.46), and LV mass (p=0.002, R²=0.58).

Conclusions

Predicting MTGC remains a challenge in routine clinical practice, as only BMI independently correlates with increased MTGC. MTGC may play a role in LV dysfunction but does not appear to be involved in the development of subclinical strain abnormalities.

Liensinine prevents ischemic injury following myocardial infarction via inhibition of Wnt/β‑catenin signaling activation

BACKGROUND

Myocardial infarction (MI) is the leading cause of deaths worldwide, triggering widespread and irreversible damage to the heart. Currently, there are no drugs that can reverse ischemic damage to the myocardium and hence, finding novel therapeutic agents that can limit the extent of myocardial damage following MI is crucial. Liensinine (LSN) is a naturally derived bisbenzylisoquinoline alkaloid that is known to exhibit numerous antioxidative and cardiovascular beneficial effects. However, the role of LSN in MI-induced injury and its underlying mechanisms remain unexplored.

PURPOSE

Our study aims to evaluate the cardioprotective effects of LSN following MI and its underlying molecular mechanisms.

METHODS

We constructed murine models of MI in order to examine the potential cardioprotective effects and mechanisms of LSN in protecting against myocardial ischemic damage both in vivo and in vitro.

RESULTS

Administration with LSN strongly protected against cardiac injuries following MI by decreasing the extent of ischemic damage and improving cardiac function. Additionally, LSN was found to be a potent inhibitor of Wnt/β‑catenin signaling pathway. Hence, the beneficial effects of LSN in preventing oxidative and DNA damage following ischemia was due to its ability to inhibit aberrant activation of Wnt/β‑catenin signaling.

CONCLUSIONS

Our findings reveal for the first time a novel cardioprotective role of LSN during myocardial infarction and most notably, its ability to protect cardiomyocytes against oxidative stress-induced damage via inhibiting Wnt/β-catenin signaling. Our study therefore suggests new therapeutic potential of LSN or plants that contain the natural alkaloid LSN in ischemic heart diseases.

Grpel2 maintains cardiomyocyte survival in diabetic cardiomyopathy through DLST-mediated mitochondrial dysfunction: a proof-of-concept study

BACKGROUND

Diabetic cardiomyopathy (DCM) has been considered as a major threat to health in individuals with diabetes. GrpE-like 2 (Grpel2), a nucleotide exchange factor, has been shown to regulate mitochondrial import process to maintain mitochondrial homeostasis. However, the effect and mechanism of Grpel2 in DCM remain unknown.

METHODS

The streptozotocin (STZ)-induced DCM mice model and high glucose (HG)-treated cardiomyocytes were established. Overexpression of cardiac-specific Grpel2 was performed by intramyocardial injection of adeno-associated virus serotype 9 (AAV9). Bioinformatics analysis, co-immunoprecipitation (co-IP), transcriptomics profiling and functional experiments were used to explore molecular mechanism of Grpel2 in DCM.

RESULTS

Here, we found that Grpel2 was decreased in DCM induced by STZ. Overexpression of cardiac-specific Grpel2 alleviated cardiac dysfunction and structural remodeling in DCM. In both diabetic hearts and HG-treated cardiomyocytes, Grpel2 overexpression attenuated apoptosis and mitochondrial dysfunction, including decreased mitochondrial ROS production, increased mitochondrial respiratory capacities and increased mitochondrial membrane potential. Mechanistically, Grpel2 interacted with dihydrolipoyl succinyltransferase (DLST), which positively mediated the import process of DLST into mitochondria under HG conditions. Furthermore, the protective effects of Grpel2 overexpression on mitochondrial function and cell survival were blocked by siRNA knockdown of DLST. Moreover, Nr2f6 bond to the Grpel2 promoter region and positively regulated its transcription.

CONCLUSION

Our study provides for the first time evidence that Grpel2 overexpression exerts a protective effect against mitochondrial dysfunction and apoptosis in DCM by maintaining the import of DLST into mitochondria. These findings suggest that targeting Grpel2 might be a promising therapeutic strategy for the treatment of patients with DCM.

