Pediatric Cardiomyopathy Research Articles

Clinical impact of genetic testing in a large cohort of pediatric cardiomyopathies

BackgroundThere are limited data that can explain the earlier penetrance and the different expressivity of pediatric cardiomyopathy (pCM) compared to adult-onset cardiomyopathy (aCM). In addition, the relationship between genotype and pCM results is poorly described. ObjectiveWe compared the genotypes between a cohort of aCM and a cohort of pCM to propose hypotheses on the earlier penetrance and expressivity of pCM. Finally, we report how genetic testing was used to guide genetic counseling in pCM. Methods253 pCM (<18 years old) and 1466 aCM patients were sequenced on a panel of 67 cardiomyopathy genes. Risk factors for death and heart transplantation were analyzed. ResultsIn pCM, the variant of interest (VOI) yield was 53.7 % including 24.2 % carrying two VOI. De novo variants represented 11 % of VOI in pCM and 50 % in restrictive pCM. An age at diagnosis younger than 1 year (HR = 2.07, p = 0.029), restrictive phenotype (HR = 2.87, p = 0.03) and the presence of two VOI (HR = 2.97, p = 0.001) were independent risk factors for death or heart transplantation.In comparison with aCM, pCM patients harbored more frequently two VOI (p = 0.02), or de novo variants (p = 4.10−13). In addition, the distribution of VOI was different in aCM and pCM. Genotyping of pCM improved genetic counseling in families and led to ten prenatal-diagnosis.Conclusions: Genetic testing provides clues for earlier penetrance of pCM. The presence of two VOI in children with CM is a risk factor for severe and early cardiac events.

Abstract 4122024: Fibroblasts Are the Primary Contributors to a Disrupted Micro-Environment in End-Stage Pediatric Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is a relatively rare but debilitating diagnosis in pediatric patients. This represents a vulnerable population who often require heart transplantation. Here, we examine the transcriptome in ventricular tissue to identify underlying cellular processes unique to pediatric HCM (pHCM). Methods: We performed single-nucleus RNA sequencing on explanted hearts at transplant in female patients with end-stage pHCM (n=3) and compared findings to pediatric control (n=2) and adult HCM (n=5; Figure 1A-1B). Results: We generated 91,682 single-cell transcriptomes from 8 tissue samples. Principal component analysis exhibited the largest source of transcriptional variation separated pHCM and controls (Figure 1C). We identified distinct underlying cellular processes in cardiomyocytes, fibroblasts, endothelial cells, and myeloid cells in pHCM. pHCM was enriched in cardiomyocytes with stressed signatures and pathways associated with hypertrophy (Figure 1D); we noted depletion of tissue-resident macrophages (Figure 1D) and increased vascular remodeling in endothelial cells in pHCM. Fibroblasts exhibited activation signatures and compared to adult HCM, showed heightened fibrotic processes and a unique pro-fibrotic cluster with increased metabolic stress, mitochondrial turnover, and anti-apoptotic properties (Figure 2). In cell-to-cell communication, the differential number and weight of interactions were higher in pHCM compared to controls and fibroblasts had the highest strength of outgoing interactions. Conclusions: Our analysis provides the first single-nuclei analysis focused on pHCM. Fibroblast-mediated cellular processes contributed most to the disrupted micro-tissue environment; they had more downstream processes associated with fibrosis and may respond to metabolic stress differently compared to adult HCM. This advances our understanding of the early presentation of pHCM, providing a crucial steppingstone toward improved patient outcomes.

