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In this Perspective, I discuss the limitations of a soft primary endpoint that is used in some of the recent randomized phase II/III clinical trials. Unfortunately, many clinicians and investigators do not interpret the data critically to recognize the limitations of such findings. I advise against over-interpreting the effects of an intervention on a soft primary endpoint. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, affecting 1:200 to 1:500 individuals worldwide. Guidelines on the diagnosis and management of HCM have been recently published by the European Society of Cardiology (ESC) and American societies. The ESC guidelines cover a broad range of cardiomyopathies, including HCM, with 119 recommendations, whereas the American guidelines focus exclusively on HCM with 141 specific recommendations. Both guidelines emphasize a comprehensive diagnostic approach, including imaging and genetic testing, but differ in some specific aspects. For example, sudden cardiac death (SCD) risk assessment is a primary point of divergence. The ESC guidelines advocate for the use of a validated Risk-SCD calculator, while the American guidelines rely on specific risk markers for individualized risk evaluation. Management strategies also vary: both guidelines prioritize beta-blockers and calcium channel blockers in patients with resting or provocable left ventricular outflow tract (LVOT) obstruction. If beta-blockers (or verapamil/diltiazem) are ineffective, either disopyramide or the myosin inhibitor mavacamten may be an option with slightly different indications among the two guidelines. Septal reduction therapy is recommended in ESC guidelines for symptomatic patients with significant LVOT gradients, while American guidelines suggest earlier myectomy for certain clinical factors and emphasize shared decision-making. The ESC guidelines recommend sequential atrioventricular pacing and dual-chamber defibrillators for reducing LVOT gradients. The American guidelines focus on genetic testing for risk assessment and suggest periodic cardiac magnetic resonance imaging. This paper provides a detailed comparison of these guidelines, highlighting key differences and areas needing further research and expert debate. [ABSTRACT FROM AUTHOR]

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac condition affecting ∼1 in 500 and exhibits marked genetic heterogeneity. Previously published in 2019, 57 HCM-associated genes were curated providing the first systematic evaluation of gene-disease validity. The authors report work by the Clinical Genome Resource Hereditary Cardiovascular Disease (HCVD) Gene Curation Expert Panel (GCEP) to reappraise the clinical validity of previously curated and new putative HCM genes. The Clinical Genome Resource systematic gene curation framework was used to reclassify the gene-disease relationships for HCM and related syndromic entities involving left ventricular hypertrophy. Genes previously curated were included if their classification was not definitive, and if the time since curation was >2 to 3 years. New genes with literature assertions for HCM were included for initial evaluation. Existing genes were curated for new inheritance patterns where evidence existed. Curations were presented on twice monthly calls, with the HCVD GCEP composed of 29 individuals from 21 institutions across 6 countries. Thirty-one genes were recurated and an additional 5 new potential HCM-associated genes were curated. Among the recurated genes, 17 (55%) genes changed classification: 1 limited and 4 disputed (from no known disease relationship), 9 disputed (from limited), and 3 definitive (from moderate). Among these, 3 (10%) genes had a clinically relevant upgrade, including TNNC1, a 9th sarcomere gene with definitive HCM association. With new evidence, 2 genes were curated for multiple inheritance patterns (TRIM63, disputed for autosomal dominant but moderate for autosomal recessive; ALPK3, strong for autosomal dominant and definitive for recessive). CSRP3 was curated for a semidominant mode of inheritance (definitive). Nine (29%) genes were downgraded to disputed, further discouraging clinical reporting of variants in these genes. Five genes recently reported to cause HCM were curated: RPS6KB1 and RBM20 (limited), KLHL24 and MT-TI (moderate), and FHOD3 (definitive). We report 29 genes with definitive, strong, or moderate evidence of causation for HCM or isolated left ventricular hypertrophy, including sarcomere, sarcomere-associated, and syndromic conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

