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BACKGROUND: LMNA (lamin A/C)-related dilated cardiomyopathy is a rare genetic cause of heart failure. In a phase 2 trial and long-term extension, the selective p38a MAPK (mitogen-activated protein kinase) inhibitor, ARRY-371797 (PF-07265803), was associated with an improved 6-minute walk test at 12 weeks, which was preserved over 144 weeks. REALM-DCM (NCT03439514) was a phase 3, randomized, double-blind, placebo-controlled trial in patients with symptomatic LMNA-related dilated cardiomyopathy. Patients with confirmed LMNA variants, New York Heart Association class II/III symptoms, left ventricular ejection fraction =50%, implanted cardioverter-defibrillator, and reduced 6-minute walk test distance were randomized to ARRY-371797 400 mg twice daily or placebo. The primary outcome was a change from baseline at week 24 in the 6-minute walk test distance using stratified Hodges-Lehmann estimation and the van Elteren test. Secondary outcomes using similar methodology included change from baseline at week 24 in the Kansas City Cardiomyopathy Questionnaire-physical limitation and total symptom scores, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) concentration. Time to a composite outcome of worsening heart failure or all-cause mortality and overall survival were evaluated using Kaplan-Meier and Cox proportional hazards analyses. RESULTS: REALM-DCM was terminated after a planned interim analysis suggested futility. Between April 2018 and October 2022, 77 patients (aged 23-72 years) received ARRY-371797 (n=40) or placebo (n=37). No significant differences (P>0.05) between groups were observed in the change from baseline at week 24 for all outcomes: 6-minute walk test distance (median difference, 4.9 m [95% CI, -24.2 to 34.1]; P=0.82); Kansas City Cardiomyopathy Questionnaire-physical limitation score (2.4 [95% CI, -6.4 to 11.2]; P=0.54); Kansas City Cardiomyopathy Questionnaire-total symptom score (5.3 [95% CI, -4.3 to 14.9]; P=0.48); and NT-proBNP concentration (-339.4 pg/mL [95% CI, -1131.6 to 452.7]; P=0.17). The composite outcome of worsening heart failure or all-cause mortality (hazard ratio, 0.43 [95% CI, 0.11-1.74]; P=0.23) and overall survival (hazard ratio, 1.19 [95% CI, 0.23-6.02]; P=0.84) were similar between groups. No new safety findings were observed. CONCLUSIONS:' Findings from REALM-DCM demonstrated futility without safety concerns. An unmet treatment need remains among patients with LMNA-related dilated cardiomyopathy. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Background: The turnover of cardiac ion channels underlying action potential duration is regulated by ubiquitination. Genome-wide association studies of QT interval identified several single-nucleotide polymorphisms located in or near genes involved in protein ubiquitination. A genetic variant upstream of LITAF (lipopolysaccharide-induced tumor necrosis factor) gene prompted us to determine its role in modulating cardiac excitation. Methods: Optical mapping was performed in zebrafish hearts to determine Ca2+ transients. Live-cell confocal calcium imaging was performed on adult rabbit cardiomyocytes to determine intracellular Ca2+handling. L-type calcium channel (LTCC) current (I Ca,L) was measured using whole-cell recording. To study the effect of LITAF on Cav1.2 (L-type voltage-gated calcium channel 1.2) channel expression, surface biotinylation, and Westerns were performed. LITAF interactions were studied using coimmunoprecipitation and in situ proximity ligation assay. Results: LITAF knockdown in zebrafish resulted in a robust increase in calcium transients. Overexpressed LITAF in 3-week-old rabbit cardiomyocytes resulted in a decrease in I Ca,L and Cavα1c abundance, whereas LITAF knockdown increased I Ca,L and Cavα1c protein. LITAF-overexpressing decreases calcium transients in adult rabbit cardiomyocytes, which was associated with lower Cavα1c levels. In tsA201 cells, overexpressed LITAF downregulated total and surface pools of Cavα1c via increased Cavα1c ubiquitination and its subsequent lysosomal degradation. We observed colocalization between LITAF and LTCC in tsA201 and cardiomyocytes. In tsA201, NEDD (neural precursor cell expressed developmentally downregulated protein) 4-1, but not its catalytically inactive form NEDD4-1-C867A, increased Cavα1c ubiquitination. Cavα1c ubiquitination was further increased by coexpressed LITAF and NEDD4-1 but not NEDD4-1-C867A. NEDD4-1 knockdown abolished the negative effect of LITAF on I Ca,L and Cavα1c levels in 3-week-old rabbit cardiomyocytes. Computer simulations demonstrated that a decrease of I Ca,L current associated with LITAF overexpression simultaneously shortened action potential duration and decreased calcium transients in rabbit cardiomyocytes. Conclusions: LITAF acts as an adaptor protein promoting NEDD4-1–mediated ubiquitination and subsequent degradation of LTCC, thereby controlling LTCC membrane levels and function and thus cardiac excitation. [ABSTRACT FROM AUTHOR]

