Cardiomyopathies: Evolution of pathogenesis concepts and potential for new therapies

Mapping the landscape of PSC-CM research through bibliometric analysis

Objectives

The discovery of pluripotent stem cell-derived cardiomyocytes (PSC-CMs) has not only deepened our understanding of the pathogenesis and progression of heart disease, but also advanced the development of engineered cardiac tissues, cardiac regenerative therapy, drug discovery and the cardiotoxicity assessment of drugs. This study aims to visualize the developmental trajectory of PSC-CM research over the past 18 years to identify the emerging research frontiers and challenges.

Methods

The literature on PSC-CMs from 2007 to 2024 was retrieved from the Web of Science and PubMed databases. Bibliometrix, VOSviewer and CiteSpace software were used for statistical analysis and visualization of scientific literature. Previous clinical trials were summarized using data from the ClinicalTrials.gov database.

Results

A total of 29,660 authors from 81 countries and regions published 6,406 papers on PSC-CMs over the past 18 years. The annual output of PSC-CM research experienced a general upward trend from 2007 to 2021, reaching its peak in 2021, followed by a notable decline in 2022 and 2023. The United States has emerged as the most influential nation in this field, with Stanford University being the most prolific institution and Joseph C. Wu standing out as the most productive and highly cited scholar. Circulation Research, Circulation, and Nature have been identified as the most co-cited journals. Organ-on-a-chip, 3D bio-printing, cardiac microtissue, extracellular vesicle, inflammation, energy metabolism, atrial fibrillation, personalized medicine etc., with a longer burst period, and maturation of PSC-CMs, with the highest burst strength of 27.19, are the major research focuses for rigorous investigation in recent years. Cardiac organoid is emerging as a promising key research frontier. While the clinical trials of stem-cell-mediated treatment for heart diseases shows promise, significant challenges remain. Further research is imperative to optimize protocols, enhance cell delivery methods, and establish standardized practices to improve clinical outcomes.

Conclusions

In conclusion, several major research hotspots, including engineered cardiac tissue and maturation, exosome-based regenerative therapy, inflammation response, energy metabolism, atrial fibrillation, and personalized medicine etc. will continue to attract substantial interest from investigators worldwide. Cardiac organoids to in vitro recapitulate the intricate human heart is emerging as a promising key research frontier. Significant challenges persist in the clinical trials of stem-cell-mediated therapies for heart diseases.

Integrative proteomic and metabolomic elucidation of cardiomyopathy with in vivo and in vitro models and clinical samples

Cardiomyopathy is a prevalent cardiovascular disease that affects individuals of all ages and can lead to life-threatening heart failure. Despite its variety in types, each with distinct characteristics and causes, our understanding of cardiomyopathy at a systematic biology level remains incomplete. Mass spectrometry-based techniques have emerged as powerful tools, providing a comprehensive view of the molecular landscape and aiding in the discovery of biomarkers and elucidation of mechanisms. This review highlights the significant potential of integrating proteomic and metabolomic approaches with specialized databases to identify biomarkers and therapeutic targets across different types of cardiomyopathies. In vivo and in vitro models, such as genetically modified mice, patient-derived or induced pluripotent stem cells, and organ chips, are invaluable in exploring the pathophysiological complexities of this disease. By integrating omics approaches with these sophisticated modeling systems, our comprehension of the molecular underpinnings of cardiomyopathy can be greatly enhanced, facilitating the development of diagnostic markers and therapeutic strategies. Among the promising therapeutic targets are those involved in extracellular matrix remodeling, sarcomere damage, and metabolic remodeling. These targets hold the potential to advance precision therapy in cardiomyopathy, offering hope for more effective treatments tailored to the specific molecular profiles of patients.

Histologic characterization of spontaneous catecholamine-induced cardiomyopathy in laboratory New Zealand White rabbits

Catecholamine-induced cardiomyopathy (CCM) is an entity associated with increased levels of catecholamines causing subendocardial and papillary muscle cardiomyocyte degeneration and necrosis. In 2020, 49 autopsies from early rabbit deaths in a colony used for medical device biocompatibility studies were submitted for microscopic examination. Of the 49 rabbits, 26 had histologic changes consistent with CCM. No common stressor for CCM was determined in affected rabbits. Animals were generally male, were 12-16-wk-old, and were found dead or had bloating, lethargy, and/or diarrhea. Those observed with clinical signs were euthanized and autopsied per the organization's standard operating procedures. Heart lesions consisted of various degrees of apical subendocardial myocardial degeneration and necrosis. Common non-cardiac lesions included pulmonary congestion and edema, hepatic congestion and centrilobular hepatocellular degeneration, and/or variable intestinal submucosal edema.

Understanding Arrhythmia-Induced Cardiomyopathy: Symptoms and Treatments

Arrhythmia-induced cardiomyopathy is a complex condition that causes a decline in heart function as a result of irregular heart rhythms. This disorder highlights the link between irregular heart rhythm and heart failure, necessitating prompt identification and intervention. It often occurs due to ongoing fast heart rhythms like atrial fibrillation or tachycardia. Understanding the mechanisms, symptoms, and available treatments is essential for enhancing patient outcomes given the complicated nature of the condition. This article delves into various aspects of arrhythmia-induced cardiomyopathy, including pathogenesis, clinical presentation, diagnostic methods, epidemiology, typical arrhythmias associated with the condition, and management options. It assesses patients' future outlook and necessary follow-up, aiming to provide healthcare providers with a comprehensive understanding of how to handle this intricate condition. The article emphasizes the important effect an integrative approach can have on both patients' lives and the clinical consequences of diagnosing and treating this condition. This extensive understanding enhances the resources at the disposal of physicians, enabling targeted treatments that enhance cardiomyopathy by targeting arrhythmia regulation. More research and development are needed in the field of cardiomyopathy and arrhythmia relationship. The presentation urges the medical field to delve deeper into the complexities of illness by emphasizing the need for continuous research and a multifaceted treatment plan. By combining these understandings, our goal is to enhance patient outcomes and create opportunities for further studies on cardiovascular wellness.

Design and Analysis of a Polymeric Left Ventricular Simulator via Computational Modelling

Preclinical testing of medical devices is an essential step in the product life cycle, whereas testing of cardiovascular implants requires specialised testbeds or numerical simulations using computer software Ansys 2016. Existing test setups used to evaluate physiological scenarios and test cardiac implants such as mock circulatory systems or isolated beating heart platforms are driven by sophisticated hardware which comes at a high cost or raises ethical concerns. On the other hand, computational methods used to simulate blood flow in the cardiovascular system may be simplified or computationally expensive. Therefore, there is a need for low-cost, relatively simple and efficient test beds that can provide realistic conditions to simulate physiological scenarios and evaluate cardiovascular devices. In this study, the concept design of a novel left ventricular simulator made of latex rubber and actuated by pneumatic artificial muscles is presented. The designed left ventricular simulator is geometrically similar to a native left ventricle, whereas the basal diameter and long axis length are within an anatomical range. Finite element simulations evaluating left ventricular twisting and shortening predicted that the designed left ventricular simulator rotates approximately 17 degrees at the apex and the long axis shortens around 11 mm. Experimental results showed that the twist angle is 18 degrees and the left ventricular simulator shortens 5 mm. Twist angles and long axis shortening as in a native left ventricle show it is capable of functioning like a native left ventricle and simulating a variety of scenarios, and therefore has the potential to be used as a test platform.