Cardiomyopathies are primary disorders of the heart muscle. Three key phenotypes have been defined, based on morphology and arrhythmia burden: hypertrophic cardiomyopathy (HCM), with thickened heart muscle and diastolic dysfunction; dilated cardiomyopathy (DCM), with left ventricular enlargement and systolic dysfunction; and arrhythmogenic cardiomyopathy (ACM), with right, left, or biventricular involvement and arrhythmias out of proportion to systolic dysfunction. Genetic discoveries of the molecular basis of disease are paving the way for greater precision in diagnosis and management and revealing mechanisms that account for distinguishing clinical features. This deeper understanding has propelled the development of new treatments for cardiomyopathies: disease-specific, mechanistically based medicines that counteract pathophysiology, and emergent gene therapies that aim to intercept disease progression and restore cardiac physiology. Together, these discoveries have advanced fundamental insights into cardiac biology and herald a new era for patients with cardiomyopathy. Research on the molecular genetic basis for cardiomyopathies, primary heart muscle disorders, has made significant progress in the past decades. This article reviews current understanding of the genetic underpinnings of inherited cardiomyopathies and discusses future therapeutic opportunities. [ABSTRACT FROM AUTHOR]

Background: Primary cardiomyopathies are major causes of heart failure, placing a substantial burden on both individuals and society. Revealing its genetic profiles can lead to a better understanding of the mechanism and is critical for disease prevention and treatment. Method: Primary cardiomyopathy patients were enrolled and whole exome sequence was conducted to analyze their genetic profiles. Retrospective clinical information extraction and analysis of sequence data were implemented. Results: A total of 77 primary cardiomyopathy patients were enrolled, comprising 65 patients with dilated cardiomyopathy (DCM) and 12 with hypertrophic cardiomyopathy (HCM). Among the DCM patients, 13 variants classified as pathogenic (P) or likely pathogenic (LP) were identified in 12 patients (18.46%), predominantly in genes associated with the nuclear envelope and sarcomere. Among HCM patients, 6 P/LP variants were discovered in 6 (50%) patients. Taking variants of uncertain significance (VUS) into consideration, an analysis of the association between the number of variants carried by patients and their clinical characteristics revealed that DCM patients with more than one variant had a higher proportion of hyperuricemia. Conclusions: We map a comprehensive profile of primary cardiomyopathy in Chinese population and, for the first time, identify a possible association between hyperuricemia and the number of genetic variants carried by DCM patients. [ABSTRACT FROM AUTHOR]

Background: Intracardiac leiomyomatosis (ICL) is an uncommon condition characterized by the proliferation of intravascular tissue within the veins, leading to the development of tumor emboli. This can pose a significant threat to life when the tumor invades cardiac structures. The diagnostic process for this condition is complex and presents considerable challenges. Case presentation: We report a case of a 38-year-old female patient whose pulmonary artery computed tomography (CT) revealed low density structure in the branches of the pulmonary artery. Echocardiography revealed a mobile tumor within the right heart chambers and pulmonary trunks as well as characteristic thickening of the ventricular septum consistent with hypertrophic cardiomyopathy (HCM). Magnetic resonance imaging (MRI) revealed a mass in the right anterior uterine wall, extending to the inferior vena cava (IVC) and right iliac vein. Post-surgery histopathological analysis confirmed a diagnosis of intravenous leiomyomatosis (IVL). Conclusions: When IVL affects the heart, echocardiography is the best diagnostic tool for detecting the disease. CT and MRI are essential in identifying the location and extent of the tumor, as well as in evaluating prognosis. [ABSTRACT FROM AUTHOR]

