Hypertrophic cardiomyopathy

MitraClip combined with PTSBME for the treatment of obstructive hypertrophic cardiomyopathy with severe mitral regurgitation: a case report

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the hereditary cardiomyopathy with the highest incidence rate. Its main pathological changes are ventricular septal myocardial hypertrophy and myocardial disorder, which are prone to fatal arrhythmia and heart failure. If left ventricular outflow tract (LVOT) obstruction is combined, it is called obstructive hypertrophic cardiomyopathy (oHCM). There is currently no report on the use of MitraClip combined with percutaneous transluminal septal branch microsphere embolization (PTSBME) for treating patients with oHCM complicated with severe mitral regurgitation (MR).

CASE PRESENTATION

This report describes a 51-year-old male patient who was admitted to the hospital due to "repeated chest tightness and shortness of breath for 2 years, worsening for 6 months". Ultrasound, left ventricular angiography (LVA), and left cardiac catheterization confirmed oHCM with moderate MR. We used MitraClip combined with PTSBME to relieve the patient's LVOT obstruction and MR simultaneously.

CONCLUSIONS

Traditionally, both interventricular septal and mitral valve lesions are treated simultaneously through surgical intervention. However, the surgical conditions are relatively strict, and many patients are unable to undergo surgical treatment, resulting in delays in their condition. For such patients, minimally invasive intervention may be used to simultaneously treat interventricular septal and mitral valve lesions, further reducing surgical risks and enhancing surgical efficacy. In this case, MitraClip combined with PTSBME was first performed. After the surgery, the patient's LVOT obstruction and MR were simultaneously relieved, and clinical symptoms improved significantly.

The clinical utility of cardiac myosin inhibitors for the management of hypertrophic cardiomyopathy: a scoping review

Hypertrophic cardiomyopathy (HCM) is an inherited condition characterized by left ventricular, non-dilated hypertrophy in the absence of another secondary underlying cause. There has been an ongoing increase in the diagnosis of HCM over the past couple of decades, prompting further work in the area of pharmacological and interventional therapies. This scoping review aimed to summarize the traditional therapeutic options for HCM and to explore emerging research on novel cardiac myosin inhibitors (CMIs) as a new option for pharmacologic management of HCM. A PRISMA search strategy was carried out to identify the pertinent literature on mavacamten and aficamten-two novel CMIs. Seventeen studies were included. Based on the results of the studies included in this review, cardiac myosin inhibitors have been proven to be a safe and efficacious second-line option for the management of HCM. In the foreseeable future, based on results of ongoing studies investigating patient outcomes and side-effect profile, CMIs may potentially play a larger role as part of standard treatment of HCM.

Mortality from Hypertrophic Cardiomyopathy in Brazil-Historical Series

Hypertrophic cardiomyopathy (HCM) is a relatively prevalent disease, primarily of a genetic etiology, affecting both sexes and characterized by left ventricular hypertrophy. However, limitations within healthcare systems, socioracial factors, and the issue of underdiagnosis hinder accurate mortality assessments in our region. This study, therefore, aimed to assess the mortality trends associated with HCM in Brazil from 2010 to 2020, with a focus on socioracial factors and healthcare disparities. This ecological, time-series study employed a quantitative approach based on secondary data from the Mortality System (SIM) developed by the Brazilian Ministry of Health. Mortality incidence and trend analyses were conducted using the average annual percent change (AAPC) and the annual percent change (APC). The results indicated a predominance of HCM-related deaths among white males aged 40 years and older. Additionally, an increasing trend in HCM-related mortality was observed among white and brown males and females aged 40 years and above from 2010 to 2018. Throughout the entire period covered in the study, the incidence of deaths due to HCM increased by 18.3% and 69.8% in the northeastern and southeastern regions. The findings suggest that health system managers should consider addressing the factors influencing HCM mortality and encourage the development and implementation of clinical protocols across healthcare institutions nationwide. Such protocols are recommended to facilitate early diagnosis and establish effective treatment strategies, ultimately aiming to improve the survival rates and quality of life for individuals affected by HCM.