Abstract 4134551: Outstanding Research Award in Pediatric Cardiology: Cardiomyopathy-Associated Pathogenic Variants in Pediatric Myocarditis: A Study from the Pediatric Cardiomyopathy Registry

Background: Recent studies have demonstrated that patients with myocarditis (MC) may have a higher burden of cardiomyopathy (CM)-associated gene variants than the general population. However, data in children is limited. The Pediatric Cardiomyopathy Registry (PCMR), a large multi-center registry of children with CM, includes patients with dilated CM (DCM) secondary to myocarditis (MC). Hypothesis: We hypothesized patients with DCM secondary to MC in the PCMR have a higher burden of CM-associated gene variants than healthy controls, and clinical genetic testing in this population is rare. Aims: We aimed to: (1) calculate the prevalence of pathogenic (P) or likely pathogenic (LP) CM-associated variants in patients with DCM secondary to MC and compare to the prevalence in heart-healthy controls and (2) report the rate of clinical genetic testing in this population. Methods: The PCMR was queried to identify patients with DCM secondary to MC who underwent exome sequencing as part of a prior prospective study at 14 sites in North America. Controls from the Indiana University Biobank were matched 4:1 with cases based on genomic similarity. A curated gene list was comprised of 46 genes associated with CM. A second gene list included 102 genes associated with CM or MC in the ClinVar database. The prevalence of variants was compared using Chi-Square or Fisher’s exact tests. Results: A total of 32 patients were identified with DCM secondary to MC. Median enrollment age was 1.5 years (IQR 0.4-10.3) and 53% were female. There was no family history in 88%. The prevalence of P/LP variants from the curated list was 34.4% in cases compared to 4.7% in controls (p&lt;0.001). The prevalence of P/LP variants from the ClinVar list was 31.3% in cases compared to 6.3% in controls (p&lt;0.001). Variants were identified in 8 genes: ABCC9, ANKRD1, MYH6, MYH7, MYPN, PLN, TPM1 and TTN. No P/LP variants were found in desmosomal genes. The prevalence of variants was higher but not significantly different in older children compared to infants (45.0% vs 16.6%, p=0.1). The prevalence of variants in MC was similar to previously reported rates in all causes of DCM (34.4% vs 28.8%, p=0.5). Only 22% of cases received clinical genetic testing. Conclusion: Approximately 1 in 3 children with DCM secondary to MC carry a CM-associated P/LP variant, which is significantly higher than the prevalence in healthy controls. Given the high prevalence, routine genetic testing should be considered in this population.

Clinical Features and Outcomes of Pediatric MYH7-Related Dilated Cardiomyopathy.

Although genetic variants in MYH7 are the most frequent cause of pediatric genetic dilated cardiomyopathy (DCM), there are no studies available describing this entity. We sought to describe clinical features, analyze variant location, and explore predictors of bad prognosis in pediatric MYH7-related DCM. We evaluated clinical records from 44 patients (24 men; median age at diagnosis, 0.54 [interquartile range, 0.01-10.8] years) with pathogenic/likely pathogenic variants in MYH7 diagnosed with DCM at pediatric age (<18 years) followed at 13 international centers. We also explored risk factors associated with a composite end point of end-stage heart failure defined as heart transplantation or heart failure-related death. Twenty-two patients (50%) were diagnosed at age <6 months, including 7 (16%) at birth. Left ventricular (LV) hypertrabeculation features were present in 15 (38%), particularly among patients with genetic variants in the head domain. After a median follow-up of 6.1 years (interquartile range, 1.9-13.4), 15 patients (36%) required a heart transplant (n=14) or died due to end-stage heart failure (n=1), 15 patients (36%) persisted with systolic dysfunction despite treatment, 12 (29%) had a significant increase in LV ejection fraction, and 2 were lost to follow-up. Overall, end-stage heart failure event rate was 25% at 5 years. New York Heart Association class III to IV (hazard ratio [HR], 7.67 [95% CI, 2.16-27.2]; P=0.002) and LV ejection fraction ≤35% (HR, 4.00 [95% CI, 1.11-14.4]; P=0.03) were the best predictors of bad prognosis. Pediatric MYH7-related DCM is characterized by early onset, frequent LV hypertrabeculation, and poor prognosis. Advanced New York Heart Association class and low LV ejection fraction emerged as predictors of end-stage heart failure.