MicroRNAs Targeting Critical Molecular Pathways in Diabetic Cardiomyopathy Emerging Valuable for Therapy

MicroRNAs have emerged as an important regulator of post-transcriptional gene expression studied extensively in many cancers, fetal development, and cardiovascular diseases. Their endogenous nature and easy manipulation have made them potential diagnostic and therapeutic molecules. Diseases with complex pathophysiology such as Diabetic Cardiomyopathy display symptoms at a late stage when the risk of heart failure has become very high. Therefore, the utilization of microRNAs as a tool to study pathophysiology and device-sustainable treatments for DCM could be considered. The present review focuses on the mechanistic insights of diabetic cardiomyopathy and the potential role of microRNAs.

Exosomal Cargo: Pro-angiogeneic, anti-inflammatory, and regenerative effects in ischemic and non-ischemic heart diseases - A comprehensive review

Heart diseases are the primary cause of mortality and morbidity worldwide which inflict a heavy social and economic burden. Among heart diseases, most deaths are due to myocardial infarction (MI) or heart attack, which occurs when a decrement in blood flow to the heart causes injury to cardiac tissue. Despite several available diagnostic, therapeutic, and prognostic approaches, heart disease remains a significant concern. Exosomes are a kind of small extracellular vesicles released by different types of cells that play a part in intercellular communication by transferring bioactive molecules important in regenerative medicine. Many studies have reported the diagnostic, therapeutic, and prognostic role of exosomes in various heart diseases. Herein, we reviewed the roles of exosomes as new emerging agents in various types of heart diseases, including ischemic heart disease, cardiomyopathy, arrhythmia, and valvular disease, focusing on pathogenesis, therapeutic, diagnostic, and prognostic roles in different areas. We have also mentioned different routes of exosome delivery to target tissues, the effects of preconditioning and modification on exosome's capability, exosome production in compliance with good manufacturing practice (GMP), and their ongoing clinical applications in various medical contexts to shed light on possible clinical translation.

Crosstalk of NLRP3 inflammasome and noncoding RNAs in cardiomyopathies

Cardiovascular diseases (CVDs) identified as a serious public health problem. Although there is a lot of evidence that inflammatory processes play a significant role in the progression of CVDs, however, the precise mechanism is not fully understood. Nevertheless, recent studies have focused on inflammation and its related agents. Nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) is a type of pattern recognition receptor (PRR) that can recognize pathogen-associated molecular patterns and trigger innate immune response. NLRP3 is a component of the NOD-like receptor (NLR) family and have a pivotal role in detecting damage to cardiovascular tissue. It is suggested that activation of NLRP3 inflammasome leads to initiating and propagating the inflammatory response in cardiomyopathy. So, late investigations have highlighted the NLRP3 inflammasome activation in various forms of cardiomyopathy. On the other side, it was shown that noncoding RNAs (ncRNAs), particularly, microRNAs, lncRNAs, and circRNAs possess a regulatory function in the immune system's inflammatory response, implicating their involvement in various inflammatory disorders. In addition, their role in different cardiomyopathies was indicated in recent studies. This review article provides a summary of recent advancements focusing on the function of the NLRP3 inflammasome in common CVDs, especially cardiomyopathy, while also discussing the therapeutic potential of inhibiting the NLRP3 inflammasome regulated by ncRNAs.

Echocardiography-based machine learning algorithm for distinguishing ischemic cardiomyopathy from dilated cardiomyopathy

BACKGROUND

Machine learning (ML) can identify and integrate connections among data and has the potential to predict events. Heart failure is primarily caused by cardiomyopathy, and different etiologies require different treatments. The present study examined the diagnostic value of a ML algorithm that combines echocardiographic data to automatically differentiate ischemic cardiomyopathy (ICM) from dilated cardiomyopathy (DCM).

METHODS

We retrospectively collected the echocardiographic data of 200 DCM patients and 199 ICM patients treated in the First Affiliated Hospital of Guangxi Medical University between July 2016 and March 2022. All patients underwent invasive coronary angiography for diagnosis of ICM or DCM. The data were randomly divided into a training set and a test set via 10-fold cross-validation. Four ML algorithms (random forest, logistic regression, neural network, and XGBoost [ML algorithm under gradient boosting framework]) were used to generate a training model for the optimal subset, and the parameters were optimized. Finally, model performance was independently evaluated on the test set, and external validation was performed on 79 patients from another center.

RESULTS

Compared with the logistic regression model (area under the curve [AUC] = 0.925), neural network model (AUC = 0.893), and random forest model (AUC = 0.900), the XGBoost model had the best identification rate, with an average sensitivity of 72% and average specificity of 78%. The average accuracy was 75%, and the AUC of the optimal subset was 0.934. External validation produced an AUC of 0.804, accuracy of 78%, sensitivity of 64% and specificity of 93%.

CONCLUSIONS

We demonstrate that utilizing advanced ML algorithms can help to differentiate ICM from DCM and provide appreciable precision for etiological diagnosis and individualized treatment of heart failure patients.

Hypoxia modeling techniques: A review

Hypoxia is the main cause and effect of a large number of diseases, including the most recent one facing the world, the coronavirus disease (COVID-19). Hypoxia is divided into short-term, long-term, and periodic, it can be the result of diseases, climate change, or living and traveling in the high mountain regions of the world. Since each type of hypoxia can be a cause and a consequence of various physiological changes, the methods for modeling these hypoxias are also different. There are many techniques for modeling hypoxia under experimental conditions. The most common animal for modeling hypoxia is a rat. Hypoxia models (hypoxia simulations) in rats are a tool to study the effect of various conditions on the oxygen supply of the body. These models can provide a necessary information to understand hypoxia and also provide effective treatment, highlighting the importance of various reactions of the body to hypoxia. The main parameters when choosing a model should be reproducibility and the goal that the scientist wants to achieve. Hypoxia in rats can be reproduced both ways exogenously and endogenously. The reason for writing this review was the aim to systematize the models of rats available in the literature in order to facilitate their selection by scientists. The relative strengths and limitations of each model need to be identified and understood in order to evaluate the information obtained from these models and extrapolate these results to humans to develop the necessary generalizations. Despite these problems, animal models have been and remain vital to understanding the mechanisms involved in the development and progression of hypoxia. The eligibility criteria for the selected studies was a comprehensive review of the methods and results obtained from the studies. This made it possible to make generalizations and give recommendations on the application of these methods. The review will assist scientists in choosing an appropriate hypoxia simulation method, as well as assist in interpreting the results obtained with these methods.

Altered Phenotype of Circulating Dendritic Cells and Regulatory T Cells from Patients with Acute Myocarditis

Dendritic cells (DCs) and regulatory T cells (Tregs) play an essential role in myocarditis. However, a particular DC phenotype in this disease has not been assessed. Herein, we aim to evaluate myeloid (mDCs) and plasmacytoid DC (pDC) phenotype, as well as Treg levels from myocarditis patients and healthy controls. Using multiparametric flow cytometry, we evaluated the levels of myeloid DCs (mDCs), plasmacytoid DCs (pDCs), and Tregs in peripheral blood from myocarditis patients (n = 16) and healthy volunteers (n = 16) and performed correlation analysis with clinical parameters through Sperman test. DCs from myocarditis patients showed a higher expression of costimulatory molecules while a diminished expression of the inhibitory receptors, ILT2 and ILT4. Even more, Treg cells from myocarditis patients displayed higher levels of FOXP3 compared to controls. Clinically, the increased levels of mDCs and their higher expression of costimulatory molecules correlate with a worse myocardial function, higher levels of acute phase reactants, and higher cardiac enzymes. This study shows an activating phenotype of circulating DCs from myocarditis patients. This proinflammatory status may contribute to the pathogenesis and immune deregulation in acute myocarditis.