Background--As DNA sequencing costs decline, genetic testing options have expanded. Whole exome sequencing and whole genome sequencing (WGS) are entering clinical use, posing questions about their incremental value compared with disease-specific multigene panels that have been the cornerstone of genetic testing. Methods and Results--Forty-one patients with hypertrophic cardiomyopathy who had undergone targeted hypertrophic cardiomyopathy genetic testing (either multigene panel or familial variant test) were recruited into the MedSeq Project, a clinical trial of WGS. Results from panel genetic testing and WGS were compared. In 20 of 41 participants, panel genetic testing identified variants classified as pathogenic, likely pathogenic, or uncertain significance. WGS identified 19 of these 20 variants, but the variant detection algorithm missed a pathogenic 18 bp duplication in myosin binding protein C (MYBPC3) because of low coverage. In 3 individuals, WGS identified variants in genes implicated in cardiomyopathy but not included in prior panel testing: a pathogenic protein tyrosine phosphatase, non-receptor type 11 (PTPN11) variant and variants of uncertain significance in integrin-linked kinase (ILK) and filamin-C (FLNC). WGS also identified 84 secondary findings (mean=2 per person, range=0-6), which mostly defined carrier status for recessive conditions. Conclusions--WGS detected nearly all variants identified on panel testing, provided 1 new diagnostic finding, and allowed interrogation of posited disease genes. Several variants of uncertain clinical use and numerous secondary genetic findings were also identified. Whereas panel testing and WGS provided similar diagnostic yield, WGS offers the advantage of reanalysis over time to incorporate advances in knowledge, but requires expertise in genomic interpretation to appropriately incorporate WGS into clinical care. [ABSTRACT FROM AUTHOR]

The article focuses on the trends in cardiovascular system education and training in the U.S. Topics discussed include the future of pediatric cardiology training, the measurement of training outcomes, the environment of the training, the cardiovascular training, and the predicted adult cardiovascular medicine training.

The article projects the future of cardiovascular genomics and genetics in the U.S. Topics discussed include an overview of cardiovascular genetics, the gap of phenotype in precision medicine, the impact of cardiovascular genomics and genetics on health, and the genetic architecture of cardiovascular system.

The article projects the future of cardiovascular treatment options in the U.S. Topics discussed include the concepts of cardiovascular disease and their association with therapy, the target population of cardiovascular community, various drug discovery approaches and their driving factors, and the emergence of different classes of therapeutics.

Background: Researchers routinely evaluate novel biomarkers for incorporation into clinical risk models, weighing tradeoffs between cost, availability, and ease of deployment. For risk assessment in population health initiatives, ideal inputs would be those already available for most patients. We hypothesized that common hematologic markers (eg, hematocrit), available in an outpatient complete blood count without differential, would be useful to develop risk models for cardiovascular events.Methods: We developed Cox proportional hazards models for predicting heart attack, ischemic stroke, heart failure hospitalization, revascularization, and all-cause mortality. For predictors, we used 10 hematologic indices (eg, hematocrit) from routine laboratory measurements, collected March 2016 to May 2017 along with demographic data and diagnostic codes. As outcomes, we used neural network-based automated event adjudication of 1 028 294 discharge summaries. We trained models on 23 238 patients from one hospital in Boston and evaluated them on 29 671 patients from a second one. We assessed calibration using Brier score and discrimination using Harrell's concordance index. In addition, to determine the utility of high-dimensional interactions, we compared our proportional hazards models to random survival forest models.Results: Event rates in our cohort ranged from 0.0067 to 0.075 per person-year. Models using only hematology indices had concordance index ranging from 0.60 to 0.80 on an external validation set and showed the best discrimination when predicting heart failure (0.80 [95% CI, 0.79-0.82]) and all-cause mortality (0.78 [0.77-0.80]). Compared with models trained only on demographic data and diagnostic codes, models that also used hematology indices had better discrimination and calibration. The concordance index of the resulting models ranged from 0.75 to 0.85 and the improvement in concordance index ranged up to 0.072. Random survival forests had minimal improvement over proportional hazards models.Conclusions: We conclude that low-cost, ubiquitous inputs, if biologically informative, can provide population-level readouts of risk. [ABSTRACT FROM AUTHOR]