Native T1 is predictive of cardiovascular death/heart failure events and all-cause mortality irrespective of the patient's volume status

Background

Native T1 has become a pivotal parameter of tissue composition that is assessed by cardiac magnetic resonance (CMR). It characterizes diseased myocardium and can be used for prognosis estimation. Recent publications have shown that native T1 is influenced by short-term fluctuations of volume status due to hydration or hemodialysis.

Methods

Patients from a prospective BioCVI all-comers clinical CMR registry were included, and native T1 and plasma volume status (PVS) were determined according to Hakim's formula as surrogate markers of patient volume status. The primary endpoint was defined as combined endpoint of cardiovascular death or hospitalization for heart failure events, the secondary endpoint was defined as all-cause mortality.

Results

A total of 2,047 patients were included since April 2017 [median (IQR); age 63 (52-72) years, 33% female]. There was a significant although weak influence of PVS on native T1 (β = 0.11, p < 0.0001). Patients with volume expansion (PVS > -13%) showed significantly higher values for tissue markers than non-volume-overloaded patients [PVS ≤ -13%; median (IQR); native T1 1,130 (1,095-1,170) vs. 1,123 (1,086-1,166) ms, p < 0.003; and T2 39 (37-40) vs. 38 (36-40) ms, p < 0.0001]. In Cox regression analysis both native T1 and PVS were independently predictive of the primary endpoint and all-cause mortality.

Conclusion

Despite a weak effect of PVS on native T1, its predictive power was not affected in a large, all-comers cohort.

L-carnitine attenuated hyperuricemia-associated left ventricular remodeling through ameliorating cardiomyocytic lipid deposition

Hyperuricemia (HUA) is associated with left ventricular remodeling (LVR) and thereby causes the initiation and development of a large number of cardiovascular diseases. LVR is typically accompanied by cardiomyocyte energy metabolic disorder. The energy supply of cardiomyocytes is provided by glucose and fatty acid (FA) metabolism. Currently, the effect of HUA on cardiomyocytic FA metabolism is unclear. In this study, we demonstrate that UA-induced cardiomyocyte injury is associated with cytoplasmic lipid deposition, which can be ameliorated by the FA metabolism-promoting drug L-carnitine (LC). UA suppresses carnitine palmitoyl transferase 1B (CPT1B), thereby inhibiting FA transport into the mitochondrial inner matrix for elimination. LC intervention can ameliorate HUA-associated left ventricular anterior wall thickening in mice. This study showed that FA transport dysfunction plays is a critical mechanism in both cardiomyocytic injury and HUA-associated LVR and promoting cytoplasmic FA transportation through pharmacological treatment by LC is a valid strategy to attenuate HUA-associated LVR.

Immune cells drive new immunomodulatory therapies for myocardial infarction: From basic to clinical translation

The high incidence of heart failure secondary to myocardial infarction (MI) has been difficult to effectively address. MI causes strong aseptic inflammation, and infiltration of different immune cells and changes in the local inflammatory microenvironment play a key regulatory role in ventricular remodeling. Therefore, the possibility of improving the prognosis of MI through targeted immunity has been of interest and importance in MI. However, previously developed immune-targeted therapies have not achieved significant success in clinical trials. Here, we propose that the search for therapeutic targets from different immune cells may be more precise and lead to better clinical translation. Specifically, this review summarizes the role and potential therapeutic targets of various immune cells in ventricular remodeling after MI, especially monocytes/macrophages and neutrophils, as a way to demonstrate the importance and potential of immunomodulatory therapies for MI. In addition, we analyze the reasons for the failure of previous immunomodulatory therapies and the issues that need to be addressed, as well as the prospects and targeting strategies of using immune cells to drive novel immunomodulatory therapies, hoping to advance the development of immunomodulatory therapies by providing evidence and new ideas.

