COQ7 defect causes prenatal onset of mitochondrial CoQ10 deficiency with cardiomyopathy and gastrointestinal obstruction

COQ7 pathogenetic variants cause primary CoQ10 deficiency and a clinical phenotype of encephalopathy, peripheral neuropathy, or multisystemic disorder. Early diagnosis is essential for promptly starting CoQ10 supplementation. Here, we report novel compound heterozygous variants in the COQ7 gene responsible for a prenatal onset (20 weeks of gestation) of hypertrophic cardiomyopathy and intestinal dysmotility in a Bangladesh consanguineous family with two affected siblings. The main clinical findings were dysmorphisms, recurrent intestinal occlusions that required ileostomy, left ventricular non-compaction cardiomyopathy, ascending aorta dilation, arterial hypertension, renal dysfunction, diffuse skin desquamation, axial hypotonia, neurodevelopmental delay, and growth retardation. Exome sequencing revealed compound heterozygous rare variants in the COQ7 gene, c.613_617delGCCGGinsCAT (p.Ala205HisfsTer48) and c.403A>G (p.Met135Val). In silico analysis and functional in vitro studies confirmed the pathogenicity of the variants responsible for abolished activities of complexes I + III and II + III in muscle homogenate, severe decrease of CoQ10 levels, and reduced basal and maximal respiration in patients' fibroblasts. The first proband deceased at 14 months of age, whereas supplementation with a high dose of CoQ10 (30 mg/kg/day) since the first days of life modified the clinical course in the second child, showing a recovery of milestones acquirement at the last follow-up (18 months of age). Our study expands the clinical spectrum of primary CoQ10 deficiency due to COQ7 gene defects and highlights the essential role of multidisciplinary and combined approaches for a timely diagnosis.

Focus on Paediatric Restrictive Cardiomyopathy: Frequently Asked Questions

Restrictive cardiomyopathy (RCM) is characterized by restrictive ventricular pathophysiology determined by increased myocardial stiffness. While suspicion of RCM is initially raised by clinical evaluation and supported by electrocardiographic and echocardiographic findings, invasive hemodynamic evaluation is often required for diagnosis and management of patients during follow-up. RCM is commonly associated with a poor prognosis and a high incidence of heart failure, and PH is reported in paediatric patients with RCM. Currently, only a few therapies are available for specific RCM aetiologies. Early referral to centres for advanced heart failure treatment is often necessary. The aim of this review is to address questions frequently asked when facing paediatric patients with RCM, including issues related to aetiologies, clinical presentation, diagnostic process and prognosis.

Echocardiographic score to predict neonatal surgery for aortic coarctation in newborns with prenatal suspicion and patent ductus arteriosus

INTRODUCTION

The evaluation of upcoming Aortic Coarctation (CoA) in new-borns with prenatal suspicion entails a close echocardiographic monitor until Arterial Duct (AD) closure, in a department with pediatric cardiological and surgical expertise. The significant number of false-positive prenatal diagnoses causes parental stress and healthcare costs.

AIM

The aim of this study was to elaborate an echocardiographic prediction model to be employed at birth when PDA is still present, in patients suspected of CoA during fetal life in order to foretell CoA requiring neonatal surgical intervention.

METHODS

This retrospective monocentric study included consecutive full-term and late preterm neonates with prenatal suspicion of CoA born from 01 January 2007 to 31 December 2020. Patients were divided into two groups according to the need for aortic surgery (CoA - NoCoA). All patients underwent a comprehensive transthoracic echocardiographic exam in presence of PDA. Multivariable logistic regression was used to create a coarctation probability model (CoMOD) including isthmal (D4), transverse arch (D3) diameters, the distance between a left common carotid artery (LCA) and left subclavian artery (LSA), presence/absence of ventricular septal defect (VSD) and bicuspid aortic valve (BAV).

RESULTS

We enrolled 87 neonates (49 male, 56%). 44 patients developed CoA in need of surgical repair. Our index CoMOD showed an AUC = 0.9382, high sensitivity (91%) and specificity (86%) in the prediction of CoA in neonates with prenatal suspicion. We classified neonates with CoMOD > 0 to be at high risk for surgical correction of CoA, with good PPV (86.9%) and NPV (90.9%).

CONCLUSIONS

CoMOD > 0 is highly suggestive of the need for CoA corrective surgery in newborns with prenatal suspicion.

Complete Isolation of Left Innominate Artery in a Patient With CHARGE Syndrome: Case Presentation and Review of Reported Cases

We report a rare case of complete isolation of the left innominate artery in a child with CHARGE (coloboma, heart defects, atresia choanae, growth retardation, genital abnormalities, and ear abnormalities) syndrome. This anatomical cluster had been undetected for a relatively large period of time and the patient was referred to us with an incomplete diagnosis even after multiple medical evaluations and a thoracic surgery during the neonatal period. In conclusion, to the best of our knowledge, this is the first case of a complete isolation of left innominate artery treated with a transcatheter approach.

Long Term Follow-Up of Patients with Systemic Right Ventricle and Biventricular Physiology: A Single Centre Experience

BACKGROUND

A progressively increasing prevalence of congenital heart disease (CHD) in adulthood has been noticed in recent decades; CHD cases with a systemic right ventricle have a poorer outcome.