Pediatric restrictive Cardiomyopathy presenting with congestive heart failure: Rare case report and literature review

Restrictive cardiomyopathy (RCM) is an uncommon form of cardiomyopathy and is characterized by impaired diastolic filling of the ventricles due to increased myocardial stiffness and a normal ventricular systolic functions. In India, RCM is frequently observed in the young and endemic endomyocardial diseases are seen in a significant number of cases. RCM is the least common of all the cardiomyopathies among pediatric patients. RCM has a poor prognosis and commonly requires a cardiac transplant. We are reporting here a case of seven-year-old female child presenting with recurrent chest infections and congestive heart failure since early childhood.

Cardiomyopathies in 100,000 genomes project: interval evaluation improves diagnostic yield and informs strategies for ongoing gene discovery

BackgroundCardiomyopathies are clinically important conditions, with a strong genetic component. National genomic initiatives such as 100,000 Genome Project (100KGP) provide opportunity to study these rare conditions at scale beyond conventional research studies.MethodsWe present the clinical and molecular characteristics of the 100KGP cohort, comparing paediatric and adult probands with diverse cardiomyopathies. We assessed the diagnostic yield and spectrum of genetic aetiologies across clinical presentations. We re-analysed existing genomic data using an updated analytical strategy (revised gene panels; unbiased analyses of de novo variants; and improved variant prioritisation strategies) to identify new causative variants in genetically unsolved children.ResultsWe identified 1918 individuals (1563 probands, 355 relatives) with cardiomyopathy (CM) in 100KGP. Probands, comprising 273 children and 1290 adults, were enrolled under > 55 different recruitment categories. Paediatric probands had higher rates of co-existing congenital heart disease (12%) compared to adults (0.9%). Diagnostic yield following 100KGP’s initial analysis was significantly higher for children (19%) than for adults (11%) with 11% of diagnoses overall made in genes not on the existing UK paediatric or syndromic CM panel. Our re-analysis of paediatric probands yields a potential diagnosis in 40%, identifying new probable or possible diagnoses in 49 previously unsolved paediatric cases. Structural and intronic variants accounted for 11% of all potential diagnoses in children while de novo variants were identified in 17%.Conclusions100KGP demonstrates the benefit of genome sequencing over a standalone panel in CM. Re-analysis of paediatric CM probands allowed a significant uplift in diagnostic yield, emphasising the importance of iterative re-evaluation in genomic studies. Despite these efforts, many children with CM remain without a genetic diagnosis, highlighting the need for better gene-disease relationship curation and ongoing data sharing. The 100KGP CM cohort is likely to be useful for further gene discovery, but heterogeneous ascertainment and key technical limitations must be understood and addressed.

Novel FLNC variants in pediatric cardiomyopathy: an insight into disease mechanisms

BackgroundFLNC gene variants have predominantly been reported in adult populations with cardiomyopathies, and early-onset cases are less common. The genotype–phenotype relationship indicates that dilated cardiomyopathy (DCM) is often associated with FLNC truncating variants.MethodsWe conducted a comprehensive genetic analysis using next generation sequencing (NGS) to identify FLNC variants in patients with cardiovascular conditions. Detailed phenotypic and variant analyses were performed to characterize the clinical features and genetic alterations. Minigene assays and structural modeling were used to investigate the pathogenicity caused by the identified variants.ResultsIn a cohort of 58 patients, novel heterozygous FLNC variants, c.3962A > T (p.Glu1321Val) and c.7543C > T (p.Leu2515Phe), were identified in patients presenting with dilated and mixed restrictive/hypertrophic cardiomyopathies, respectively. The c.3962A > T variant disrupted normal splicing, as demonstrated through the splicing prediction tool and minigene studies, further emphasizing its pathogenic potential.ConclusionFor missense variants of FLNC in patients with DCM, the splicing effect of the variant should be carefully checked. Early detection and intervention are crucial given the high risk of sudden cardiac death and severe cardiac complications.

