Current State of Pediatric Heart Failure

Advancement of the Dragon Heart 7-Series for Pediatric Patients With Heart Failure

BACKGROUND

Safe and effective pediatric blood pumps continue to lag far behind those developed for adults. To address this growing unmet clinical need, we are developing a hybrid, continuous-flow, magnetically levitated, pediatric total artificial heart (TAH). Our hybrid TAH design, the Dragon Heart (DH), integrates both an axial flow and centrifugal flow blood pump within a single, compact housing. The axial pump is embedded in the central hub region of the centrifugal pump, and both pumps rotate around a common central axis, while maintaining separate fluid domains.

METHODS

In this work, we concentrated our design and development effort on the centrifugal blood pump by performing computational modeling. An iterative process was employed to improve the DH design. The pressure generation, scalar stress levels, and fluid forces exerted on the magnetically levitated impellers were computationally estimated. A shaft driven centrifugal prototype was also manufactured and tested using a hydraulic flow loop circulating a water-glycerol blood analog. Pressure and flow performance of the pump prototype was measured for a given rotational speed for comparison to computational predictions.

RESULTS

Our design achieved the target pump pressures of 60-140 mm Hg for flow rates of 1-5 L/min, and strong agreement in pressure rise was demonstrated between the experimental data and simulation results (less than 10% deviation on average). Fluid stress levels were, however, found to exceed thresholds in the outflow region of the pump, and fluid residence times were less than 600 ms.

CONCLUSION

The findings of this work demonstrate that the more compact, next-gen DH's centrifugal pump design is able to achieve pressure-capacity requirements. Next steps will require a focused strategy to reduce hemolytic potential and to integrate magnetic suspension components for full rotor levitation.

Epidemiology of paediatric chronic heart failure in Germany-A population-based analysis

AIMS

Paediatric chronic heart failure (CHF) is associated with significant morbidity. The aim of this study was to describe paediatric CHF epidemiology in Germany.

METHODS AND RESULTS

This is a retrospective cross-sectional analysis of anonymized healthcare claims data in the InGef database. This database includes longitudinal data from a representative sample of the German population of approximately 4.8 million insured members. We included individuals <18 years from 2016 to 2021. CHF was defined by ≥2 diagnoses in different quarters of the year as inpatient or outpatient, using ICD-10-GM codes I50.- or P29.0. The number of eligible children in the database was 674 462 in 2016 and 660 692 in 2021. Prevalence of CHF per 100 000 children was 20.6 [95% confidence interval (CI), 17.3-24.3] in 2016 and 19.4 (95% CI, 16.2 to 23.0) in 2021. Incidence per 100 000 children was 9.6 (95% CI, 7.4 to 12.3) in 2016 and 7.6 (95% CI, 5.6 to 10.0) in 2021 for newly diagnosed CHF. All-cause hospitalizations occurred in 47.3% to 57.7% of children with CHF per year. Up to 6.3% of children with CHF were hospitalized, coded primarily for heart failure. Mortality of children with CHF was <5 death per year in the studied population. In 128 children with CHF in 2021, the most common ICD-coded comorbidities were congenital malformations of cardiac septa (57.8%), atrial septal defect (44.5%), congenital malformations of the great arteries (43.0%) and ventricular septal defect (32.0%). Coded treatment modalities for paediatric CHF in 2021 included angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers (18.8%), beta-blockers (17.2%), mineralocorticoid receptor antagonists (14.8%) and surgical procedures (13.3%).

CONCLUSIONS

This representative cohort study reveals a relatively high incidence proportion. Approximately half of the children with CHF are hospitalized annually while mortality is low.