METHODS

Seventy-three patients with SRV evaluated in an outpatient clinic between 2014 and 2020 were enrolled in this study. Thirty-four patients had a transposition of the great arteries treated with an atrial switch operation; 39 patients had a congenitally corrected transposition of the great arteries (ccTGA).

RESULTS

Mean age at the first evaluation was 29.6 ± 14.2 years; 48% of the patients were female. The NYHA class at the visit was III or IV in 14% of the cases. Thirteen patients had at least one previous pregnancy. In 25% of the cases, complications occurred during pregnancy. Survival free from adverse events was 98.6% at one year and 90% at 6-year follow-up without any difference between the two groups. Two patients died and one received heart transplantation during follow-up. The most common adverse event during follow-up was the presence of arrhythmia requiring hospitalization (27.1%), followed by heart failure (12.3%). The presence of LGE together with lower exercise capacity, higher NYHA class and more dilated and/or hypokinetic RV predicted a poorer outcome. Quality of life was similar to the QoL of the Italian population.

CONCLUSIONS

Long-term follow-up of patients with a systemic right ventricle is characterized by a high incidence of clinical events, prevalently arrhythmias and heart failure, which cause most of the unscheduled hospitalizations.

Candidacy for heart transplantation in adult congenital heart disease patients: a cohort study

Objective

The object of the present study is to evaluate factors precluding heart transplantation (HTx) in adult congenital heart disease patients (ACHD) with end-stage heart failure (HF) referred for HTx evaluation.

Methods

This retrospective cohort study enrolled consecutive ACHD patients considered for HTx in our institution between 2014 and 2020 and patients receiving HTx between 2001 and 2013. HTx refusal due to poor candidacy status for excess risk of mortality after transplantation, served as the main study outcome.

Results

Between 2014 and 2020, 46 ACHD patients were evaluated for HTx, 14 ACHD patients underwent HTx between 2001 and 2013. We compared clinical, anatomical and demographic data of 41 patients suitable for transplantation (including both listed/transplanted patients, not yet listed because too well and patients who chose to refuse transplantation) with 15 patients refused after screening (excluding 4 patients with ongoing screening). Risk factors for refusal were: multiple high risk features (odds ratio [OR]: 3.6; 95% confidence interval [CI]: 1.1 to 12.9; p 0.048); anatomical factors (OR: 14.5; 95% CI: 3.1 to 68.4; p 0.001), out-of-center ACHD/HTx program referral (OR: 5.3; 95% CI: 1.5 to 19.0; p 0.01). HTx refusal identifies a high risk ACHD patient subgroup (hazard ratio for overall mortality: 3.1; 95% CI: 1.1 to 8.3; p 0.02).

Conclusions

In our study risk factors for refusal from HTx are adverse anatomical features, multiple conventional HTx high risk factors and out-of-center referral. ACHD patients refused from HTx present shorter time to death. Efforts to increase HTx candidacy are strongly necessary for this growing population.

Funding Acknowledgement

Type of funding sources: None.

[Clinical pathway on pediatric cardiomyopathies: a genetic testing strategy proposed by the Italian Society of Pediatric Cardiology]

Pediatric cardiomyopathies are rare diseases, heterogeneous in clinical presentation, etiology and prognosis. Etiological diagnosis, where genetic analysis plays a key role, is of fundamental importance for defining diagnostic and therapeutic pathways. Furthermore, the identification of the genetic substrate represents a prerequisite for cascade screening in the proband's family members and to allow conscious reproductive choices. To date, genetic testing is performed with the analysis of gene panels (targeted panels) or with the study of the entire exome (whole exome sequencing) using next generation sequencing (NGS) technology. The great genetic heterogeneity and the temporal variability of the clinical manifestations lead to unique problems for pediatric cardiomyopathies, distinct from those of the adult, such as the possible indications for access to the test, the type of test to be used (exome or panel of genes), the importance of analyzing parents, especially in cases with neonatal onset; moreover, the correct execution of bioinformatics analysis and the interpretation of NGS data play a crucial role in the impact of the results on clinical management.

Clinical Features and Natural History of Preadolescent Nonsyndromic Hypertrophic Cardiomyopathy

BACKGROUND

Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized.

OBJECTIVES

The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years.

METHODS

Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years.

RESULTS

At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age.

CONCLUSIONS

Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages.

Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy

BACKGROUND

Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.

METHODS

The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).

RESULTS

MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.

CONCLUSIONS

In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

BAG3-related myofibrillar myopathy: a further observation with cardiomyopathy at onset in pediatric age

Myofibrillar myopathies are a heterogeneous group of neuromuscular disorders characterized by degeneration of Z-disk, causing the disintegration of myofibrils. They may be caused by mutations in different genes, among these, the BAG3 gene (Bcl-2 associed-athanogene-3) encodes a multidomain protein that plays an important role in many cellular processes. We report the case of a 16-year-old male who at 4 years of age presented with a hypertrophic obstructive cardiomyopathy, then developed axonal sensory motor polyneuropathy, muscle weakness, rigid spine, severe kyphoscoliosis and respiratory failure. Muscle biopsy showed the typical hallmark of myofibrillar myopathy with abnormal cytoplasmic expression of multiple proteins. Ade novo heterozygous common mutation in the BAG3 gene with a c.626C > T (p.Pro209Leu) was discovered on NGS genetic analysis. Mutations in the BAG3 gene are causes of a severe and progressive condition and natural history data are important to be collected. An early diagnosis is critical for prognostic implications in cardiomyopathy and respiratory failure treatment.