Cardiac fibroblasts and mechanosensation in heart development, health and disease

The term 'mechanosensation' describes the capacity of cells to translate mechanical stimuli into the coordinated regulation of intracellular signals, cellular function, gene expression and epigenetic programming. This capacity is related not only to the sensitivity of the cells to tissue motion, but also to the decryption of tissue geometric arrangement and mechanical properties. The cardiac stroma, composed of fibroblasts, has been historically considered a mechanically passive component of the heart. However, the latest research suggests that the mechanical functions of these cells are an active and necessary component of the developmental biology programme of the heart that is involved in myocardial growth and homeostasis, and a crucial determinant of cardiac repair and disease. In this Review, we discuss the general concept of cell mechanosensation and force generation as potent regulators in heart development and pathology, and describe the integration of mechanical and biohumoral pathways predisposing the heart to fibrosis and failure. Next, we address the use of 3D culture systems to integrate tissue mechanics to mimic cardiac remodelling. Finally, we highlight the potential of mechanotherapeutic strategies, including pharmacological treatment and device-mediated left ventricular unloading, to reverse remodelling in the failing heart.

Global Research Trends on Ventricular Remodeling: A Bibliometric Analysis From 2012 to 2022

Ventricular remodeling is the progressive pathologic change of the original substance and morphology of the ventricle caused by various injuries and has attracted increasing attention in the past decade. This study aims to conduct a bibliometric analysis of articles on ventricular remodeling published in the Web of Science Core Collection database from 2012 to 2022 to understand the current research state in the field of ventricular remodeling and provide insights for clinicians and researchers. As a result, a total of 1710 articles on ventricular remodeling were included. Annual publications have been gradually increasing and have remained at a high level over the past 10 years. The United States of America contributed the most publications, followed by China. Circulation was the most mainstream and authoritative journal focusing on ventricular remodeling. Research hotspot analysis suggested that myocardial infarction was the primary risk factor for ventricular remodeling, and emerging risk factor studies have focused on pulmonary hypertension, aortic stenosis, and diabetes. The mechanisms in the pathogenesis of ventricular remodeling were mainly closely associated with inflammation, apoptosis, oxidative stress, and myocardial fibrosis. Intensive investigation of the interactions between different mechanisms might be a future research direction. In terms of treatment, cardiac resynchronization therapy was a hot topic of research. These findings can help researchers grasp the research status of ventricular remodeling and determine future research directions.

Direct actions of dapagliflozin and interactions with LCZ696 and spironolactone on cardiac fibroblasts of patients with heart failure and reduced ejection fraction

AIMS

Inhibitors of SGLT2 (SGLT2i) have shown a positive impact in patients with chronic heart failure and reduced ejection fraction (HFrEF). Nonetheless, the direct effects of SGLT2i on cardiac cells and how their association with main drugs used for HFrEF affect the behaviour and signalling pathways of myocardial fibroblasts are still unknown. We aimed to determine the effects of dapagliflozin alone and in combination with sacubitril/valsartan (LCZ696) or spironolactone on the function of myocardial fibroblasts of patients with heart failure and reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Myocardial fibroblasts isolated from HFrEF patients (n = 5) were treated with dapagliflozin alone (1 nM-1 μM) or combined with LCZ696 (100 nM) or spironolactone (100 nM). The migratory rate was determined by wound-healing scratch assay. Expression of heart failure (HF) markers and signalling pathways activation were analysed with multiplexed protein array. Commercially available cardiac fibroblasts from healthy donors were used as Control (n = 4). Fibroblasts from HFrEF show higher migratory rate compared with control (P = 0.0036), and increased expression of HF markers [fold-change (Log2): COL1A1-1.3; IL-1b-1.9; IL-6-1.7; FN1-2.9 (P < 0.05)]. Dapagliflozin slowed the migration rate of HFrEF fibroblasts in a dose-dependent manner and markedly decreased the expression of IL-1β, IL-6, MMP3, MMP9, GAL3, and FN1. SGLT2i had no effect on control fibroblasts. These effects were associated with decreased phosphorylation of AKT/GSK3 and PYK2 kinases and the signal transducer and activator of transcription (STAT). A combination of dapagliflozin + LCZ696 further decreased fibroblast migration, although it did not have a significant effect on the regulation of signalling pathways and the expression of biomarkers induced by SGLT2 inhibition alone. In contrast, the combination of dapagliflozin + spironolactone did not change the migration rate of fibroblast but significantly altered SGLT2i responses on MMP9, GAL3, and IL-1b expression, in association with increased phosphorylation of the kinases AKT/GSK3 and ERK1/2.

