Progression and regression of left ventricular hypertrophy and myocardial fibrosis in a mouse model of hypertension and concomitant cardiomyopathy

Elevated septal native T1 time in cardiac magnetic resonance imaging suggesting myocardial fibrosis in young kidney transplant recipients

BACKGROUND

Patients after kidney transplantation (KTx) in childhood show a high prevalence of cardiac complications, but the underlying mechanism is still poorly understood. In adults, myocardial fibrosis detected in cardiovascular magnetic resonance (CMR) imaging is already an established risk factor. Data for children after KTx are not available. This study aimed to explore cardiac function and structure with focus on myocardial fibrosis and associated risk factors in KTx recipients.

METHODS

Forty-six KTx recipients (mean age 16.0 ± 3.5 years) and 46 age- and sex-matched healthy controls were examined with non-contrast CMR imaging. Native T1 time (nT1), a marker for myocardial fibrosis, was measured at the interventricular septum. Other parameters comprised left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), and global longitudinal strain (GLS). Multivariable linear regression analyses were used to explore associations with nT1.

RESULTS

Mean nT1 was significantly higher in KTx recipients compared to controls (1198.1 ± 48.8 vs 1154.4 ± 23.4 ms, p < 0.0001). 46% (21/46) had a nT1 above the upper limit of the normal range (mean + 2 standard deviations of controls). KTx recipients showed higher LVMI z-scores (0.1 ± 1.1 vs -0.3 ± 0.7, p = 0.026), higher LVEF (67.3 ± 3.8% vs 65.3 ± 3.6%, p = 0.012), and lower GLS (-19.0 ± 2.1% vs -20.3 ± 2.7%, p = 0.010). Higher systolic blood pressure (ß = 1.284, p = 0.001), LVMI (ß = 1.542, p < 0.001), and LVEF (ß = 3.535, p = 0.026) were associated with longer nT1 only in KTx recipients, but not in controls. Only 2 KTx recipients exhibited left ventricular hypertrophy; however, a total of 18 displayed elevated nT1 with LVMI z-score within the normal range.

CONCLUSION

Our data suggest the presence of cardiac remodeling with myocardial fibrosis in a significant proportion of young KTx recipients. Non-contrast CMR imaging has the potential to visualize early structural cardiac changes and could become an important diagnostic adjunct in the follow-up of KTx recipients. Longitudinal studies are needed to further evaluate the importance of nT1 in early identification of those at high risk for sudden cardiac death allowing to integrate preventive strategies.

Exploring synergistic effects of Achyranthes bidentata Blume and Paeonia lactiflora Pall. on hypertension with liver yang hyperactivity using the multidisciplinary integrative strategy

Traditional Chinese Medicine (TCM) formulations serve as a multi-component pharmacological combination therapy with various potential targets and have collected extensive knowledge regarding the in vivo efficacy of treating cardiovascular disorders in clinical practice for thousands of years. However, the obscurity of the chemicals and the molecular mechanisms are impediments to their continued growth and globalization. Therefore, new modern medications based on the combination of beneficial TCM components with precise clinical efficacy are required. The goal of this study was to find the best combination of Achyranthes bidentata Blume (AB) and Paeonia lactiflora Pall. (PL) for hypertension with liver yang hyperactivity (HLYH). The integrated research consisting of principal component analysis (PCA), metabolomics, microbiology, and weighted correlation network analysis (WGCNA) were used to find the optimal combination of AB-PL combinations and reveal the mechanism of action. The result showed AB-PL (2:3) had a substantial protective impact on HLYH, as shown by lower blood pressure, improved liver yang hyperactivity, reduced cardiac remodeling and malondialdehyde (MDA), and increased NO content. Furthermore, the essential elements for AB-PL reducing hypertension may be related to 135 metabolites and 23 microorganisms. In conclusion, our findings support the efficacy of herbal remedies in the treatment of hypertension and provide some pharmacological evidence for the ongoing development of novel modern Chinese drugs for cardiovascular disorders.

Impact of hematopoietic cell transplantation on myocardial fibrosis in young patients with sickle cell disease

ABSTRACT

Serial cardiovascular magnetic resonance evaluation of children and young adults with SCD who underwent hematopoietic cell transplantation showed mean ECV, representing diffuse myocardial fibrosis, decreased 3.4% from baseline to 12 months posttransplantation. This trial was registered at www.clinicaltrials.gov as #NCT04362293.

CTRP3 inhibits myocardial fibrosis through the P2X7R-NLRP3 inflammasome pathway in SHR rats

BACKGROUND AND PURPOSE

Reducing hypertensive myocardial fibrosis is the fundamental approach to preventing hypertensive ventricular remodelling. C1q/TNF-related protein-3 (CTRP3) is closely associated with hypertension. However, the role and mechanism of CTRP3 in hypertensive myocardial fibrosis are unclear. In this study, we aimed to explore the effect of CTRP3 on hypertensive myocardial fibrosis and the potential mechanism.