Deciphering metabolomics and lipidomics landscape in zebrafish hypertrophic cardiomyopathy model

To elucidate the lipidomic and metabolomic alterations associated with hypertrophic cardiomyopathy (HCM) pathogenesis, we utilized cmybpc3-/- zebrafish model. Fatty acid profiling revealed variability of 10 fatty acids profiles, with heterozygous (HT) and homozygous (HM) groups exhibiting distinct patterns. Hierarchical cluster analysis and multivariate analyses demonstrated a clear separation of HM from HT and control (CO) groups related to cardiac remodeling. Lipidomic profiling identified 257 annotated lipids, with two significantly dysregulated between CO and HT, and 59 between HM and CO. Acylcarnitines and phosphatidylcholines were identified as key contributors to group differentiation, suggesting a shift in energy source. Untargeted metabolomics revealed 110 and 53 significantly dysregulated metabolites. Pathway enrichment analysis highlighted perturbations in multiple metabolic pathways in the HM group, including nicotinate, nicotinamide, purine, glyoxylate, dicarboxylate, glycerophospholipid, pyrimidine, and amino acid metabolism. Our study provides comprehensive insights into the lipidomic and metabolomic unique signatures associated with cmybpc3-/- induced HCM in zebrafish. The identified biomarkers and dysregulated pathways shed light on the metabolic perturbations underlying HCM pathology, offering potential targets for further investigation and potential new therapeutic interventions.

Early left atrial reverse remodelling in patients with hypertrophic obstructive cardiomyopathy receiving transapical beating-heart septal myectomy

OBJECTIVES

This study aims to investigate the short-term effects of transapical beating-heart septal myectomy (TA-BSM) on left atrial (LA) anatomy and function and its association with clinical indicators in patients with hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

A total of 105 HOCM patients who received TA-BSM were included. Clinical and comprehensive echocardiographic data were obtained before surgery, at discharge, and 3 months after myectomy. LA reverse remodelling was defined as LA maximum volume index (LAVI) ≤34 ml/m2 and a change of ≥10%.

RESULTS

At 3 months after TA-BSM, New York Heart Association (NYHA) functional class and 6-min walking test were significantly improved, N-terminal pro-B-type natriuretic peptide (NT-proBNP) decreased, left ventricular outflow tract (LVOT) peak gradient and mitral regurgitation were significantly reduced. LAVI decreased in 76%, with a median change of 20%, and the criteria for LA reverse remodelling were met in 48%. LA strain parameters were improved at 3 months after TA-BSM. Moreover, left ventricular (LV) diastolic function was significantly improved, but LV global longitudinal strain was not significantly changed at 3 months after operation. Improvement in LVOT peak gradient, LAVI, LA reservoir strain (LASr) and conduit strain (LAScd) were associated with reduction in NT-proBNP.

CONCLUSIONS

Along with effectively relieving the obstruction of the LVOT and mitral regurgitation, TA-BSM could significantly improve LA size and function during the short-term follow-up for HOCM patients. The indicators of LA reverse remodelling were associated with reduction in a biomarker of myocardial wall stress, indicating the early recovery of LV relaxation and clinical status for patients.

Myosin-Catalyzed ATP Hydrolysis in the Presence of Disease-Causing Mutations: Mavacamten as a Way to Repair Mechanism

Hypertrophic cardiomyopathy is one of the most common forms of genetic cardiomyopathy. Mavacamten is a first-in-class myosin modulator that was identified via activity screening on the wild type, and it is FDA-approved for the treatment of obstructive hypertrophic cardiomyopathy (HCM). The drug selectively binds to the cardiac β-myosin, inhibiting myosin function to decrease cardiac contractility. Though the drug is thought to affect multiple steps of the myosin cross-bridge cycle, its detailed mechanism of action is still under investigation. Individual steps in the overall cross-bridge cycle must be queried to elucidate the full mechanism of action. In this study, we utilize the rare-event method of transition path sampling to generate reactive trajectories to gain insights into the action of the drug on the dynamics and rate of the ATP hydrolysis step for human cardiac β-myosin. We study three known HCM causative myosin mutations: R453C, P710R, and R712L to observe the effect of the drug on the alterations caused by these mutations in the chemical step. Since the crystal structure of the drug-bound myosin was not available at the time of this work, we created a model of the drug-bound system utilizing a molecular docking approach. We find a significant effect of the drug in one case, where the actual mechanism of the reaction is altered from the wild type by mutation. The drug restores both the rate of hydrolysis to the wildtype level and the mechanism of the reaction. This is a way to check the effect of the drug on untested mutations.

A novel pathogenic variant in the carnitine transporter gene, SLC22A5, in association with metabolic carnitine deficiency and cardiomyopathy features

BACKGROUND

Primary carnitine deficiency (PCD) denotes low carnitine levels with an autosomal recessive pattern of inheritance. Cardiomyopathy is the most common cardiac symptom in patients with PCD, and early diagnosis can prevent complications. Next-generation sequencing can identify genetic variants attributable to PCD efficiently.

