Competing risks for death and cardiac transplantation in children with dilated cardiomyopathy: results from the pediatric cardiomyopathy registry

The impact of fragmented QRS on clinical findings and outcomes in children with dilated cardiomyopathy with or without left ventricular non-compaction

OBJECTIVE

The aim of this study is to investigate the frequency of fragmented QRS and its associations with clinical findings and prognosis in children diagnosed with dilated cardiomyopathy with or without left ventricular non-compaction.

METHODS

This retrospective study was conducted between 2010 and 2020. Patients with dilated cardiomyopathy were classified into two groups according to the presence of left ventricular non-compaction: Dilated cardiomyopathy with left ventricular non-compaction and dilated cardiomyopathy without left ventricular non-compaction. Patients were also divided into two groups according to the presence of fragmented QRS (fragmented QRS group and non-fragmented QRS group).

RESULTS

Twenty-three of 44 patients (52.3%) were male. Among left ventricular non-compaction patients, the fragmented QRS group had more complex ventricular arrhythmias (p = 0.003). Patients with fragmented QRS had a significantly higher rate of major adverse cardiac events and/or cardiac death in both cardiomyopathy groups (p = 0.003 and p = 0.005). However, the rate of major adverse cardiac events and/or cardiac death was similar between dilated cardiomyopathy patients with and without left ventricular non-compaction. Multivariate logistic regression analysis showed that the presence of fragmented QRS strongly predicts major adverse cardiac events and/or cardiac death (odds ratio, 31.186; 95% confidence interval, 2.347-414.307). Although the survival rates between cardiomyopathy groups were similar, patients with fragmented QRS had a markedly lower survival rate during the follow-up period, as mean of 15 months (p = 0.001).

CONCLUSION

Our study showed that the presence of fragmented QRS may be an important ECG sign predicting an major adverse cardiac event and/or cardiac death in patients with dilated cardiomyopathy. We believe that recognising fragmented QRS could be valuable in forecasting patient prognosis and identifying high-risk patients who require additional support.

Progressive Left Ventricular Remodeling for Predicting Mortality in Children With Dilated Cardiomyopathy: The Pediatric Cardiomyopathy Registry

BACKGROUND

Pediatric dilated cardiomyopathy often leads to death or cardiac transplantation. We sought to determine whether changes in left ventricular (LV) end-diastolic dimension (LVEDD), LV end-diastolic posterior wall thickness, and LV fractional shortening (LVFS) over time may help predict adverse outcomes.

METHODS AND RESULTS

We studied children up to 18 years old with dilated cardiomyopathy, enrolled between 1990 and 2009 in the Pediatric Cardiomyopathy Registry. Changes in LVFS, LVEDD, LV end-diastolic posterior wall thickness, and the LV end-diastolic posterior wall thickness:LVEDD ratio between baseline and follow-up echocardiograms acquired ≈1 year after diagnosis were determined for children who, at the 1-year follow-up had died, received a heart transplant, or were alive and transplant-free. Within 1 year after diagnosis, 40 (5.0%) of the 794 eligible children had died, 117 (14.7%) had undergone cardiac transplantation, and 585 (73.7%) had survived without transplantation. At diagnosis, survivors had higher median LVFS and lower median LVEDD Z scores. Median LVFS and LVEDD Z scores improved among survivors (Z score changes of +2.6 and -1.1, respectively) but remained stable or worsened in the other 2 groups. The LV end-diastolic posterior wall thickness:LVEDD ratio increased in survivors only, suggesting beneficial reverse LV remodeling. The risk for death or cardiac transplantation up to 7 years later was lower when LVFS was improved at 1 year (hazard ratio [HR], 0.83; P=0.004) but was higher in those with progressive LV dilation (HR, 1.45; P<0.001).

CONCLUSIONS

Progressive deterioration in LV contractile function and increasing LV dilation are associated with both early and continuing mortality in children with dilated cardiomyopathy. Serial echocardiographic monitoring of these children is therefore indicated.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00005391.

Feasibility of the Omaha system for the care of children with dilated cardiomyopathy

Aim

To explore the feasibility of Omaha system theory in the care of children with dilated cardiomyopathy (DCM), which may provide a practical basis for the continuous nursing of DCM children.

Methods

A total of 1,392 records describing symptoms, signs, and nursing interventions were extracted from the medical records of 76 children suffered from DCM. Content analysis method was used to find out existent nursing problems, make precise nursing plans, and take corresponding nursing measurements according to the medical records of DCM children. Cross-mapping method was utilized to compare the conceptual consistency of the medical records and Omaha system (problem classification and intervention subsystems).

Results

Of the total 1,392 records, 1,094 (78.59%) were complete consistency, while 245 (17.60%) were partial consistency, and 53 (3.81%) were inconsistency with the Omaha system concepts. The concept matching degree of medical records and Omaha system was approximately 96.19%.

Conclusions

The Omaha system may be an effective nursing language for Chinese DCM children, which may be useful to guide nurses in the care of DCM. Further well-design studies need to fully evaluate the feasibility and effectiveness of the Omaha system in nursing children with DCM.

Poor efficacy of oral iron replacement therapy in pediatric patients with heart failure

INTRODUCTION

Iron deficiency is associated with worse outcomes in children and adults with systolic heart failure. While oral iron replacement has been shown to be ineffective in adults with heart failure, its efficacy in children with heart failure is unknown. We hypothesised that oral iron would be ineffective in replenishing iron stores in ≥50% of children with heart failure.

METHODS

We performed a single-centre retrospective cohort study of patients aged ≤21 years with systolic heart failure and iron deficiency who received oral iron between 01/2013 and 04/2019. Iron deficiency was defined as ≥2 of the following: serum iron <50 mcg/dL, serum ferritin <20 ng/mL, transferrin >300 ng/mL, transferrin saturation <15%. Iron studies and haematologic indices pre- and post-iron therapy were compared using paired-samples Wilcoxon test.

RESULTS

Fifty-one children with systolic heart failure and iron deficiency (median age 11 years, 49% female) met inclusion criteria. Heart failure aetiologies included cardiomyopathy (51%), congenital heart disease (37%), and history of heart transplantation with graft dysfunction (12%). Median dose of oral iron therapy was 2.9 mg/kg/day of elemental iron, prescribed for a median duration of 96 days. Follow-up iron testing was available for 20 patients, of whom 55% (11/20) remained iron deficient despite oral iron therapy.

CONCLUSIONS

This is the first report on the efficacy of oral iron therapy in children with heart failure. Over half of the children with heart failure did not respond to oral iron and remained iron deficient.

Pediatric and adult dilated cardiomyopathy are distinguished by distinct biomarker profiles

BACKGROUND

Emerging evidence suggests that pediatric and adult dilated cardiomyopathy (DCM) represent distinct diseases. Few diagnostic tools exist for pediatric cardiologists to assess clinical status and prognosis. We hypothesized that pediatric DCM would have a unique biomarker profile compared to adult DCM and controls.

METHODS

We utilized a DNA aptamer array (SOMAScan) to compare biomarker profiles between pediatric and adult DCM. We simultaneously measured 1310 plasma proteins and peptides from 39 healthy children (mean age 3 years, interquartile range (IQR) 1-14), 39 ambulatory subjects with pediatric DCM (mean age 2.7 years, IQR 1-13), and 40 ambulatory adults with DCM (mean age 53 years, IQR 46-63).

RESULTS

Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics. We identified 20 plasma peptides and proteins that were increased in pediatric DCM compared to age- and sex-matched controls. Unbiased multidimensionality reduction analysis suggested previously unrecognized heterogeneity among pediatric DCM subjects. Biomarker profile analysis identified four subgroups of pediatric DCM with distinguishing clinical characteristics.

CONCLUSIONS

These findings support the emerging concept that pediatric and adult DCM are distinct disease entities, signify the need to develop pediatric-specific biomarkers for disease prognostication, and challenge the paradigm that pediatric DCM should be viewed as a single disease.