METHODS AND RESULTS

WKY and SHR rats were employed, blood pressure, body weight, heart weight, H/BW were measured, and fibrotic-related proteins, CTRP3 and Collagen I were tested in myocardium at 12 and 20 weeks by immunohistochemical staining and Western blotting, respectively. The results showed that compared with the WKY, SBP, DBP, mean arterial pressure and heart rate (HR) were all significantly increased in SHR at 12 and 20 weeks, while heart weight and H/BW were only increased at 20 weeks. Meanwhile, CTRP3 decreased, while Collagen I increased significantly in the SHR rat myocardium at 20 weeks, which compared to the WKY. Moreover, the expression of α-SMA increased from 12 weeks, Collagen I/III and MMP2/9 increased and TIMP-2 decreased until 20 weeks. In order to explore the function and mechanism of CTRP3 in hypertensive fibrosis, Angiotensin II (Ang II) was used to induce hypertension in primary neonatal rat cardiac fibroblasts in vitro . CTRP3 significantly inhibited the Ang II induced activation of fibrotic proteins, purinergic 2X7 receptor (P2X7R)-NLRP3 inflammasome pathway. The P2X7R agonist BzATP significantly exacerbated Ang II-induced NLRP3 inflammasome activation, which was decreased by the P2X7R antagonists A43079, CTRP3 and MCC950.

CONCLUSION

CTRP3 expression was decreased in the myocardium of SHR rats, and exogenous CTRP3 inhibited Ang II-induced fibrosis in cardiac fibroblasts by regulating the P2X7R-NLRP3 inflammasome pathway, suggesting that CTRP3 is a potential drug for alleviating myocardial fibrosis in hypertensive conditions.

Myocardial Interstitial Fibrosis in Hypertensive Heart Disease: From Mechanisms to Clinical Management

Hypertensive heart disease (HHD) can no longer be considered as the beneficial adaptive result of the hypertrophy of cardiomyocytes in response to pressure overload leading to the development of left ventricular hypertrophy. The current evidence indicates that in patients with HHD, pathological lesions in the myocardium lead to maladaptive structural remodeling and subsequent alterations in cardiac function, electrical activity, and perfusion, all contributing to poor outcomes. Diffuse myocardial interstitial fibrosis is probably the most critically involved lesion in these disorders. Therefore, in this review, we will focus on the histological characteristics, the mechanisms, and the clinical consequences of myocardial interstitial fibrosis in patients with HHD. In addition, we will consider the most useful tools for the noninvasive diagnosis of myocardial interstitial fibrosis in patients with HHD, as well as the most effective available therapeutic strategies to prevent its development or facilitate its regression in this patient population. Finally, we will issue a call to action for the need for more fundamental and clinical research on myocardial interstitial fibrosis in HHD.

Aspirin and Celecoxib Regulate Notch1/Hes1 Pathway to Prevent Pressure Overload-Induced Myocardial Hypertrophy

This study aimed to investigate the molecular mechanisms underlying the protective effects of cyclooxygenase (cox) inhibitors against myocardial hypertrophy.Rat H9c2 cardiomyocytes were induced by mechanical stretching. SD rats underwent transverse aortic constriction to induce pressure overload myocardial hypertrophy. Rats were subjected to echocardiography and tail arterial pressure in 12W. qPCR and western blot were used to detect the expression of Notch-related signaling. The inflammatory factors were tested by ELISA in serum, heart tissue, and cell culture supernatant.Compared with control, levels of pro-inflammatory cytokines IL-6, TNF-α, and IL-1β were increased and anti-inflammatory cytokine IL-10 was reduced in myocardial tissues and serum of rat models. Levels of Notch1 and Hes1 were reduced in myocardial tissues. However, cox inhibitor treatment (aspirin and celecoxib), the improvement of exacerbated myocardial hypertrophy, fibrosis, dysfunction, and inflammation was parallel to the activation of Notch1/Hes1 pathway. Moreover, in vitro experiments showed that, in cardiomyocyte H9c2 cells, application of ~20% mechanical stretching activated inflammatory mediators (IL-6, TNF-α, and IL-1β) and hypertrophic markers (ANP and BNP). Moreover, expression levels of Notch1 and Hes1 were decreased. These changes were effectively alleviated by aspirin and celecoxib.Cox inhibitors may protect heart from hypertrophy and inflammation possibly via the Notch1/Hes1 signaling pathway.