CONCLUSIONS

SGLT2i, LCZ696, and spironolactone modulate the function of isolated myocardial fibroblasts from HFrEF patients through the activation of different signalling pathways. The combination of SGLT2i + LCZ696 shows an additive effect on migration, while spironolactone modifies the signalling pathways activated by SGLT2i and its beneficial effects of biomarkers of heart failure.

Protective Effect of Natural Medicinal Plants on Cardiomyocyte Injury in Heart Failure: Targeting the Dysregulation of Mitochondrial Homeostasis and Mitophagy

Heart failure occurs because of various cardiovascular pathologies, such as coronary artery disease or cardiorenal syndrome, eventually reaching end-stage disease. Various factors contribute to cardiac structural or functional changes that result in systolic or diastolic dysfunction. Several studies have confirmed that the key factor in heart failure progression is myocardial cell death, and mitophagy is the major mechanism regulating myocardial cell death in heart failure. The clinical mechanisms of heart failure are well understood in practice. However, the essential role of mitophagic regulation in heart failure has only recently received widespread attention. Receptor-mediated mitophagy is involved in various mitochondrial processes like oxidative stress injury, energy metabolism disorders, and calcium homeostasis, which are also the main causes of heart failure. Understanding of the diverse regulatory mechanisms in mitophagy and the complexity of its pathophysiology in heart failure remains incomplete. Related studies have found that various natural medicinal plants and active ingredients, such as flavonoids and saponins, can regulate mitophagy to a certain extent, improve myocardial function, and protect myocardial cells. This review comprehensively covers the relevant mechanisms of different types of mitophagy in regulating heart failure pathology and controlling mitochondrial adaptability to stress injury. Further, it explores the relationship between mitophagy and cardiac ejection dysfunction. Natural medicinal plant-targeted regulation strategies and scientific evidence on mitophagy were provided to elucidate current and potential strategies to apply mitophagy-targeted therapy for heart failure.

Tumstatin (69-88) alleviates heart failure via attenuating oxidative stress in rats with myocardial infarction

Background

This study aimed to elucidate the effects of tumstatin (69–88) on heart failure and the underlying mechanism.

Materials and methods

Myocardial infarction (MI) was induced by ligating the left coronary artery in rats to trigger heart failure.

Results

Tumstatin (69–88) can reduce cardiac insufficiency in rats with heart failure. The increased cardiac fibrosis in MI rat was attenuated by tumstatin (69–88). Increase of cardiac atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in rats with myocardial infarction, and Ang II-treated NRCMs or H9C2 cells was inhibited by tumstatin (69–88). In the heart of MI rats, and Ang II-treated NRCMs or H9C2 cells, the superoxide anions and NADPH oxidase (Nox) activity rose and the superoxide dismutase (SOD) activity was reduced, which was inhibited by tumstatin (69–88). Diethyldithiocarbamate, an SOD inhibitor, increased the ANP and BNP in NRCMs or H9C2 cells. Tumstatin (69–88) inhibited the Ang II-induced raises of ANP and BNP in NRCMs or H9C2 cells, which was reversed by DETC.

Conclusions

These results indicate that tumstatin (69–88) alleviates cardiac dysfunction of heart failure. Tumstatin (69–88) improves the hypertrophy of cardiomyocytes via attenuation of oxidative stress. Tumstatin (69–88) may be a potential drug for heart failure in the future.