488 Candidacy for heart transplantation in adult congenital heart disease patients: a single-centre, retrospective, cohort study

Aims

End-stage heart failure (HF) is the leading cause of death in adult congenital heart disease (ACHD) population. Heart transplantation (HTx) improves prognosis in ACHD end-stage HF but candidacy evaluation, referral pattern, and correct listing timing are not fully elucidated in this population. To evaluate factors associated to refusal from Htx in ACHD patients with end-stage HF referred for HTx evaluation.

Methods and results

This retrospective cohort study enrolled consecutive ACHD patients considered for HTx in our institution between 2014 and 2020 and patients undergone HTx between 2000 and 2013. Refusal from HTx served as primary study endpoint. Between 2014 and 2020, 46 ACHD patients were evaluated for HTx, 14 ACHD patients underwent HTx between 2001 and 2013. The main indication to HTx in patients with single ventricle physiology was Fontan failure, while in patients with systemic left ventricle and systemic right ventricle physiology, it was systemic ventricular dysfunction. We compared clinical, anatomical and demographic data of 41 patients accepted for transplantation with 15 patients refused after screening. Risk factors for refusal were: coexistence of multiple high risk features [odds ratio (OR): 3.6; 95% confidence interval (CI): 1.1–12.9; P 0.048]; anatomical factors (OR: 14.5; 95% CI: 3.1–68.4; P 0.001), out-of-centre ACHD/HTx program referral (OR: 5.3; 95% CI: 1.5 to 19.0; p 0.01). Survival in patients accepted for HTx was significantly higher than survival in patients declined from HTx with landmark comparison at 20, 40 and 60 months of 87%, 78%, and 72% vs. 70%, 59%, and 20%, respectively. HTx refusal identifies a high risk ACHD patient subgroup (hazard ratio for overall mortality: 3.1; 95% CI: 1.1–8.3; P 0.02).

Conclusions

In our study risk factors for refusal from HTx are adverse anatomical features, coexistence of multiple conventional HTx high risk factors and out-of-centre referral. ACHD patients refused from HTx present shorter time to death. Efforts to increase HTx candidacy and to reduce referral delay in tertiary centre are strongly necessary for this growing population.

Bi-allelic variants in MDH2: Expanding the clinical phenotype

Bi-allelic alterations in the MDH2 gene have recently been reported in three unrelated toddlers with early-onset severe encephalopathy. Here, we describe a new case of a child carrying novel variants in MDH2. This child presented with early-onset encephalocardiopathy requiring heart transplant and showed cerebellar ataxia and drug-responsive epilepsy; his family history was significant for multiple cancers, a feature often associated with monoallelic variants in MDH2. Functional studies in cultured skin fibroblasts from the proband showed reduced protein levels and impaired enzyme activity, further corroborating the genetic results. The relatively mild neurological presentation and severe cardiac manifestations requiring heart transplant distinguish this case from previous reports. This patient thus expands the spectrum of clinical features associated with MDH2 variants.

Study design and rationale of the pAtients pResenTing with cOngenital heaRt dIseAse Register (ARTORIA-R)

Aim

Due to improved therapy in childhood, many patients with congenital heart disease reach adulthood and are termed adults with congenital heart disease (ACHD). ACHD often develop heart failure (HF) as a consequence of initial palliative surgery or complex anatomy and subsequently require advanced HF therapy. ACHD are usually excluded from trials evaluating heart failure therapies, and in this context, more data about heart failure trajectories in ACHD are needed to guide the management of ACHD suffering from HF.

Methods and results

The pAtients pResenTing with cOngenital heaRt dIseAse Register (ARTORIA‐R) will collect data from ACHD evaluated or listed for heart or heart‐combined organ transplantation from 16 countries in Europe and the Asia/Pacific region. We plan retrospective collection of data from 1989–2020 and will include patients prospectively. Additional organizations and hospitals in charge of transplantation of ACHD will be asked in the future to contribute data to the register. The primary outcome is the combined endpoint of delisting due to clinical worsening or death on the waiting list. The secondary outcome is delisting due to clinical improvement while on the waiting list. All‐cause mortality following transplantation will also be assessed. The data will be entered into an electronic database with access to the investigators participating in the register. All variables of the register reflect key components important for listing of the patients or assessing current HF treatment.

Conclusion

The ARTORIA‐R will provide robust information on current management and outcomes of adults with congenital heart disease suffering from advanced heart failure.

The frequency of rare and monogenic diseases in pediatric organ transplant recipients in Italy

Background

Rare diseases are chronic and life-threatening disorders affecting < 1 person every 2,000. For most of them, clinical symptoms and signs can be observed at birth or childhood. Approximately 80% of all rare diseases have a genetic background and most of them are monogenic conditions. In addition, while the majority of these diseases is still incurable, early diagnosis and specific treatment can improve patients’ quality of life. Transplantation is among the therapeutic options and represents the definitive treatment for end-stage organ failure, both in children and adults. The aim of this paper was to analyze, in a large cohort of Italian patients, the main rare genetic diseases that led to organ transplantation, specifically pointing the attention on the pediatric cohort.