Cardiovascular magnetic resonance imaging for sequential assessment of cardiac fibrosis in mice: technical advancements and reverse translation

Cardiovascular magnetic resonance (CMR) imaging has become an essential technique for the assessment of cardiac function and morphology, and is now routinely used to monitor disease progression and intervention efficacy in the clinic. Cardiac fibrosis is a common characteristic of numerous cardiovascular diseases and often precedes cardiac dysfunction and heart failure. Hence, the detection of cardiac fibrosis is important for both early diagnosis and the provision of guidance for interventions/therapies. Experimental mouse models with genetically and/or surgically induced disease have been widely used to understand mechanisms underlying cardiac fibrosis and to assess new treatment strategies. Improving the appropriate applications of CMR to mouse studies of cardiac fibrosis has the potential to generate new knowledge, and more accurately examine the safety and efficacy of antifibrotic therapies. In this review, we provide 1) a brief overview of different types of cardiac fibrosis, 2) general background on magnetic resonance imaging (MRI), 3) a summary of different CMR techniques used in mice for the assessment of cardiac fibrosis including experimental and technical considerations (contrast agents and pulse sequences), and 4) provide an overview of mouse studies that have serially monitored cardiac fibrosis during disease progression and/or therapeutic interventions. Clinically established CMR protocols have advanced mouse CMR for the detection of cardiac fibrosis, and there is hope that discovery studies in mice will identify new antifibrotic therapies for patients, highlighting the value of both reverse translation and bench-to-bedside research.

Coronary Microvascular Dysfunction and Hypertension: A Bond More Important than We Think

Coronary microvascular dysfunction (CMD) is a clinical entity linked with various risk factors that significantly affect cardiac morbidity and mortality. Hypertension, one of the most important, causes both functional and structural alterations in the microvasculature, promoting the occurrence and progression of microvascular angina. Endothelial dysfunction and capillary rarefaction play the most significant role in the development of CMD among patients with hypertension. CMD is also related to several hypertension-induced morphological and functional changes in the myocardium in the subclinical and early clinical stages, including left ventricular hypertrophy, interstitial myocardial fibrosis, and diastolic dysfunction. This indicates the fact that CMD, especially if associated with hypertension, is a subclinical marker of end-organ damage and heart failure, particularly that with preserved ejection fraction. This is why it is important to search for microvascular angina in every patient with hypertension and chest pain not associated with obstructive coronary artery disease. Several highly sensitive and specific non-invasive and invasive diagnostic modalities have been developed to evaluate the presence and severity of CMD and also to investigate and guide the treatment of additional complications that can affect further prognosis. This comprehensive review provides insight into the main pathophysiological mechanisms of CMD in hypertensive patients, offering an integrated diagnostic approach as well as an overview of currently available therapeutical modalities.

Advanced Cardiac Imaging in the Assessment of Aortic Stenosis

Aortic stenosis is the most common form of valve disease in the Western world and a major healthcare burden. Although echocardiography remains the central modality for the diagnosis and assessment of aortic stenosis, recently, advanced cardiac imaging with cardiovascular magnetic resonance, computed tomography, and positron emission tomography have provided invaluable pathological insights that may guide the personalized management of the disease. In this review, we discuss applications of these novel non-invasive imaging modalities for establishing the diagnosis, monitoring disease progression, and eventually planning the invasive treatment of aortic stenosis.

Hemoglobin A1c in type 2 diabetes mellitus patients with preserved ejection fraction is an independent predictor of left ventricular myocardial deformation and tissue abnormalities

BACKGROUND

Early detection of subclinical myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) is essential for preventing heart failure. This study aims to search for predictors of left ventricular (LV) myocardial deformation and tissue abnormalities in T2DM patients with preserved ejection fraction by using CMR T1 mapping and feature tracking.

METHODS

70 patients and 44 sex- and age-matched controls (Cs) were recruited and underwent CMR examination to obtain LV myocardial extracellular volume fraction (ECV) and global longitudinal strain (GLS). The patients were subdivided into three groups, including 19 normotensive T2DM patients (G1), 19 hypertensive T2DM patients (G2) and 32 hypertensive patients (HT). The baseline biochemical indices were collected before CMR examination.

RESULTS

LV ECV in T2DM patients was significantly higher than that in Cs (30.75 ± 3.65% vs. 26.33 ± 2.81%; p < 0.05). LV GLS in T2DM patients reduced compared with that in Cs (-16.51 ± 2.53% vs. -19.66 ± 3.21%, p < 0.001). In the subgroup analysis, ECV in G2 increased compared with that in G1 (31.92 ± 3.05% vs. 29.59 ± 3.90%, p = 0.032) and that in HT, too (31.92 ± 3.05% vs. 29.22 ± 6.58%, p = 0.042). GLS in G2 significantly reduced compared with that in G1 (-15.75 ± 2.29% vs. -17.27 ± 2.57%, p < 0.05) and in HT, too (-15.75 ± 2.29% vs. -17.54 ± 3.097%, p < 0.05). In T2DM group, including both G1 and G2, hemoglobin A1c (HbA1c) can independently forecast the increase in ECV (β = 0.274, p = 0.001) and decrease in GLS (β = 0.383, p = 0.018).