An editorial is presented which discusses the state-of-the-art strategies to assess the causality of newly identified variants in potential cardiovascular disease genes. It mentions the discovery of numerous disease genes for cardiomyopathies, arrhythmias, aortopathies, and other disorders through genetic and genomic studies which demontsrate complex relationships between genotype and phenotype.

The article presents the case study of a 34-year-old female who is 4 months postpartum after a nocturnal seizure having epileptic-type movements before spontaneously recovering. Topics discussed include Long QT syndrome (LQTS) inherited cardiac condition, Genetic and Molecular Mechanism of LQTS, and correlation between Genotype and Phenotype characteristics of patients suffering from LQTS.

Left ventricular hypertrophy (LVH) typically manifests during or after adolescence in sarcomere mutation carriers at risk for developing hypertrophic cardiomyopathy. Guidelines recommend serial imaging of mutation carriers without LVH (G+/LVH-) to monitor for phenotypic evolution, but the optimal strategy is undefined. Compared with echocardiography (echo), cardiac MRI (CMR) offers improved endocardial visualization and potential to assess scar. However, the incremental advantage offered by CMR for early diagnosis of hypertrophic cardiomyopathy is unclear. Therefore, we systematically compared echo and CMR in G+/LVH- subjects.A total of 40 sarcomere mutation carriers with normal echo wall thickness (<12 mm or z score <2.5 in children) underwent concurrent CMR. Mean age was 21.7±11.1 years, 55% were female. If left ventricular wall thickness seemed nonuniform, the size and location of relatively thickened segments were noted. Late gadolinium enhancement was assessed with CMR. Diagnostic agreement between echo and CMR was good (90%), although CMR measurements of left ventricular wall thickness were ≈19% lower than echo. Four subjects had mild hypertrophy (12.6-14 mm; 2 segments) appreciated by CMR but not echo. No subjects had late gadolinium enhancement. During median 35-month follow-up, 2 subjects developed overt hypertrophic cardiomyopathy, including 1 with mild LVH by CMR at baseline.Echo is unlikely to miss substantial LVH; however, CMR identified mild hypertrophy in ≈10% of mutation carriers with normal echo wall thickness. CMR may be a useful adjunct in hypertrophic cardiomyopathy family screening, particularly in higher risk situations, or if echocardiographic images are suboptimal or suggest borderline LVH. [ABSTRACT FROM AUTHOR]

Background: Rare variants in cardiac ion channel genes are associated with sudden cardiac death in rare primary arrhythmic syndromes; however, it is unknown whether common variation in these same genes may contribute to sudden cardiac death risk at the population level.Methods and Results: We examined the association between 147 single nucleotide polymorphisms (SNPs) (137 tag, 5 noncoding SNPs associated with QT interval duration, and 5 nonsynonymous SNPs) in 5 cardiac ion channel genes, KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2, and sudden and/or arrhythmic death in a combined nested case-control analysis among 516 cases and 1522 matched control subjects of European ancestry enrolled in 6 prospective cohort studies. After accounting for multiple testing, 2 SNPs (rs2283222 located in intron 11 in KCNQ1 and rs11720524 located in intron 1 in SCN5A) remained significantly associated with sudden/arrhythmic death (false discovery rate=0.01 and 0.03, respectively). Each increasing copy of the major T-allele of rs2283222 or the major C-allele of rs1172052 was associated with an odds ratio of 1.36 (95% confidence interval, 1.16 to 1.60; P=0.0002) and 1.30 (95% confidence interval, 1.12 to 1.51; P=0.0005), respectively. Control for cardiovascular risk factors and/or limiting the analysis to definite sudden cardiac death did not significantly alter these relationships.Conclusion: In this combined analysis of 6 prospective cohort studies, 2 common intronic variants in KCNQ1 and SCN5A were associated with sudden cardiac death in individuals of European ancestry. Further study in other populations and investigation into the functional abnormalities associated with noncoding variation in these genes may lead to important insights into predisposition to lethal arrhythmias. [ABSTRACT FROM AUTHOR]