Results

To the purpose of our analysis, we considered heart, lung, liver and kidney transplants included in the Transplant Registry (TR) of the Italian National Transplantation Center in the 2002–2019 timeframe. Overall, 49,404 recipients were enrolled in the cohort, 5.1% of whom in the pediatric age. For 40,909 (82.8%) transplant recipients, a disease diagnosis was available, of which 38,615 in the adult cohort, while 8,495 patients (17.2%) were undiagnosed. There were 128 disease categories, and of these, 117 were listed in the main rare disease databases. In the pediatric cohort, 2,294 (5.6%) patients had a disease diagnosis: of the 2,126 (92.7%) patients affected by a rare disease, 1,402 (61.1%) presented with a monogenic condition. As expected, the frequencies of pathologies leading to organ failure were different between the pediatric and the adult cohort. Moreover, the pediatric group was characterized, compared to the adult one, by an overall better survival of the graft at ten years after transplant, with the only exception of lung transplants. When comparing survival considering rare vs non-rare diseases or rare and monogenic vs rare non-monogenic conditions, no differences were highlighted for kidney and lung transplants, while rare diseases had a better survival in liver as opposed to heart transplants.

Conclusions

This work represents the first national survey analyzing the main genetic causes and frequencies of rare and/or monogenic diseases leading to organ failure and requiring transplantation both in adults and children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02013-x.

Myocardial oxygen consumption during histidine-tryptophan-ketoglutarate cardioplegia in young human hearts

OBJECTIVES

Energy demand and supply need to be balanced to preserve myocardial function during paediatric cardiac surgery. After a latent aerobic period, cardiac cells try to maintain energy production by anaerobic metabolism and by extracting oxygen from the given cardioplegic solution. Myocardial oxygen consumption (MVO2) changes gradually during the administration of cardioplegia.

METHODS

MVO2 was measured during cardioplegic perfusion in patients younger than 6 months of age (group N: neonates; group I: infants), with a body weight less than 10 kg. Histidine-tryptophan-ketoglutarate crystalloid solution was used for myocardial protection and was administered during a 5-min interval. To measure pO2 values during cardioplegic arrest, a sample of the cardioplegic fluid was taken from the inflow line before infusion. Three fluid samples were taken from the coronary venous effluent 1, 3 and 5 min after the onset of cardioplegia administration. MVO2 was calculated using the Fick principle.

RESULTS

The mean age of group N was 0.2 ± 0.09 versus 4.5 ± 1.1 months in group I. The mean weight was 3.1 ± 0.2 versus 5.7 ± 1.6 kg, respectively. MVO2 decreased similarly in both groups (min 1: 0.16 ± 0.07 vs 0.36 ± 0.1 ml/min; min 3: 0.08 ± 0.04 vs 0.17 ± 0.09 ml/min; min 5: 0.05 ± 0.04 vs 0.07 ± 0.05 ml/min).

CONCLUSIONS

We studied MVO2 alterations after aortic cross-clamping and during delivery of cardioplegia in neonates and infants undergoing cardiac surgery. Extended cardioplegic perfusion significantly reduces energy turnover in hearts because the balance procedures are both volume- and above all time-dependent. A reduction in MVO2 indicates the necessity of a prolonged cardioplegic perfusion time to achieve optimized myocardial protection.

Atypical cardiac defects in patients with RASopathies: Updated data on CARNET study

BACKGROUND

RASopathies are a set of relatively common autosomal dominant clinically and genetically heterogeneous disorders. Cardiac outcomes in terms of mortality and morbidity for common heart defects (such as pulmonary valve stenosis and hypertrophic cardiomyopathy) have been reported. Nevertheless, also Atypical Cardiac Defects (ACDs) are described. The aim of the present study was to report both prevalence and cardiac outcome of ACDs in patients with RASopathies.

METHODS

A retrospective, multicentric observational study (CArdiac Rasopathy NETwork-CARNET study) was carried out. Clinical, surgical, and genetic data of the patients who were followed until December 2019 were collected.

RESULTS

Forty-five patients out of 440 followed in CARNET centers had ACDs. Noonan Syndrome (NS), NS Multiple Lentigines (NSML) and CardioFacioCutaneous Syndrome (CFCS) were present in 36, 5 and 4 patients, respectively. Median age at last follow-up was 20.1 years (range 6.9-47 years). Different ACDs were reported, including mitral and aortic valve dysfunction, ascending and descending aortic arch anomalies, coronary arteries dilation, enlargement of left atrial appendage and isolated pulmonary branches diseases. Five patients (11%) underwent cardiac surgery and one of them underwent a second intervention for mitral valve replacement and severe pericardial effusion. No patients died in our cohort until December 2019.

CONCLUSIONS

Patients with RASopathies present a distinct CHD spectrum. Present data suggest that also ACDs must be carefully investigated for their possible impact on the clinical outcome. A careful longitudinal follow up until the individuals reach an adult age is recommended.