Pediatric Chronic Heart Failure: Age-Specific Considerations of Medical Therapy

Chronic heart failure (CHF) is a rare entity in children but carries a burden of high mortality and morbidity. Medical treatment of pediatric CHF is largely based on guidelines for the adult population. In contrast to adults, evidence for the efficacy of medications in treating CHF in children is sparse. This may be due to the difficulty of conducting high-powered studies in children or to true differences in the mechanisms of CHF pathophysiology. Recent observations suggest that CHF in children differs from adults at the molecular and cellular levels. Different pathways are involved, leading to less fibrosis and hypertrophy than in adults, with potential implications for therapy. The main pathophysiological goals of medical treatment of pediatric CHF due to systemic left ventricular dysfunction are discussed in this review. These include preload and afterload optimization, diminishing cardiomyocyte apoptosis and necrosis as well as interstitial fibrosis, and optimizing myocardial oxygen consumption. The pediatric myocardium should be provided with optimal conditions to achieve its regenerative potential. The cornerstones of medical CHF therapy are angiotensin converting enzyme inhibitors (ACEI), beta blockers and mineralocorticoid receptor antagonists. There are potential benefits of tissue ACEI and ?1-selective beta blockers in children. Angiotensin receptor blockers are an alternative to ACEI and their slightly different mechanism of action may confer certain advantages and disadvantages. Diuretics are employed to achieve a euvolemic state. Digoxin is used more frequently in children than in adults. Promising new drugs already routinely used in adults include angiotensin receptor-neprilysin inhibitors and sodium-glucose contransporter 2 inhibitors. Key words: Pediatric heart failure, Heart failure with reduced ejection fraction (HFrEF), ACE inhibitor, Beta blocker, Digoxin.

Pharmacogenetics of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) in cardiovascular diseases

Cardiovascular diseases (CVDs) have a high mortality rate, and despite the several available therapeutic targets, non-response to antihypertensives remains a common problem. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are important classes of drugs recommended as first-line therapy for several CVDs. However, response to ACEIs and ARBs varies among treated patients. Pharmacogenomics assesses how an individual's genetic characteristics affect their likely response to drug therapy. Currently, numerous studies suggest that genetic polymorphisms may contribute to variability in drug response. Moreover, further studies evaluating gene-gene interactions within signaling pathways in response to antihypertensives might help to unravel potential genetic predictors for antihypertensive response. This review summarizes the pharmacogenetic data for ACEIs and ARBs in patients with CVD, and discusses the potential pharmacogenetics of these classes of antihypertensives in clinical practice. However, replication studies in different populations are needed. In addition, studies that evaluate gene-gene interactions that share signaling pathways in the response to antihypertensive drugs might facilitate the discovery of genetic predictors for antihypertensive response.

Series Multiblood Pump Design With Dual Activation for Pediatric Patients With Heart Failure

The translational development of pediatric ventricular assist devices (VADs) lags years behind adult device options, negatively impacting pediatric patient outcomes. To address this need, we are developing a novel, series-flow, double-blood pump VAD that integrates an axial and centrifugal pump into a single device. The axial pump is used for initial circulatory assistance in younger patients; then, an internal activation mechanism triggers the centrifugal pump to activate in line with the axial pump, providing additional pressure and flow to match pediatric patient growth cycles. Here, we focused on the design and improvement of the device flow paths through computational analysis and in vitro hydraulic testing of a prototype. We estimated pressure-flow generation, fluid scalar stresses, and blood damage levels. In vitro hydraulic tests correlated well with shear stress transport (SST) predictions, with an average deviation of 4.5% for the complex, combined flow path. All data followed expected pump performance trends. The device exceeded target levels for blood damage in the blade tip clearances, and this must be both investigated and addressed in the next design phase. These study findings establish a strong foundation for the future development of the Drexel Double-Dragon VAD.

Exploring Caregiver Learning and Experiences Caring for a Child With Heart Failure: A Qualitative Study

Background

Paediatric heart failure poses life-long, burdensome symptoms for the health care system and families. Diagnosis and discharge are stressful and anxiety-provoking for caregivers. They face uncertainty about their child's health and become responsible for administering complex care in the home. Little is known about this topic. Our study aimed to explore caregiver learning and experiences caring for a child with heart failure to design and implement a knowledge translation tool.

Methods

Qualitative description guided our study. Recruitment occurred in a tertiary cardiac centre in Edmonton, Alberta, Canada. Data collection and analysis occurred concurrently until data redundancy was achieved. Inductive conventional content analysis was used to develop categories.

Results

Eleven interviews identified 2 main categories. One relates to how traumatic life experiences impact learning (eg, new diverse ways of learning, stress steepens the learning curve, and learning heart failure takes time). The other relates to families' new life reality after diagnosis (eg, emotional distress and the new reality).

Conclusions

This study provides insight into caregivers' learning needs and experiences caring for a child with heart failure. Caregivers describe how the trauma of having their child diagnosed with heart failure negatively impacts their learning capabilities and way of life going forward. Caregiver learning experiences and preferences for digital platforms is also highlighted. This knowledge will inform the design of an online educational tool about pediatric heart failure for caregiver audiences. This tool will empower and improve caregiver decision-making related to their child's daily heart failure management, with the goal to positively impact clincal outcomes, lessen stress and anxiety.