OBJECTIVE

We aimed to detect the genetic cause of the early manifestations of hypertrophic cardiomyopathy and metabolic abnormalities in an Iranian family.

METHODS

We herein describe an 8-year-old boy with symptoms of weakness and lethargy diagnosed with PCD through clinical evaluations, lab tests, echocardiography, and cardiac magnetic resonance imaging. The candidate variant was confirmed through whole-exome sequencing, polymerase chain reaction, and direct Sanger sequencing. The binding efficacy of normal and mutant protein-ligand complexes were evaluated via structural modeling and docking studies.

RESULTS

Clinical evaluations, echocardiography, and cardiac magnetic resonance imaging findings revealed hypertrophic cardiomyopathy as a clinical presentation of PCD. Whole-exome sequencing identified a new homozygous variant, SLC22A5 (NM_003060.4), c.821G > A: p.Trp274Ter, associated with carnitine transport. Docking analysis highlighted the impact of the variant on carnitine transport, further indicating its potential role in PCD development.

CONCLUSIONS

The c.821G > A: p.Trp274Ter variant in SLC22A5 potentially acted as a pathogenic factor by reducing the binding affinity of organic carnitine transporter type 2 proteins for carnitine. So, the c.821G > A variant may be associated with carnitine deficiency, metabolic abnormalities, and cardiomyopathic characteristics.

Hypertrophic Cardiomyopathy Diagnosis and Treatment in High- and Low-Income Countries: A Narrative Review

Hypertrophic cardiomyopathy (HCM) is a hereditary cardiac condition characterized by unexplained left ventricular hypertrophy without a hemodynamic cause. This condition is prevalent in the United States, resulting in various clinical manifestations, including diastolic dysfunction, left ventricular outflow obstruction, cardiac ischemia, and atrial fibrillation. HCM is associated with several genetic mutations, with sarcomeric mutations being the most common and contributing to a more complex disease course. Early diagnosis of HCM is essential for effective management, as late diagnosis often requires invasive treatments and creates a substantial financial burden. Disparities in HCM diagnosis and treatment exist between high-income and low-income countries. High-income countries have more resources to investigate and implement advanced diagnostic and treatment modalities. In contrast, low-income countries face challenges in accessing diagnostic equipment, trained personnel, and affordable medications, leading to a lower quality of life and life expectancy for affected individuals. Diagnostic tools for HCM include imaging studies such as 2D echocardiography, cardiovascular magnetic resonance (CMR), and electrocardiograms (ECGs). CMR is considered the gold standard but remains inaccessible to a significant portion of the world's population, especially in low-income countries. Genetics plays a crucial role in HCM, with numerous mutations identified in various genes. Genetic counseling is essential but often limited in low-income countries due to resource constraints. Disparities in healthcare access and adherence to treatment recommendations exist between high-income and low-income countries, leading to differences in patient outcomes. Addressing these disparities is essential to improve the overall management of HCM on a global scale. In conclusion, this review highlights the complex nature of HCM, emphasizing the importance of early diagnosis, genetic counseling, and access to appropriate diagnostic and therapeutic interventions. Addressing healthcare disparities is crucial to ensure that all individuals with HCM receive timely and effective care, regardless of their geographic location or socioeconomic status.

Cardiac magnetic resonance of hypertrophic heart phenotype: A review

Hypertrophic heart phenotype is characterized by an abnormal left ventricular (LV) thickening. A hypertrophic phenotype can develop as adaptive response in many different conditions such as aortic stenosis, hypertension, athletic training, infiltrative heart muscle diseases, storage disorders and metabolic disorders. Hypertrophic cardiomyopathy (HCM) is the most frequent primary cardiomyopathy (CMP) and a genetical cause of cardiac hypertrophy. It requires the exclusion of any other cause of LV hypertrophy. Cardiac magnetic resonance (CMR) is a comprehensive imaging technique that allows a detailed evaluation of myocardial diseases. It provides reproducible measurements and myocardial tissue characterization. In clinical practice CMR is increasingly used to confirm the presence of ventricular hypertrophy, to detect the underlying cause of the phenotype and more recently as an efficient prognostic tool. This article aims to provide a detailed overview of the applications of CMR in the setting of hypertrophic heart phenotype and its role in the diagnostic workflow of such condition.