Prenatal sonography of the foramen ovale predicts urgent balloon atrial septostomy in neonates with complete transposition of the great arteries

BACKGROUND

Hypoxia caused by inadequate intracardiac mixing owing to a restrictive foramen ovale is a potentially life-threatening complication in neonates with dextro-transposition of the great arteries. An urgent balloon atrial septostomy is a procedure of choice in such cases, but dependent on the availability of a 24-hour interventional cardiology facility. The prenatal identification of predictors for an urgent balloon atrial septostomy at birth would help in optimizing the management of these neonates, minimizing the risk of hypoxic damage.

OBJECTIVE

This study aimed to predict with prenatal echocardiography the need of urgent balloon atrial septostomy in neonates with dextro-transposition of the great arteries.

STUDY DESIGN

This was a retrospective cohort study of patients with a prenatal diagnosis of transposition of the great arteries that were delivered in our center between 2010 and 2019, for whom fetal ultrasound echocardiograms obtained at less than 3 weeks before delivery were available. The following parameters were systematically obtained at fetal echocardiography: size and appearance of the foramen ovale, septum primum excursion (foramen ovale flap angle at the maximal excursion), diameters of the atria, and size of the ductus arteriosus. Balloon atrial septostomy was defined as urgent if performed within 12 hours from birth in neonates with restrictive foramen ovale. Neonatal follow-up was obtained through medical records analysis.

RESULTS

From November 2007 to April 2019, 160 fetuses with complete transposition of the great arteries were referred to our echocardiography laboratory and 60 of these were included in the analysis; 27 underwent urgent balloon atrial septostomy, 11 elective balloon atrial septostomy, and 22 no balloon atrial septostomy. The size of the foramen ovale was the best predictor of an urgent balloon atrial septostomy. A measurement of >6.5 mm had a sensitivity of 100% and a false positive rate of 45%.

CONCLUSION

Fetal echocardiography predicts the need of an urgent balloon atrial septostomy in fetuses with dextro-transposition of the great arteries although with a limited precision. In our experience, a measurement of the foramen ovale within 3 weeks of delivery had the greatest accuracy.

Lung ultrasound compared with bedside chest radiography in a paediatric cardiac intensive care unit

AIM

Postoperative recovery of children with heart disease is encumbered by pulmonary complications like pneumothorax (PNX), pleural effusion (PLE), interstitial oedema and pulmonary consolidation (PC). Recently, lung ultrasound (LUS) has become an important diagnostic tool for evaluation of pulmonary diseases in the paediatric context. LUS is accurate in diagnosing pleural and parenchymal diseases. The aim of this study was to evaluate the accuracy of LUS in the identification of PNX, PLE and PC in a paediatric population of patients with congenital heart disease after heart surgery.

METHODS

Fifty-three patients aged 0-17 years who underwent cardiac surgery were evaluated in the postoperative period by chest X-ray (CXR) and LUS at the same time. The methods where compared for recognition of PNX, PLE and PC.

RESULTS

LUS showed a good agreement for PNX and a moderate agreement for both PLE and PC. LUS also showed a significantly superior relative sensitivity than CXR for PC and PLE and a significantly inferior relative sensitivity for PNX.

CONCLUSION

This study confirms that LUS has a sufficient agreement rate with the current clinical standard (CXR). Non-inferiority in diagnosis together with the easiness of bedside performance makes LUS a very attractive tool for the paediatric cardiac intensive care unit.

The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy

AIMS

The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events.

METHODS AND RESULTS

Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7.

CONCLUSION

In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

Enteral Nutrition in Term Infants with Congenital Heart Disease: Knowledge Gaps and Future Directions to Improve Clinical Practice

Optimal nutrition is essential to improve short- and long-term outcomes in newborns with congenital heart disease (CHD). Nevertheless, several issues on nutritional management and concerns about the potential risk of complications related to enteral feeding exist. This narrative review aims to summarize and discuss the available literature on enteral feeding in term infants with CHD. A wide variability in feeding management exists worldwide. Emerging approaches to improve nutritional status and outcomes in infants with CHD include: implementation of a standardized enteral feeding protocol, both preoperative and postoperative, clearly defining time of initiation and advancement of enteral feeds, reasons to withhold, and definitions of feeding intolerance; early minimal enteral feeding; enteral feeding in stable term infants on hemodynamic support; evaluation of enteral feeding in term infants with umbilical arterial catheters and during prostaglandin infusion; assessment and support of oro-motor skills; and promotion and support of breastfeeding and provision of mother's own milk or donor milk when mother's own milk is not available. As evidence from term infants is scarce, available observations and recommendations partially rely on studies in preterm infants. Thus, well-designed studies assessing standardized clinically relevant outcomes are needed to provide robust evidence and shared recommendations and practices.