Comparative analysis of LVAD patients in regard of ischaemic or idiopathic cardiomyopathy: A propensity-score analysis of EUROMACS data

BACKGROUND

Despite recent advances in management of patients with advanced heart failure, mortality remains high. Aim of this study was to compare impact of different aetiology of ischaemic and idiopathic cardiomyopathy on early outcomes and long-term survival of patients after left ventricular assist device implantation.

METHODS

European Registry for Patients with Mechanical Circulatory Support (EUROMACS) gathers clinical data and follow-up parameters of LVAD recipients. Patients enrolled in the EUROMACS registry with primary diagnosis of either ischaemic (n = 1190) or idiopathic (n = 812) cardiomyopathy were included. Primary Endpoints were early mortality as well as long-term survival. Secondary endpoint were major postoperative adverse events, such as need for rethoracotomy. Additionally, a propensity-score matching analysis was performed for patients with ischaemic (n = 509) and idiopathic (n = 509) cardiomyopathy.

RESULTS

In terms of basic demographics and baseline parameters the two groups significantly differed as expected before propensity-score matching due to different aetiology of cardiomyopathy. Seven-day (52 (4.4%) versus 18 (2.2%); p = 0.009), 30-day (153 (12.9%) versus 73 (9.0%); p = 0.008) and in-hospital mortality (253 (19.7%) versus 123 (15.1%); p = 0.009) were significantly lower in the idiopathic cardiomyopathy group compared to the ischaemic cardiomyopathy group, whereas after propensity-score matching 30-day (p = 0.169) was comparable and in-hospital mortality (p = 0.051) was almost significant. Kaplan-Meier survival analysis revealed no significant difference in regard of long-term survival after propensity-score matching (Breslow-test p = 0.161 and LogRank-test p = 0.113).

CONCLUSION

Though patients with ischaemic and idiopathic cardiomyopathy suffer from different cardiomyopathy aetiologies, 30-day-mortality and long-term survival of both groups were similar leading to the conclusion that covariates predominately influence mortality and survival of ischaemic and idiopathic cardiomyopathies.

Genetic predisposition study of heart failure and its association with cardiomyopathy

Heart failure (HF) is a clinical condition distinguished by structural and functional defects in the myocardium, which genetic and environmental factors can induce. HF is caused by various genetic factors that are both heterogeneous and complex. The incidence of HF varies depending on the definition and area, but it is calculated to be between 1 and 2% in developed countries. There are several factors associated with the progression of HF, ranging from coronary artery disease to hypertension, of which observed the most common genetic cause to be cardiomyopathy. The main objective of this study is to investigate heart failure and its association with cardiomyopathy with their genetic variants. The selected novel genes that have been linked to human inherited cardiomyopathy play a critical role in the pathogenesis and progression of HF. Research sources collected from the human gene mutation and several databases revealed that numerous genes are linked to cardiomyopathy and thus explained the hereditary influence of such a condition. Our findings support the understanding of the genetics aspect of HF and will provide more accurate evidence of the role of changing disease accuracy. Furthermore, a better knowledge of the molecular pathophysiology of genetically caused HF could contribute to the emergence of personalized therapeutics in future.

Pediatric Diastolic Heart Failure: Clinical Features Description of 421 Cases

BACKGROUND AND AIM

Heart failure in children differs substantially from the adult population. Clinical characteristics of pediatric diastolic heart failure has rarely been reported. In this study, we aimed to summary the causes, clinical features, lab tests, and treatment effect of pediatric diastolic heart failure.

METHODS

This study was a single center, retrospective study conducted in Children's Hospital of Chongqing Medical University. Children who were diagnosed with diastolic heart failure (DHF) without systolic heart failure (SHF) between 2006 and 2014 were included. Meanwhile, SHF (without DHF) cases were also collected from 2013 to 2014.

RESULTS

A total of 421 DHF and 42 SHF cases were included. The average age of pediatric DHF was 1.89 ± 3.29 years old, significant younger than that of SHF (4.65 ± 4.90). The top three cardiovascular causes of DHF were complex congenital heart malformations (53.4%), simple congenital heart defect (15.7%), and cardiomyopathy (7.4%). Alternatively, number of cardiomyopathy cases (57.1%) ranked first in SHF group. Simple congenital heart diseases (CHDs) rarely caused SHF. The most common symptom and sign were tachypnea and hepatomegaly in pediatric HF. Symptoms like cyanosis, feeding difficulty, be fidgety, pale, fatigue, and edema were valuable in differential diagnosis of DHF and SHF in children. B-type natriuretic peptide (BNP) increase was found in 36.9% of DHF children, and 60% in SHF patients. Sensitivity of BNP greater than 100 pg/ml in diagnosis of DHF was 0.37, and specificity of it was 0.86. Diastolic function indicators, such as E/A (early wave/late wave) ratio, IVRT (isovolumic relaxation time) were significant recovered after treatment in DHF patients. Less therapeutic benefits were achieved in children with cardiomyopathy induced DHF, in compared with non-cardiomyopathy patients.

CONCLUSION

Pediatric DHF and SHF were largely different in primary causes, clinical symptoms and signs and short-term prognosis. There was a limit diagnostic value of BNP with 100 pg/ml as cut-off value in pediatric DHF. Larger, multicenter studies of pediatric DHF are required in the future.

Factors associated with the risk of cardiac death in children with hypertrophic cardiomyopathy: a systematic review and meta-analysis

BACKGROUND

Studies on risk factors of sudden cardiac death (CD) or CD in children with hypertrophic cardiomyopathy (HCM) are lacking.

OBJECTIVES

To assess factors associated with the risk of sudden CD or CD in HCM children.

METHODS

Pubmed, Embase, Cochrane Library, and Web of Science databases were searched.

RESULTS

The results indicated that children with previous adverse cardiac events during childhood and with a history of syncope had an increased risk of sudden CD or CD. Non-sustained ventricular tachycardia (VT) in HCM children was associated with sudden CD or CD. Children with left ventricular hypertrophy (LVH) were at higher risk of sudden CD or CD. And left ventricular outflow tract (LVOT) obstruction was a potential risk factor for sudden CD in children with HCM (all P<0.05).

CONCLUSION

Optimal care and appropriate monitoring is necessary for HCM children with higher risk of sudden CD or CD.

Comparative Study of Functional Changes in Heart Mitochondria in Two Modes of Epinephrine Exposure Modeling Myocardial Injury in Rats

The parameters of coupled respiration and transport of calcium ions in mitochondria isolated from the heart of rats were studied in two modes of exposure to epinephrine for modelling myocardial damage. In 24 h after injection of 1.5 mg/kg epinephrine to rats, we observed a decrease in the efficiency of oxidative phosphorylation in heart mitochondria in the presence of both NADH- and FADH-dependent respiratory substrates. Increasing the epinephrine dose and exposure (2 mg/kg, 72 h) led to a more pronounced decrease in the ADP/O coefficient when succinate was used as a substrate, which indicated a predominant decrease in the activity of complex II of the respiratory chain. The injection of epinephrine in the two modes resulted in a decrease in the rate of calcium entry in rat heart mitochondria, but had no effect on mitochondrial calcium retention capacity, which reflects the resistance of the organelles to the induction of the Са²⁺-dependent pore. These findings suggest that both cardiomyopathy models in rats can be used to study the effectiveness of pharmacological therapy using mitochondria-targeted agents.