A Review of Contemporary and Future Pharmacotherapy for Chronic Heart Failure in Children

This review delves into the most recent therapeutic approaches for pediatric chronic heart failure (HF) as proposed by the International Society for Heart and Lung Transplantation (ISHLT), which are not yet publicly available. The guideline proposes an exhaustive overview of the evolving pharmacological strategies that are transforming the management of HF in the pediatric population. The ISHLT guidelines recognize the scarcity of randomized clinical trials in children, leading to a predominance of consensus-based recommendations, designated as Level C evidence. This review article aims to shed light on the significant paradigm shifts in the proposed 2024 ISHLT guidelines for pediatric HF and their clinical ramifications for pediatric cardiology practitioners. Noteworthy advancements in the updated proposed guidelines include the endorsement of angiotensin receptor-neprilysin inhibitors (ARNIs), sodium-glucose cotransporter 2 inhibitors (SGLT2is), and soluble guanylate cyclase (sGC) stimulators for treating chronic HF with reduced ejection fraction (HFrEF) in children. These cutting-edge treatments show potential for enhancing outcomes in pediatric HFrEF. Nonetheless, the challenge persists in validating the efficacy of therapies proven in adult HFrEF for the pediatric cohort. Furthermore, the proposed ISHLT guidelines address the pharmacological management of chronic HF with preserved ejection fraction (HFpEF) in children, marking a significant step forward in pediatric HF care. This review also discusses the future HF drugs in the pipeline, their mechanism of actions, potential uses, and side effects.

In the era of outpatient ventricular assist devices, is it time to reconsider the practice of bridging older children to transplant on outpatient inotropes?

OBJECTIVE

Ventricular assist devices (VADs) and inotropes are feasible modalities to bridge children to heart transplant (HT) in outpatient settings. However, it is unclear which modality yields superior clinical status at HT and posttransplant survival.

METHODS

The United Network for Organ Sharing was used to identify patients aged 18 years or younger, weighing >25 kg, from 2012 to 2022 who were outpatients at HT (n = 835). Patients were grouped by bridging modality at HT: VAD (n = 235 [28%]), inotropes (n = 176 [21%]), or neither (no support) (n = 424 [50%]).

RESULTS

VAD patients were of similar age (P = .260) but heavier (P = .007) and more likely to have dilated cardiomyopathy (P < .001) than their inotrope counterparts. VAD patients had similar clinical status at HT but superior functional status (performance scale >70%) (59% vs 31%) (P < .001). Overall posttransplant survival in VAD patients (1-year and 5-year survival, 97% and 88%, respectively) was comparable to patients with no support (93% and 87%, respectively) (P = .090) and those on inotropes (98% and 83%, respectively) (P = .089). One-year conditional survival was superior for VAD vs inotrope (2-year and 6-year survival, 96% and 91%, respectively vs 97% and 79%, respectively) (P = .030) and 5-year conditional survival for VAD patients was superior to inotrope (7-year and 10-year survival, 100% and 100%, respectively vs 100% and 88%, respectively) (P = .022) and no support (100% and 83%, respectively) (P = .011).

CONCLUSIONS

Consistent with prior studies, short-term outcomes for pediatric patients bridged to HT in the outpatient setting with VAD or inotropes is excellent. However, compared with outpatients bridged to HT on inotropes, outpatient VAD support allowed for better functional status at HT and superior late posttransplant survival.

Successful explantation of children from the Berlin Heart EXCOR® ventricular assist device: A systematic review

BACKGROUND

The Berlin Heart EXCOR® (BHE) can bridge children with severe heart failure to transplantation, but some are successfully weaned and spared transplantation. This study seeks to identify characteristics of children amenable to successful explantation with BHE support.

METHODS

Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines were used. Five databases were screened for original, English articles measuring BHE support in patients <18 years old based on title and abstract. Exclusion criteria were applied: full-text availability, <10 total pediatric BHE patients, zero successful explantations from BHE, nonprimary literature, adult and pediatric results that could not be separated, and studies with overlapping patient information. Studies were analyzed with descriptive statistics.