Integrative network analysis interweaves the missing links in cardiomyopathy diseasome

Cardiomyopathies are progressive disease conditions that give rise to an abnormal heart phenotype and are a leading cause of heart failures in the general population. These are complex diseases that show co-morbidity with other diseases. The molecular interaction network in the localised disease neighbourhood is an important step toward deciphering molecular mechanisms underlying these complex conditions. In this pursuit, we employed network medicine techniques to systematically investigate cardiomyopathy's genetic interplay with other diseases and uncover the molecular players underlying these associations. We predicted a set of candidate genes in cardiomyopathy by exploring the DIAMOnD algorithm on the human interactome. We next revealed how these candidate genes form association across different diseases and highlighted the predominant association with brain, cancer and metabolic diseases. Through integrative systems analysis of molecular pathways, heart-specific mouse knockout data and disease tissue-specific transcriptomic data, we screened and ascertained prominent candidates that show abnormal heart phenotype, including NOS3, MMP2 and SIRT1. Our computational analysis broadens the understanding of the genetic associations of cardiomyopathies with other diseases and holds great potential in cardiomyopathy research.

Case report: Genomic screening for inherited cardiac conditions in Ecuadorian mestizo relatives: Improving familial diagnose

INTRODUCTION

Genomic screening is an informative and helpful tool for the clinical management of inherited conditions such as cardiac diseases. Cardiac-inherited diseases are a group of disorders affecting the heart, its system, function, and vasculature. Among the cardiac inherited abnormalities, one of the most common is Wolff-Parkinson-White syndrome. Similarly, hypertrophic cardiomyopathy is another common autosomal dominant inherited cardiac disease. Hypertrophic cardiomyopathy is associated with an increased incidence of Wolff-Parkinson-White syndrome; reports have suggested that it could be caused by a mutation in the protein-coding gene PRKAG2, which encodes a subunit of the AMP-activated protein kinase.

CASE PRESENTATION

A 37-year-old Ecuadorian male (Subject A) with familiar history of bradycardia, cardiac pacemaker implantation, and undiagnosed cardiac conditions began with episodes of tachycardia, dizziness, shortness of breath, and a feeling of fainting. He was diagnosed with hypertrophic myocardiopathy and Wolff Parkinson White preexcitation syndrome. Furthermore, his cousin's son, an 18-year-old Ecuadorian male (Subject B), started suffering from migraine and tachycardia at any time of the day. He was diagnosed with hypertrophic myocardiopathy; his electrocardiogram showed a systolic overload. Next-generation sequencing and ancestry analyses were performed. A c.905G>A p.(Arg302Gln) mutation in the gene PRKAG2 and a mainly European composition were identified in both subjects.

CONCLUSION

Genetic testing is a valuable tool as it can provide important information regarding a disease, including its cause and consequences, not only for single individuals but to identify at-risk relatives. Furthermore, NGS results could guide the physician into targeted therapy. In the present case report, a missense pathogenic Arg302Gln mutation in the PRKAG2 gene has been identified in two related Ecuadorian Subjects diagnosed with hypertrophic myocardiopathy and Wolff-Parkinson-White. The variant has not been reported in Latin America; hence, this is the first report of the Arg302Gln mutation in the PRKAG2 gene in mestizo Ecuadorian subjects with mainly European ancestry components.

Transcriptome Profile Identifies Actin as an Essential Regulator of Cardiac Myosin Binding Protein C3 Hypertrophic Cardiomyopathy in a Zebrafish Model

Variants in cardiac myosin-binding protein C (cMyBP-C) are the leading cause of inherited hypertrophic cardiomyopathy (HCM), demonstrating the key role that cMyBP-C plays in the heart’s contractile machinery. To investigate the c-MYBPC3 HCM-related cardiac impairment, we generated a zebrafish mypbc3-knockout model. These knockout zebrafish displayed significant morphological heart alterations related to a significant decrease in ventricular and atrial diameters at systolic and diastolic states at the larval stages. Immunofluorescence staining revealed significant hyperplasia in the mutant’s total cardiac and ventricular cardiomyocytes. Although cardiac contractility was similar to the wild-type control, the ejection fraction was significantly increased in the mypbc3 mutants. At later stages of larval development, the mutants demonstrated an early cardiac phenotype of myocardium remodeling, concurrent cardiomyocyte hyperplasia, and increased ejection fraction as critical processes in HCM initiation to counteract the increased ventricular myocardial wall stress. The examination of zebrafish adults showed a thickened ventricular cardiac wall with reduced heart rate, swimming speed, and endurance ability in both the mypbc3 heterozygous and homozygous groups. Furthermore, heart transcriptome profiling showed a significant downregulation of the actin-filament-based process, indicating an impaired actin cytoskeleton organization as the main dysregulating factor associated with the early ventricular cardiac hypertrophy in the zebrafish mypbc3 HCM model.