Epigenetic Regulation of Cardiac Troponin Genes in Pediatric Patients with Heart Failure Supported by Ventricular Assist Device

Ventricular Assist Device (VAD) therapy is considered as a part of standard care for end-stage Heart Failure (HF) children unresponsive to medical management, but the potential role of miRNAs in response to VAD therapy on molecular pathways underlying LV remodeling and cardiac function in HF is unknown. The aims of this study were to evaluate the effects of VAD on miRNA expression profile in cardiac tissue obtained from HF children, to determine the putative miRNA targets by an in-silico analysis as well as to verify the changes of predicated miRNA target in the same cardiac samples. The regulatory role of selected miRNAs on predicted targets was evaluated by a dedicated in vitro study. miRNA profile was determined in cardiac samples obtained from 13 HF children [median: 29 months; 19 LVEF%; 9 Kg] by NGS before VAD implant (pre-VAD) and at the moment of heart transplant (Post-VAD). Only hsa-miR-199b-5p, hsa-miR-19a-3p, hsa-miR-1246 were differentially expressed at post-VAD when compared to pre-VAD, and validated by real-time PCR. Putative targets of the selected miRNAs were involved in regulation of sarcomere genes, such as cardiac troponin (cTns) complex. The expression levels of fetal ad adult isoforms of cTns resulted significantly higher after VAD in cardiac tissue of HF pediatric patients when compared with HF adults. An in vitro study confirmed a down-regulatory effect of hsa-miR-19a-3p on cTnC expression. The effect of VAD on sarcomere organization through cTn isoform expression may be epigenetically regulated, suggesting for miRNAs a potential role as therapeutic targets to improve heart function in HF pediatric patients.

Right ventricular free wall strain in acutely decompensated heart failure patients with ischemic and non-ischemic cardiomyopathy

AIMS

Right ventricular (RV) dysfunction is a predictor of adverse outcomes among patients with HF with reduced ejection fraction (HFrEF); however, differences in RV parameters in HFrEF patients with ischemic (ICM) and non-ischemic cardiomyopathies (NICM) are not well understood. We investigated echocardiographic characteristics, including RV strain, in patients with acute decompensated heart failure (ADHF) and compared patients with ICM and NICM etiology.

METHODS

Consecutive patients who presented with ADHF and NYHA class III-IV were prospectively enrolled if they had LVEF < 40% and history of ICM or NICM. All patients underwent clinical exam, laboratory evaluation and 2-D echocardiographic assessment of the left ventricular (LV) and RV function, LV and RV global longitudinal strain (LVGLS, RVGLS), and RV free wall strain (RVfwLS).

RESULTS

Of 84 patients, 44 had ICM and 40 NICM. The groups had similar blood pressure, NT-proBNP, and echocardiographic parameters of LV function including LVGLS. Absolute RVGLS values were lower than RVfwLS values in both groups. Patients with NICM had significantly lower RVfwLS, but not RVGLS, compared to patients with ICM (-13% to -17%, p = 0.006). Similar differences in RVfwLS were seen in patients in NYHA class III (NICM vs ICM: -13% and -17%, respectively, 95% CI: -8.5 to -.5) and NYHA class IV (NICM vs ICM: -13.8% and -17%, respectively, 95% CI: -6.4 to -.59).

CONCLUSION

Among patients hospitalized with ADHF, patients with nonischemic etiology compared with the patients with ICM, have more severe RV dysfunction measured by RVfwLS, despite similar extent of LV impairment and the same functional limitation class.

Early treatment with combination of SS31 and entresto effectively preserved the heart function in doxorubicin-induced dilated cardiomyopathic rat

BACKGROUND

This study tested the hypothesis that early administration of SS31 and entresto (En) was superior to either one alone on preserving the heart function in setting of dilated cardiomyopathy (DCM) induced by doxorubicin (Dox) [accumulated dosage of 12.5 mg/kg/administered by intraperitoneal (IP) at 4 separated time points within 20 days] in rat.

METHODS AND RESULTS

Adult-male SD rats (n = 40) were equally categorized into groups 1 (sham-control), 2 (DCM), 3 (DCM + SS31/0.7 mg/kg/day/IP, since day-14 after DCM induction to day-60), 4 [DCM + En (30 mg/kg/day/orally since day-14 after DCM induction to day-60)] and 5 (DCM + combined SS31-En), and animals were euthanized by day 60. By day 60, left-ventricular ejection-fraction (LVEF) was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3 and 4 (all p < 0.0001), but it showed no difference between groups 3/4. The microscopic study showed that the fibrosis area/cardiomyocyte size and DNA-damaged (γ-H2AX+)/inflammatory (CD14+//CD68+) markers, and flow analysis of inflammatory (Ly6G+/MPO+/CD11^b/c+) and early/late apoptosis (AN-V⁺/PI^-//AN-V⁺/PI⁺) cells exhibited an opposite pattern of LVEF among the five groups (all p < 0.0001). The protein expressions of inflammatory upstream (TLR2/TLR4/MyD88/Mal/ TRAF6/IKK-α/IKK-ß) and downstream (p-NF-κb/TNF-α/IL-1ß/MMP-9), oxidative-stress/mitochondrial-damaged (NOX-1/NOX-2/cytosolic cytochrome-C/cyclophilin-D/DRP1) and autophagic/apoptotic (ratio of LC3B-II/LC3B-I and mitochondrial-Bax/caspase3/9) signaling pathways also exhibited an opposite pattern of LVEF among the five groups (all p < 0.0001).

CONCLUSION

Combined SS31-En therapy was superior to either one alone on protecting the heart structural and functional integrities against Dox-induced DCM damage.

Human iPSCs and Genome Editing Technologies for Precision Cardiovascular Tissue Engineering

Induced pluripotent stem cells (iPSCs) originate from the reprogramming of adult somatic cells using four Yamanaka transcription factors. Since their discovery, the stem cell (SC) field achieved significant milestones and opened several gateways in the area of disease modeling, drug discovery, and regenerative medicine. In parallel, the emergence of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR-Cas9) revolutionized the field of genome engineering, allowing the generation of genetically modified cell lines and achieving a precise genome recombination or random insertions/deletions, usefully translated for wider applications. Cardiovascular diseases represent a constantly increasing societal concern, with limited understanding of the underlying cellular and molecular mechanisms. The ability of iPSCs to differentiate into multiple cell types combined with CRISPR-Cas9 technology could enable the systematic investigation of pathophysiological mechanisms or drug screening for potential therapeutics. Furthermore, these technologies can provide a cellular platform for cardiovascular tissue engineering (TE) approaches by modulating the expression or inhibition of targeted proteins, thereby creating the possibility to engineer new cell lines and/or fine-tune biomimetic scaffolds. This review will focus on the application of iPSCs, CRISPR-Cas9, and a combination thereof to the field of cardiovascular TE. In particular, the clinical translatability of such technologies will be discussed ranging from disease modeling to drug screening and TE applications.

Pathophysiology and Treatment of Hypertrophic Cardiomyopathy: New Perspectives

PURPOSE OF REVIEW

We provide a state of the art of therapeutic options in hypertrophic cardiomyopathy (HCM), focusing on recent advances in our understanding of the pathophysiology of sarcomeric disease.

RECENT FINDINGS

A wealth of novel information regarding the molecular mechanisms associated with the clinical phenotype and natural history of HCM have been developed over the last two decades. Such advances have only recently led to a number of controlled randomized studies, often limited in size and fortune. Recently, however, the allosteric inhibitors of cardiac myosin adenosine triphosphatase, countering the main pathophysiological abnormality associated with HCM-causing mutations, i.e. hypercontractility, have opened new management perspectives. Mavacamten is the first drug specifically developed for HCM used in a successful phase 3 trial, with the promise to reach symptomatic obstructive patients in the near future. In addition, the fine characterization of cardiomyocyte electrophysiological remodelling has recently highlighted relevant therapeutic targets. Current therapies for HCM focus on late disease manifestations without addressing the intrinsic pathological mechanisms. However, novel evidence-based approaches have opened the way for agents targeting HCM molecular substrates. The impact of these targeted interventions will hopefully alter the natural history of the disease in the near future.