Regulators of G protein signaling (RGS) proteins fine-tune signaling via heterotrimeric G proteins to maintain physiologic homeostasis in various organ systems of the human body including the brain, kidney, heart, and vasculature. Impaired regulation of G protein signaling by RGS proteins is implicated in the pathogenesis of several human diseases including various forms of cardiomyopathy such as hypertrophic cardiomyopathy and dilated cardiomyopathy (DCM). Both genetic and nongenetic changes that impinge on G protein signaling in cardiomyocytes are implicated in the etiology of DCM, and there is accumulating evidence that such genetic and nongenetic changes affecting G protein signaling in cell types other than cardiomyocytes could serve as a DCM trigger in humans. This review discusses and highlights mammalian RGS proteins and their roles in cardiac physiology and disease, with a specific focus on the current understanding of the etiology of DCM and the pathogenic roles of RGS proteins that are prominently expressed in the cardiovascular system. Growing evidence suggests that defects in G protein regulation by RGS proteins in the cardiovascular system likely contribute to cardiomyocyte structural damage and decreased contractile function that hallmark DCM. Further studies that enhance the understanding of the dynamics of G protein regulation by RGS proteins in several cell types in the myocardium and the vasculature are critical to gaining more insight into the etiology of DCM and heart failure, and to the identification of novel therapeutic targets. [ABSTRACT FROM AUTHOR]

Pediatric cardiology fellows receive limited training on delivering serious news. This is a teachable skill through simulation-based communication. While studies have shown the use of communication courses in pediatrics, there have been none in pediatric cardiology. Pediatric cardiologists recognize the importance of good communication and desire further development of these skills. Based on an internal needs assessment, three cases were developed; fetal hypoplastic left heart syndrome, teenager with new hypertrophic cardiomyopathy, and young-adult with Fontan failure. A 4-h simulation course using evidence-based methods to teach delivering serious news was designed, consisting of a didactic session, case demonstration and small group case-based encounters with simulated patients. Trainees completed standardized pre/post-course surveys to assess perception of skill and preparedness. Paired survey responses were compared. Six pediatric cardiology fellows participated. Only 33% had received formal training in delivering serious news and 17% in techniques of responding to patient's emotions. The proportion of participants who felt good about their ability to deliver serious news and deal with a family's emotions increased from 0 to 83%. The proportion of participants who felt prepared to provide serious news about a patient's illness increased from 17 to 67%. Given the small number of participants, results were not statistically significant. All participants felt that the course was valuable in improving communication skills. A formal communication course increased perception of skill and preparedness among trainees. We provide an evidence-based framework and clinical cases for delivering serious news in pediatric cardiology, which is generalizable to other training programs. [ABSTRACT FROM AUTHOR]

We report on a sporadic patient suffering Leigh syndrome characterized by bilateral lesions in the lenticular nuclei and spastic dystonia, intellectual disability, sensorineural deafness, hypertrophic cardiomyopathy, exercise intolerance, and retinitis pigmentosa. Complete sequencing of mitochondrial DNA revealed the heteroplasmic nucleotide change m.15635T>C affecting a highly conserved amino acid position (p.Ser297Pro) in the cytochrome b (MT-CYB) gene on a haplogroup K1c1a background, which includes a set of four non-synonymous polymorphisms also present in the same gene. Biochemical studies documented respiratory chain impairment due to complex III defect. This variant fulfils the criteria for being pathogenic and was previously reported in a sporadic case of fatal neonatal polyvisceral failure. [ABSTRACT FROM AUTHOR]

Background/Objectives: Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. The most frequently mutated genes encode proteins of the thick filament of the sarcomere, while mutations in thin-filament genes are rare findings in HCM cohorts. Recent studies have revealed distinct mechanisms of disease development linked to thin-filament mutations, highlighting the need for further investigation into this rare subgroup. Methods: A total of 82 adult patients with sarcomere-positive HCM were enrolled. Baseline characteristics and nearly five years of follow-up data from 15 patients with thin-filament mutations were analyzed and compared with those from 67 patients with thick-filament mutations and findings from other studies. Results: Compared to thick-filament HCM patients, individuals with thin-filament mutations exhibited significantly lower maximum left ventricular wall thickness, as measured by both echocardiography (p = 0.024) and cardiac magnetic resonance (p = 0.006), showed more rapid progression to advanced heart failure (HR = 5.6, p = 0.018), and less often underwent septal reduction therapy (p = 0.025). None of the thin-filament HCM patients experienced malignant arrhythmic events. Conclusions: In adults, thin-filament HCM is associated with a 'thinner' phenotype and a more rapid progression to advanced heart failure compared to thick-filament HCM. Data on a higher risk of malignant arrhythmias in thin-filament HCM remain controversial between studies and rather depend on the age of onset and genotype in each particular family. [ABSTRACT FROM AUTHOR]