The authors reflect on the insights from genome-wide associations (GWAs). Topics include correlation between common variants and peripheral or tissue-specific expression quantitative trait loci (eQTL), a study by N. A. M. Almontashiri and colleagues on disruption of specific transcription factor (TF) binding sites, and a phenotype gap in modern human genetics.

The authors reflect on the next-generation genome-wide association studies (GWAS). They states that cohorts of over 100,000 individuals projected as the solution to the omitted heritability from the first generation studies, in which the outcomes GWAS have been unequivocally linked with a certain diseases. The authors suggests that to fully describe the genetic architecture of disease, it would be essential to add hybrid approaches proficient of identifying alleles.

The article reports on the need of proper and accurate measurement of patients' quality of life with regards to symptoms of atrial fibrillation (AF). Stroke risk among people who have atrial fibrillation is highly heterogeneous and difficult to predict but there are supporting data for anticoagulation algorithms. Though there is no standard scoring system for subjective symptoms, there is a developed semi-objective scale of symptom severity in AF, the Severity in Atrial Fibrillation (SAF) scale.

The article presents information on the pathogenecity of DNA sequence variation. It explains the fundamental importance of a strong genotype-phenotype correlation if genetic diagnosis or prognostication is ever to be useful. It also discusses the absence of robust genetic support in humans or in animal models. The challenges of genome-wide association studies are explored.

The article reports that patient care and biomedical research will undoubtedly be increasingly influenced by genomic medicine efforts in the coming years. In his 2016 budget proposal, former U.S. President Barack Obama allocated $215 million to fund the Precision Medicine Initiative. Some groups have already taken steps to develop and implement genomics training into various medical education paths.

The article focuses on the projected future of the U.S. cardiovascular biomedicine. Topics discussed include the application of molecular medicine and its mechanistic insights to clinical medicine, the generation of recombinant proteins, and the significance of cardiovascular biomedicine in transformation biomedicine.

The completion of the Human Genome Project has unleashed a wealth of human genomics information, but it remains unclear how best to implement this information for the benefit of patients. The standard approach of biomedical research, with researchers pursuing advances in knowledge in the laboratory and, separately, clinicians translating research findings into the clinic as much as decades later, will need to give way to new interdisciplinary models for research in genomic medicine. These models should include scientists and clinicians actively working as teams to study patients and populations recruited in clinical settings and communities to make genomics discoveries—through the combined efforts of data scientists, clinical researchers, epidemiologists, and basic scientists—and to rapidly apply these discoveries in the clinic for the prediction, prevention, diagnosis, prognosis, and treatment of cardiovascular diseases and stroke. The highly publicized US Precision Medicine Initiative, also known as All of Us, is a large-scale program funded by the US National Institutes of Health that will energize these efforts, but several ongoing studies such as the UK Biobank Initiative; the Million Veteran Program; the Electronic Medical Records and Genomics Network; the Kaiser Permanente Research Program on Genes, Environment and Health; and the DiscovEHR collaboration are already providing exemplary models of this kind of interdisciplinary work. In this statement, we outline the opportunities and challenges in broadly implementing new interdisciplinary models in academic medical centers and community settings and bringing the promise of genomics to fruition. [ABSTRACT FROM AUTHOR]

The article discusses research concerning the need for quantitative tools in clinical genomic studies to determine the association of genotype to phenotype. An overview on the establishment of initial disease gene in segregation studies of multiple independent families and specific variant in the gene, is provided. Also outlined is the opportunities for genomic medicine and the hurdles with combination of remarkable degradation in pedigree information.

The author discusses a study by S. Pan and colleagues, published within the issue on the intolerance of genetic variation shown by cardiac structural and sarcomeric genes associated with cardiomyopathy. The exome sequence data provide a baseline for the assessment of potentially pathological variants in the human cardiomyopathy genes. The researchers also raise the possibility that the findings may suggest more complex patterns of inheritance.