Sex differences in paediatric onset hypertrophic cardiomyopathy

Abstract Background Hypertrophic Cardiomyopathy (HCM) is a heterogeneous disease characterised by age related incomplete penetrance and variable long term outcomes. Sex differences have been described in both the clinical phenotype and natural history of adults with the disease, which have been attributed to both biological (eg sex hormone effect) and non-biological (eg societal and cultural effects) factors. It is unknown if similar sex differences exist in childhood-onset HCM. Purpose This study aimed to investigate the influence of biological sex on the clinical characteristics and outcomes of children with HCM. Methods Retrospective cohort study from an international registry of patients diagnosed under the age of 18 years with HCM. Patients with syndromic disease (RASopathy syndromes, inborn errors of metabolism, neuromuscular disease) were excluded. Sex differences in baseline characteristics and clinical outcomes were described. Primary outcomes were all-cause mortality or cardiac transplantation, Major Arrhythmic Cardiac Event (MACE) and heart failure event (defined as heart failure death or cardiac transplantation) Results Of 1262 patients, 851 (67.4%) were male (median age 11 yrs (IQR 7.4, 14.4) vs 11.1 (IQR 6.9, 14.0) in females, p=0.0312). Female patients were more likely to have a sarcomeric variant identified (n=208, 85.6% vs 388 (79.4%), p=0.041) despite equivalent genetic testing utilisation between sexes. Female patients were more likely to have severe heart failure symptoms (NYHA 3 or 4) (n=19, 6.1% vs n=20, 2.5% p value 0.030) but there was no difference in the proportion on medical therapy (male n=328, 39.7%, female n=167, 41.8, p value 0.476). The clinical phenotype in terms of degree of hypertrophy, left atrial size and left ventricular outflow tract gradient did not differ by sex. Over a median follow up of 5.2 years (IQR 2.4, 9.9) all-cause mortality or cardiac transplantation did not vary by sex but females were more likely to experience a heart failure event (females 0.6/100,000 pt years (95% CI 0.39-0.92) vs males 0.32/100,000 pt years (95% CI 0.21 – 0.50), hazard ratio 1.89, p value 0.0467). The incidence of MACE did not differ by sex but there was a trend towards higher implantable cardioverter defibrillator implantation in females (n=123, 30.7% vs n=210, 25.4%, p value 0.051). Conclusions For the first time, this study has shown sex differences in paediatric-onset hypertrophic cardiomyopathy. Despite no difference in baseline clinical phenotype, young female patients are more likely to experience heart failure symptoms and heart failure events over follow up. Further studies are required to explore the underlying mechanisms for these observed differences.Table summarising outcomes by sexSurvival free from heart failure

Phenotype progression in pediatric RASopathy-associated hypertrophic cardiomyopathy

Abstract Background RASopathy syndromes represent the second most common cause of hypertrophic cardiomyopathy (HCM) in children. RASopathy associated HCM (Ras-HCM) has been shown to differ both in cardiac phenotype and long-term outcomes from sarcomeric HCM. However, there is a lack of knowledge from large cohort studies of how the cardiac phenotype of Ras-HCM changes over time. Aim To describe cardiac phenotype changes over time in children with Ras-HCM Methods Retrospective data from 148 patients diagnosed with Ras-HCM aged &amp;lt;18 years with ³2 follow-up visits were included. Clinical and echocardiographic data were collected at baseline assessment, 1, 2, and 5 years of follow up. Separate analyses were performed for patients who survived, versus patients who died or had a heart transplant (censoring events). Results One-hundred-and-two (68.9%) patients with Noonan syndrome, 25 (16.9%) with Noonan-syndrome with multiple lentigines, 10 (6.8%) with Costello syndrome, 9 (6.1%) with cardio-facio-cutaneous syndrome and 2 (1.4%) patients with Noonan-like syndrome with a median age of diagnosis 0.16 years (0.01-0.89) were seen at a median baseline age of 1.41 years (0.37-5.71) and followed up for a median of 12.1 years (4.8-17.4). During follow up, 18 patients (12.2%) died at a median age of 1.8 years (0.5-8.7) and 17 (12.5%) had a left ventricular myectomy, at a median age of 7.0 years (3.1-12.7). At baseline evaluation, patients who died compared to those who survived had a lower median age [0.4 years (0.1-0.8) versus 2.3 years (0.5-7.6), p&amp;lt;0.001], a higher proportion of them had a NYHA class&amp;gt;I (54.5% vs 15.1%, p&amp;lt;0.001), a higher maximal left ventricular wall thickness (MLVWT) z-score [13.4 (7.5) vs 9.6 (6.2), p=0.04], a higher proportion of left ventricular outflow tract obstruction (LVOTO) [64.7% vs 43.8%, p=0.087] and a higher proportion of biventricular hypertrophy [75% vs 49.2%, p=0.045]. For survivors, the MLVWT z-score improved over follow up [+9.6(6.2) at baseline vs. +7.9(5.5) at 5 years, p=0.072], and the proportion of patients with LVOTO (43.8% at baseline vs. 27.9% at 5 years, p=0.019) and biventricular hypertrophy (49.2% at baseline vs. 35.5% at 5 years, p=0.012) decreased over follow up. Conclusion While at baseline evaluation Ras-HCM has a high burden of symptoms, biventricular hypertrophy and LVOTO for patients who die or have a heart transplant, we have demonstrated that for survivors, over follow up, the phenotype becomes milder.Table 1