Cardiac magnetic resonance imaging (CMR) is an exciting noninvasive imaging modality with increasing utilization in the field of cardiovascular medicine. In conjunction with echocardiogram, computed tomography, and invasive therapies, CMR has provided exceptional capability to further evaluate complex clinical cardiac conditions. CMR provides both anatomical and physiological information of a variety of tissue types, without the need for ionizing radiation. This article aims to first review basic principles of CMR and later discuss MRI's role in diagnosis of cardiomyopathy and treatment implications. [ABSTRACT FROM AUTHOR]

The purpose of the cardiac portion of the preparticipation physical evaluation is to identify potential health risks in young athletes, particularly sudden cardiac death. The preparticipation evaluation begins with a detailed screening questionnaire. Sudden cardiac death in athletes is considered rare, but the incidence in athletes is higher than in the general population. Leading causes of sudden cardiac death include hypertrophic cardiomyopathy, coronary artery anomalies, myocarditis, arrhythmogenic right ventricular cardiomyopathy, and aortic dissection. It also can be due to ventricular fibrillation, sometimes preceded by ventricular tachycardia. Electrocardiogram results may be abnormal in athletes who are at risk for sudden cardiac death, but diagnosis is made using cardiac imaging. Guidelines exist with recommendations for return to play for athletes who are at risk for sudden cardiac death. [ABSTRACT FROM AUTHOR]

Aims Myocardial disarray, an early feature of hypertrophic cardiomyopathy (HCM) and a substrate for ventricular arrhythmia, is poorly characterized in pre-hypertrophic sarcomeric variant carriers (SARC+LVH−). Using diffusion tensor cardiac magnetic resonance (DT-CMR) we assessed myocardial disarray and fibrosis in both SARC+LVH− and HCM patients and evaluated the relationship between microstructural alterations and electrocardiographic (ECG) parameters associated with arrhythmic risk. Methods and results Sixty-two individuals (24 SARC+LVH−, 24 HCM, and 14 matched controls) were evaluated with multi-parametric CMR including stimulated echo acquisition mode DT-CMR, and blinded quantitative 12-lead ECG analysis. Mean diastolic fractional anisotropy (FA) was reduced in HCM compared with SARC+LVH− and controls (0.49 ± 0.05 vs. 0.52 ± 0.04 vs. 0.53 ± 0.04, P = 0.009), even after adjustment for differences in extracellular volume (ECV) (P = 0.038). Both HCM and SARC+LVH− had segments with significantly reduced diastolic FA relative to controls (54 vs. 25 vs. 0%, P = 0.002). Multiple repolarization parameters were prolonged in HCM and SARC+LVH−, with corrected JT interval (JTc) being most significant (354 ± 42 vs. 356 ± 26 vs. 314 ± 26 ms, P = 0.002). Among SARC+LVH−, JTc duration correlated negatively with mean diastolic FA (r = −0.6, P = 0.002). In HCM, the JTc interval showed a stronger association with ECV (r = 0.6 P = 0.019) than with mean diastolic FA (r = −0.1 P = 0.72). JTc discriminated SARC+LVH− from controls [area under the receiver operator curve 0.88, confidence interval 0.76–1.00, P < 0.001], and in HCM correlated with the European Society of Cardiology HCM sudden cardiac death risk score (r = 0.5, P = 0.014). Conclusion Low diastolic FA, suggestive of myocardial disarray, is present in both SARC+LVH− and HCM. Low FA and raised ECV were associated with repolarization prolongation. Myocardial disarray assessment using DT-CMR and repolarization parameters such as the JTc interval demonstrate significant potential as markers of disease activity in HCM. [ABSTRACT FROM AUTHOR]