RESULTS

From 41 857 potential studies, 14 were analyzed with data from 58 hospitals on four continents from 1990 to 2020. There were 984 BHE patients. The most common diagnosis was dilated cardiomyopathy (n = 318, 32.3%), followed by congenital heart disease (n = 249, 25.3%). There were 85 (8.6%) children explanted with favorable outcomes. The underlying diagnosis was known in 44 (51.8%) cases: 14 (8.4%) of 166 cardiomyopathies, 17 (48.6%) of 35 myocarditis, and 12 (16.7%) of 72 with congenital heart disease were explanted. When the type of support was known, the rate of LVAD patients explanted was 21.3% (n = 19/89) and 2.4% (n = 1/42) of BiVAD patients were explanted.

CONCLUSION

Explantation from BHE is not uncommon at 8.6%, but significant variation exists in the explantation data reported. Myocarditis and LVAD support may be populations suitable for weaning. Standardization of reporting measures and prospective registries may help identify patients suitable for this alternative to transplant and help develop weaning protocols.

[Formula: see text] The multifaceted role of neuropsychology in pediatric solid organ transplant: preliminary guidelines and strategies for clinical practice

The incidence of pediatric solid organ transplantation (SOT) has increased in recent decades due to medical and surgical advances as well as improvements in organ procurement. Survival rates for pediatric kidney, liver, and heart transplantation are above 85% but patients continue to experience complex healthcare needs over their lifetime. Long-term developmental and neuropsychological sequelae are becoming increasingly recognized in this population, although preliminary work is limited and deserves further attention. Neuropsychological weaknesses are often present prior to transplantation and may be related to underlying congenital conditions as well as downstream impact of the indicating organ dysfunction on the central nervous system. Neuropsychological difficulties pose risk for functional complications, including disruption to adaptive skill development, social-emotional functioning, quality of life, and transition to adulthood. The impact of cognitive dysfunction on health management activities (e.g., medication adherence, medical decision-making) is also an important consideration given these patients' lifelong medical needs. The primary aim of this paper is to provide preliminary guidelines and clinical strategies for assessment of neuropsychological outcomes across SOT populations for pediatric neuropsychologists and the multidisciplinary medical team, including detailing unique and shared etiologies and risk factors for impairment across organ types, and functional implications. Recommendations for clinical neuropsychological monitoring as well as multidisciplinary collaboration within pediatric SOT teams are also provided.

Baseline Characteristics of Pediatric Patients With Heart Failure Due to Systemic Left Ventricular Systolic Dysfunction in the PANORAMA-HF Trial

BACKGROUND

Sacubitril/valsartan has been approved for the management of heart failure (HF) with reduced ejection fraction in adults. PANORAMA-HF trial (Prospective Trial to Assess the Angiotensin Receptor Blocker Neprilysin Inhibitor LCZ696 Versus Angiotensin-Converting Enzyme Inhibitor for the Medical Treatment of Pediatric HF) investigated its effects on clinical outcomes in pediatric patients with HF.

METHODS

PANORAMA-HF is a multicenter, Phase II/III study using an adaptive, seamless, 2-part design. The study aimed to evaluate the pharmacokinetics and pharmacodynamics of single doses of sacubitril/valsartan (Part 1), and the efficacy and safety of sacubitril/valsartan versus enalapril administered twice daily for 52 weeks (Part 2) in pediatric patients with HF due to left ventricular systolic dysfunction with biventricular heart physiology. An innovative trial design using a novel global rank assessment of severity was employed. For analysis, eligible patients were stratified into 3 age groups (Group 1, 6 to <18 years; Group 2a, 2 to <6 years; and Group 3a, 1 month to <2 years) and functional classification (New York Heart Association/Ross class I/II and III/IV).

RESULTS

We report the key demographic, baseline, and clinical characteristics of 375 pediatric patients randomized to receive the study medication. The mean age for patients in Groups 1, 2a, and 3a was 12.2, 3.2, and 1.3 years, respectively. About 70% of patients had a prior HF hospitalization, 85% had New York Heart Association/Ross class I/II HF, and ≈8% were angiotensin-converting enzyme inhibitor/angiotensin receptor blocker naïve.

CONCLUSIONS

Compared to other pediatric HF studies, PANORAMA-HF recruited a relatively homogeneous pediatric HF population across 3 age groups, enabling a more robust evaluation of pharmacokinetics/pharmacodynamics and efficacy/safety of sacubitril/valsartan. Most patients had mildly symptomatic HF at baseline.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02678312.

Fibroblast growth factor 23 in children with or without heart failure: a prospective study

BACKGROUND

Elevated fibroblast growth factor 23 (FGF23) levels have been associated with mortality in adults with heart failure (HF), but data on FGF23 levels in paediatric HF are limited. In this prospective cohort study, we aimed to assess the prognostic value of FGF23 in children with chronic HF.