Prognostic role of gene variants in sudden cardiac death risk associated to paediatric hypertrophic cardiomyopathy

Abstract Introduction Genetic testing plays an important role in diagnosis of hypertrophic cardiomyopathy (HCM), being sarcomeric genes commonly involved, particularly MYBPC3. However, arrhythmic risk related to genotype remains unclear in adults and almost unexplored in children. Hence, current sudden cardiac death (SCD) risk calculators do not include genetic information. Purpose To analyse risk of arrhythmic events associated with causal variants in MYBPC3 respecting to other genes in a paediatric cohort with non-syndromic HCM from a cardiomyopathy referral centre. Methods This retrospective study included patients with non-syndromic HCM 0-18 years old between 2009-2022. Demographic, clinical, and genetic data were collected. Genetic variants pathogenicity followed American College of Medical Genetics criteria. A positive genetic test was considered if a likely pathogenic or pathogenic variant in HCM related genes was found. Considered outcomes were SCD or a major arrhythmic cardiac event (MACE) within 5 years follow-up: recovered SCD, appropriate ICD therapy, or sustained ventricular tachycardia. Some SCD-risk estimation models (in 5 years) as HCM Risk-SCD model for patients &amp;gt;=15 y.o and/or 55 kg, ESC Guidelines paediatric algorithm, and HCM Risk-Kids model were applied. Results 77 patients were diagnosed with non-syndromic HCM. A causal variant was found in 45/73 (62%). No significant differences in cardiac phenotype were found related to genes. 10/77 patients (13%) presented a MACE in 5 years follow-up. A positive genetic study was significantly associated with having an event (p=0.011). Most patients with a positive genetic test harboured MYBPC3 variants (21/45, 47%), however only 2 patients who suffered a MACE had a causal variant in MYBPC3. Those with causal variants in genes other than MYBPC3 presented more and earlier events (p=0.022). Risk of having a MACE during follow-up was higher when presenting causal variants in genes other than MYBPC3: Hazard Ratio 18.5 (95% CI 2.31, 148), p=0.006. Applying HCM Risk-SCD calculator, model had better predictive discrimination when variable "causal variant in gene other than MYBPC3" was added in multivariate analysis, with high-risk category &amp;gt;=6% (C-statistic =0.931 vs 0.844) and intermediate-risk category 4-6% (C-statistic =0.845 vs 0.514). Same occurred with ESC Guidelines algorithm, adding that variable to 2 risk factors category (C-statistic =0.881 vs 0.742) or 1 risk factor (C-statistic =0.844 vs 0.635). HCM Risk-Kids also improved its predictive discrimination adding the genetic value to high-risk category &amp;gt;=6% (C-statistic =0.896 vs 0.796) and intermediate-risk (C-statistic =0.821 vs 0.506). Conclusions Genotype may have prognostic value in SCD risk in HCM in children. Our results suggests that causal genetic variants in genes other than MYBPC3 can lead to higher risk of SCD. Genetic information might be considered for future models of arrhythmic risk in children with HCM.