Cardiac Organoids to Model and Heal Heart Failure and Cardiomyopathies

Cardiac tissue engineering aims at creating contractile structures that can optimally reproduce the features of human cardiac tissue. These constructs are becoming valuable tools to model some of the cardiac functions, to set preclinical platforms for drug testing, or to alternatively be used as therapies for cardiac repair approaches. Most of the recent developments in cardiac tissue engineering have been made possible by important advances regarding the efficient generation of cardiac cells from pluripotent stem cells and the use of novel biomaterials and microfabrication methods. Different combinations of cells, biomaterials, scaffolds, and geometries are however possible, which results in different types of structures with gradual complexities and abilities to mimic the native cardiac tissue. Here, we intend to cover key aspects of tissue engineering applied to cardiology and the consequent development of cardiac organoids. This review presents various facets of the construction of human cardiac 3D constructs, from the choice of the components to their patterning, the final geometry of generated tissues, and the subsequent readouts and applications to model and treat cardiac diseases.

Evaluation of histopathological findings of cardiac deaths in forensic autopsies

BACKGROUND

The vast majority of sudden and unexpected natural deaths are related to cardiovascular diseases, especially coronary artery diseases.

AIMS

In this study, we aimed to reveal the epidemiological differences between men and women and to investigate the most common pathologies that cause cardiac deaths.

METHODS

Five thousand seven hundred sixty-eight autopsy cases that were done in 2016 were reviewed for the autopsy information and histopathological findings. Of the 5768 autopsies performed, 866 were due to cardiac causes. Eight hundred thirty-two cases were reviewed due to lack of autopsy information in 34 cases.

RESULTS

One hundred sixteen (13.9%) were female, and 716 (86.1%) were male. Coronary artery disease was detected in 760 of 832 cases. There were findings of acute or previous myocardial infarction in 595 (71.5%), perivascular and interstitial fibrosis in 159 (19.1%), myocardial rupture and tamponade in 31 (%3.7), valvular disease in 6 (0.7%), cardiomyopathy in 4 (0.5%), and congenital heart disease in 3 (0.4%). In the study, it was observed that the mean age of death due to cardiac pathology other than coronary artery disease was significantly lower than deaths due to coronary artery disease (p < 0.05). The presence of coronary artery disease in men was found to be significantly higher than in women (p < 0.001).

CONCLUSION

In our study, it was found that deaths due to coronary artery disease are seen at an older age than cardiac deaths other than coronary artery disease. In addition, in line with current knowledge, it has been confirmed that the mortality rate of coronary artery disease is higher in men than in women.

Comprehensive Analysis of Cardiac Xeno-Graft Unveils Rejection Mechanisms

Porcine heart xenotransplantation is a potential treatment for patients with end-stage heart failure. To understand molecular mechanisms of graft rejection after heart transplantation, we transplanted a 31-day-old alpha-1,3-galactosyltransferase knockout (GTKO) porcine heart to a five-year-old cynomolgus monkey. Histological and transcriptome analyses were conducted on xenografted cardiac tissue at rejection (nine days after transplantation). The recipient monkey's blood parameters were analyzed on days -7, -3, 1, 4, and 7. Validation was conducted by quantitative real-time PCR (qPCR) with selected genes. A non-transplanted GTKO porcine heart from an age-matched litter was used as a control. The recipient monkey showed systemic inflammatory responses, and the rejected cardiac graft indicated myocardial infarction and cardiac fibrosis. The transplanted heart exhibited a total of 3748 differentially expressed genes compared to the non-transplanted heart transcriptome, with 2443 upregulated and 1305 downregulated genes. Key biological pathways involved at the terminal stage of graft rejection were cardiomyopathies, extracellular interactions, and ion channel activities. The results of qPCR evaluation were in agreement with the transcriptome data. Transcriptome analysis of porcine cardiac tissue at graft rejection reveals dysregulation of the key molecules and signaling pathways, which play relevant roles on structural and functional integrities of the heart.

The efficacy of baroreflex activation therapy for heart failure: A meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of baroreflex activation therapy for heart failure is elusive. This meta-analysis aims to evaluate the impact of baroreflex activation therapy on treatment efficacy of heart failure.

METHODS

Several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases have been searched, and we include randomized controlled trials (RCTs) regarding the efficacy of baroreflex activation therapy for patients with heart failure.

RESULTS

This meta-analysis includes 4 RCTs. Baroreflex activation therapy shows significantly positive impact on the quality of life score (standard mean difference SMD = -4.61; 95% confidence interval CI = -6.24 to -2.98; P < .00001), 6-minute hall walk (6MHW) distance (SMD = 2.83; 95% CI = 1.44- 4.22; P < .0001), New York Heart Association (NYHA) Class (SMD = -3.23; 95% CI = -4.76 to -1.69; P < .0001), N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD = -1.24; 95% CI = -1.58 to -0.89; P < .00001) and the duration of hospitalization (SMD = -1.65; 95% CI = -2.90 to -0.39; P = .01) compared with control group for heart failure, but has no obvious effect on left ventricular ejection fraction (LVEF) (SMD = 1.43; 95% CI = -0.15-3.01; P = .08), or the number of hospitalization per year (SMD = -1.17; 95% CI = -2.56-0.22; P = .10).

CONCLUSIONS

Baroreflex activation therapy can improve the treatment efficacy for heart failure.

Machine learning-based classification and diagnosis of clinical cardiomyopathies

Dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) are two common types of cardiomyopathies leading to heart failure. Accurate diagnostic classification of different types of cardiomyopathies is critical for precision medicine in clinical practice. In this study, we hypothesized that machine learning (ML) can be used as a novel diagnostic approach to analyze cardiac transcriptomic data for classifying clinical cardiomyopathies. RNA-Seq data of human left ventricle tissues were collected from 41 DCM patients, 47 ICM patients, and 49 nonfailure controls (NF) and tested using five ML algorithms: support vector machine with radial kernel (svmRadial), neural networks with principal component analysis (pcaNNet), decision tree (DT), elastic net (ENet), and random forest (RF). Initial ML classifications achieved ~93% accuracy (svmRadial) for NF vs. DCM, ~82% accuracy (RF) for NF vs. ICM, and ~80% accuracy (ENet and svmRadial) for DCM vs. ICM. Next, 50 highly contributing genes (HCGs) for classifying NF and DCM, 68 HCGs for classifying NF and ICM, and 59 HCGs for classifying DCM and ICM were selected for retraining ML models. Impressively, the retrained models achieved ~90% accuracy (RF) for NF vs. DCM, ~90% accuracy (pcaNNet) for NF vs. ICM, and ~85% accuracy (pcaNNet and RF) for DCM vs. ICM. Pathway analyses further confirmed the involvement of those selected HCGs in cardiac dysfunctions such as cardiomyopathies, cardiac hypertrophies, and fibrosis. Overall, our study demonstrates the promising potential of using artificial intelligence via ML modeling as a novel approach to achieve a greater level of precision in diagnosing different types of cardiomyopathies.