IMPACT

Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics and outcomes. Our findings suggest that pediatric DCM may be a heterogeneous disease with various sub-phenotypes, including differing biomarker profiles and clinical findings. These data provide prerequisite information for future prospective studies that validate the identified pediatric DCM biomarkers, address their diagnostic accuracy and prognostic significance, and explore the full extent of heterogeneity amongst pediatric DCM patients.

Non-Cardiac Cause of Death in Selected Group Children with Cardiac Pathology: A Retrospective Single Institute Study

Background: Pediatricians and pediatric surgeons often face children with cardiomegaly and dilatative or hypertrophic cardiomyopathies presenting with or without symptoms. Some of these patients have already been diagnosed and received medication, and some present with completely unrelated pathologies. Methods: We performed a 4-year retrospective study on the causes and mechanisms of death of children with cardiac pathology who died outside the cardiology clinic of our hospital by studying the hospital charts and necropsy reports. All children who were in this situation in our hospital were included. Results: Most children in our study group were infants (81.82%), most were boys (81.82%), and in most cases, the cause or mechanism of death was unrelated to their heart condition, whether it had already been diagnosed or not (one case probably died as a result of a malignant ventricular arrhythmia). Additionally, 27.27% of children died as a consequence of bronchopneumonia, the same percentage died as a consequence of an acquired non-pulmonary disease or after surgery, and 18.18% died as a consequence of congenital malformations. Conclusions: Cardiac disease needs to be thoroughly investigated using multiple tools for all children presenting with heart failure symptoms, those with heart murmurs, and children scheduled for surgery of any type. The intensive care specialist and surgeon need to be aware of any heart pathology before non-cardiac surgical interventions.

Cardiomyopathies in Children and Systemic Disorders When Is It Useful to Look beyond the Heart?

Cardiomyopathy (CMP) is a rare disease in the pediatric population, with a high risk of morbidity and mortality. The genetic etiology of CMPs in children is extremely heterogenous. These two factors play a major role in the difficulties of establishing standard diagnostic and therapeutic protocols. Isolated CMP in children is a frequent finding, mainly caused by sarcomeric gene variants with a detection rate that can reach up to 50% of analyzed cohorts. Complex multisystemic forms of pediatric CMP are even more heterogenous. Few studies in literature take into consideration this topic as the main core since it represents a rarity (systemic CMP) within a rarity (pediatric population CMP). Identifying etiology in this cohort is essential for understanding prognosis, risk stratification, eligibility to heart transplantation and/or mechanical-assisted procedures, preventing multiorgan complications, and relatives' recurrence risk calculation. The previous points represent a cornerstone in patients' empowerment and personalized medical care approach. The aim of this work is to propose a new approach for an algorithm in the setting of the diagnostic framework of systemic pediatric CMP. On the other hand, during the literature review, we noticed a relatively common etiologic pattern in some forms of complex/multisystem CMP. In other words, certain syndromes such as Danon, Vici, Alström, Barth, and Myhre syndrome share a common pathway of directly or indirectly defective "autophagy" process, which appears to be a possible initiating/triggering factor for CMPs. This conjoint aspect could be important for possible prognostic/therapeutic implications in this category of patients. However, multicentric studies detailed functional and experimental models are needed prior to deriving conclusions.

Clinical Profile and Risk Factors for Cardiac Death in Pediatric Patients With Primary Dilated Cardiomyopathy at a Tertiary Medical Center in China

AIM

We sought to identify the clinical characteristics and risk factors for cardiac mortality in pediatric patients with primary dilated cardiomyopathy (DCM) in China.

METHODS

A total of 138 pediatric patients who were consecutively diagnosed with primary DCM from January 2011 to December 2020 were included. We assessed patients' clinical symptoms and performed laboratory examinations, electrocardiography, and echocardiography.

RESULTS

Of these patients, 79 (57%) had severe systolic dysfunction (left ventricular ejection fraction of < 30%), 79 (57.2%) developed DCM before 12 months of age, 62 (45%) were male, 121 (87.7%) presented with advanced heart failure (cardiac functional class III/IV), and 54 (39.1%) presented with arrhythmia. At a median follow-up of 12 months, the overall cardiac mortality rate was 33%, and 40 of 46 deaths occurred within 6 months following DCM diagnosis. A multivariate Cox regression analysis identified several independent cardiac death predictors, including an age of 12 months to 5 years [hazard ratio (HR) 2.799; 95% confidence interval (CI) 1.160-6.758; P = 0.022] or 10-15 years (HR 3.617; 95% CI 1.336-9.788; P = 0.011) at diagnosis, an elevated serum alanine aminotransferase (ALT) concentration (≥ 51.5 U/L) (HR 2.219; 95% CI 1.06-4.574; P = 0.031), and use of mechanical ventilation (HR 4.223; 95% CI 1.763-10.114; P = 0.001).

CONCLUSION

The mortality rate of primary DCM without transplantation is high. Age, an elevated serum ALT concentration, and the need for mechanical ventilation predict mortality in patients with primary DCM, providing new insights into DCM risk stratification.

Outcomes of Dilated Cardiomyopathy in Japanese Children - A Retrospective Cohort Study

BACKGROUND

There has been no nationwide survey on the prognosis of pediatric dilated cardiomyopathy (DCM) in Japan. Therefore, we designed this retrospective multicenter study to investigate the long-term survival rate in pediatric patients with DCM in Japan.Methods and Results:In this multicenter retrospective observational study, data were reviewed for 106 patients aged <18 years who had been diagnosed with DCM at any 1 of 18 Japanese institutions between 1990 and 2014. The median age at diagnosis was 2.0 years and the median duration of observation was 3.3 years. Most DCM patients were diagnosed because of symptoms of heart failure. On echocardiography, the median left ventricular end-diastolic dimension z score was 5.4 and fractional shortening was 0.10. Freedom from death or transplantation rates at 1, 3, 5, 10, and 20 years after diagnosis were 76%, 66%, 64%, 58%, and 43%, respectively. Freedom from death rates at 1, 5, 10, and 20 years after diagnosis were 81%, 75%, 72%, and 53%, respectively. The incidence of heart transplantation at 1, 5, 10, and 20 years after diagnosis was 6%, 15%, 20%, and 20%, respectively, suggesting that only 15% of patients in Japan underwent heart transplantation within 5 years of diagnosis.

CONCLUSIONS

In Japan, the prognosis of pediatric DCM is poor and the rate of heart transplantation is low.

Advanced Heart Failure in Special Population-Pediatric Age

Heart failure (HF) is an important health care issue in children because of its considerable morbidity and mortality. Advanced HF encompasses patients who remained symptomatic despite optimal medical treatment and includes patients who require special management, such as continuous inotropic therapy, mechanical circulatory support, or heart transplantation (HT). HT is the gold standard for children with advanced HF; nonetheless, the number of suitable donors has not increased for decades, leading to prolonged waitlist times and increased mortality rates. Therefore, the role of pediatric mechanic circulatory support has been assessed as an alternative treatment in patients in whom heart transplant could not be performed. The authors discuss the epidemiology, causes, pathophysiology, clinical manifestation, medical treatment, device therapy, and HT in pediatric HF, and a particular emphasis was posed on patients with advanced HF.

SARS-CoV-2 Myocarditis: Insights Into Incidence, Prognosis, and Therapeutic Implications

Purpose of Review

In coronavirus disease 2019 (COVID-19), myocardial injury occurs frequently in severe or critically ill hospitalized patients, yet myocarditis is much less common. In this context, revisiting the definition of myocarditis is appropriate with a specific focus on diagnostic and management considerations in patients infected with SARS-CoV-2.