CONCLUSIONS

T2DM patients with preserved ejection fraction show increased ECV but deteriorated GLS, which may be exacerbated by hypertension of these patients. Hemoglobin A1c is an index that can independently predict T2DM patients' LV myocardial deformation and tissue abnormalities.

Growing Heart Failure Burden of Hypertensive Heart Disease: A Call to Action

Hypertensive heart disease (HHD) is currently the second leading cause of heart failure. The prevalence of HHD and its associated risk of heart failure have increased despite substantial improvement in arterial hypertension treatment and control in the recent decades. Therefore, the prevention of heart failure in patients with HHD represents an unmet medical need, due to its clinical, economic, and social impact. In this conceptual framework, we call to action because the time has come for diagnosis and treatment of patients with HHD not to be limited to assessment of morphological and functional left ventricular changes, blood pressure control, and left ventricular hypertrophy regression. We propose a further perspective incorporating also the detection and reversal of the histological changes that develop in the hypertensive heart and that lead to the structural remodeling of the myocardium. In particular, we focus on the diagnosis and treatment of myocardial interstitial fibrosis, likely the lesion most critically involved in the transition from subclinical HHD to clinically overt heart failure. In this context, it is worth considering whether the use of imaging and circulating biomarkers for the noninvasive diagnosis of myocardial interstitial fibrosis should be incorporated in the medical study of hypertensive patients, especially of those with HHD.

Quantification of Early Diffuse Myocardial Fibrosis Through 7.0 T Cardiac Magnetic Resonance T1 Mapping in a Type 1 Diabetic Mellitus Mouse Model

BACKGROUND

Diffuse myocardial interstitial fibrosis (DMIF) is a key factor for heart failure (HF) in diabetic cardiomyopathy. MRI T1-mapping technique can quantitatively evaluate DMIF.

PURPOSE

To evaluate of early DMIF in a type 1 diabetes mellitus (T1DM) mouse model through 7.0 T MRI T1 mapping.

STUDY TYPE

Prospective.

ANIMAL MODEL

A total of 50 8-week-old C57Bl/6J male mice were divided into control (n = 20) and T1DM (n = 30) groups.

FIELD STRENGTH/SEQUENCE

A 7.0 T small animal MRI; gradient echo Look-Locker inversion recovery T1-mapping sequence; cine MRI. Scans were acquired in control and T1DM mice every 4 weeks until 24 weeks.

ASSESSMENT

End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), left ventricle (LV) mass, fractional shortening (FS), and E/A ratio. They were evaluated through echocardiography and cine MRI. The extracellular volume fraction (ECV) was calculated. Sirius Red staining was performed and calculated collagen volume fraction (CVF).

STATISTICAL TESTS

Differences in ECV and CVF between two groups were analyzed using one-way analysis of variance. The correlation between ECV and CVF was assessed using Pearson's correlations.

RESULTS

Compared with the control group, a progressive decrease in FS, EF, and E/A ratio was observed in the T1DM group. Both ECV and CVF values gradually increased during diabetes progression. A significant increase in ECV and CVF values was observed at 12 weeks (ECV: 32.5% ± 1.6% vs. 28.1% ± 1.8%; CVF: 6.9% ± 1.8% vs. 3.3% ± 1.1%). ECV showed a strong correlation with CVF (r = 0.856).

DATA CONCLUSION

ECV is an accurate and feasible imaging marker that can be used to quantitatively assess DMIF changes over time in T1DM mice. ECV has potential to accurately detect DMIF in the early stage and may be a useful imaging tool to assess the need for early intervention in T1DM mice.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 3.

T1 values and extracellular volume fraction in asymptomatic subjects: variations in left ventricular segments and correlation with cardiovascular risk factors

To evaluate variations in pre-contrast (preT1) and post-contrast (postT1) myocardial T1 values and extracellular volume fraction (ECV) according to left ventricular (LV) segments and to find correlations between them and cardiovascular risk factors. The 233 asymptomatic subjects (210 men, 23 women; aged 54.1 ± 6.0 years) underwent cardiac magnetic resonance imaging with preT1 and postT1 mapping on a 1.5-T scanner. T1 values and ECVs were evaluated according to LV segments, age, sex, and estimated glomerular filtration rate (eGFR). Based on the presence of hypertension (HTN) and diabetes mellitus (DM), subjects were subdivided into the control, HTN, DM, and HTN and DM (HTN-DM) groups. T1 values and ECV showed significant differences between septal and lateral segments at the mid-ventricular and basal levels (p ≤ 0.003). In subgroup analysis, the HTN-DM group showed a significantly higher ECV (0.260 ± 0.023) than the control (0.240 ± 0.021, p = 0.011) and HTN (0.241 ± 0.024, p = 0.041) groups. Overall postT1 and ECV of the LV had significant correlation with eGFR (r = 0.19, p = 0.038 for postT1; r =  − 0.23, p = 0.011 for ECV). Septal segments show higher preT1 and ECV but lower postT1 than lateral segments at the mid-ventricular and basal levels. ECV is significantly affected by HTN, DM, and eGFR, even in asymptomatic subjects.