Modulation of Nrf2 by quercetin in doxorubicin-treated rats

Doxorubicin (DOXO), a potent and widely used chemotherapeutic agent, causes irreversible heart failure by increasing oxidative stress, which limits its clinical utility. Nuclear factor erythroid-derived 2 -like 2 (Nrf2) is a prominent central regulator of cellular impenetrable to oxidants. The purpose of the study is to assess the ameliorative outcome of quercetin in cardiomyopathic rats induced by doxorubicin. Cardiomyopathy was produced in rats by single intraperitoneal weekly with DOXO (2 mg/kg) for 4 weeks. The rats were divided into five groups: (I) control group; (II) DOXO (2 mg/kg, i.p.) group; (III-V) DOXO + quercetin (10 mg/kg, 25 mg/kg and 50 mg/kg, orally), and were treated for 7 weeks. At the end of the treatment duration, cardiac function and biochemical parameters were assessed. Quercetin (10 mg/kg, 25 mg/kg and 50 mg/kg, orally) treatment reduced the raised blood pressure (BP) and left ventricular dysfunction. Withal, it prevented the rise in CKMB and LDH, suggesting the effect of quercetin in the maintaining the integrity of the cell membrane Besides, it also prevented the alteration in electrolyte levels, the activity of ATPase, and antioxidant status. Quercetin increased Nrf2 mRNA expression and reduced histological abnormalities compared to the DOXO control group. In conclusion, quercetin protected against DOXO- induced cardiomyopathy, by increasing expression of NRF2, and thereby increasing antioxidant defense and restoring biochemical and histological abnormalities.

Cardiac Alterations in Patients with Familial Lipodystrophy

Familial lipodystrophy is a rare genetic condition in which individuals have, besides metabolic changes and body fat deposits, a type of cardiomyopathy that has not been well studied. Many of the patients develop cardiovascular changes, the most commonly reported in the literature being the expression of a type of hypertrophic cardiomyopathy. This article, presented as a bibliographic review, reviews the clinical and cardiovascular imaging aspects in this scenario of cardiomyopathy in a rare metabolic disease, based on the latest scientific evidence published in the area. Despite the frequent association of congenital lipodystrophy and ventricular hypertrophy described in the literature, the pathophysiological mechanisms of this cardiomyopathy have not yet been definitively elucidated, and new information on cardiac morphological aspects is emerging in the aegis of recent and advanced imaging methods, such as cardiac magnetic resonance.

Therapeutic efficacy of shenmai injection as an adjuvant treatment in dilated cardiomyopathy: A protocol for systematic review

BACKGROUND

Shenmai injection (SMI) is a Traditional Chinese Medicine patent prescription consisting of extractions from ophiopogonis radix and ginseng radix rubra. Clinical studies showed that SMI combined with conventional medicine treatment (CMT) can enhance the therapeutic efficacy for dilated cardiomyopathy (DCM). However, there is still a lack of comprehensive and systematic evidence, which urgently requires us to verify its therapeutic efficacy. Hence, we provide a protocol for systematic review and meta-analysis.

METHODS

The systematic search on the MEDLINE/PubMed, China National Knowledge Infrastructure (CNKI), Wanfang database, VIP database, the Cochrane Library, Embase and Chinese Biomedical Database (CBM) in Chinese and English language with dates ranging from the earliest record to August 8, 2019. Next, the quality of each trial was assessed according to the criteria of the Cochrane Handbook for Systematic Reviews of Interventions. Then, the outcome data were recorded and pooled by RevMan 5.3 software.

RESULTS

The systematic review and meta-analysis aims to review and pool current clinical outcomes of SMI for the adjuvant treatment of DCM.

CONCLUSION

This study will provide a high-quality evidence of SMI for the adjuvant treatment on DCM patients.

PROSPERO REGISTRATION NUMBER

CRD42019146369.

Cellular models for human cardiomyopathy: What is the best option?

The genetic cardiomyopathies are a group of disorders related by abnormal myocardial structure and function. Although individually rare, these diseases collectively represent a significant health burden since they usually develop early in life and are a major cause of morbidity and mortality amongst affected children. The heterogeneity and rarity of these disorders requires the use of an appropriate model system in order to characterize the mechanism of disease and develop useful therapeutics since standard drug trials are infeasible. A common approach to study human disease involves the use of animal models, especially rodents, but due to important biological and physiological differences, this model system may not recapitulate human disease. An alternative approach for studying the metabolic cardiomyopathies relies on the use of cellular models which have most frequently been immortalized cell lines or patient-derived fibroblasts. However, the recent introduction of induced pluripotent stem cells (iPSCs), which have the ability to differentiate into any cell type in the body, is of great interest and has the potential to revolutionize the study of rare diseases. In this paper we review the advantages and disadvantages of each model system by comparing their utility for the study of mitochondrial cardiomyopathy with a particular focus on the use of iPSCs in cardiovascular biology for the modeling of rare genetic or metabolic diseases.

Fully automated and comprehensive MRI-based left-ventricular contractility analysis in post-chemotherapy breast cancer patients

OBJECTIVE

This study investigated the occurrence of cardiotoxicity-related left-ventricular (LV) contractile dysfunction in breast cancer patients following treatment with antineoplastic chemotherapy agents.

METHODS

A validated and automated MRI-based LV contractility analysis tool consisting of quantization-based boundary detection, unwrapping of image phases and the meshfree Radial Point Interpolation Method was used toward measuring LV chamber quantifications (LVCQ), three-dimensional strains and torsions in patients and healthy subjects. Data were acquired with the Displacement Encoding with Stimulated Echoes (DENSE) sequence on 21 female patients and 21 age-matched healthy females. Estimates of patient LVCQs from DENSE acquisitions were validated in comparison to similar steady-state free precession measurements and their strain results validated via Bland-Altman interobserver agreements. The occurrence of LV abnormalities was investigated via significant differences in contractility measurements (LVCQs, strains and torsions) between patients and healthy subjects.

RESULTS

Repeated measures analysis showed similarities between LVCQ measurements from DENSE and steady-state free precession, including cardiac output (4.7 ± 0.4 L, 4.6 ± 0.4 L, p = 0.8), and LV ejection fractions (59±6%, 58±5%, p = 0.2). Differences found between patients and healthy subjects included enlarged basal diameter (5.0 ± 0.5 cm vs 4.4 ± 0.5 cm, p < 0.01), apical torsion (6.0 ± 1.1° vs 9.7 ± 1.4°, p < 0.001) and global longitudinal strain (-0.15 ± 0.02 vs. -0.21 ± 0.04, p < 0.001), but not LV ejection fraction (59±6% vs. 63±6%, p = 0.1).

CONCLUSION

The results from the statistical analysis reveal the possibility of LV abnormalities in the post-chemotherapy patients via enlarged basal diameter and reduced longitudinal strain and torsion, in comparison to healthy subjects.

ADVANCES IN KNOWLEDGE

This study shows that subclinical LV abnormalities in post-chemotherapy breast cancer patients can be detected with an automated technique for the comprehensive analysis of contractile parameters.

Cardiovascular disease models: A game changing paradigm in drug discovery and screening

Cardiovascular disease is the leading cause of death worldwide. Although investment in drug discovery and development has been sky-rocketing, the number of approved drugs has been declining. Cardiovascular toxicity due to therapeutic drug use claims the highest incidence and severity of adverse drug reactions in late-stage clinical development. Therefore, to address this issue, new, additional, replacement and combinatorial approaches are needed to fill the gap in effective drug discovery and screening. The motivation for developing accurate, predictive models is twofold: first, to study and discover new treatments for cardiac pathologies which are leading in worldwide morbidity and mortality rates; and second, to screen for adverse drug reactions on the heart, a primary risk in drug development. In addition to in vivo animal models, in vitro and in silico models have been recently proposed to mimic the physiological conditions of heart and vasculature. Here, we describe current in vitro, in vivo, and in silico platforms for modelling healthy and pathological cardiac tissues and their advantages and disadvantages for drug screening and discovery applications. We review the pathophysiology and the underlying pathways of different cardiac diseases, as well as the new tools being developed to facilitate their study. We finally suggest a roadmap for employing these non-animal platforms in assessing drug cardiotoxicity and safety.