Recent Findings

Pathologic cardiac specimens from patients with COVID-19 suggest a mixed inflammatory response involving lymphocytes and macrophages, and importantly, cellular injury occurs predominantly at the level of pericytes and endothelial cells, less often involving direct myocyte necrosis. In COVID-19, the diagnosis of myocarditis has understandably been based predominantly on clinical criteria, and the number of patients with clinically suspected myocarditis who would meet diagnostic histological criteria is unclear. Echocardiography and cardiac magnetic resonance are important diagnostic tools, although the prognostic implications of abnormalities are still being defined. Importantly, SARS-CoV2 myocarditis should be diagnosed within an appropriate clinical context and should not be based on isolated imaging findings. Therapies in COVID-19 have focused on the major clinical manifestation of pneumonia, but the promotion of viral clearance early in the disease could prevent the development of myocarditis, and further study of immunosuppressive therapies once myocarditis has developed are indicated.

Summary

A strict and uniform approach is needed to diagnose myocarditis due to SARS-CoV-2 to better understand the natural history of this disease and to facilitate evaluation of potential therapeutic interventions. A methodological approach will also better inform the incidence of COVID-19 associated myocarditis and potential long-term health effects.

Cardiosphere-derived exosomal microRNAs for myocardial repair in pediatric dilated cardiomyopathy

Although cardiosphere-derived cells (CDCs) improve cardiac function and outcomes in patients with single ventricle physiology, little is known about their safety and therapeutic benefit in children with dilated cardiomyopathy (DCM). We aimed to determine the safety and efficacy of CDCs in a porcine model of DCM and translate the preclinical results into this patient population. A swine model of DCM using intracoronary injection of microspheres created cardiac dysfunction. Forty pigs were randomized as preclinical validation of the delivery method and CDC doses, and CDC-secreted exosome (CDCex)-mediated cardiac repair was analyzed. A phase 1 safety cohort enrolled five pediatric patients with DCM and reduced ejection fraction to receive CDC infusion. The primary endpoint was to assess safety, and the secondary outcome measure was change in cardiac function. Improved cardiac function and reduced myocardial fibrosis were noted in animals treated with CDCs compared with placebo. These functional benefits were mediated via CDCex that were highly enriched with proangiogenic and cardioprotective microRNAs (miRNAs), whereas isolated CDCex did not recapitulate these reparative effects. One-year follow-up of safety lead-in stage was completed with favorable profile and preliminary efficacy outcomes. Increased CDCex-derived miR-146a-5p expression was associated with the reduction in myocardial fibrosis via suppression of proinflammatory cytokines and transcripts. Collectively, intracoronary CDC administration is safe and improves cardiac function through CDCex in a porcine model of DCM. The safety lead-in results in patients provide a translational framework for further studies of randomized trials and CDCex-derived miRNAs as potential paracrine mediators underlying this therapeutic strategy.

Myc is involved in Genistein protecting against LPS-induced myocarditis in vitro through mediating MAPK/JNK signaling pathway

BACKGROUND

Genistein is widely used as a pharmacological compound as well as a food additive. However, the pharmaceutical effects of Genistein on myocarditis and its potential mechanisms have not been studied in detail.

METHODS

H9c2 cells were continuously stimulated by lipopolysaccharide (LPS) for 12 h to simulate the in vitro model of myocarditis injury. DrugBank, String, and GEO dataset were used to investigate specific genes that interacting with Genistein. KEGG and GO enrichment analysis were employed to explore Myc-related signaling pathways. Biological behaviors of H9c2 cells were observed with the support of cell counting kit-8, MTT and flow cytometry. Expression levels of cytokines including TNF-α and ILs were evaluated by enzyme-linked immunosorbent assay. Western blot was applied to detect the expression of Myc and MAPK pathway related proteins.

RESULTS

Genistein alleviated the damage of H9c2 cells subjected to LPS from the perspective of elevating cells growth ability, and inhibiting cells apoptosis and inflammatory response. Through bioinformatics analysis, we identified Myc as the potential target of Genistein in myocarditis, and MAPK as the signaling pathway. Significantly, Myc was highly up-regulated in myocarditis samples. More importantly, by performing biological experiments, we discovered that Genistein relieved H9c2 cells apoptosis and inflammatory reaction which caused by LPS stimulation through inhibiting Myc expression. Additionally, the marked augmentation of p-P38 MAPK and p-JNK expression in LPS-induced cardiomyocyte model were blocked by Genistein and si-Myc.

CONCLUSIONS

Our research revealed that Myc mediated the protective effects of Genistein on H9c2 cells damage caused by LPS partly through modulation of MAPK/JNK signaling pathway.

Predicting outcome in children with dilated cardiomyopathy: the use of repeated measurements of risk factors for outcome

Aims

We aimed to determine whether in children with dilated cardiomyopathy repeated measurement of known risk factors for death or heart transplantation (HTx) during disease progression can identify children at the highest risk for adverse outcome.

Methods and results

Of 137 children we included in a prospective cohort, 36 (26%) reached the study endpoint (SE: all‐cause death or HTx), 15 (11%) died at a median of 0.09 years [inter‐quartile range (IQR) 0.03–0.7] after diagnosis, and 21 (15%) underwent HTx at a median of 2.9 years [IQR 0.8–6.1] after diagnosis. Median follow‐up was 2.1 years [IQR 0.8–4.3]. Twenty‐three children recovered at a median of 0.6 years [IQR 0.5–1.4] after diagnosis, and 78 children had ongoing disease at the end of the study. Children who reached the SE could be distinguished from those who did not, based on the temporal evolution of four risk factors: stunting of length growth (−0.42 vs. −0.02 length Z‐score per year, P < 0.001), less decrease in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) (−0.26 vs. −1.06 2log pg/mL/year, P < 0.01), no decrease in left ventricular internal diastolic dimension (LVIDd; 0.24 vs. −0.60 Boston Z‐score per year, P < 0.01), and increase in New York University Pediatric Heart Failure Index (NYU PHFI; 0.49 vs. −1.16 per year, P < 0.001). When we compared children who reached the SE with those with ongoing disease (leaving out the children who recovered), we found similar results, although the effects were smaller. In univariate analysis, NT‐proBNP, length Z‐score, LVIDd Z‐score, global longitudinal strain (%), NYU PHFI, and age >6 years at presentation (all P < 0.001) were predictive of adverse outcome. In multivariate analysis, NT‐proBNP appeared the only independent predictor for adverse outcome, a two‐fold higher NT‐proBNP was associated with a 2.8 times higher risk of the SE (hazard ratio 2.78, 95% confidence interval 1.81–3.94, P < 0.001).

Conclusions

The evolution over time of NT‐proBNP, LVIDd, length growth, and NYU PHFI identified a subgroup of children with dilated cardiomyopathy at high risk for adverse outcome. In this sample, with a limited number of endpoints, NT‐proBNP was the strongest independent predictor for adverse outcome.

Efficacy of L-Carnitine for Dilated Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

L-carnitine mediates the utilization of fatty acids and glucose in the myocardium. The potential of L-carnitine in managing dilated cardiomyopathy (DCM) in patients has been extensively reported, with additional benefits.

OBJECTIVE

This meta-analysis purposed to explore the clinical efficacy of L-carnitine therapy on DCM patients.

METHODS

We searched publications up to May 2020 from several databases including PubMed, Embase, Cochrane Library, Chinese Biomedical (CBM) database, Chinese Science and Technology Periodicals database (VIP), Chinese National Knowledge Infrastructure (CNKI) database, and Wanfang database. Subsequently, publications that met the inclusion criteria were systematically evaluated by two independent reviewers.