Myocardial extracellular volume quantified by cardiac magnetic resonance predicts left ventricular aneurysm following acute myocardial infarction

OBJECTIVE

This study aimed to investigate the correlation between increased extracellular matrix estimated by cardiac magnetic resonance (CMR) and left ventricular aneurysm after acute myocardial infarction.

METHODS

A total of 175 patients from 3 centers with an isolated left anterior descending culprit vessel underwent CMR examinations within 1 week and at a 6-month follow-up. Of these, 92 were identified to have left ventricular aneurysms (LVAs): 74 with functional aneurysm and 18 with anatomical aneurysm. The predictive significance of acute extracellular volume (ECV), left gadolinium enhancement (LGE), and other characteristics were analyzed using binary logistic regression analysis.

RESULTS

Patients with LVA were more likely to present with left ventricular adverse remodeling (LVAR) than those without (p = 0.009). With optimal cutoff values of 30.90% for LGE and 33% for ECV to discriminate LVA from non-LVA, the area under the curve (AUC) by receiver operator characteristic curve (ROC) analysis was 0.92 (95% CI: 0.87-0.96; p < 0.001) and 0.93 (95% CI: 0.88-0.96; p < 0.001), respectively. ECV was significantly better than LGE at discriminating between functional and anatomical LVA (p < 0.001). Both acute LGE and ECV were predictors of LVA, with an odds ratio of 1.35 (95% CI: 1.21-1.52, p < 0.001) and 1.23 (95% CI: 1.13-1.33, p < 0.001), respectively, by multivariable logistic regression analysis.

CONCLUSIONS

Acute LGE and ECV of the myocardium provided predictive significance for LVA. The discriminative significance of ECV for functional versus anatomical LVA was better than the discriminative significance of LGE.

KEY POINTS

• Patients with LVA were more likely to present with LVAR. • Acute LGE and ECV of the myocardium provided the strongest predictive significance for LVA. • The discriminative significance of ECV for functional versus anatomical LVA was better than that of LGE.

Determinants of left atrioventricular coupling index: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Recent studies have described a novel left atrioventricular coupling index (LACI), which had a better prognostic value in predicting cardiovascular events than individual left atrial (LA) or left ventricular (LV) variables.

AIMS

To identify determinants of LACI and its 10-year annual change (ΔLACI), measured by cardiac magnetic resonance (CMR), and to better understand the variables governing this left atrioventricular coupling.

METHODS

In the Multi-Ethnic Study of Atherosclerosis, 2112 study participants, free from cardiovascular disease at baseline, had LACI assessed by CMR imaging at baseline (LACI_Baseline; 2000-2002) and 10 years later (2010-2012). The LACI was defined as the ratio of LA to LV end-diastolic volumes. Linear regression analyses were performed to identify independent determinants of LACI_Baseline and ΔLACI.

RESULTS

In the 2112 participants (mean age 58.8±9.1 years; 46.6% male), after adjustment for all covariates, age was independently associated with LACI_Baseline (R²=0.10, slope=0.16) and ΔLACI (R²=0.15, slope=0.008; both P<0.001). African Americans had the highest LACI_Baseline value (18.0±7.7%). Although there was no difference in LACI_Baseline between women and men (P=0.19), ΔLACI was higher in women (1.0±1.1 vs 0.8±1.1%/year; P<0.001). Diabetes and higher body mass index (BMI) were independently associated with LACI_Baseline (both P<0.001). LACI_Baseline was independently associated with LV myocardial fibrosis markers (native T1: R²=0.11, slope=0.09 [P=0.038]; extracellular volume: R²=0.08, slope=0.28 [P=0.035]) and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) concentration (R²=0.10, slope=-1.11; P<0.001), but was not associated with interleukin 6 or high-sensitivity C-reactive protein.

CONCLUSIONS

Age, sex, ethnicity, diabetes and BMI were independent determinants of LACI. LACI was independently associated with myocardial fibrosis markers and NT-proBNP concentration.