Role of Septal Myectomy in Pediatric Hypertrophic Cardiomyopathy

Role of Septal Myectomy in Pediatric Hypertrophic Cardiomyopathy

05P Pediatric cardiomyopathy may be more prevalent amongst ACTA1 mutation related myopathies: a single center case-series

05P Pediatric cardiomyopathy may be more prevalent amongst ACTA1 mutation related myopathies: a single center case-series

The pericardium forms as a distinct structure during heart formation.

The heart integrates diverse cell lineages into a functional unit, including the pericardium, a mesothelial sac that supports heart movement, homeostasis, and immune responses. However, despite its critical roles, the developmental origins of the pericardium remain uncertain due to disparate models. Here, using live imaging, lineage tracking, and single-cell transcriptomics in zebrafish, we find the pericardium forms within the lateral plate mesoderm from dedicated anterior mesothelial progenitors and distinct from the classic heart field. Imaging of transgenic reporters in zebrafish documents lateral plate mesoderm cells that emerge lateral of the classic heart field and among a continuous mesothelial progenitor field. Single-cell transcriptomics and trajectories of hand2-expressing lateral plate mesoderm reveal distinct populations of mesothelial and cardiac precursors, including pericardial precursors that are distinct from the cardiomyocyte lineage. The mesothelial gene expression signature is conserved in mammals and carries over to post-natal development. Light sheet-based live-imaging and machine learning-supported cell tracking documents that during heart tube formation, pericardial precursors that reside at the anterior edge of the heart field migrate anteriorly and medially before fusing, enclosing the embryonic heart to form a single pericardial cavity. Pericardium formation proceeds even upon genetic disruption of heart tube formation, uncoupling the two structures. Canonical Wnt/β-catenin signaling modulates pericardial cell number, resulting in a stretched pericardial epithelium with reduced cell number upon canonical Wnt inhibition. We connect the pathological expression of secreted Wnt antagonists of the SFRP family found in pediatric dilated cardiomyopathy to increased pericardial stiffness: sFRP1 in the presence of increased catecholamines causes cardiomyocyte stiffness in neonatal rats as measured by atomic force microscopy. Altogether, our data integrate pericardium formation as an independent process into heart morphogenesis and connect disrupted pericardial tissue properties such as pericardial stiffness to pediatric cardiomyopathies.

How effective is disopyramide in treating pediatric hypertrophic cardiomyopathy? State of the art and future directions.

Pediatric hypertrophic cardiomyopathy (HCM) has a wide range of clinical manifestations. Left ventricular outflow tract obstruction (LVOTO) at rest is present in up to one-third of children with HCM, with a further 50-60% of symptomatic children developing a gradient under exertion. Treatment options are limited, and there is a relative lack of data on the pediatric population. Disopyramide is a sodium channel blocker with negative inotropic properties. This therapy effectively reduces LVOTO in adults with HCM and delays surgical interventions, but it is not licensed for use in children. We aimed to review and analyze the influence of disopyramide over the pathophysiological, clinical, electrocardiographic, and echocardiographic characteristics of patients with HCM in infancy, childhood, adolescence, and adult age. While disopyramide remains a cornerstone in the management of pediatric HCM, the advent of mavacamten and aficamten heralds a new era of potential advancements. These emerging therapies could significantly improve the quality of life and prognosis for young patients with HCM.

Abnormal left atrial strain and left atrial stiffness index are associated with adverse outcomes in children with cardiomyopathies: a pilot study