Dark or Bright Half of the Moon: A Qualitative Study Exploring the Experience of Iranian Heart Failure Patients Regarding their Quality of Life

BACKGROUND

Heart failure (HF) is a major public health problem in different societies and has numerous impacts on quality of life (QOL).

AIM

The present study was carried out with the aim to explore the experience of HF patients regarding the negative effects of the disease on their QOL.

METHODS

In this qualitative exploratory study data collection was performed through face-to-face, semi-structured, in-depth interviews with 19 patients with HF, who were selected through purposive sampling method from April to September 2017. Data analysis was carried out based on the framework analysis method.

RESULTS

The negative consequences of HF on QOL emerged in the form of 6 main themes including symptoms, disease complications, cognitive impairment, psychological distress, functional limitations and economic problems. Most of the participants (14 out of 19) assessed their QOL as well or very well.

CONCLUSION

The majority of the patients in this study, despite the many negative impacts of HF, had a high QOL that could indicate their satisfaction and effective coping with HF by creating a positive outlook and the perceived positive effects of the disease.

AUTOMATED CHARACTERIZATION OF CARDIOVASCULAR DISEASES USING WAVELET TRANSFORM FEATURES EXTRACTED FROM ECG SIGNALS

Cardiovascular disease has been the leading cause of death worldwide. Electrocardiogram (ECG)-based heart disease diagnosis is simple, fast, cost effective and non-invasive. However, interpreting ECG waveforms can be taxing for a clinician who has to deal with hundreds of patients during a day. We propose computing machinery to reduce the workload of clinicians and to streamline the clinical work processes. Replacing human labor with machine work can lead to cost savings. Furthermore, it is possible to improve the diagnosis quality by reducing inter- and intra-observer variability. To support that claim, we created a computer program that recognizes normal, Dilated Cardiomyopathy (DCM), Hypertrophic Cardiomyopathy (HCM) or Myocardial Infarction (MI) ECG signals. The computer program combined Discrete Wavelet Transform (DWT) based feature extraction and K-Nearest Neighbor (K-NN) classification for discriminating the signal classes. The system was verified with tenfold cross validation based on labeled data from the PTB diagnostic ECG database. During the validation, we adjusted the number of neighbors [Formula: see text] for the machine learning algorithm. For [Formula: see text], training set has an accuracy and cross validation of 98.33% and 95%, respectively. However, when [Formula: see text], it showed constant for training set but dropped drastically to 80% for cross-validation. Hence, training set [Formula: see text] prevails. Furthermore, a confusion matrix proved that normal data was identified with 96.7% accuracy, 99.6% sensitivity and 99.4% specificity. This means an error of 3.3% will occur. For every 30 normal signals, the classifier will mislabel only 1 of the them as HCM. With these results, we are confident that the proposed system can improve the speed and accuracy with which normal and diseased subjects are identified. Diseased subjects can be treated earlier which improves their probability of survival.

Identification of putative pathogenic single nucleotide variants (SNVs) in genes associated with heart disease in 290 cases of stillbirth

The incidence of stillbirth in Sweden has essentially remained constant since the 1980’s, and despite thorough investigation, many cases remain unexplained. It has been suggested that a proportion of stillbirth cases is caused by heart disease, mainly channelopathies. The aim of this study was to analyze DNA from 290 stillbirth cases without chromosomal abnormalities for pathogenic single nucleotide variants (SNVs) in 70 genes associated with cardiac channelopathies and cardiomyopathies. The HaloPlex Target Enrichment System (Agilent Technologies) was utilized to prepare sequencing libraries which were sequenced on the Illumina NextSeq platform. We found that 12.1% of the 290 investigated stillbirth cases had one (n = 31) or two (n = 4) variants with evidence supporting pathogenicity, i.e. loss-of-function variants (nonsense, frameshift, splice site substitutions), evidence from functional studies, or previous identification of the variants in affected individuals. Regarding identified putative pathogenic variants in genes associated with channelopathies, the prevalence was significantly higher in the stillbirth cohort (n = 23, 7.93%) than the corresponding prevalence of the same variants in the non-Finnish European population of the Exome Aggregation Consortium (2.70%, p<0.001) and SweGen, (2.30%, p<0.001). Our results give further support to the hypothesis that cardiac channelopathies might contribute to stillbirth. Screening for pathogenic SNVs in genes associated with heart disease might be a valuable complement for stillbirth cases where today’s conventional investigation does not reveal the underlying cause of fetal demise.

Development of a multivariate model to predict significant coronary artery disease in Thai patients with left ventricular systolic dysfunction and determine the applicability of coronary angiography: a single-center, retrospective, case–control study

Background

Coronary angiography (CAG) or stress imaging has been performed in almost all Thai patients with left ventricular (LV) systolic dysfunction. If CAG results reveal insignificant coronary stenosis, such patients are diagnosed with nonischemic cardiomyopathy (NICM); however, CAG is considered to provide no benefit and may even harm these patients because it is invasive.

Objectives

To identify predictors associated with significant coronary artery disease (CAD) (stenosis) in Thai patients with LV systolic dysfunction without angina and without LV regional wall motion abnormality and create a prediction score.

Method

Retrospective data from patients at a single tertiary-care center with LV systolic dysfunction (LV ejection fraction <50%) diagnosed between August 2000 and October 2014 were separated into a group with ischemic cardiomyopathy (ICM) and a group with NICM according to CAG. Predictors associated with CAD found in normal populations were determined. Multivariate analysis was used to identify predictors associated with significant coronary stenosis in patients with LV systolic dysfunction to develop a model to create a prediction score.

Results

We included data registered from 240 Thai patients with LV systolic dysfunction. Predictors associated with ICM were age (>60 years), sex (male), and a history of diabetes mellitus (DM). Predictors associated with NICM were body mass index (BMI) >25 kg/m2 and the presence of left bundle branch block (LBBB) on electrocardiography. A simplified equation to predict significant CAD in patients with LV systolic dysfunction is: 3(male sex) + 3(age >60 y) – 5(BMI >25 kg/m2) - 5(LBBB) + 5(DM) - 5. The sensitivity and specificity of this score are 60.5% and 85.1%, respectively.

Conclusion

Our prediction score has modest sensitivity, but high specificity for predicting significant CAD and can be used to determine who should not undergo CAG.

Histopathological Aspects of the Myocardium in Dilated Cardiomyopathy

Dilated cardiomyopathy is the most common form of cardiac muscle disease, accounting for approximately 60% of all cardiomyopathies. We proposed to identify histopathological changes of the myocardium in dilative cardiomyopathy. This study comprised a total of 19 cases, represented by myocardial fragments from deceased patients with diagnosis of dilated cardiomyopathy. Histopathological analysis allowed changes to be observed for both myocytes and myocardial interstitial components. We have found a combination of hypertrophic, atrophic and normal myocardocytes, or associated with the presence of hydropic changes. We rarely identified the aspect of myocytosis, cytoplasmic accumulation of lipofuscin pigment or mucinous material, and variable nuclear pleomorphism. At the interstitial level we noticed changes in fibrosis, lipomatosis and rarely the presence of inflammatory infiltrate. Histopathological characteristics of the myocardium in dilated cardiomyopathy are numerous but nonspecific, similar to those in the terminal stages of other cardiac diseases.