RESULTS

A total of 23 RCTs conducted in China with 1455 DCM patients were included in this study. In the meta-analysis, L-carnitine therapy was associated with a considerable improvement in the overall efficacy (RR = 1.28, 95% CI (1.21-1.36), P < 0.0001), left ventricular ejection fraction (LVEF) (MD = 6.16%, 95% CI (4.50, 7.83), P < 0.0001), and cardiac output (CO) (MD = 0.88 L/min, 95% CI (0.51, 1.25), P < 0.0001) as compared to the control group. Moreover, L-carnitine therapy significantly decreased left ventricular end-diastolic dimension (LVEDD) (MD = -2.53, 95% CI (-3.95, -1.12), P = 0.0005), brain natriuretic peptide (BNP) (SMD = -1.71 ng/L, 95% CI (-3.02, -0.40), P = 0.01), and the transforming growth factor-beta (TGF-β1) (MD = -56.78 ng/L, 95% CI (-66.02, -47.53), P < 0.0001).

CONCLUSIONS

L-carnitine potentially enhanced the therapeutic efficiency in DCM patients. Following weaknesses in the evidence due to low methodological quality and high clinical heterogeneity in the included studies, well-designed trials are recommended.

Development of Cardiac Events and Functional Recovery Prediction Models for Pediatric Dilated Cardiomyopathy

Background: Since both the risk of death and the probability of spontaneous functional recovery (FR) coexist in association with pediatric dilated cardiomyopathy (DCMP), management should be based on individualized outcome predictions. Methods: A single-center retrospective review of 105 pediatric patients (age at presentation ≤ 18 years) with DCMP, managed between 1994 and 2017, was performed. Logistic regression was conducted to identify variables associated with FR and cardiac events (CEs), i.e., death or heart transplantation (HTPL), within 2 years after initial presentation. Two outcome prediction models were formulated using these variables. Results: Twenty-six (24.8%) and 51 patients (48.6%) experienced FR and CE, respectively, within 2 years after initial presentation. Predictors of mortality without HTPL were earlier era at presentation (HR: 4.13; 95% CI: 1.88-9.06; p < 0.001) and significant TR (≥moderate; HR: 4.31; 95% CI: 1.26-14.77; p = 0.020) in multivariable Cox regression model. Predictors of FR were recent era (HR: 4.49; 95% CI: 1.40-14.44; p = 0.0012), younger age at initial presentation (HR: 0.98 per 1 month increase; 95% CI: 0.97-0.99, p < 0.001), post-myocarditis DCMP (HR: 4.29; 95% CI: 1.32-13.93; p = 0.015), and arrhythmia-mediated DCMP (HR: 26.88; 95% CI: 2.61-276.70; p = 0.006). Risk factors for CEs was idiopathic DCMP (HR: 2.95; 95% CI: 1.32-6.56, p = 0.008). The low-risk group who had higher probability of FR than CE in prediction model had a slightly higher overall survival rate (71.4 vs. 52.2% at 10 years after presentation; log-rank p = 0.09) and a significantly higher HTPL-free survival rate (67.5 vs. 24.9% at 10 years after presentation; log-rank p < 0.001) than the high-risk group. Conclusions: Prognostication and management strategies for pediatric DCMP may be enhanced by risk stratification using outcome prediction modeling.

Differential Expression Profiles and Functional Analysis of Long Non-coding RNAs in Children With Dilated Cardiomyopathy

Aim: To evaluate the expression profile of long non-coding RNAs (lncRNAs) in different left ventricular function of dilated cardiomyopathy (DCM) in children and explore their possible functions. Methods: The lncRNA microarray experiment was used to determine the differential expression profile of lncRNA in three children with DCM and three healthy volunteers. The functional analysis and the construction of the lncRNA-mRNA interaction network were carried out to study the biological functions. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to verify the microarray data. Results: There were 369 up-regulated lncRNAs identified in the DCM patients (fold change >2, P < 0.05), and 505 down-regulated lncRNAs. Based on target gene prediction and co-expression network construction, 9 differentially expressed lncRNAs were selected for the PCR to verify the accuracy of the microarray data, of which 5 were up-regulated and 4 were down-regulated, and finally proved that 7 of them were consistent with the trend of microarray data results. Four of these lncRNAs had significant differences between the patients with poor cardiac function and patients with improved left ventricle function. Conclusion: LncRNAs may play an important role in pediatric DCM and may provide a new perspective for the pathogenesis, diagnosis, and treatment of this disease.

Paediatric dilated cardiomyopathy in Khartoum state, Sudan: a prospective study

BACKGROUND

Dilated cardiomyopathy (DCM) is a disease of the heart muscle that affects ventricular function; it is a debilitating disease that can lead to heart failure and death in children. There is a lack of good epidemiological data about paediatric DCM in Sudan or in sub-Saharan Africa.

OBJECTIVE

To study the incidence, causes and outcome of DCM among children in Sudan.

METHODS

A prospective cross-sectional study that was conducted in three paediatric hospitals in Khartoum state, Sudan over the period of 6 months.

RESULTS

During the study period, 55 children were seen with the diagnosis of DCM; The female: male ratio was 1.9:1. The incidence of DCM in Khartoum state was found to be 1.4 cases per 100 000 children per year, 10 children (18 %) were diagnosed in the first year of their life. Twenty-seven children (49 %) showed evidence of failure to thrive, being below the fifth percentile for weight. The most common cause of DCM was found to be postviral in 27 children (49%), followed by Idiopathic in 25 children (45%). The most common presentation was the shortness of breath in 53 children (97%), on echocardiography 26 children (47 %) showed evidence of severe left ventricular impairment and 23 children (42%) showed moderate ventricular impairment. Regarding the outcome, 8 children (15%) recovered, the condition of 11 children (20%) remained static and there were 36 deaths (65%).

CONCLUSION

The incidence of DCM in Sudanese children was found to high with a higher mortality compared with middle-income and high-income countries; Improvement in the entire health system is needed to tackle this condition.

Longitudinal Prediction of Transplant-Free Survival by Echocardiography in Pediatric Dilated Cardiomyopathy

BACKGROUND

The prognostic significance of serial echocardiography and its rate of change in children with dilated cardiomyopathy (DCM) is incompletely defined.

METHODS

We retrospectively analysed up to 4 serial echocardiograms. Associations between mortality/transplant and echocardiographic parameters over time and between outcomes and the rate of change of echocardiographic parameters were analysed. Estimation of patient-specific intercepts and slopes was done using linear regression models.

RESULTS

Fifty-seven DCM children were studied (50% male; median age, 0.6 year; average follow-up, 2.1 ± 2.4 years). The median time to transplant or death was 2.0 years. Increased left ventricular (LV) diastolic (LVEDD) and systolic (LVESD) dimensions and myocardial performance index (MPI) were associated with increased mortality and transplant risk. Increased LV ejection fraction, mitral E-deceleration time, right ventricular (RV) fractional area change, and tricuspid annular plane systolic excursion were associated with reduced mortality and transplant risk. Transplant/mortality likelihood increased by 41.6% and 19.8% for each unit increase in LVEDD and LVESD z scores, respectively (LVEDD: hazard ratio [HR], 1.416; 95% confidence interval [CI], 1.285-1.560; P < 0.001; LVESD: HR, 1.198; 95% CI, 1.147-1.251; P < 0.001). A higher monthly change in LVESD z score increased transplant/mortality likelihood by 85.6% (HR, 1.856; 95% CI, 1.572-2.191; P = 0.015). Greater changes in mitral E/e' (HR, 0.707; 95% CI, 0.636-0.786; P < 0.001) and RV MPI (HR, 0.412; 95% CI, 0.277-0.613; P < 0.001) were associated with reduced mortality and transplant risk.

CONCLUSIONS

LV and RV systolic and diastolic dimensions and function over time and their rate of change are associated with risk for transplant and mortality in childhood DCM. Serial changes in these parameters may be useful to predict clinical outcomes.