Conventional diastolic dysfunction parameters seem to be imperfect when applied to the pediatric cardiomyopathy population. The aim of this pilot study was to search for novel echocardiographic parameters associated with adverse outcomes in children with the most common cardiomyopathies. Fifty-six patients with pediatric cardiomyopathies (28 with dilated, 21 with hypertrophic, 7 with left ventricular non-compaction cardiomyopathy) and 28 healthy subjects were included in the study. Left atrial reservoir (LASr), conduit (LAScd) and contraction (LASct) strain, left atrial stiffness index (LASI), as well as conventional diastolic dysfunction parameters were measured using echocardiography. Adverse outcomes were defined as heart failure (including heart transplant) and arrhythmic endpoints. Patients with adverse outcomes presented with significantly lower LASr (16.68% ± 8.64% vs. 33.97% ± 9.99%, p-value < 0.001), lower LAScd (− 10.37% ± 5.83% vs. − 25.50% ± 9.24%, p-value < 0.001) and higher values of LASI (0.69 [IQR 0.34; 1.11] vs. 0.21 [IQR 0.16; 0.31], p-value < 0.001). LASr < 20%, LAScd ≥ − 12%, and LASI ≥ 0.26 were all associated with reduced survival. LASr, LAScd and LASI seem to be promising parameters in predicting adverse outcomes in the most common pediatric cardiomyopathies. Left atrial strain parameters and LASI are helpful in differentiating healthy control subjects from children with hypertrophic and dilated cardiomyopathies.

Pediatric cirrhotic cardiomyopathy: literature review and effect size estimations of selected parameters

Liver cirrhosis is a significant global health concern, and cirrhotic cardiomyopathy (CCM) is a notable complication affecting both adults and children. While CCM is well-studied in adults, understanding its manifestation and diagnostic criteria in pediatric patients remains a challenge. This review explores the evidence for structural and functional cardiac alterations in children with liver cirrhosis. Structural abnormalities, including increased left ventricular mass index (LVMI) and altered left ventricular wall thickness ratios, are prevalent in pediatric CCM. These abnormalities persist even after liver transplantation, highlighting the systemic impact of liver disease. Evidence suggests that altered systolic and diastolic function, as well as electrocardiographic abnormalities such as prolonged QT intervals, are common in pediatric CCM. Blood biomarkers, including brain natriuretic peptide (BNP) and troponin levels, offer insights into cardiac function in pediatric cirrhotic patients. Elevated BNP levels correlate with adverse outcomes, indicating its potential as a prognostic marker. However, further research is needed to elucidate the diagnostic utility of these biomarkers in pediatric CCM. Conclusion: This review provides estimates of the standardized mean difference among selected cardiac parameters in children with and without cirrhosis. Tailored diagnostic criteria and comprehensive assessment methods will be essential for accurate diagnosis and effective management of pediatric CCM. What is Known:• CCM adds to the burden of care of patients with cirrhosis.• Diagnostic criteria for adults are evolving, but there are no specific criteria for pediatric CCM.What is New:• Cardiac function in children with cirrhosis indicates some parameters not considered in adults are altered.• Effect size estimations for certain parameters provide a guideline for future research into pediatric CCM.

Clinical Characteristics and Outcomes of Dilated Cardiomyopathy in Chinese Children: A Single-Center Retrospective Study.

The reported outcomes of pediatric dilated cardiomyopathy (DCM) have varied across studies. There are few outcome data concerning DCM in Chinese children. Therefore, we conducted a retrospective study to describe clinical features and determine risk factors for poor outcomes in children with DCM. We enrolled 121 children with DCM in our hospital from 2003 to 2021. General information and laboratory and echocardiographic data were collected and analyzed. Cox regression analysis was performed to determine risk factors for poor outcomes. This study included 121 patients (69 males and 52 females). The median age at diagnosis was 10.8 years, and the follow-up time was 10.0 months. Eighty-two patients (67.8%) exhibited cardiac function classes III-IV at the time of diagnosis. Tachypnea was the most common symptom (78.5%). In echocardiography, the mean left ventricular end-diastolic dimension z score was 7.36 ± 2.73, and the left ventricular ejection fraction z score was -6.58 ± 2.17. The 1-, 2-, and 5-year survival rates were 51.2%, 43.8%, and 32.2%, respectively. Cox analysis revealed that cardiac function classes III-IV (hazard ratio [HR] = 1.801, 95% confidence interval [95% CI] = 1.030-3.149, p = 0.039) and calcium levels (HR = 0.219, 95% CI = 0.084-0.576, p = 0.002) were predictors of poor outcomes in children with DCM. Children with DCM are at high risk of death. Cardiac function class III-IV and calcium levels were related to the prognosis of pediatric DCM patients.

Further exploration of cardiac channelopathy and cardiomyopathy genes in stillbirth.