METHODS

We prospectively enrolled 40 children with chronic HF and 20 matched healthy controls. In each patient, a complete diagnostic workup was performed, including transthoracic echocardiography to evaluate cardiac systolic and diastolic functions. Serum FGF23, renal function tests, parathyroid hormone, serum calcium and phosphate were measured in patients and controls. N-terminal probrain natriuretic peptide (NT-proBNP) was measured in patients. The severity of symptoms was assessed using the modified Ross HF classification for children. Patients were followed for 1 year, and clinical worsening events such as death and HF hospitalisation were recorded.

RESULTS

Patients with HF had significantly higher FGF23 levels compared with controls (355.68±97.27 pg/mL and 60.20±11.04 pg/mL, respectively; p<0.001). Three patients died and 11 were admitted with HF. In comparison with patients without clinical worsening events, these 14 patients exhibited significantly higher FGF23 levels (320.04±89.56 pg/mL and 421.86±75.50 pg/mL, respectively; p<0.001). FGF23 was positively correlated with NT-proBNP and left ventricular end-diastolic diameter and negatively correlated with ejection fraction and fractional shortening. The ability of FGF23 to predict clinical worsening events in patients was analysed using a receiver operating characteristic curve. The optimal cut-off point was 375 pg/mL, with 85.71% sensitivity, 84.62% specificity, positive predictive value of 75.0, negative predictive value of 91.7 and area under the curve (AUC) of 0.878. Multivariable regression analysis revealed that FGF23 is the only independent predictor of clinical worsening events in children with chronic HF.

CONCLUSION

FGF23 levels were elevated in children with chronic HF and increased significantly as Ross score class increased. FGF23 levels increased in patients who experienced clinical worsening events.

A Review of the Mechanism of Action of Drugs Used in Congestive Heart Failure in Pediatrics

Congestive heart failure (CHF) is a complex, heterogeneous medically ill condition that can occur due to diverse primary (cardiomyopathies, coronary artery diseases, and hypertension) and secondary causes (high salt intake and noncompliance toward treatment) and leads to significant morbidity and mortality. The approach toward managing the patient of CHF in the pediatric age group is more complex than in the adult population. Currently, in the adult group of the population of CHF, there are well-established guidelines for managing these patients, but in the case of children, there are no well-established guidelines; therefore, this systematic review gives more ideas for managing the pediatric population undergoing CHF. Treatment of the underlying cause, rectification of any advancing event, and management of pulmonary or systemic obstruction are the principles for management. The most widely used drugs are diuretics and angiotensin-converting enzyme (ACE) inhibitors, whereas beta-blockers are less commonly used in children than in adults. ACE inhibitors such as captopril, enalapril, and cilazapril are widely used in the pediatric age group. ACE inhibitors act on the renin-angiotensin-aldosterone system (RAAS) similar to those in the adult population. In children with heart failure (HF), ACE inhibitors reduce the pressure in the aorta, resistance in the systemic blood vessels, and upper left and right chamber pressures but do not appreciably influence pulmonary vascular resistance. We use a patient's initial perfusion and volume status assessment to decide further action for the supervision of acute HF. This paradigm was adopted from adult studies that showed higher rates of morbidity and mortality in patients with HF whose hemodynamic or volume status assessment results were stable with a pulmonary capillary wedge pressure >18 mmHg and a combined index (CI) of 2.2 L/minute/m². ACE inhibitors, beta-blockers, and spironolactone are the most widely prescribed drugs for the chronic condition of CHF. This study shows the current status of medical therapy for critical as well as persistent pediatric HF.

Development of the Centrifugal Blood Pump for a Hybrid Continuous Flow Pediatric Total Artificial Heart: Model, Make, Measure