The relationship between electrocardiographic data and mortality in children diagnosed with dilated cardiomyopathy

The mortality causes of patients followed up due to dilated cardiomyopathy (DCM) include complications related to heart failure, ventricular arrhythmia, and transplantation. This study aims to evaluate the electrocardiographic findings of patients diagnosed with dilated cardiomyopathy and determine its relationship with mortality. The electrocardiographic, clinical, and laboratory findings of patients diagnosed with dilated cardiomyopathy between January 1, 2012, and September 1, 2018, in our university's pediatric cardiology department were retrospectively evaluated. The electrocardiographic findings of surviving and exitus dilated cardiomyopathy patients were compared and their effect on mortality was investigated. Twelve of the total 85 patients diagnosed with dilated cardiomyopathy were deceased. According to the electrocardiographic findings of surviving and exitus patients, there was a statistically significant difference in terms of P maximum (Pmax), P dispersion (Pdis), QT dispersion (QTdis), QTc maximum (QTcmax), QTc dispersion (QTcdis), Tp-e maximum (Tp-emax), Tp-e dispersion (Tp-edis), and QRS time. Hypertrophy and ischemia findings of electrocardiography were also statistically significant. There was a statistically significant difference between the two groups according to the echocardiographic findings of left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVSF), left ventricular end-diastolic diameter (LVEDd), and left ventricular end-systolic diameter (LVESd) measurements. It is well known that children diagnosed with dilated cardiomyopathy are at greater risk of arrhythmia compared with normal children. Although previous studies have determined the relationship between mortality and a limited number of electrocardiographic findings, especially in adults, the relationship between electrocardiography findings of children diagnosed with DCM and mortality has not been investigated before in such detail, as in our study.Conclusion: In this study, the significant difference between the electrocardiographic data of deceased and surviving dilated cardiomyopathy patients suggests that electrocardiographic data should be evaluated in detail in order to determine the low and high risk of mortality in patients with dilated cardiomyopathy.What is Known:• Previous studies on the relationship between limited electrocardiography data of adult patients diagnosed with DCM and mortality have been determinedWhat is New:• ECG data has not been investigated in such detail in child DCM patients, as in our study.

Paediatric cardiomyopathies: echocardiographic diagnosis, clinical profile, and demographic characteristics: the experience of a tertiary referral centre for Latin American paediatric cardiology

BACKGROUND

Although multiple studies have been conducted in the adult population, there is a vast knowledge gap regarding the epidemiologic characteristics of cardiomyopathies in the paediatric population. This issue is even more crucial when the precarious situation of medical research in Latin America is considered. Given the potential impact that these disorders could have on Latin American health systems, a comprehensive epidemiologic study regarding the clinical profile and sociodemographic characteristics of these patients will influence the way we approach paediatric cardiomyopathies.

METHODS

An observational retrospective study was conducted at a tertiary referral centre for Colombian and Latin American paediatric cardiology. We analysed all cases of primary cardiomyopathies in children younger than 18 years of age who presented at our institution between 2010 and 2016. Cases of cardiomyopathies were classified according to World Health Organization guidelines.

RESULTS

From a total of 29,533 children who attended our institution during the study period, 89 new cases of primary cardiomyopathies were identified. The median age at diagnosis was 11 years (interquartile range 4-9). Dilated cardiomyopathy accounted for 57.3% (n = 51) of cases; hypertrophic cardiomyopathy, 12.3% (n = 11); restrictive cardiomyopathy, 8.9% (n = 8); non-compacted cardiomyopathy, 7.8% (n = 7); arrhythmogenic ventricular cardiomyopathy, 6.7% (n = 6); and unspecified cardiomyopathy, 6.7% (n = 6). Heart failure was observed in 53.93% of the patients. The overall mortality was 12.36% (n = 11), which included two of eight patients who underwent cardiac transplantation.

[Association of T-wave amplitude on electrocardiogram with left ventricular ejection fraction in children with dilated cardiomyopathy]

OBJECTIVE

To study the association of T-wave amplitude on electrocardiogram (ECG) with left ventricular ejection fraction (LVEF) in children with dilated cardiomyopathy.

METHODS

A retrospective analysis was performed for the clinical data of 44 children who were diagnosed with dilated cardiomyopathy from May 2009 to June 2018. According to LVEF, they were divided into two groups: LVEF ≥50% group (n=26) and LVEF <50% group (n=18). After treatment, 25 children were followed up for 3-42 months (mean 14±9 months). The Guangdong Zhongshan SR-1000A ECG Automatic Analyzer was used to obtain the 12-lead body surface ECG results in the supine position. T-wave amplitude on ECG was evaluated by software and manual measurement.

RESULTS

Compared with the LVEF ≥50% group, the LVEF <50% group had a significant reduction in the T-wave amplitude in leads II, V4, V5 and V6 (P<0.05). The increased-LVEF group (an increase in LVEF > 5% after treatment) had a significant increase in the T-wave amplitude in leads aVR, V5, and V6 after treatment (P<0.05), while the unchanged-LVEF group (an increase in LVEF ≤ 5% after treatment) had a significant reduction in the T-wave amplitude in lead aVR after treatment (P<0.05). The receiver operating characteristic curve analysis showed that the T-wave amplitude in leads II, V4, V5 and V6 had a certain value in predicting LVEF <50% in children with dilated cardiomyopathy (P<0.05). A combination of T-wave amplitude of ≤0.20 mV in lead II, ≤0.40 mV in lead V4, and ≤0.30 mV in leads V5 and V6 had a sensitivity of 88.2% and specificity of 76.0% in the predication of LVEF <50% in children with dilated cardiomyopathy.

CONCLUSIONS

T-wave amplitude on ECG can be used as the indexes for the evaluation of the left ventricular systolic function in children with dilated cardiomyopathy.

Prognostic significance of tissue Doppler imaging-derived myocardial performance index in pediatric patients with dilated cardiomyopathy

TDI-MPI has been shown to predict cardiovascular mortality in adults; there are a paucity of data on its use in children. We sought to determine the prognostic significance of TDI-MPI at time of DCM diagnosis in children. Patients aged ≤18 years diagnosed with DCM were included along with age- and sex-matched controls. Echo at diagnosis was analyzed to obtain standard measures of LV function, PW-MPI, and septal and LV free wall TDI-MPI. Survival analysis was used to assess the time to composite outcome of death, VAD, or transplant, stratified by TDI-MPI z-score. The study included 79 patients with DCM and 79 controls. During a median follow-up of 182 days (IQR 41-815 days), 16 underwent VAD placement, 21 underwent cardiac transplant, 6 died, and 36 had event-free survival. The median septal TDI-MPI for cases was 0.70 for patients with DCM vs 0.45 for controls (P < .001). Those with septal TDI-MPI z-scores ≥2 develop events significantly earlier than those with z-score <2 (P = .014). In multivariable analysis, TDI-MPI z-score ≥2 was significantly associated with poor outcomes (HR 2.12, 95% CI 1.06-4.23). TDI-MPI can be reliably performed in pediatric patients with DCM. A TDI-MPI z-score ≥2 at diagnosis may be associated with earlier poor outcome. Further studies evaluating the use of TDI-MPI in longitudinal follow-up of patients with DCM may be helpful in refining its clinical use.

Left Ventricular Layer-Specific Myocardial Strains in Children with Recovered Primary Dilated Cardiomyopathy: What Lies Beneath the Iceberg?

We aimed to detect residual cardiac dysfunction-if any-in children with recovered primary dilated cardiomyopathy (DCM) by using the left ventricular (LV) layer-specific myocardial strains. Fifty children with recovered primary DCM both clinically and echocardiographically were included as the patient group. Fifty healthy children of matched age and sex served as the control group. Echocardiographic evaluation was performed for all included children in the form of conventional echocardiography, tissue Doppler imaging (TDI), two-dimensional speckle tracking echocardiography (2D-STE), and LV layer-specific myocardial strain. Both LV systolic and diastolic functions measured by conventional echocardiography were similar in children with recovered DCM and the control group. There was a significant reduction in LV systolic and diastolic functions measured by TDI in the patient group. Moreover, there was a significant reduction of LV global longitudinal systolic strain (GLSS) by 2D-STE in children with recovered DCM. Interestingly, there was a significant reduction of LV layer-specific myocardial strain from endocardium to epicardium in children with recovered DCM compared to the healthy control. There was a significant positive correlation between different layer-specific myocardial strains and LV GLSS, LV ejection fraction, and LV peak systolic velocity. Left ventricular layer-specific myocardial strain can be a promising tool for early identifications of LV dysfunction in children with DCM. Subtle cardiac dysfunction is present in patients with recovered DCM, so long-term follow-up is recommended in these patients.