Beta Blockers can mask not only Hypoglycemia, but also Hypotension

Background:

Beta-adrenergic (β-AR) receptor blockers (BBs) are an essential class of drugs as they have numerous indications. On the other hand, they have numerous unwanted effects which decrease the compliance, adherence, and persistence of this very useful group of drugs.

Objective:

The paper aims to analyze the possibility that an unnoticed side effect may contribute to a less favorable pharmacologic profile of BBs, e.g., a diminished reaction to a sudden fall in BP.

Methods:

We searched two medical databases for abstracts and citations (Medline and SCOPUS). Moreover, we searched the internet for drug prescription leaflets (of the individual BBs).

Results:

Whichever cause of stress is considered, the somatic manifestations of stress will be (partially) masked if a patient takes BB. Stress–induced hypercatecholaminemia acts on β-AR of cardiomyocytes; it increases heart rate and contractility, effects suppressed by BBs. The answers of the organism to hypoglycemia and hypotension share the main mechanisms such as sympathetic nervous system activation and hypercatecholaminemia. Thus, there is a striking analogy: BBs can cover up symptoms of both hypoglycemia (which is widely known) and of hypotension (which is not recognized). It is widely known that BBs can cause hypotension. However, they can also complicate recovery by spoiling the defense mechanisms in hypotension as they interfere with the crucial compensatory reflex to increase blood pressure in hypotension.

Conclusion:

Beta blockers can cause hypotension, mask it, and make recovery more difficult. This is clinically important and deserves to be more investigated and probably to be stated as a warning.

Novel Hypertrophic Cardiomyopathy Diagnosis Index Using Deep Features and Local Directional Pattern Techniques

Hypertrophic cardiomyopathy (HCM) is a genetic disorder that exhibits a wide spectrum of clinical presentations, including sudden death. Early diagnosis and intervention may avert the latter. Left ventricular hypertrophy on heart imaging is an important diagnostic criterion for HCM, and the most common imaging modality is heart ultrasound (US). The US is operator-dependent, and its interpretation is subject to human error and variability. We proposed an automated computer-aided diagnostic tool to discriminate HCM from healthy subjects on US images. We used a local directional pattern and the ResNet-50 pretrained network to classify heart US images acquired from 62 known HCM patients and 101 healthy subjects. Deep features were ranked using Student’s t-test, and the most significant feature (SigFea) was identified. An integrated index derived from the simulation was defined as 100·log10(SigFea/2) in each subject, and a diagnostic threshold value was empirically calculated as the mean of the minimum and maximum integrated indices among HCM and healthy subjects, respectively. An integrated index above a threshold of 0.5 separated HCM from healthy subjects with 100% accuracy in our test dataset.

Global PIEZO1 Gain-of-Function Mutation Causes Cardiac Hypertrophy and Fibrosis in Mice

PIEZO1 is a subunit of mechanically-activated, nonselective cation channels. Gain-of-function PIEZO1 mutations are associated with dehydrated hereditary stomatocytosis (DHS), a type of anaemia, due to abnormal red blood cell function. Here, we hypothesised additional effects on the heart. Consistent with this hypothesis, mice engineered to contain the M2241R mutation in PIEZO1 to mimic a DHS mutation had increased cardiac mass and interventricular septum thickness at 8–12 weeks of age, without altered cardiac contractility. Myocyte size was greater and there was increased expression of genes associated with cardiac hypertrophy (Anp, Acta1 and β-MHC). There was also cardiac fibrosis, increased expression of Col3a1 (a gene associated with fibrosis) and increased responses of isolated cardiac fibroblasts to PIEZO1 agonism. The data suggest detrimental effects of excess PIEZO1 activity on the heart, mediated in part by amplified PIEZO1 function in cardiac fibroblasts.

Relation between lymphocyte to monocyte ratio and survival in patients with hypertrophic cardiomyopathy: a retrospective cohort study

Background

The lymphocyte-to-monocyte ratio (LMR) has been proposed as a novel prognostic factor in malignancies and cardiovascular diseases. Our study aimed to ascertain whether LMR is a useful biomarker in discriminating the hypertrophic cardiomyopathy (HCM) patients at higher risk of all-cause mortality.

Methods

This retrospective study consisted of 354 adult HCM patients. Cox's proportional hazards regression models were used to analyze the association between LMR and all-cause mortality. Smooth curve fitting was conducted to explore the linear relationship between LMR and all-cause mortality.