Clinically-available blood pumps and total artificial hearts for pediatric patients continue to lag well behind those developed for adults. We are developing a hybrid, continuous-flow, magnetically levitated, pediatric total artificial heart (TAH). The hybrid TAH design integrates both an axial and centrifugal blood pump within a single, compact housing. The centrifugal pump rotates around the separate axial pump domain, and both impellers rotate around a common central axis. Here, we concentrate our development effort on the centrifugal blood pump by performing computational fluid dynamics (CFD) analysis of the blood flow through the pump. We also conducted transient CFD analyses (quasi-steady and transient rotational sliding interfaces) to assess the pump's dynamic performance conditions. Through modeling, we estimated the pressure generation, scalar stress levels, and fluid forces exerted on the magnetically levitated impellers. To further the development of the centrifugal pump, we also built magnetically-supported prototypes and tested these in an in vitro hydraulic flow loop and via 4-h blood bag hemolytic studies (n = 6) using bovine blood. The magnetically levitated centrifugal prototype delivered 0–6.75 L/min at 0–182 mmHg for 2,750–4,250 RPM. Computations predicted lower pressure-flow performance results than measured by testing; axial and radial fluid forces were found to be <3 N, and mechanical power usage was predicted to be <5 Watts. Blood damage indices (power law weighted exposure time and scalar stress) were <2%. All data trends followed expectations for the centrifugal pump design. Six peaks in the pressure rise were observed in the quasi-steady and transient simulations, correlating to the blade passage frequency of the 6-bladed impeller. The average N.I.H value (n = 6) was determined to be 0.09 ± 0.02 g/100 L, which is higher than desired and must be addressed through design improvement. These data serve as a strong foundation to build upon in the next development phase, whereby we will integrate the axial flow pump component.

Numerical and Experimental Analysis for a Magnetic Levitation System in a Hemocompatibility Assessment Platform

Development of pediatric left ventricular assist devices (LVADs) has lagged behind that of adult LVADs, primarily due to the size and hemocompatibility constraints of pediatric anatomy. To quantify sources of blood trauma during LVAD development, we proposed a hemocompatibility assessment platform (HAP) that can evaluate the hemocompatibility of individual components of LVADs. To eliminate the hemolysis induced by the HAP itself, we incorporated passive magnetic (PM) bearings to suspend the rotor radially and an active magnetic bearing (AMB) to control the axial position. In this study, we numerically evaluated AMB forces of 2 geometries and validated the model by comparing its predictions with experimental results. The magnetic forces generated by the AMB were evaluated by increasing the rotor-stator gap from 0.1 mm to 0.5 mm with a 0.1 mm increment and by varying the coil current from -2 A to 2 A with a 1 A increment. The average error of the numerical models was 8.8% and 7.0% for the two geometries, respectively. Higher errors were found at smaller (<0.2mm) rotor-stator gaps. For both biasing ring sizes, the AMB exhibits high magnetic stiffness from -1 A to 1 A, though it saturates for currents of -2 A and 2 A. This region of high current stiffness was identified as the optimal control region. In future work, this function will be used to tune a control algorithm to modulate current supplied to the AMB, ultimately stabilizing the rotor axially. Clinical Relevance- This work furthers the development of a hemocompatibility assessment platform that will enhance and accelerate the development of adult and pediatric LVADs.

Congenital Heart Disease: The State-of-the-Art on Its Pharmacological Therapeutics

Congenital heart disease is one of the most common causes of death derived from malformations. Historically, its treatment has depended on timely diagnosis and early pharmacological and surgical interventions. Survival rates for patients with this disease have increased, primarily due to advancements in therapeutic choices, but mortality remains high. Since this disease is a time-sensitive pathology, pharmacological interventions are needed to improve clinical outcomes. Therefore, we analyzed the applications, dosage, and side effects of drugs currently used for treating congenital heart disease. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and potassium-sparing diuretics have shown a mortality benefit in most patients. Other therapies, such as endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostaglandins, and soluble guanylyl cyclase stimulators, have benefited patients with pulmonary artery hypertension. Likewise, the adjunctive symptomatic treatment of these patients has further improved the outcomes, since antiarrhythmics, digoxin, and non-steroidal anti-inflammatory drugs have shown their benefits in these cases. Conclusively, these drugs also carry the risk of troublesome adverse effects, such as electrolyte imbalances and hemodynamic compromise. However, their benefits for survival, symptom improvement, and stabilization outweigh the possible complications from their use. Thus, cases must be assessed individually to accurately identify interventions that would be most beneficial for patients.

Technology Landscape of Pediatric Mechanical Circulatory Support Devices- A Systematic Review 2010-2021

BACKGROUND

Mechanical circulatory support (MCS) devices, such as ventricular assist devices (VADs) and total artificial hearts (TAHs), have become a vital therapeutic option in the treatment of end-stage heart failure for adult patients. Such therapeutic options continue to be limited for pediatric patients. Clinicians initially adapted or scaled existing adult devices for pediatric patients; however, these adult devices are not designed to support the anatomical structure and varying flow capacities required for this population and are generally operated "off-design", which risks complications such as hemolysis and thrombosis. Devices designed specifically for the pediatric population that seek to address these shortcomings are now emerging and gaining FDA approval.