Insights from Cardiopulmonary Exercise Testing in Pediatric Patients with Hypertrophic Cardiomyopathy

The usefulness of cardiopulmonary exercise test (CPET) in adult hypertrophic cardiomyopathy (HCM) patients is well-known, whereas its role in pediatric HCM patients has not yet been explored. The present study investigates possible insights from a CPET assessment in a cohort of pediatric HCM outpatients in terms of functional and prognostic assessment. Sixty consecutive pediatric HCM outpatients aged <18 years old were enrolled, each of them undergoing a full clinical assessment including a CPET; a group of 60 healthy subjects served as controls. A unique composite end-point of heart failure (HF) related and sudden cardiac death (SCD) or SCD-equivalent events was also explored. During a median follow-up of 53 months (25th–75th: 13–84 months), a total of 13 HF- and 7 SCD-related first events were collected. Compared to controls, HCM patients showed an impaired functional capacity with most of them showing peak oxygen uptake (pVO₂) values of <80% of the predicted, clearly discrepant with functional New York Heart Association class assessment. The composite end-point occurred more frequently in patients with the worst CPETs’ profiles. At the univariate analysis, pVO₂% was the variable with the strongest association with adverse events at follow-up (C-index = 0.72, p = 0.025) and a cut-off value equal to 60% was the most accurate in identifying those patients at the highest risk. In a pediatric HCM subset, the CPET assessment allows a true functional capacity estimation and it might be helpful in identifying early those patients at high risk of events.

Neonatal heart failure and noncompaction/dilated cardiomyopathy from mucopolysaccharidosis. First description in literature

Mucopolysaccharidosis are genetic disorders due to deficiency of lysosomal enzymes, resulting in abnormal glycosaminoglycans accumulation in several tissues. Heart involvement tends to be progressive and worsens with age. We describe the first case of mucopolysaccharidosis type I presenting with noncompaction/dilated-mixed cardiomyopathy and heart failure within neonatal period, which responded successfully to specific metabolic treatment. Cardiac function recovered after enzyme replacement therapy and hematopoietic stem cell transplantation, adding to the existing knowledge of the disease.

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MPS can present with acute cardiac failure and cardiomyopathy within neonatal period.

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Cardiomyopathies associated with MPS include also noncompaction phenotypes.

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Heart failure due to MPS can respond successfully to specific metabolic treatment.

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Consider complete metabolic tests in case of inexplicable neonatal heart failure.

Pediatric Restrictive Cardiomyopathies

Restrictive cardiomyopathy (RCM) is the least frequent phenotype among pediatric heart muscle diseases, representing only 2.5-3% of all cardiomyopathies diagnosed during childhood. Pediatric RCM has a poor prognosis, high incidence of pulmonary hypertension (PH), thromboembolic events, and sudden death, is less amenable to medical or surgical treatment with high mortality rates. In this scenario, heart transplantation remains the only successful therapeutic option. Despite a shared hemodynamic profile, characterized by severe diastolic dysfunction and restrictive ventricular filling, with normal ventricle ejection fraction and wall thickness, RCM recognizes a broad etiological spectrum, consisting of genetic/familial and acquired causes, each of which has a distinct pathophysiology and natural course. Hence, the aim of this review is to cover the causes, clinical presentation, diagnostic evaluation, treatment, and prognosis of pediatric RCM.

P1599 Longue term outcome after surgical repair of complete atrioventricular septal defect: 2D versus 3D echocardiographic evaluation

Purpose

Assessment of longue term follow-up after surgical repair of Complete Atrioventricular Septal Defect (cAVSD). Evaluation of 3D versus standard 2D echocardiographic accuracy during the last follow-up.

Methods

43 patients were included in this study. Mean age at surgical repair was 7 months, 48.8% of patients were male; 67.4% had Down Syndrome. Mean time follow-up was 13 ± 6 years. During the last follow-up 2D and 3D echo evaluation were performed.

Results

All patients were alive and had a NYHA class I at the last follow-up. Survival free from new cardiac surgery at 13 years was 86%. During follow-up a progressive moderate to severe/severe mitral regurgitation (MR) was observed in 6 patients (16.3%) while 4 patients developed a progressive left ventricular outflow tract obstruction (LVOTO); overall 5 patients underwent new cardiac surgery (3 for MR and 2 for LVOTO). Echocardiographic evaluation showed: LV end diastolic volume 55.7 ± 13.0ml/m2, LV ejection fraction 64 ± 5%, left atrium volume 24.9 ± 13.9ml/m2, right ventricle systolic pression 21.0 ± 2.0 and a LVOT gradient 14.6 ± 16.4 mmHg. Mitral valve evaluation is evidenced in Table 1. Predictor factors of severe MR during follow-up were the cleft area and depth and the presence of anterior leaflet prolapse. Cohen’s kappa evidenced a good correlation between 2D and 3D VC evaluation with a higher sensibility of 3D evaluation to identify severe MR, data confirmed by the ROC curve analysis (Figure A and B).

Conclusions

Clinical outcome after cAVSD surgical repair is excellent with a low rate of reintervention. 3D echo evaluation is more sensitive to identify both predictors and severity of MR ì.

LAST Follow-up echocardiography 2D evaluation 3D evaluation Mitral Valve evaluation Vena contracta, mm 4.8 ± 2.5 5.3 ± 2.5 Regurgitant volume, ml 25 ± 20 ERO, cm2 0.17 ± 0.13 Mean gradient, mmHg 4 ± 2.4 Residual cleft, n(%) A1 A2 A3 30 (90.7) 4 (9.3) 33 (76.8) 6 (13.9) Cleft area,cm2 0.19 ± 0.21 Cleft depth, mm 5 .0 ± 2.9 Valve thickening, n(%) 14 (13.6) Leaflet Prolapse, n (%) Anterior Leaflet Prolapse, n (%) Posterior Leaflet Prolapse, n (%) 30 (69.7) 25 (58.1) 10 (23.2) Single papilary, n(%) 10 (23.2)

Abstract P1599 Figure.