Results

During the follow-up, 44 patients reached the study endpoint. The all-cause mortality rate was 7.3 per 100 person-years in the first tertile and decreased across the three tertiles of LMR. With the first tertile as reference, adjusted hazard ratios (HR) for all-cause mortality were 0.43 for the second tertile (95% CI [0.20-0.91], p = 0.027) and 0.39 for the third tertile (95% CI [0.17-0.90], p = 0.028), respectively. Smooth curve fitting exhibited a nonlinear relationship between LMR values and all-cause mortality. For LMR < 6.5, per SD increase resulted in a significantly decreased risk of all-cause mortality by 62% (HR: 0.38, 95% CI [0.21-0.68]). For LMR ≥ 6.5, the all-cause mortality risk did not progressively increase. Stratified and subgroup analyses revealed similar results to the main analyses,andE-value analysis suggested robustness to unmeasured confounding.

Conclusions

The study demonstrated that LMR was an independent predictor of all-cause mortality in HCM patients, and LMR may be useful for identifying HCM patients at high mortality risk.

The mechanics of the heart: zooming in on hypertrophic cardiomyopathy and cMyBP-C

Hypertrophic cardiomyopathy (HCM), a disease characterized by cardiac muscle hypertrophy and hypercontractility, is the most frequently inherited disorder of the heart. HCM is mainly caused by variants in genes encoding proteins of the sarcomere, the basic contractile unit of cardiomyocytes. The most frequently mutated among them is MYBPC3, which encodes cardiac myosin-binding protein C (cMyBP-C), a key regulator of sarcomere contraction. In this review, we summarize clinical and genetic aspects of HCM and provide updated information on the function of the healthy and HCM sarcomere, as well as on emerging therapeutic options targeting sarcomere mechanical activity. Building on what is known about cMyBP-C activity, we examine different pathogenicity drivers by which MYBPC3 variants can cause disease, focussing on protein haploinsufficiency as a common pathomechanism also in nontruncating variants. Finally, we discuss recent evidence correlating altered cMyBP-C mechanical properties with HCM development.

Humans and machines in biomedical knowledge curation: hypertrophic cardiomyopathy molecular mechanisms' representation

Background

Biomedical knowledge is dispersed in scientific literature and is growing constantly. Curation is the extraction of knowledge from unstructured data into a computable form and could be done manually or automatically. Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease, with genotype–phenotype associations still incompletely understood. We compared human- and machine-curated HCM molecular mechanisms’ models and examined the performance of different machine approaches for that task.

Results

We created six models representing HCM molecular mechanisms using different approaches and made them publicly available, analyzed them as networks, and tried to explain the models’ differences by the analysis of factors that affect the quality of machine-curated models (query constraints and reading systems’ performance). A result of this work is also the Interactive HCM map, the only publicly available knowledge resource dedicated to HCM. Sizes and topological parameters of the networks differed notably, and a low consensus was found in terms of centrality measures between networks. Consensus about the most important nodes was achieved only with respect to one element (calcium). Models with a reduced level of noise were generated and cooperatively working elements were detected. REACH and TRIPS reading systems showed much higher accuracy than Sparser, but at the cost of extraction performance. TRIPS proved to be the best single reading system for text segments about HCM, in terms of the compromise between accuracy and extraction performance.

Conclusions

Different approaches in curation can produce models of the same disease with diverse characteristics, and they give rise to utterly different conclusions in subsequent analysis. The final purpose of the model should direct the choice of curation techniques. Manual curation represents the gold standard for information extraction in biomedical research and is most suitable when only high-quality elements for models are required. Automated curation provides more substance, but high level of noise is expected. Different curation strategies can reduce the level of human input needed. Biomedical knowledge would benefit overwhelmingly, especially as to its rapid growth, if computers were to be able to assist in analysis on a larger scale.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13040-021-00279-2.

CSRP3, p.Arg122*, is responsible for hypertrophic cardiomyopathy in a Chinese family

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a hereditary disease manifested by a thickened ventricular wall. Cysteine and glycine-rich protein 3 (CSRP3), the gene encoding muscle LIM protein, is important for initiating hypertrophic gene expression. The mutation of CSRP3 causes dilated cardiomyopathy or HCM.

METHODS

In the present study, we enrolled a Chinese family with HCM across three generations. Whole-exome sequencing (WES) was performed in the proband to detect the candidate genes of the family. Sanger sequencing was performed for mutational analysis and confirmation of cosegregation.