METHODS

To analyze the competitive landscape of pediatric MCS devices, we conducted a systematic literature review. Approximately 27 devices were studied in detail: 8 were established or previously approved designs, and 19 were under development (11 VADs, 5 Fontan assist devices, and 3 TAHs).

RESULTS

Despite significant progress, there is still no pediatric pump technology that satisfies the unique and distinct design constraints and requirements to support pediatric patients, including the wide range of patient sizes, increased cardiovascular demand with growth, and anatomic and physiologic heterogeneity of congenital heart disease.

CONCLUSIONS

Forward-thinking design solutions are required to overcome these challenges and to ensure the translation of new therapeutic MCS devices for pediatric patients.

Patient-Specific Modelling and Parameter Optimisation to Simulate Dilated Cardiomyopathy in Children

PURPOSE

Lumped parameter modelling has been widely used to simulate cardiac function and physiological scenarios in cardiovascular research. Whereas several patient-specific lumped parameter models have been reported for adults, there is a limited number of studies aiming to simulate cardiac function in children. The aim of this study is to simulate patient-specific cardiovascular dynamics in children diagnosed with dilated cardiomyopathy, using a lumped parameter model.

METHODS

Patient data including age, gender, heart rate, left and right ventricular end-systolic and end-diastolic volumes, cardiac output, systolic and diastolic aortic pressures were collected from 3 patients at Great Ormond Street Hospital for Children, London, UK. Ventricular geometrical data were additionally retrieved from cardiovascular magnetic resonance images. 23 parameters in the lumped parameter model were optimised to simulate systolic and diastolic pressures, end-systolic and end-diastolic volumes, cardiac output and left and right ventricular diameters in the patients using a direct search optimisation method.

RESULTS

Difference between the haemodynamic parameters in the optimised cardiovascular system models and clinical data was less than 10%.

CONCLUSION

The simulation results show the potential of patient-specific lumped parameter modelling to simulate clinical cases. Modelling patient specific cardiac function and blood flow in the paediatric patients would allow us to evaluate a variety of physiological scenarios and treatment options.

Vein of Galen Malformation Manifesting as High-Output Heart Failure

The sudden onset of vomiting in a previously healthy term neonate has a broad differential requiring a thorough history and physical examination. When this does not reveal the underlying cause, a workup must be performed to rule out potentially devastating diagnoses that must be addressed in a timely fashion. In infants, this clinical presentation could be due to infections such as sepsis or meningitis, gastrointestinal causes such as anatomical abnormalities or ingestions, or cardiac causes such as congenital heart disease. Conversely, inborn errors of metabolism or neurologic issues such as vascular anomalies or a tumor with associated increased intracranial pressure could also be the culprit. In this report, we discuss the case of a previously healthy newborn with a rare cause of vomiting and feeding intolerance, which was ultimately discovered to be due to the vein of Galen malformation.

Anesthetic Considerations in Pediatric Patients With Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) in pediatrics is a significant cause for morbidity and mortality in children. Congenital heart disease and cardiomyopathy are the leading etiologies of ADHF. It is common for these children to undergo diagnostic, therapeutic, or surgical procedure under anesthesia, which may be associated with significant morbidity and mortality. The importance of preanesthetic multidisciplinary planning with all involved teams, including anesthesia, cardiology, intensive care, perfusion, and cardiac surgery, cannot be emphasized enough. In order to safely manage these patients, it is imperative for the anesthesiologist to understand the complex pathophysiological interactions between cardiopulmonary systems and anesthesia during these procedures. This review discusses the etiology, pathophysiology, clinical manifestations, and perioperative management of these patients.

Severe Acute Malnutrition among Unoperated Ethiopian Children with Congenital Heart Disease: A Wake-up Call to Reverse the Situation, A Retrospective Cross-Sectional Study

Background

Children with Congenital Heart Disease (CHD) are at increased risk for severe acute malnutrition (SAM). We aimed to determine the magnitude and determinants of SAM among children with CHD in a tertiary hospital.

Methods

Retrospective cross-sectional study was conducted among children with CHD between 2016 and 2019. Clinical and anthropometric data were retrieved from medical records. Anthropometric assessment was done by using WHO standard growth curves. Data analysis was done using Statistical Package for Social Sciences V22. Statistical significance was set at p-value <0.05, and multivariable logistic regression was used to determine predictors.