Sudden Cardiac Death in Children Affected by Cardiomyopathies: An Update on Risk Factors and Indications at Transvenous or Subcutaneous Implantable Defibrillators

In the present paper, we will discuss the main cardiomyopathies affecting children with a specific focus on risk stratification and prevention of sudden cardiac death (SCD). We will discuss the main clinical features of hypertrophic cardiomyopathy (HCM), dilated and restrictive cardiomyopathies, left ventricular non-compaction (LVNC) and arrhythmogenic cardiomyopathy (AC), always highlighting their peculiarities in the pediatric age. Since sudden cardiac death may be the first manifestation of the disease, even in children, the identification of the specific underlying condition and of risk factors are pivotal to carry out the appropriate preventing strategies. ICD recommendations in children are similar to adults, but supporting evidences are not so solid, being based on registries or single center studies. Furthermore, children and young patients are most likely to manifest long term complications related to an implanted ICD, and this should be taken into account when evaluating the risk benefit ratio. In this perspective, subcutaneous ICDs (S-ICDs) could carry an advantage; however, they cannot be considered in small children for technical reasons. Data on effectiveness and safety of S-ICDs in a pediatric population is still lacking, although some limited experiences are reported and will be discussed in the current review.

Does Repeated Measurement of a 6-Min Walk Test Contribute to Risk Prediction in Children with Dilated Cardiomyopathy?

A single 6-min walk test (6MWT) can be used to identify children with dilated cardiomyopathy (DCM) with a high risk of death or heart transplantation. To determine if repeated 6MWT has added value in addition to a single 6MWT in predicting death or heart transplantation in children with DCM. Prospective multicenter cohort study including ambulatory DCM patients ≥ 6 years. A 6MWT was performed 1 to 4 times per year. The distance walked was expressed as percentage of predicted (6MWD%). We compared the temporal evolution of 6MWD% in patients with and without the study endpoint (SE: all-cause death or heart transplantation), using a linear mixed effects model. In 57 patients, we obtained a median of 4 (IQR 2-6) 6MWTs per patient during a median of 3.0 years of observation (IQR 1.5-5.1). Fourteen patients reached a SE (3 deaths, 11 heart transplantations). At any time during follow-up, the average estimate of 6MWD% was significantly lower in patients with a SE compared to patients without a SE. In both patients groups, 6MWD% remained constant over time. An absolute 1% lower 6MWD% was associated with an 11% higher risk (hazard) of the SE (HR 0.90, 95% CI 0.86-0.95 p < 0.001). Children with DCM who died or underwent heart transplantation had systematically reduced 6MWD%. The performance of all patients was stable over time, so repeated measurement of 6MWT within this time frame had little added value over a single test.

Cardiac Biomarkers in Pediatric Cardiomyopathy: Study Design and Recruitment Results from the Pediatric Cardiomyopathy Registry

Background

Cardiomyopathies are a rare cause of pediatric heart disease, but they are one of the leading causes of heart failure admissions, sudden death, and need for heart transplant in childhood. Reports from the Pediatric Cardiomyopathy Registry (PCMR) have shown that almost 40% of children presenting with symptomatic cardiomyopathy either die or undergo heart transplant within 2 years of presentation. Little is known regarding circulating biomarkers as predictors of outcome in pediatric cardiomyopathy.

Study Design

The Cardiac Biomarkers in Pediatric Cardiomyopathy (PCM Biomarkers) study is a multi-center prospective study conducted by the PCMR investigators to identify serum biomarkers for predicting outcome in children with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Patients less than 21 years of age with either DCM or HCM were eligible. Those with DCM were enrolled into cohorts based on time from cardiomyopathy diagnosis: categorized as new onset or chronic. Clinical endpoints included sudden death and progressive heart failure.

Results

There were 288 children diagnosed at a mean age of 7.2±6.3 years who enrolled in the PCM Biomarkers Study at a median time from diagnosis to enrollment of 1.9 years. There were 80 children enrolled in the new onset DCM cohort, defined as diagnosis at or 12 months prior to enrollment. The median age at diagnosis for the new onset DCM was 1.7 years and median time from diagnosis to enrollment was 0.1 years. There were 141 children enrolled with either chronic DCM or chronic HCM, defined as children ≥2 years from diagnosis to enrollment. Among children with chronic cardiomyopathy, median age at diagnosis was 3.4 years and median time from diagnosis to enrollment was 4.8 years.

Conclusion

The PCM Biomarkers study is evaluating the predictive value of serum biomarkers to aid in the prognosis and management of children with DCM and HCM. The results will provide valuable information where data are lacking in children.

Clinical Trial Registration NCT01873976

https://clinicaltrials.gov/ct2/show/NCT01873976?term=PCM+Biomarker&rank=1.

Left Atrial Strain to Identify Diastolic Dysfunction in Children with Cardiomyopathies

Background: Left ventricular (LV) diastolic dysfunction (DD) carries worse prognosis in childhood. 2-dimensional (2-D) left atrial (LA) strain accurately categorizes DD in adults but its role in children is unknown. Thus, the aim of this study is to investigate whether LA strain and strain rate could diagnose and classify DD in children with dilated (CMD), hypertrophic (HCM) and restrictive (RCM) cardiomyopathies (CM). Methods and Results: The study includes 136 children (aged 8.8 ± 6 years): 44 with DCM, 40 with HCM, 7 with RCM and 45 healthy controls (CTRL). They underwent standard echocardiographic examination and 2-D speckle-tracking analyses (LV longitudinal peak systolic strain (LS), LA peak systolic strain and strain rate). No significant differences in mitral E/A and pulmonary S/D ratios were observed among the four groups. Although E/E’ and indexed left atrial volumes were found to be significantly higher in HCM, DCM and RCM compared to CTRL (p < 0.001), they showed no significant difference among the three CM groups. LV LS values were significantly reduced in CM vs CTRL (p < 0.001) and in DCM vs HCM (p < 0.01), with no other differences between the remaining groups. LA peak systolic strain and strain rate values showed a steady and significant decrease with worsening of DD. Receiver Operating Characteristics (ROC) curves showed area under the curve of 0.976 (p < 0.001) for LA strain and 0.946 (p < 0.001) for LA strain rate, to distinguish CTRL from CMs. Conclusions: LA strain and strain rate could be a promising tool to better understand and classify DD in children with cardiomyopathies, opening the way to its clinical use.

Outcome for children following admission to hospital with a first episode of heart failure, due to heart muscle disease, in the ventricular assist device (VAD) era

AIMS

Most reports on the outcome of children who present with heart failure, due to heart muscle disease, are from an era when ventricular assist devices were not available. This study provides outcome data for the current era where prolonged circulatory support can be considered for most children.

METHODS & RESULTS

Data was retrieved on 100 consecutive children, who presented between 2010 - 2016, with a first diagnosis of unexplained heart failure. Hospital outcome was classified as either death, transplantation, recovery of function or persistent heart failure. Median age at presentation was 24 months and 58% were < 5 years old. Hospital mortality was 12% and 59% received a heart transplant. Most, 79%, of the transplants were carried out on patients with a device. Recovery of function was observed in 18% and 10% stabilised on oral therapy. Eighty-four percent of the deaths occurred in the <5 year old group. Shorter duration of support was associated with survival (34 days in survivors versus 106 in non-survivors, p = 0.01) and 72% were on an assist device at time of death.