Development of a Novel Risk Prediction Model for Sudden Cardiac Death in Childhood Hypertrophic Cardiomyopathy (HCM Risk-Kids)

Importance

Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk.

Objective

To develop and validate an SCD risk prediction model that provides individualized risk estimates.

Design, Setting, and Participants

A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017.

Exposures

The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping.

Main Outcomes and Measures

A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise).

Results

Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95% CI, 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years.

Conclusions and Relevance

This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

[Cardiologists and mucopolysaccharidoses. Recommendations of GICEM (Cardiology Experts on Metabolic Disease Italian Group) for diagnosis, follow-up and cardiological management]

Mucopolysaccharidoses (MPS) represent a group of rare lysosomal storage disorders, with a heterogeneous clinical presentation in terms of inheritance (autosomal and X-linked recessive), age of onset (infants, children, and adults), systemic and cardiac manifestations (mild to severe disease forms). Evidence-based recommendations on the diagnosis and management of cardiovascular disease in MPS are scarce. GICEM (Gruppo Italiano Cardiologi Esperti Malattie Metaboliche) is a group of cardiologists, cardiac surgeons and pediatricians with a specific expertise in metabolic diseases including MPS. In this paper, we report our experience and recommendations on the diagnosis and management of cardiovascular aspects in MPS, with a tailored approach based on current evidence, and taking into account MPS phenotype (particularly, I, II, IVa, VI), age at presentation, and severity of systemic and cardiac manifestations.

Dilated cardiomyopathy in a pediatric population: etiology and outcome predictors - a single-center experience

AIM

The aim of the study was to assess predictors of outcome in patients hospitalized for dilated cardiomyopathy (DCM) and severe left ventricular dysfunction. Patients & methods: 83 pediatric patients hospitalized for heart failure due to DCM with coexistent left ventricular dysfunction were enrolled.

RESULTS

Overall, 5-year survival free from heart transplantation was 69.8%. Normalization of left ventricular function was achieved in 39.8% of patients during follow-up: younger age, less necessity of inotropic support and other than idiopathic DCM predicted left ventricular function, while familial history for cardiac disease or sudden death and inotropic support during hospitalization were associated with poorer outcome.

CONCLUSION

Almost 40% of patients with DCM experienced a complete normalization of cardiac function. Outcome was extremely variable according to the type of DCM.

Multimodality imaging, single center, cross-sectional study in adolescents or young adults with repaired tetralogy of Fallout

BACKGROUND

Proper integration of multiple imaging modalities in the routine follow-up of patients with repaired tetralogy of Fallout (TOF) is poorly supported by data. We report our single center comparative study between cardiac magnetic resonance (CMR) and echocardiography to assess equipoise in the clinical utility of these two imaging methods in an unselected consecutive cohort of TOF patients referred to our outpatient clinic.

MATERIAL AND METHODS

In this cross-sectional study, repaired TOF patients who underwent CMR and echocardiography within a 4-week period between 2010 and 2011 at our Center were included. Linear regression was used to analyze degree of inter modality correlation. A prediction model tested the association between functional data/probrain natriuretic peptide (Pro-BNP) with CMR.

RESULTS

Fifty patients were included in the study (mean age 31 ± 18 years). The best predictors of right ventricle (RV) ejection fraction at CMR were tricuspid anular plane systolic excursion (tricuspid valve anular plane systolic excursion, R 0.37, P < 0.0001) and RV peak S-wave velocity (R 0.40, P < 0.001). Pro-BNP levels did present weak correlation with New York Heart Association functional class (R 0.31, P < 0.002) and QRS duration (R 0.32, P < 0.002) and a moderate correlation with right atrium area at CMR (R 0.46, P < 0.0001).

CONCLUSION

We found limited correlation between the two imaging modalities in the evaluation of RV after intracardiac repair of TOF. Pro-BNP level presents moderate correlation with right atrium area measured with echocardiography. Serial CMR evaluations are needed in this patient population, but they may be interchanged by routine echocardiography in particular in patients with normal or stable echocardiographic parameters.

[Pulmonary embolism in complex corrected congenital heart disease]

Pulmonary embolism is an uncommon but potentially fatal disease in children, especially with congenital heart disease where pulmonary perfusion depends on caval flow. Anticoagulation is the mainstay of therapy for children with pulmonary embolism. However, thrombolytic therapy can also be considered. The outcome of pediatric pulmonary embolism is uncertain and needs further investigation. We suggest increased awareness and a high index of suspicion in the presence of suggestive clinical signs in high-risk patients in order to initiate prompt diagnostic imaging and treatment.

New clinical and molecular insights on Barth syndrome

Background

Barth syndrome (BS) is an X-linked infantile-onset cardioskeletal disease characterized by cardiomyopathy, hypotonia, growth delay, neutropenia and 3-methylglutaconic aciduria. It is caused by mutations in the TAZ gene encoding tafazzin, a protein involved in the metabolism of cardiolipin, a mitochondrial-specific phospholipid involved in mitochondrial energy production.