Serum complement C1q level is associated with left ventricular hypertrophy induced by coarctation of the aorta: A retrospective observational study

BACKGROUND

The complement system plays an important role in the development of left ventricular hypertrophy. Complement C1q is an initial component of the classical complement pathway and is related to many inflammatory diseases. We aimed to determine whether there was an association between serum complement C1q and left ventricular hypertrophy induced by coarctation of the aorta (CoA).

METHODS

Based on whether CoA was combined with a large ventricular septal defect (VSD) or patent ductus arteriosus (PDA), the patients were divided into a simple CoA group (n = 15) and a complex CoA group (n = 13). Meanwhile, we selected simple large VSD (n = 14) patients and normal children (n = 28) as the control group. The serum complement C1q level was compared using immunity transmission turbidity among different groups.

RESULTS

The preoperative content of C1q in the simple CoA group was significantly lower than that in the complex CoA group and normal group (96.97 ± 20.66 vs. 130.73 ± 35.78, 96.97 ± 20.66 vs. 156.21 ± 29.14, P < 0.05). There was no significant difference in the preoperative content of C1q between the complex CoA group and the large VSD group (P > 0.05). There was a negative correlation between the preoperative complement C1q content and the interventricular septal thickness and left ventricular posterior wall thickness (r = - 0.035, r = - 0.288, P < 0.05). The percentage of postoperative decrease in C1q in children with simple CoA or complex CoA was positively correlated with the time of cardiopulmonary bypass and aortic cross clamp, respectively (r = 0.797, r = 0.622, r = 0.898, r = 0.920, P < 0.05). There was no significant difference in the content of preoperative triglycerides (TG), total cholesterol (TCHO), high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C) among the different groups (P > 0.05). In the simple CoA group and complex CoA group, the preoperative complement C1q, TG, TCHO, HDL-C and LDL-C levels were significantly higher than those after the operation (P < 0.05). There was no significant correlation between preoperative complement C1q and TG, TCHO, HDL-C or LDL-C (P > 0.05).

CONCLUSIONS

Complement C1q has an inhibitory effect on the formation of left ventricular hypertrophy, which may not be mediated by regulating lipid metabolism. During cardiac surgery, complement C1q may have a protective effect against myocardial injury.

Biomedical Imaging in Experimental Models of Cardiovascular Disease

Major advances in biomedical imaging have occurred over the last 2 decades and now allow many physiological, cellular, and molecular processes to be imaged noninvasively in small animal models of cardiovascular disease. Many of these techniques can be also used in humans, providing pathophysiological context and helping to define the clinical relevance of the model. Ultrasound remains the most widely used approach, and dedicated high-frequency systems can obtain extremely detailed images in mice. Likewise, dedicated small animal tomographic systems have been developed for magnetic resonance, positron emission tomography, fluorescence imaging, and computed tomography in mice. In this article, we review the use of ultrasound and positron emission tomography in small animal models, as well as emerging contrast mechanisms in magnetic resonance such as diffusion tensor imaging, hyperpolarized magnetic resonance, chemical exchange saturation transfer imaging, magnetic resonance elastography and strain, arterial spin labeling, and molecular imaging.

Occurrence and morphology of ventricular arrhythmias in apparently normal hearts in relation to late gadolinium enhancement on cardiovascular magnetic resonance

Cardiac magnetic resonance (CMR) is the gold standard for evaluating myocardial fibrosis. Few studies have explored the association between ventricular arrhythmias (VAs) and fibrosis in apparently normal hearts. We aimed to investigate the association between the occurrence and morphology of VAs and left ventricular late gadolinium enhancement (LV-LGE) in patients without known structural heart diseases. This study enrolled 78 patients with apparently normal hearts who underwent 24-h ambulatory Holter electrocardiogram (ECG) and CMR examinations simultaneously. The presence and extent of LGE was determined using CMR imaging and compared based on occurrence and morphology of VAs. The clinical characteristics were also recorded and calculated. LV-LGE was observed in 19 (37.3%) and 4 (14.8%) patients with and without VAs, respectively (P = 0.039). It was more frequently observed in patients with polymorphic VAs (P = 0.024). The polymorphic VAs had a higher tendency of LGE extent than monomorphic VAs, while the difference did not reach statistical significance (P = 0.055). In multivariable analyses, the presence of polymorphic VAs [hazard ratio (HR) 11.19, 95% CI 1.64-76.53, P = 0.014] and hypertension (HR 4.64, 95% CI 1.08-19.99, P = 0.039) were associated with greater prevalence of LV-LGE. In patients without structural heart diseases, besides hypertension, multiple VA morphologies on Holter ambulatory ECG measurements is another important marker of increased incidence of myocardial fibrosis.