CONCLUSION

Heart failure in children who require referral to a transplant unit is a serious illness with a high chance of either transplantation or death. Modifications in assist devices will be required to improve safety, especially for children < 5 years old where the donor wait may be prolonged. The identification of children who may recover function requires further study.

Cardiomyopathy in Children: Classification and Diagnosis: A Scientific Statement From the American Heart Association

In this scientific statement from the American Heart Association, experts in the field of cardiomyopathy (heart muscle disease) in children address 2 issues: the most current understanding of the causes of cardiomyopathy in children and the optimal approaches to diagnosis cardiomyopathy in children. Cardiomyopathies result in some of the worst pediatric cardiology outcomes; nearly 40% of children who present with symptomatic cardiomyopathy undergo a heart transplantation or die within the first 2 years after diagnosis. The percentage of children with cardiomyopathy who underwent a heart transplantation has not declined over the past 10 years, and cardiomyopathy remains the leading cause of transplantation for children >1 year of age. Studies from the National Heart, Lung, and Blood Institute-funded Pediatric Cardiomyopathy Registry have shown that causes are established in very few children with cardiomyopathy, yet genetic causes are likely to be present in most. The incidence of pediatric cardiomyopathy is ≈1 per 100 000 children. This is comparable to the incidence of such childhood cancers as lymphoma, Wilms tumor, and neuroblastoma. However, the published research and scientific conferences focused on pediatric cardiomyopathy are sparcer than for those cancers. The aim of the statement is to focus on the diagnosis and classification of cardiomyopathy. We anticipate that this report will help shape the future research priorities in this set of diseases to achieve earlier diagnosis, improved clinical outcomes, and better quality of life for these children and their families.

Effects of pulmonary artery banding in doxorubicin-induced left ventricular cardiomyopathy

OBJECTIVE

Central pulmonary banding has been proposed as a novel alternative for the treatment of left ventricular dilated cardiomyopathy in children. We sought to investigate the effects of central pulmonary banding in an experimental model of doxorubicin-induced left ventricular dilated cardiomyopathy.

METHODS

Four-month-old sheep (n = 28) were treated with intermittent intracoronary injections of doxorubicin (0.75 mg/kg/dose) into the left main coronary artery. A total dose of up to 2.15 mg/kg of doxorubicin was administered until signs of left ventricular dilation with functional impairment occurred by transthoracic echocardiography evaluation. Animals that survived were treated with surgical central pulmonary banding through a left anterior thoracotomy or sham surgery. Transthoracic echocardiography and pressure-volume loop measurements were used to compare left ventricular function preoperatively and 3 months later. Macroscopic and microscopic histologic examinations followed after hearts were harvested.

RESULTS

Nine animals from the central pulmonary banding group and 8 animals from the sham group survived and were included in the final analysis. Both groups showed similar inflammation and fibrosis upon histologic examination consistent with the toxic myocardial effects of doxorubicin. There were no differences in the echocardiographic measurements before central pulmonary banding or sham operation. Baseline measurements before the central pulmonary banding/sham operation were considered as 100%. The central pulmonary banding group had better left ventricular ejection fraction (102.5% ± 21.6% vs 76.7% ± 11.7%, P = .01), with a tendency for smaller left ventricular end-diastolic (101.2% ± 7.4% vs 120.4% ± 10.8%, P = .18) and significantly smaller end-systolic (100.3% ± 12.9% vs 116.5 ± 9.6%, P = .02) diameter of the left ventricle in comparison with the sham animals at 3 months. The end-systolic volume (101.4% ± 31.6% vs 143.4% ± 28.6%, P = .02) was significantly lower in the central pulmonary banding group 3 months postoperatively. Fractional shortening in the long axis (118.5% ± 21.5% vs 85.2% ± 22.8%, P = .016) and short axis (122.5% ± 18% vs 80.9% ± 13.6%, P = .0005) revealed significantly higher values in the central pulmonary banding group. In the conductance catheter measurements, no significant differences were seen between the groups for the parameters of systolic and diastolic function.

CONCLUSIONS

Central pulmonary artery banding in the setting of experimental toxic left ventricular dilated cardiomyopathy improved left ventricular echocardiographic function and dimensions.

Ventricular Arterial Coupling: A Novel Echocardiographic Risk Factor for Disease Progression in Pediatric Dilated Cardiomyopathy

In adult heart failure (HF) patients, a higher ventricular arterial (VA) coupling ratio measured non-invasively is associated with worse HF prognosis and response to treatment. There are no data regarding the relationship of VA coupling to outcome in pediatric dilated cardiomyopathy (DCM) patients. We investigated the association of VA coupling ratio with worse outcome (mechanical circulatory support, transplant, or death) in 48 children with DCM and 97 age-gender matched controls. Mean age at presentation was 9 ± 7 years; DCM patients had a higher arterial elastance (3.8 ± 1.7 vs 2.7 ± 0.7 respectively p = 0.001), a lower LV elastance (1.1 ± 0.65 vs 4.5 ± 1.4, respectively p = 0.001) and higher VA coupling ratio (5.0 ± 3.9 vs 0.34 ± 0.14, respectively p = 0.001). Outcome events occurred in 27/48 (56%) patients. Patients with an outcome event had a higher NYHA class (p = 0.001), lower LV elastance (0.8 ± 0.47 vs 1.6 ± 0.57, respectively p = 0.001), higher arterial elastance (4.5 ± 1.8 vs 2.9 ± 1.1, respectively p = 0.002), and a higher VA coupling ratio (7.1 ± 3.8 vs 2.2 ± 1.5, respectively p = 0.001) compared to those without. In a multivariate CART analysis, VA coupling was the top and only discriminator of poor outcome. In conclusion, a higher VA coupling ratio is associated with worse outcome in pediatric patients with DCM. VA coupling is promising as a bedside analysis tool that may provide insight into the mechanisms of HF in pediatric DCM and identify potential targets for therapy.

Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a clinical diagnosis characterized by left ventricular or biventricular dilation and impaired contraction that is not explained by abnormal loading conditions (for example, hypertension and valvular heart disease) or coronary artery disease. Mutations in several genes can cause DCM, including genes encoding structural components of the sarcomere and desmosome. Nongenetic forms of DCM can result from different aetiologies, including inflammation of the myocardium due to an infection (mostly viral); exposure to drugs, toxins or allergens; and systemic endocrine or autoimmune diseases. The heterogeneous aetiology and clinical presentation of DCM make a correct and timely diagnosis challenging. Echocardiography and other imaging techniques are required to assess ventricular dysfunction and adverse myocardial remodelling, and immunological and histological analyses of an endomyocardial biopsy sample are indicated when inflammation or infection is suspected. As DCM eventually leads to impaired contractility, standard approaches to prevent or treat heart failure are the first-line treatment for patients with DCM. Cardiac resynchronization therapy and implantable cardioverter-defibrillators may be required to prevent life-threatening arrhythmias. In addition, identifying the probable cause of DCM helps tailor specific therapies to improve prognosis. An improved aetiology-driven personalized approach to clinical care will benefit patients with DCM, as will new diagnostic tools, such as serum biomarkers, that enable early diagnosis and treatment.

Application of competing risks analysis improved prognostic assessment of patients with decompensated chronic heart failure and reduced left ventricular ejection fraction

OBJECTIVE

The Kaplan-Meier method may overestimate absolute mortality risk (AMR) in the presence of competing risks. Urgent heart transplantation (UHT) and ventricular assist device implantation (VADi) are important competing events in heart failure. We sought to quantify the extent of bias of the Kaplan-Meier method in estimating AMR in the presence of competing events and to analyze the effect of covariates on the hazard for death and competing events in the clinical model of decompensated chronic heart failure with reduced ejection fraction (DCHFrEF).

STUDY DESIGN AND SETTING

We studied 683 patients. We used the cumulative incidence function (CIF) to estimate the AMR at 1 year. CIF estimate was compared with the Kaplan-Meier estimate. The Fine-Gray subdistribution hazard analysis was used to assess the effect of covariates on the hazard for death and UHT/VADi.