RESULTS

Through histopathological and imaging examinations, an obvious left ventricular hypertrophy was found in the proband. After WES data filtering, bioinformatic prediction and co-segregation analysis, a nonsense mutation (NM_003476.5:c.364C>T; NP_003467.1:p.Arg122*) of CSRP3 was identified in this family. This variant was predicted to be disease-causing and resulted in a truncated protein.

CONCLUSIONS

This is the first HCM family case of CSRP3 (p.Arg122*) variation in Asia. The finding here not only contributes to the genetic diagnosis and counseling of the family, but also provides a new case with detailed phenotypes that may be caused by the CSRP3 variant.

Hypertrophic Cardiomyopathy Diagnosed on Point-of-Care Echocardiogram in an Elderly Patient With Syncope

A bedside echocardiogram in the emergency department can provide a wealth of information about a patient’s hemodynamic status, anatomical structures, and response to medical interventions. This readily available tool can drastically guide management within minutes as soon as the undifferentiated critically ill patient enters the hospital. In this clinical scenario, we report a case of hypertrophic obstructive cardiomyopathy (HOCM) that was diagnosed for the first time in an elderly male, who was brought to the emergency department after a syncopal episode, utilizing bedside ultrasound and it highlights the significance of considering a broad differential.

The Emerging Role of Epigenetics in Therapeutic Targeting of Cardiomyopathies

Cardiomyopathies (CMPs) are a heterogeneous group of myocardial diseases accountable for the majority of cases of heart failure (HF) and/or sudden cardiac death (SCD) worldwide. With the recent advances in genomics, the original classification of CMPs on the basis of morphological and functional criteria (dilated (DCM), hypertrophic (HCM), restrictive (RCM), and arrhythmogenic ventricular cardiomyopathy (AVC)) was further refined into genetic (inherited or familial) and acquired (non-inherited or secondary) forms. Despite substantial progress in the identification of novel CMP-associated genetic variations, as well as improved clinical recognition diagnoses, the functional consequences of these mutations and the exact details of the signaling pathways leading to hypertrophy, dilation, and/or contractile impairment remain elusive. To date, global research has mainly focused on the genetic factors underlying CMP pathogenesis. However, growing evidence shows that alterations in molecular mediators associated with the diagnosis of CMPs are not always correlated with genetic mutations, suggesting that additional mechanisms, such as epigenetics, may play a role in the onset or progression of CMPs. This review summarizes published findings of inherited CMPs with a specific focus on the potential role of epigenetic mechanisms in regulating these cardiac disorders.

Effects of Bergamot Polyphenols on Mitochondrial Dysfunction and Sarcoplasmic Reticulum Stress in Diabetic Cardiomyopathy

Cardiovascular disease is the leading cause of death and disability in the Western world. In order to safeguard the structure and the functionality of the myocardium, it is extremely important to adequately support the cardiomyocytes. Two cellular organelles of cardiomyocytes are essential for cell survival and to ensure proper functioning of the myocardium: mitochondria and the sarcoplasmic reticulum. Mitochondria are responsible for the energy metabolism of the myocardium, and regulate the processes that can lead to cell death. The sarcoplasmic reticulum preserves the physiological concentration of the calcium ion, and triggers processes to protect the structural and functional integrity of the proteins. The alterations of these organelles can damage myocardial functioning. A proper nutritional balance regarding the intake of macronutrients and micronutrients leads to a significant improvement in the symptoms and consequences of heart disease. In particular, the Mediterranean diet, characterized by a high consumption of plant-based foods, small quantities of red meat, and high quantities of olive oil, reduces and improves the pathological condition of patients with heart failure. In addition, nutritional support and nutraceutical supplementation in patients who develop heart failure can contribute to the protection of the failing myocardium. Since polyphenols have numerous beneficial properties, including anti-inflammatory and antioxidant properties, this review gathers what is known about the beneficial effects of polyphenol-rich bergamot fruit on the cardiovascular system. In particular, the role of bergamot polyphenols in mitochondrial and sarcoplasmic dysfunctions in diabetic cardiomyopathy is reported.

Assesment of Markers of Endothelial Dysfunction and Myocardial Stress in Patients with Hypertrophic Cardyomyopathy

Aim. To study the level of serum biomarkers of endothelial dysfunction and myocardial stress in patients with various types of hypertrophic cardiomyopathy (HCM).