Evolution and Prognostic Impact of Cardiac Damage After Aortic Valve Replacement

BACKGROUND

The impact of aortic valve replacement (AVR) on progression/regression of extra-valvular cardiac damage and its association with subsequent prognosis is unknown.

OBJECTIVES

To describe evolution of cardiac damage post-AVR and its association with outcomes.

METHODS

Patients undergoing transcatheter or surgical AVR from the PARTNER 2 and 3 trials were pooled and classified by cardiac damage stage at baseline and 1-year (Stage 0, no damage; Stage 1, left ventricular damage; Stage 2, left atrial or mitral valve damage; Stage 3, pulmonary vasculature or tricuspid valve damage; Stage 4, right ventricular damage). Proportional hazards models determined association between change in cardiac damage post-AVR and 2-year outcomes.

RESULTS

Among 1974 patients, 121 (6.1%) were Stage 0, 287 (14.5%) Stage 1, 1014 (51.4%) Stage 2, 412 (20.9%) Stage 3, and 140 (7.1%) Stage 4 pre-AVR. Two-year mortality was associated with extent of cardiac damage at baseline and 1-year. Compared with baseline, cardiac damage improved in ∼15%, remained unchanged in ∼60%, and worsened in ∼25% of patients at 1-year. One-year change in cardiac damage stage was independently associated with mortality (adjHR for improvement=0.49; no change=1.0; worsening=1.95; p=0.023) and composite of death or heart failure hospitalization (adjHR for improvement=0.60; no change=1.0; worsening=2.25; p<0.001) at 2 years.

CONCLUSION

In patients undergoing AVR, extent of extravalvular cardiac damage at baseline and its change at 1-year have important prognostic implications. These findings suggest that earlier detection of AS and intervention prior to development of irreversible cardiac damage may improve global cardiac function and prognosis.

Cardiac Fibrosis in the Pressure Overloaded Left and Right Ventricle as a Therapeutic Target

Myocardial fibrosis is a remodeling process of the extracellular matrix (ECM) following cardiac stress. "Replacement fibrosis" is a term used to describe wound healing in the acute phase of an injury, such as myocardial infarction. In striking contrast, ECM remodeling following chronic pressure overload insidiously develops over time as "reactive fibrosis" leading to diffuse interstitial and perivascular collagen deposition that continuously perturbs the function of the left (L) or the right ventricle (RV). Examples for pressure-overload conditions resulting in reactive fibrosis in the LV are systemic hypertension or aortic stenosis, whereas pulmonary arterial hypertension (PAH) or congenital heart disease with right sided obstructive lesions such as pulmonary stenosis result in RV reactive fibrosis. In-depth phenotyping of cardiac fibrosis has made it increasingly clear that both forms, replacement and reactive fibrosis co-exist in various etiologies of heart failure. While the role of fibrosis in the pathogenesis of RV heart failure needs further assessment, reactive fibrosis in the LV is a pathological hallmark of adverse cardiac remodeling that is correlated with or potentially might even drive both development and progression of heart failure (HF). Further, LV reactive fibrosis predicts adverse outcome in various myocardial diseases and contributes to arrhythmias. The ability to effectively block pathological ECM remodeling of the LV is therefore an important medical need. At a cellular level, the cardiac fibroblast takes center stage in reactive fibrotic remodeling of the heart. Activation and proliferation of endogenous fibroblast populations are the major source of synthesis, secretion, and deposition of collagens in response to a variety of stimuli. Enzymes residing in the ECM are responsible for collagen maturation and cross-linking. Highly cross-linked type I collagen stiffens the ventricles and predominates over more elastic type III collagen in pressure-overloaded conditions. Research has attempted to identify pro-fibrotic drivers causing fibrotic remodeling. Single key factors such as Transforming Growth Factor β (TGFβ) have been described and subsequently targeted to test their usefulness in inhibiting fibrosis in cultured fibroblasts of the ventricles, and in animal models of cardiac fibrosis. More recently, modulation of phenotypic behaviors like inhibition of proliferating fibroblasts has emerged as a strategy to reduce pathogenic cardiac fibroblast numbers in the heart. Some studies targeting LV reactive fibrosis as outlined above have successfully led to improvements of cardiac structure and function in relevant animal models. For the RV, fibrosis research is needed to better understand the evolution and roles of fibrosis in RV failure. RV fibrosis is seen as an integral part of RV remodeling and presents at varying degrees in patients with PAH and animal models replicating the disease of RV afterload. The extent to which ECM remodeling impacts RV function and thus patient survival is less clear. In this review, we describe differences as well as common characteristics and key players in ECM remodeling of the LV vs. the RV in response to pressure overload. We review pre-clinical studies assessing the effect of anti-fibrotic drug candidates on LV and RV function and their premise for clinical testing. Finally, we discuss the mode of action, safety and efficacy of anti-fibrotic drugs currently tested for the treatment of left HF in clinical trials, which might guide development of new approaches to target right heart failure. We touch upon important considerations and knowledge gaps to be addressed for future clinical testing of anti-fibrotic cardiac therapies.