RESULTS

The Kaplan-Meier estimate of the AMR was 0.272, whereas the CIF estimate was 0.246. The difference was more pronounced in the patient subgroup with advanced DCHF (0.424 vs. 0.338). The Fine-Gray subdistribution hazard analysis revealed that established risk markers have qualitatively different effects on the incidence of death or UHT/VADi.

CONCLUSION

Competing risks analysis allows more accurately estimating AMR and better understanding the association between covariates and major outcomes in DCHFrEF.

The highest mortality rates in childhood dilated cardiomyopathy occur during the first year after diagnosis

Aim

The aim of the study was to assess the incidence, mortality and morbidity of dilated cardiomyopathy (DCM) and noncompaction of the left ventricle (LVNC) in Swedish children.

Methods

We reviewed hospital records of all children with dilated cardiomyopathy (DCM) or left ventricular noncompaction cardiomyopathy (LVNC) up to the age of 18 in the healthcare region of western Sweden from 1991 to 2015.

Results

In total, 69 cases (61% males) were identified. The combined incidence of DCM and LVNC was 0.77 (95% CI 0.59‐0.96) per 100 000 person years. Children were divided into six groups, and their outcomes were analysed depending on their aetiology. Idiopathic DCM was reported in 43%, and familial dilated and left ventricular noncompaction aetiology was present in 32%. DCM due to various diseases occurred in 8%. DCM associated with neuromuscular diseases was present in 16%. The overall risk of death or receiving transplants in children with idiopathic and familial DCM was 30% over the study period, and 21% died in the first year after diagnosis.

Conclusion

The combined incidence of DCM and LVNC was similar to previous reports. Most children with idiopathic DCM presented during infancy, and mortality was highest during the first year after diagnosis.

Circulating microRNA signature for the diagnosis of childhood dilated cardiomyopathy

Circulating miRNAs are proposed as a biomarker of heart disease. This study evaluated whether circulating miRNAs could be used as a biomarker for childhood dilated cardiomyopathy (CDCM). A total of 28 participants were enrolled in a discovery set, including patients with CDCM (n = 16) and healthy children (n = 12). The cardiac function of patients with CDCM was characterized by echocardiography and serum miRNA profiles of all participants were assessed by miRNA sequencing. After miRNA profiling, we quantitatively confirmed 148 regulated miRNAs in patients with CDCM compared with healthy subjects, and none were downregulated. Validation of candidate miRNAs was assessed by quantitative real-time polymerase chain reaction in other patients with CDCM (n = 30) and healthy controls (n = 16). A unique signature comprising mir-142-5p, mir-143-3p, mir-27b-3p, and mir-126-3p differentiated patients with CDCM from healthy subjects. Importantly, we observed an increase in mir-126-3p or let-7g in parallel with a robust decrease in the ejection fraction in patients with CDCM, which could differentiate heart failure patients from non-heart failure patients with CDCM. Moreover, mir-126-3p and let-7g were significantly negatively associated with the left ventricular ejection fraction. This study shows that a signature of four serum miRNAs may be a potential biomarker for diagnosing CDCM and assessing heart failure.

Systematic Literature Review on the Incidence and Prevalence of Heart Failure in Children and Adolescents

While the epidemiology of adult heart failure has been extensively researched, this systematic review addresses the less well characterized incidence and prevalence of pediatric HF. The search strategy used Cochrane methodology and identified 83 unique studies for inclusion. Studies were categorized according to whether the HF diagnosis was reported as primary (n = 10); associated with other cardiovascular diseases (CVDs) (n = 49); or associated with non-CVDs (n = 24). A narrative synthesis of the evidence is presented. For primary HF, the incidence ranged from 0.87/100,000 (UK and Ireland) to 7.4/100,000 (Taiwan). A prevalence of 83.3/100,000 was reported in one large population-based study from Spain. HF etiology varied across regions with lower respiratory tract infections and severe anemia predominating in lower income countries, and cardiomyopathies and congenital heart disease major causes in higher income countries. Key findings for the other categories included a prevalence of HF associated with cardiomyopathies ranging from 36.1% (Japan) to 79% (US); associated with congenital heart disease from 8% (Norway) to 82.2% (Nigeria); associated with rheumatic heart diseases from 1.5% (Turkey) to 74% (Zimbabwe); associated with renal disorders from 3.8% (India) to 24.1% (Nigeria); and associated with HIV from 1% (US) to 29.3% (Brazil). To our knowledge, this is the first systematic review of the topic and strengthens current knowledge of pediatric HF epidemiology. Although a large body of research was identified, heterogeneity in study design and diagnostic criteria limited the ability to compare regional data. Standardized definitions of pediatric HF are required to facilitate cross-regional comparisons of epidemiological data.

Survival Without Cardiac Transplantation Among Children With Dilated Cardiomyopathy

BACKGROUND

Studies of children with dilated cardiomyopathy (DCM) have suggested that improved survival has been primarily due to utilization of heart transplantation.

OBJECTIVES

This study sought to determine transplant-free survival for these children over 20 years and identify the clinical characteristics at diagnosis that predicted death.

METHODS

Children <18 years of age with some type of DCM enrolled in the Pediatric Cardiomyopathy Registry were divided by year of diagnosis into an early cohort (1990 to 1999) and a late cohort (2000 to 2009). Competing risks and multivariable modeling were used to estimate the cumulative incidence of death, transplant, and echocardiographic normalization by cohort and to identify the factors associated with death.

RESULTS

Of 1,953 children, 1,199 were in the early cohort and 754 were in the late cohort. Most children in both cohorts had idiopathic DCM (64% vs. 63%, respectively). Median age (1.6 vs. 1.7 years), left ventricular end-diastolic z-scores (+4.2 vs. +4.2), and left ventricular fractional shortening (16% vs. 17%) at diagnosis were similar between cohorts. Although the rates of echocardiographic normalization (30% and 27%) and heart transplantation (24% and 24%) were similar, the death rate was higher in the early cohort than in the late cohort (18% vs. 9%; p = 0.04). Being in the early cohort (hazard ratio: 1.4; 95% confidence interval: 1.04 to 1.9; p = 0.03) independently predicted death.

CONCLUSIONS

Children with DCM have improved survival in the more recent era. This appears to be associated with factors other than heart transplantation, which was equally prevalent in both eras. (Pediatric Cardiomyopathy Registry [PCMR]; NCT00005391).

Pediatric Cardiomyopathies

Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534.

Disturbed Desmoglein-2 in the intercalated disc of pediatric patients with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) leads to disturbed contraction and force transduction, and is associated with substantial mortality in all age groups. Involvement of a disrupted composition of the intercalated disc (ID) has been reported. However, in children, little is established about such subcellular changes during disease, because of the pathological mix-up with the ongoing cardiac maturation. This leaves maladaptive remodeling often undetected. We aimed at illustrating subcellular alterations in children diagnosed with DCM compared to age-matched controls, focusing on ID proteins known to be crucially stable under healthy conditions and destabilized during cardiac injury in adults. Left ventricular or septal pediatric specimens were collected from 7 individuals diagnosed with DCM (age: 23 weeks in utero to 8 weeks postnatal) and age-matched controls that died of non-cardiovascular cause. We determined the amount of fibrosis and localization of ID proteins by immunohistochemistry. In pediatric DCM, most ID proteins follow similar spatiotemporal changes in localization as in controls. However, although no mutations were found, the signal of the desmosomal protein Desmoglein-2 was reduced in all pediatric DCM specimens, but not in controls or adult DCM patients. Endocardial and transmural fibrosis was increased in all pediatric DCM patients compared to age-matched controls. Composition of the ID in pediatric DCM patients is similar to controls, except for the localization of Desmoglein-2 and presence of severe fibrosis. This suggests that the architecture of desmosomes is already disturbed in the early stages of DCM. These findings contribute to the understanding of pediatric DCM.