Regional Strain Score as Prognostic Marker of Cardiovascular Events From the Multi-Ethnic Study of Atherosclerosis (MESA)

Background

Left ventricular (LV) circumferential strain (Ecc) is an accurate indicator of regional myocardial function, particularly using the regional Ecc or layer-specific strain.

Aim

This study aimed to investigate the prognostic value of a regional strain score (RSS) for predicting the incident of heart failure (HF) and coronary heart disease (CHD) in a population without a history of cardiovascular disease at baseline.

Materials and Methods

Data from participants in the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent tagged magnetic resonance imaging for strain determination were analyzed. Using −17% and −10% as Ecc cut-offs, each segment was rated from 0 to 2 points according to the Ecc value of each layer. The endo-Ecc, mid-Ecc, and epi-Ecc values from the 16-segment model were used to calculate three RSS: Endo-, Mid-, and Epi-RSS, respectively, which were defined as a percentage of good LV regional function. The Intramyocardial-RSS was the sum of these three RSS. Cox proportional hazard models were used to evaluate the association between each RSS and incident HF and hard CHD.

Results

Among the 1,506 participants (63.3 ± 9.4 years, 54.6% men), 122 cases of hard CHD and 91 cases of HF were observed [median (IQR) follow-up 15.9 (12.9–16.6) years]. After adjustment, Mid-, Epi-, and Intramyocardial-RSS values <50% were independently associated with HF [adjusted HR 1.43; 95% CI (1.08–2.87), p = 0.004; HR 1.80; 95% CI (1.12–3.07), p < 0.001; and HR 2.01; 95% CI (1.19–3.20), p < 0.001]. After adjustment, Endo-, Mid-, Epi-, and Intramyocardial-RSS <50% were also independently associated with hard CHD [adjusted HR 1.31; 95% CI (1.03–1.51), p = 0.04; HR 1.79; 95% CI (1.26–2.57), p < 0.001; HR 2.03; 95% CI (1.45–3.40), p < 0.001; and HR 2.28; 95% CI (1.51–3.53), p < 0.001].

Conclusions

Layer-specific regional Ecc, assessed by RSS, provides a robust, independent predictive value for incident HF and hard CHD in asymptomatic participants without any history of previous clinical cardiovascular disease.

Clinical Trial Registration

Unique identifier: NCT00005487.

SS31 Alleviates Pressure Overload-Induced Heart Failure Caused by Sirt3-Mediated Mitochondrial Fusion

Heart failure caused by pressure overload is one of the leading causes of heart failure worldwide, but its pathological origin remains poorly understood. It remains critical to discover and find new improvements and treatments for pressure overload-induced heart failure. According to previous studies, mitochondrial dysfunction and myocardial interstitial fibrosis are important mechanisms for the development of heart failure. The oligopeptide Szeto-Schiller Compound 31 (SS31) can specifically interact with the inner mitochondrial membrane and affect the integrity of the inner mitochondrial membrane. Whether SS31 alleviates pressure overload-induced heart failure through the regulation of mitochondrial fusion has not yet been confirmed. We established a pressure-overloaded heart failure mouse model through TAC surgery and found that SS31 can significantly improve cardiac function, reduce myocardial interstitial fibrosis, and increase the expression of optic atrophy-associated protein 1 (OPA1), a key protein in mitochondrial fusion. Interestingly, the role of SS31 in improving heart failure and reducing fibrosis is inseparable from the presence of sirtuin3 (Sirt3). We found that in Sirt3KO mice and fibroblasts, the effects of SS31 on improving heart failure and improving fibroblast transdifferentiation were disappeared. Likewise, Sirt3 has direct interactions with proteins critical for mitochondrial fission and fusion. We found that SS31 failed to increase OPA1 expression in both Sirt3KO mice and fibroblasts. Thus, SS31 can alleviate pressure overload-induced heart failure through Sirt3-mediated mitochondrial fusion. This study provides new directions and drug options for the clinical treatment of heart failure caused by pressure overload.