Methods

Clinical, biochemical and molecular characterization of a group of six male patients suspected of having BS. Three patients presented early with severe metabolic decompensation including respiratory distress, oxygen desaturation and cardiomyopathy and died within the first year of life. The remaining three patients had cardiomyopathy, hypotonia and growth delay and are still alive. Cardiomyopathy was detected during pregnancy through a routine check-up in one patient. All patients exhibited 3-methylglutaconic aciduria and neutropenia, when tested and five of them also had lactic acidosis.

Results

We confirmed the diagnosis of BS with sequence analysis of the TAZ gene, and found five new mutations, c.641A>G p.His214Arg, c.284dupG (p.Thr96Aspfs*37), c.678_691del14 (p.Tyr227Trpfs*79), g.8009_16445del8437 and g.[9777_9814del38; 9911-?_14402del] and the known nonsense mutation c.367C>T (p.Arg123Term). The two gross rearrangements ablated TAZ exons 6 to 11 and probably originated by non-allelic homologous recombination and by Serial Replication Slippage (SRS), respectively. The identification of the breakpoints boundaries of the gross deletions allowed the direct detection of heterozygosity in carrier females.

Conclusions

Lactic acidosis associated with 3-methylglutaconic aciduria is highly suggestive of BS, whilst the severity of the metabolic decompensation at disease onset should be considered for prognostic purposes. Mutation analysis of the TAZ gene is necessary for confirming the clinical and biochemical diagnosis in probands in order to identify heterozygous carriers and supporting prenatal diagnosis and genetic counseling.

Primary cardiac tumours in the paediatric population

Primary cardiac tumours are relatively rare in the paediatric population, and they may occur with different signs and symptoms in foetal or post-natal life. The clinical manifestations of cardiac tumours in foetal life may include arrhythmias, congestive heart failure and hydrops. In post-natal life, cardiac tumours may cause cyanosis, respiratory distress, myocardial dysfunction, valvular insufficiency, arrhythmias, inflow or outflow tract obstructions and sudden death. Surgical treatment is essential when symptoms are present, while the role of medical therapy can merely be palliative. Results are various and related to the patients' and tumour characteristics. Primary benign heart tumours mainly have a good prognosis, while malignant neoplasms usually have a poor prognosis; in both cases, however, a strict follow-up is always mandatory in order to detect the recurrence of cardiac neoplasms after surgery.

[The "big heart" of carnitine]

Fat is the primary energy source for heart muscle. In the heart, carnitine is essential for normal fatty acid beta-oxidation and even partial deficiency could lead to organ dysfunction. Dilated cardiomyopathy is one of the cardinal manifestations of carnitine deficiency in children. We report the case of a female infant referred to our hospital at the age of 15 months with a 2-week history of dyspnea. She presented signs and symptoms of congestive heart failure. Severe cardiomegaly was seen on chest radiographs, while the echocardiogram showed a dilated and hypokinetic left ventricle with depressed systolic function, decreased fractional shortening and ejection fraction, and left atrial enlargement. Laboratory investigations showed carnitine deficiency. She needed intravenous inotropic support in association with conventional heart failure therapy. Treatment with L-carnitine was started as soon as the samples for laboratory testing were taken. Cardiac function clearly and rapidly improved while on treatment.

Heart transplantation in infants with idiopathic hypertrophic cardiomyopathy

Whereas it is well known that idiopathic HCM can present in newborns and infants, little information is available on HT in this very young age group. We report a series of 17 infants with idiopathic HCM, including two neonates with rapidly progressive severe HF for whom HT was necessary. When HF manifests in a newborn/infant with idiopathic HCM and extreme cavity size reduction, the possibility of a rapidly progressive clinical course should be anticipated and HT may become the only available therapeutic solution.

Heart transplantation in hypertrophic cardiomyopathy

Heart transplantation (HT) is the sole therapeutic option for selected patients with hypertrophic cardiomyopathy (HC) and refractory heart failure. However, the results of HT have not been systematically investigated in HC. We assessed the pathophysiologic profile of HT candidates and the outcome after transplantation in 307 patients with HC consecutively evaluated at our tertiary referral center from 1987 to 2005; follow-up was 9.9+8.2 years. Outcome of recipients with HC was compared with that of 141 patients who underwent transplantation for idiopathic dilated cardiomyopathy at our center over the same period. Of 21 patients with HC who entered the transplantation list, 20 had end-stage evolution with systolic dysfunction and 1 had an extremely small left ventricular cavity with impaired filling and recurrent cardiogenic shock during paroxysmal atrial fibrillation. Of 33 study patients with HC who showed end-stage evolution during follow-up, the 23 who were included on the waiting list or died from refractory heart failure (2 patients) were significantly younger than the 10 patients who remained clinically stable (37+/-14 vs 57+/-17 years, p=0.004). Of the 21 HT candidates, 18 underwent transplantation during follow-up. In heart transplant recipients, 7-year survival rate was 94% and not different from that of the 141 patients who received transplants for idiopathic dilated cardiomyopathy (p=0.66). In conclusion, long-term outcome after HT in patients with HC is favorable and similar to that of patients with idiopathic dilated cardiomyopathy. In patients with end-stage HC, young age is associated with more rapid progression to refractory heart failure.