Myocardial Extracellular Volume Fraction Measured by Cardiac Magnetic Resonance Imaging Negatively Correlates With Cardiomyocyte Breadth in a Healthy Porcine Model

Background

The extracellular volume fraction (ECV) derived from cardiac magnetic resonance imaging (MRI) is extensively used to evaluate myocardial fibrosis. However, due to the limited histological verification in healthy individuals, it remains unclear whether the size of cardiomyocytes may play a potential role in the physiological changes of ECV. The aim of this study was to examine the association between cardiomyocyte size and myocardial ECV by using a healthy porcine model.

Methods

Sixteen domestic healthy pigs were anesthetized and underwent cardiac MRI with mechanical controlled breathing. Intravenous contrast medium was introduced at a dose of 0.2–0.25 mmol/kg. The interventricular septum ECV was calculated using an established MRI procedure, which was based on the pre- and post-contrast T1 values of the heart and individual blood hematocrit. The cardiomyocyte breadth (CmyB) in cross section was measured by hematoxylin and eosin staining to reflect the cardiomyocyte size.

Results

Data were successfully acquired from 14 pigs. The CmyB was obtained from the myocardial tissues corresponding to the region of interest on cardiac MRI. The mean ± SD of the ECV was 0.253 ± 0.043, and the mean ± SD of the CmyB was 10.02 ± 0.84 μm. The ECV exhibited a negative correlation with the CmyB (r = −0.729, p = 0.003).

Conclusion

The myocardial ECV detected by cardiac MRI is negatively correlated with the CmyB in healthy pigs, demonstrating that the size of cardiomyocytes is potentially associated with the ECV under physiological conditions.

The role of metabolic syndrome in sudden cardiac death risk: Recent evidence and future directions

Metabolic syndrome (MetS) is a frequent condition whose deleterious effects on the cardiovascular system are often underestimated. MetS is nowadays considered a real pandemic with an estimated prevalence of 25% in general population. Individuals with MetS are at high risk of sudden cardiac death (SCD) as this condition accounts for 50% of all cardiac deaths in such a population. Of interest, recent studies demonstrated that individuals with MetS show 70% increased risk of SCD even without previous history of coronary heart disease (CHD). However, little is known about the interplay between the two conditions. MetS is a complex disease determined by genetic predisposition, unhealthy lifestyle and ageing with deleterious effects on different organs. MetS components trigger a systemic chronic low-grade pro-inflammatory state, associated with excess of sympathetic activity, cardiac hypertrophy, arrhythmias and atherosclerosis. Thus, MetS has an important burden on the cardiovascular system as demonstrated by both preclinical and clinical evidence. The aim of this review is to summarize recent evidence concerning the association between MetS and SCD, showing possible common aetiological processes, and to indicate prospective for future studies and therapeutic targets.

The Role of CD147 in Pathological Cardiac Hypertrophy Is Regulated by Glycosylation

CD147, also known as EMMPRIN or basigin, is a transmembrane glycoprotein receptor that activates matrix metalloproteinases and promotes inflammation. CD147 function is regulated by posttranslational modifications of which glycosylation has attracted the most attention. In this study, we demonstrated that glycosylated CD147 was the dominant form in heart tissue, and its levels were markedly elevated in response to transverse aortic constriction (TAC). Adeno-associated virus 9-mediated, cardiac-specific overexpression of wild-type CD147 in mice significantly promoted pressure overload-induced pathological cardiac remodeling accompanied by augmented oxidative stress and ferroptosis. By contrast, mutations of CD147 glycosylation sites notably weakened these detrimental effects of CD147. Mechanistically, CD147 exacerbated TAC-induced pathological cardiac remodeling via direct binding with the adaptor molecule TRAF2 and subsequent activation of TAK1 signalling, which was dependent on glycosylation of CD147. Collectively, our findings provide the first evidence that CD147 promoted pathological cardiac remodeling and dysfunction in a glycosylation-dependent manner through binding the adaptor protein TRAF2 and activating the downstream TRAF2-TAK1 signalling pathway. Thus, glycosylation of CD147 may be a potent interventional target for heart failure treatment.