Material and Methods. 48 patients with hypertrophic cardiomyopathy (27 men and 21 women) were examined, the mean age was 54±13 years. The patients were divided into two groups according to the course options: group 1 - symptomatic stable course (n=14); group 2 - progressive course of symptomatic HCM (n=34). In accordance with the assigned tasks, all patients underwent determination of biological markers of neurohumoral systems in blood serum using immunofluorescence assay analysis: N-terminal fragment of brain natriuretic peptide (NT-proBNP), von Willebrand factor (vWF), endothelin-1, E-selectin with subsequent evaluation and correlation of results with clinical and instrumental characteristics of patients. When performing echocardiography following parameters were assessed: dimensions of the heart chambers, the thickness of the interventricular septum, the thickness of the posterior wall of the left ventricle (LV), LV mass, LV mass index, the ratio between LV filling in diastole (peak E) and atrial systole (peak A)-(E/A), relative myocardial thickness index, left atrial volume index.

Results. Both groups showed increased levels of NT-proBNP and endothelin-1. E-selectin and vonWillebrand factor remained within the normal range. There was no statistically significant intergroup difference. There was a correlation between the level of the index of the relative myocardial thickness and the level of NT-proBNP (r=0.30; p=0.04). A correlation was found between the level of the vWF marker and the left atrial volume index (r=0.32; p=0.04). When assessing the association of indicators of intracardiac hemodynamics with other markers (E-selectin and endothelin-1, no statistically significant relationships were found.

Conclusion. In the course of the research, it was found that the high activity of endothelin-1 and NT-proBNP reflects endothelial dysfunction and myocardial stress in patients with HCM, especially in patients with a progressive variant of HCM. However, we did not find any changes in the levels of E-selectin and von Willebrand factor, as well as their intergroup differences. These results require additional studies to assess endothelial dysfunction in patients with HCM.

Cardiac mechanical efficiency is preserved in primary cardiac hypertrophy despite impaired mechanical function

Increased heart size is a major risk factor for heart failure and premature mortality. Although abnormal heart growth subsequent to hypertension often accompanies disturbances in mechano-energetics and cardiac efficiency, it remains uncertain whether hypertrophy is their primary driver. In this study, we aimed to investigate the direct association between cardiac hypertrophy and cardiac mechano-energetics using isolated left-ventricular trabeculae from a rat model of primary cardiac hypertrophy and its control. We evaluated energy expenditure (heat output) and mechanical performance (force length work production) simultaneously at a range of preloads and afterloads in a microcalorimeter, we determined energy expenditure related to cross-bridge cycling and Ca²⁺ cycling (activation heat), and we quantified energy efficiency. Rats with cardiac hypertrophy exhibited increased cardiomyocyte length and width. Their trabeculae showed mechanical impairment, evidenced by lower force production, extent and kinetics of shortening, and work output. Lower force was associated with lower energy expenditure related to Ca²⁺ cycling and to cross-bridge cycling. However, despite these changes, both mechanical and cross-bridge energy efficiency were unchanged. Our results show that cardiac hypertrophy is associated with impaired contractile performance and with preservation of energy efficiency. These findings provide direction for future investigations targeting metabolic and Ca²⁺ disturbances underlying cardiac mechanical and energetic impairment in primary cardiac hypertrophy.

Prognostic nutritional index and the risk of mortality in patients with hypertrophic cardiomyopathy

AIMS

Nutritional status has been related to clinical outcomes in patients with cardiovascular diseases. The prognostic impact of poor nutritional status in hypertrophic cardiomyopathy (HCM) is not clearly understood. The aim of the present study is to investigate the prognostic value of prognostic nutritional index (PNI), calculated from serum albumin level and total lymphocyte count, in HCM patients.

METHODS

A total of 393 HCM patients in a tertiary medical centre were enrolled. The primary and secondary endpoints were all-cause mortality and cardiovascular death. The association between PNI and endpoints was analysed.

RESULTS

During a mean follow-up duration of 4.8 years, patients with high PNI values (PNI ≥ 48.8) had significantly lower incidence of all-cause mortality (9.3% vs. 33.1%, P < 0.001) and cardiovascular death (7.1% vs. 21.0%, P < 0.001). After adjusting for potential confounders, PNI was independently associated with all-cause mortality and cardiovascular death (hazard ratio per 1 SD increase: 0.46 [95% CI: 0.34-0.62, P < 0.001] and 0.44 [95% CI: 0.30-0.63, P < 0.001]). In subgroup analysis stratified by age, gender, New York Heart Association class, atrial fibrillation, estimated glomerular filtration rate, left ventricular ejection fraction or left ventricular outflow tract obstruction, PNI was consistently related to mortality.

CONCLUSIONS

PNI is an independent prognostic factor for mortality in patients with HCM.