To explore genetic variation including whole genome copy number variation and sequence analysis of 98 genes associated with pediatric or adult cardiomyopathies, cardiac channelopathies, and sudden death in an unexplained intrauterine fetal death cohort. The study population included 55 stillbirth cases that remained unexplained after thorough postmortem examination, excluding maternal, fetal, and placental causes of stillbirth. Molecular karyotyping was performed in 55 cases and the trio exome sequencing approach was applied in 19 cases. The analysis revealed six rare variants with predicted effects on protein function in six genes (CASQ2, DSC2, KCNE1, LDB3, MYH6, and SCN5A) previously reported in cases of stillbirth or severe early onset pediatric cardiac related phenotypes. When applying strict American College of Genetics and Genomics classification guidelines, these are still variants of uncertain significance. Several potentially stillbirth-related genetic variants were detected in our cohort, adding to the growing literature on cardiac phenotype gene variation in stillbirth. However, the mechanisms of action, gene-gene interaction, and contribution of the uterine environment are still to be deciphered. In order to advance our knowledge of the genetics of unexplained fetal death, there is an evident need for international collaboration and field standardization.

Uric acid elevation in pediatric patients with dilated cardiomyopathy and prediction of mortality.

Pediatric dilated cardiomyopathy (DCM) is a primary cause of heart failure, highlighting the urgent need for effective prognostic markers. We performed a single-center retrospective study involving 145 children diagnosed with DCM, with a median follow-up period of 4.0 months (interquartile range: 6.2-108.4 months). The relationship between serum uric acid (SUA) levels and all-cause mortality was assessed using Kaplan-Meier survival curves, multivariate Cox proportional hazard models, and restricted cubic spline (RCS) models. Of the 145 children with DCM (median age 5.7 years; 61.4% male), 45 (31%) died within 1 year, and 65 (44.8%) died during the maximum follow-up period. In adjusted multivariate Cox regression models, each log2 SUA increase was linked to a higher risk of 1-year mortality [hazard ratio (HR), 2.66; 95% confidence interval (CI), 1.41-5.01] and overall mortality (HR, 1.97; 95% CI, 1.15-3.37). The highest SUA tertile showed a greater risk of mortality at 1 year (HR, 4.26; 95% CI: 1.5-12.06) and during the maximum follow-up (HR, 2.56; 95% CI: 1.06-6.16) compared with the lowest tertile. RCS models indicated an inverted L-shaped association between baseline SUA levels and overall mortality risk, with age-stratified analyses revealing a linear and U-shaped relationship in children ≤10 and >10 years, respectively. Further age-stratified analyses highlighted the modifying effect of age on this association. Elevated SUA levels are a significant predictor of mortality in pediatric DCM, with a pronounced impact on children under 10 years of age. Therefore, SUA levels could serve as potential biomarkers for risk stratification in this population.

Unraveling the genetic tapestry of pediatric sarcomeric cardiomyopathies and masquerading phenocopies in Jordan

Pediatric cardiomyopathies are mostly attributed to variants in sarcomere-related genes. Unfortunately, the genetic architecture of pediatric cardiomyopathies has never been previously studied in Jordan. We sought to uncover the genetic landscape of 14 patients from nine families with several subtypes of pediatric cardiomyopathies in Jordan using Exome sequencing (ES). Our investigation identified pathogenic and likely pathogenic variants in seven out of nine families (77.8%), clustering in sarcomere-related genes. Surprisingly, phenocopies of sarcomere-related hypertrophic cardiomyopathies were evident in probands with glycogen storage disorder and mitochondrial-related disease. Our study underscored the significance of streamlining ES or expanding cardiomyopathy-related gene panels to identify plausible phenocopies of sarcomere-related cardiomyopathies. Our findings also pointed out the need for genetic testing in patients with cardiomyopathy and their at-risk family members. This can potentially lead to better management strategies, enabling early interventions, and ultimately enhancing their prognosis. Finally, our findings provide an initial contribution to the currently absent knowledge about the molecular underpinnings of cardiomyopathies in Jordan.