Current Understanding of piRNA in Cardiovascular Diseases

The relationship regarding non-coding genomes and cardiovascular disease (CVD) has been explored in the past decade. As one of the leading causes of death, there remains a lack of sensitive and specific genomic biomarkers in the diagnosis and prognosis of CVD. Piwi-interacting RNA (piRNA) is a group of small non-coding RNA (ncRNA) which associated with Piwi proteins. There is an emerging strong body of evidence in support of a role for ncRNAs, including piRNAs, in pathogenesis and prognosis of CVD. This article reviews the current evidence for piRNA-regulated mechanisms in CVD, which could lead to the development of new therapeutic strategies for prevention and treatment.

Study on the correlation between Left Ventricular Hypertrophy and Coronary Artery disease in the very elderly patients with hypertension

Objective:

To investigate the relationship between left ventricular hypertrophy (LVH) and coronary artery disease in the very elderly (over 80 years old) patients with hypertension.

Methods:

One hundred twenty cases of very elderly patients with hypertension admitted to our hospital from March 2018 to December 2020 were selected and divided into two groups: the LVH group and the non-LVH group, all of whom were older aged over 80 years, including 62 patients in the LVH group and 58 patients in the non-LVH group. All patients underwent cardiac color Doppler ultrasound examination, 24-hour dynamic ECG examination, and coronary angiography or coronary CTA examination. The clinical data of the two groups were analyzed statistically.

Results:

There were significant differences in the number of diseased vessels, degree of coronary stenosis and vascular calcification between the two groups (P<0.05). Moreover, the results of risk factors for the degree of coronary artery disease in the two groups showed that the history of diabetes, 2hPG and LVH were independent risk factors for the three-vessel disease, while the history of LVH, FPG and alcohol intake were independent risk factors for diffuse lesions, but there was no statistical difference in the correlation between them and the degree of coronary stenosis.

Conclusion:

LVH is an independent risk factor for coronary artery stenosis and calcification in the very elderly patients with hypertension, but there is no statistical difference in the correlation between LVH and the degree of coronary stenosis.

Sirtuin 3 deficiency aggravates angiotensin II-induced hypertensive cardiac injury by the impairment of lymphangiogenesis

Lymphangiogenesis is possibly capable of attenuating hypertension‐induced cardiac injury. Sirtuin 3 (SIRT3) is an effective mitochondrial deacetylase that has the potential to modulate this process; however, its role in hypertension‐induced cardiac lymphangiogenesis to date has not been investigated. Our experiments were performed on 8‐week‐old wild‐type (WT), SIRT3 knockout (SIRT3‐KO) and SIRT3 overexpression (SIRT3‐LV) mice infused with angiotensin II (Ang II) (1000 ng/kg per minute) or saline for 28 days. After Ang II infusion, SIRT3‐KO mice developed a more severe cardiac remodelling, less lymphatic capillaries and lower expression of lymphatic marker when compared to wild‐type mice. In comparison, SIRT3‐LV restored lymphangiogenesis and attenuated cardiac injury. Furthermore, lymphatic endothelial cells (LECs) exposed to Ang II in vitro exhibited decreased migration and proliferation. Silencing SIRT3 induced functional decrease in LECs, while SIRT3 overexpression LECs facilitated. Moreover, SIRT3 may up‐regulate lymphangiogenesis by affecting vascular endothelial growth factor receptor 3 (VEGFR3) and ERK pathway. These findings suggest that SIRT3 could promote lymphangiogenesis and attenuate hypertensive cardiac injury.

Comparative efficacy of different types of antihypertensive drugs in reversing left ventricular hypertrophy as determined with echocardiography in hypertensive patients: A protocol for systematic review and meta-analysis

BACKGROUND

Reversing left ventricular hypertrophy (LVH) can reduce the incidence of adverse cardiovascular events. The lack of direct comparison between different antihypertensive drugs cannot evaluate the superiority-inferiority differentiation of different antihypertensive drugs in reversing LVH. Therefore, the objective of this protocol for systematic review and meta-analysis was to compare the efficacy of different types of antihypertensive drugs in reversing LVH in hypertensive patients.

METHODS

This meta-analysis was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement guidelines. Studies were identified through systematic searches in June 2021 with no restrictions on date and time, language, and publication status using the following bibliographic databases: Embase, Medline, PubMed, Web of Science, Science Direct, and the Cochrane Library. The risk of bias assessment of the included studies was performed by two authors independently using the tool recommended in the Cochrane Handbook for Systematic Reviews of Interventions (version 5.1.0). All calculations were carried out with Stata 11.0 (The Cochrane Collaboration, Oxford, United Kingdom).

RESULTS

The results of this systematic review and meta-analysis will be published in a peer-reviewed journal.

CONCLUSION

We hypothesized that the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in antihypertensive therapy could achieve better efficacy in reversing LVH in hypertensive patients.