Guanxin V Acts as an Antioxidant in Ventricular Remodeling

Background: Our previous studies have shown that Guanxin V (GXV) is safe and effective in the treatment of ventricular remodeling (VR), but its mechanism related to oxidative stress has not been studied deeply.

Methods: We applied integrating virtual screening and network pharmacology strategy to obtain the GXV-, VR-, and oxidative stress-related targets at first, and then highlighted the shared targets. We built the networks and conducted enrichment analysis. Finally, the main results were validated by molecular docking and solid experiments.

Results: We obtained 251, 11,425, and 9,727 GXV-, VR-, and oxidative stress-related targets, respectively. GXV-component-target-VR and protein–protein interaction networks showed the potential mechanism of GXV in the treatment of VR. The following enrichment analysis results gathered many biological processes and “two GXV pathways” of oxidative stress-related to VR. All our main results were validated by molecular docking and solid experiments.

Conclusion: GXV could be prescribed for VR through the mechanism, including complex interactions between related components and targets, as predicted by virtual screening and network pharmacology and validated by molecular docking and solid experiments. Our study promotes the explanation of the biological mechanism of GXV for VR.

Echocardiographic Global Longitudinal Strain Is Associated With Myocardial Fibrosis and Predicts Outcomes in Aortic Stenosis

Aims: Left ventricular ejection fraction is the conventional measure used to guide heart failure management, regardless of underlying etiology. Left ventricular global longitudinal strain (LV-GLS) by speckle tracking echocardiography (STE) is a more sensitive measure of intrinsic myocardial function. We aim to establish LV-GLS as a marker of replacement myocardial fibrosis on cardiovascular magnetic resonance (CMR) and validate the prognostic value of LV-GLS thresholds associated with fibrosis.

Methods and results: LV-GLS thresholds of replacement fibrosis were established in the derivation cohort: 151 patients (57 ± 10 years; 58% males) with hypertension who underwent STE to measure LV-GLS and CMR. Prognostic value of the thresholds was validated in a separate outcome cohort: 261 patients with moderate-severe aortic stenosis (AS; 71 ± 12 years; 58% males; NYHA functional class I–II) and preserved LVEF ≥50%. Primary outcome was a composite of cardiovascular mortality, heart failure hospitalization, and myocardial infarction. In the derivation cohort, LV-GLS demonstrated good discrimination (c-statistics 0.74 [0.66–0.83]; P < 0.001) and calibration (Hosmer-Lemeshow χ² = 6.37; P = 0.605) for replacement fibrosis. In the outcome cohort, 47 events occurred over 16 [3.3, 42.2] months. Patients with LV-GLS > −15.0% (corresponding to 95% specificity to rule-in myocardial fibrosis) had the worst outcomes compared to patients with LV-GLS < −21.0% (corresponding to 95% sensitivity to rule-out myocardial fibrosis) and those between −21.0 and −15.0% (log-rank P < 0.001). LV-GLS offered independent prognostic value over clinical variables, AS severity and echocardiographic LV mass and E/e′.

Conclusion: LV-GLS thresholds associated with replacement myocardial fibrosis is a novel approach to risk-stratify patients with AS and preserved LVEF.

Left Atrioventricular Coupling Index to Predict Incident Heart Failure: The Multi-Ethnic Study of Atherosclerosis