Coronary Microcirculatory Dysfunction in Human Cardiomyopathies: A Pathologic and Pathophysiologic Review

Cardiomyopathies are a heterogeneous group of diseases of the myocardium. The term cardiomyopathy involves a wide range of pathogenic mechanisms that affect the structural and functional states of cardiomyocytes, extravascular tissues, and coronary vasculature, including both epicardial coronary arteries and the microcirculation. In the developed phase, cardiomyopathies present with various clinical symptoms: dyspnea, chest pain, palpitations, swelling of the extremities, arrhythmias, and sudden cardiac death. Due to the heterogeneity of cardiomyopathic patterns and symptoms, their diagnosis and therapies are great challenges. Despite extensive research, the relation between the structural and functional abnormalities of the myocardium and the coronary circulation are still not well understood in the various forms of cardiomyopathy. The main pathological characteristics of cardiomyopathies and the coronary microcirculation develop in a progressive manner due to (1) genetic-immunologic-systemic factors; (2) comorbidities with endothelial, myogenic, metabolic, and inflammatory changes; (3) aging-induced arteriosclerosis; and (4) myocardial fibrosis. The aim of this review is to summarize the most important common pathological features and/or adaptations of the coronary microcirculation in various types of cardiomyopathies and to integrate the present understanding of the underlying pathophysiological mechanisms responsible for the development of various types of cardiomyopathies. Although microvascular dysfunction is present and contributes to cardiac dysfunction and the potential outcome of disease, the current therapeutic approaches are not specific for the given types of cardiomyopathy.

A Genome-Wide Association Study of Idiopathic Dilated Cardiomyopathy in African Americans

Idiopathic dilated cardiomyopathy (IDC) is the most common form of non-ischemic chronic heart failure. Despite the higher prevalence of IDC in African Americans, the genetics of IDC have been relatively understudied in this ethnic group. We performed a genome-wide association study to identify susceptibility genes for IDC in African Americans recruited from five sites in the U.S. (662 unrelated cases and 1167 controls). The heritability of IDC was calculated to be 33% (95% confidence interval: 19-47%; p = 6.4 × 10-7). We detected association of a variant in a novel intronic locus in the CACNB4 gene meeting genome-wide levels of significance (p = 4.1 × 10-8). The CACNB4 gene encodes a calcium channel subunit expressed in the heart that is important for cardiac muscle contraction. This variant has not previously been associated with IDC in any racial group. Pathway analysis, based on the 1000 genes most strongly associated with IDC, showed an enrichment for genes related to calcium signaling, growth factor signaling, neuronal/neuromuscular signaling, and various types of cellular level signaling, including gap junction and cAMP signaling. Our results suggest a novel locus for IDC in African Americans and provide additional insights into the genetic architecture and etiology.

Clinical Course and Treatment of Dilated Cardiomyopathy During Twenty Years of Follow-up

OBJECTIVE

Demonstration of idiopathic dilated cardiomyopathy with unusual flow, unpredictable clinical picture and complex therapy.

CASE REPORT

Patient A.P., female, 38 years old, had symptoms of dilated cardiomyopathy (with possible infectious myocarditis in the background) at age 17. After hospitalization for ten months and ten days, while waiting for heart transplantation (with threatening death outcome), without a clearly pronounced threatening arrhythmia, but with a low ejection fraction and a poor general condition, remission occurred. The therapy focused primarily on the treatment of heart failure, prevention of arrhythmia and thromboembolism. Normalization of the disease by improving the function of the left ventricle (expected in 16% of patients) occurred and lasted for 4 years, followed by an exacerbation of the disease that lasted for two years. In the next few years the patient was stable, had a first child with normal pregnancy. During the second trimester of the second pregnancy, there was an exacerbation (postpartum dilatation cardiomyopathy) lasting for couple of months. At the time of case report (May 2017), the patient is stable on therapy (ACE inhibitor, beta blocker, diuretics, If channel blocker), without limitation of physical capacity, mother of two children, unemployed.

CONCLUSION

The clinical course of dilated cardiomyopathy is extremely unpredictable and therapy is very complex and demanding.

The P2X7 purinergic receptor: An emerging therapeutic target in cardiovascular diseases

The P2X7 purinergic receptor, a calcium permeable cationic channel, is activated by extracellular ATP. Most studies show that P2X7 receptor plays an important role in the nervous system diseases, immune response, osteoporosis and cancer. Mounting evidence indicates that P2X7 receptor is also associated with cardiovascular disease. For example, the P2X7 receptor activated by ATP can attenuate myocardial ischemia-reperfusion injury. By contrast, inhibition of P2X7 receptor decreases arrhythmia after myocardial infarction, prolongs cardiac survival after a long term heart transplant, alleviates the dilated cardiomyopathy and the autoimmune myocarditis process. The P2X7 receptor also mitigates vascular diseases including atherosclerosis, hypertension, thrombosis and diabetic retinopathy. This review focuses on the latest research on the role and therapeutic potential of P2X7 receptor in cardiovascular diseases.

Overexpression of miRNA-9 Generates Muscle Hypercontraction Through Translational Repression of Troponin-T in Drosophila melanogaster Indirect Flight Muscles

MicroRNAs (miRNAs) are small noncoding endogenous RNAs, typically 21-23 nucleotides long, that regulate gene expression, usually post-transcriptionally, by binding to the 3'-UTR of target mRNA, thus blocking translation. The expression of several miRNAs is significantly altered during cardiac hypertrophy, myocardial ischemia, fibrosis, heart failure, and other cardiac myopathies. Recent studies have implicated miRNA-9 (miR-9) in myocardial hypertrophy. However, a detailed mechanism remains obscure. In this study, we have addressed the roles of miR-9 in muscle development and function using a genetically tractable model system, the indirect flight muscles (IFMs) of Drosophila melanogaster Bioinformatics analysis identified 135 potential miR-9a targets, of which 27 genes were associated with Drosophila muscle development. Troponin-T (TnT) was identified as major structural gene target of miR-9a. We show that flies overexpressing miR-9a in the IFMs have abnormal wing position and are flightless. These flies also exhibit a loss of muscle integrity and sarcomeric organization causing an abnormal muscle condition known as "hypercontraction." Additionally, miR-9a overexpression resulted in the reduction of TnT protein levels while transcript levels were unaffected. Furthermore, muscle abnormalities associated with miR-9a overexpression were completely rescued by overexpression of TnT transgenes which lacked the miR-9a binding site. These findings indicate that miR-9a interacts with the 3'-UTR of the TnT mRNA and downregulates the TnT protein levels by translational repression. The reduction in TnT levels leads to a cooperative downregulation of other thin filament structural proteins. Our findings have implications for understanding the cellular pathophysiology of cardiomyopathies associated with miR-9 overexpression.

Proteasome dysfunction in cardiomyopathies

The ubiquitin-proteasome system (UPS) plays a critical role in removing unwanted intracellular proteins and is involved in protein quality control, signalling and cell death. Because the heart is subject to continuous metabolic and mechanical stress, the proteasome plays a particularly important role in the heart, and proteasome dysfunction has been suggested as a causative factor in cardiac dysfunction. Proteasome impairment has been detected in cardiomyopathies, heart failure, myocardial ischaemia, and hypertrophy. Proteasome inhibition is also sufficient to cause cardiac dysfunction in healthy pigs, and patients using a proteasome inhibitor for cancer therapy have a higher incidence of heart failure. In this Topical Review we discuss the experimental data which suggest UPS dysfunction is a common feature of cardiomyopathies, with an emphasis on hypertrophic cardiomyopathy caused by sarcomeric mutations. We also propose potential mechanisms by which cardiomyopathy-causing mutations may lead to proteasome impairment, such as altered calcium handling and increased oxidative stress due to mitochondrial dysfunction.