Background: Although left atrial (LA) and left ventricular (LV) structural and functional parameters have independent prognostic value as predictors of heart failure (HF), the close physiological relationship between the LA and LV suggest that the assessment of LA/LV coupling could better reflect left atrioventricular dysfunction and be a better predictor of HF. Aim: We investigated the prognostic value of a left atrioventricular coupling index (LACI), measured by cardiovascular magnetic resonance (CMR), as well as change in LACI to predict incident HF in the Multi-Ethnic Study of Atherosclerosis (MESA). Materials and Methods: In the MESA, 2,250 study participants, free of clinically recognized HF and cardiovascular disease (CVD) at baseline, had LACI assessed by CMR imaging at baseline (Exam 1, 2000-2002), and 10 years later (Exam 5, 2010-2012). Left atrioventricular coupling index was defined as the ratio of LA to LV end-diastolic volumes. Univariable and multivariable Cox proportional hazard models were used to evaluate the associations of LACI and average annualized change in LACI (ΔLACI) with incident HF after adjustment for traditional MESA-HF risk factors. The incremental risk prediction was calculated using C-statistic, categorical net reclassification index (NRI) and integrative discrimination index (IDI). Results: Among the 2,250 participants (mean age 59.3 ± 9.3 years and 47.6% male participants), 50 incident HF events occurred over 6.8 ± 1.3 years after the second CMR exam. After adjustment, greater LACI and ΔLACI were independently associated with HF (adjusted HR 1.44, 95% CI [1.25-1.66] and adjusted HR 1.55, 95% CI [1.30-1.85], respectively; both p < 0.0001). Adjusted models for LACI showed significant improvement in model discrimination and reclassification compared to currently used HF risk score model for predicting HF incidence (C-statistic: 0.81 vs. 0.77; NRI = 0.411; IDI = 0.043). After adjustment, ΔLACI showed also significant improvement in model discrimination compared to the multivariable model with traditional MESA-HF risk factors for predicting incident HF (C-statistic: 0.82 vs. 0.77; NRI = 0.491; IDI = 0.058). Conclusions: In a multi-ethnic population, atrioventricular coupling (LACI), and coupling change (ΔLACI) are independently associated with incident HF. Both have incremental prognostic value for predicting HF events over traditional HF risk factors.

Identification of reference genes for gene expression studies among different developmental stages of murine hearts

Background

Real-time quantitative polymerase chain reaction (RT-qPCR) is a widely-used standard assay for assessing gene expression. RT-qPCR data requires reference genes for normalization to make the results comparable. Therefore, the selected reference gene should be highly stable in its expression throughout the experimental datasets. So far, reports about the optimal set of reference genes in murine left ventricle (LV) across embryonic and postnatal stages are few. The objective of our research was to identify the appropriate reference genes in murine LV among different developmental stages.

Methods

We investigated the gene expression profiles of 21 widely used housekeeping genes in murine LV from 7 different developmental stages (almost throughout the whole period of the mouse lifespan). The stabilities of the potential reference genes were evaluated by five methods: GeNorm, NormFinder, BestKeeper, Delta-Ct and RefFinder.

Results

We proposed a set of reliable reference genes for normalization of RT-qPCR experimental data in different conditions. Furthermore, our results showed that 6 genes (18S, Hmbs, Ubc, Psmb4, Tfrc and Actb) are not recommended to be used as reference genes in murine LV development studies. The data also suggested that the Rplp0 gene might serve as an optimal reference gene in gene expression analysis.

Conclusions

Our study investigated the expression stability of the commonly used reference genes in process of LV development and maturation. We proposed a set of optimal reference genes that are suitable for accurate normalization of RT-qPCR data in specific conditions. Our findings may be helpful in future studies for investigating the gene expression patterns and mechanism of mammalian heart development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12861-021-00244-6.

Myocardial Infarction: The Protective Role of MiRNAs in Myocardium Pathology

Cardiovascular diseases have been regarded as the leading cause of death around the world, with myocardial infarction (MI) being the most severe form. MI leads to myocardial apoptosis, cardiomyocyte fibrosis, and cardiomyocyte hypertrophy, ultimately leading to heart failure, and death. Micro RNAs (miRNAs) participate in the genesis and progression of myocardial pathology after MI by playing an important regulatory role. This review aims to summarize all available knowledge on the role of miRNAs in the myocardial pathological process after MI to uncover potential major target pathways. In addition, the main therapeutic methods and their latest progress are also reviewed. miRNAs can regulate the main signaling pathways as well as pathological processes. Thus, they have the potential to induce therapeutic effects. Hence, the combination of miRNAs with recently developed exosome nanocomplexes may represent the future direction of therapeutics.