Results

There were 2400 pediatric admissions during the study period, CHD accounted for 6.5%(156) of admissions. For review, 141 records were eligible. The gender distribution was comparable, males 51.1% (72). Infants (<12 months) and older children (≥12 months) accounted for 57.4% (81) and 42.6% (60) of study subjects, respectively. SAM was documented in 51.8% (73) of the study subjects, [95% CI: 44.7-60.2]. Infants had higher odds of SAM compared to children aged ≥12 months[adjusted odds ratio (AOR)= 4.48, 95%CI:2.07-9.70]. Anemic children had higher odds for SAM[AOR =3.76, 95% CI:1.54-9.18]. Children without acyanotic CHD with heart failure(HF) were 58% less likely to develop SAM[AOR= 0.42, 95% CI:0.19-0.96].

Conclusion

The burden of SAM among children with CHD is high. Younger age, anemia and acyanotic CHD with HF predicted SAM. Screening for anemia and targeted anthropometric assessment are recommended for early SAM detection.

Pathophysiology and clinical presentation of paediatric heart failure related to congenital heart disease

Congenital heart disease (CHD) and cardiomyopathies represent the two most important causes of paediatric heart failure (HF) in developed countries. We made a review of the literature on pathophysiology and clinical presentation of paediatric HF in children with CHD. Two main pathophysiologic models can be identified: the 'over-circulation failure', characterised by signs and symptoms of congestion or hypoperfusion, due respectively to volume or pressure overload, and the 'pump failure'. CONCLUSIONS: The comprehension of the HF pathophysiology in paediatric patients with CHD is of paramount importance for the optimal management and for addressing the best therapeutic choices.

Relative Bioavailability of Omecamtiv Mecarbil Pediatric Minitablet Formulations in Healthy Adult Subjects

BACKGROUND AND OBJECTIVE

Omecamtiv mecarbil (OM) is a cardiac myosin activator under clinical development for the treatment of heart failure. Two modified-release (MR) novel OM minitablet formulations were developed to support the planned investigation of chronic heart failure in pediatric patients. The primary objective of this study was to determine the bioavailability of the minitablets relative to the adult matrix MR formulation tablets.

METHODS

In a randomized, 5-period, crossover study, 20 healthy subjects received each of the following treatments orally: one 25-mg adult matrix MR tablet, 25 1-mg slow-release minitablets, 25 1-mg fast-release minitablets, six 1-mg slow-release minitablets, or six 1-mg fast-release minitablets after an overnight fast of at least 10 h with a minimum washout of 7 days between treatments. Blood samples were collected for up to 168 h. OM pharmacokinetic parameters were estimated using non-compartmental methods.

RESULTS

When OM was administered as 25 1-mg OM slow-release minitablets, AUC_last, AUC_inf, and C_max were 0.998-, 1.00-, and 1.29-fold of a single 25-mg OM matrix MR tablet, respectively. When OM was administered as 25 1-mg OM fast-release minitablets, AUC_last, AUC_inf, and C_max were 1.26-, 1.25-, and 2.21-fold of a single 25-mg OM matrix MR tablet, respectively. The slow- and fast-release minitablets display approximately dose-proportional pharmacokinetics. There were no serious adverse events or treatment-emergent adverse events leading to discontinuation from the study.

CONCLUSIONS

Relative bioavailability of slow-release minitablets was demonstrated to be similar to the adult matrix MR formulation.

Current and Future Drug and Device Therapies for Pediatric Heart Failure Patients: Potential Lessons from Adult Trials

This review discusses the potential drug and device therapies for pediatric heart failure (HF) due to reduced systolic function. It is important to realize that most drugs that are used in pediatric HF are extrapolated from adult cardiology practices or consensus guidelines based on expert opinion rather than on evidence from controlled clinical trials. It is difficult to conclude whether the drugs that are well established in adult HF trials are also beneficial for children because of tremendous heterogeneity in the mechanism of HF in children and variations in the pharmacokinetics and pharmacodynamics of drugs from birth to adolescence. The lessons learned from adult trials can guide pediatric cardiologists to design clinical trials of the newer drugs that are in the pipeline to study their efficacy and safety in children with HF. This paper's focus is that the reader should specifically think through the pathophysiological mechanism of HF and the mode of action of drugs for the selection of appropriate pharmacotherapy. We review the drug and device trials in adults with HF to highlight the knowledge gap that exists in the pediatric HF population.

Complications in children with ventricular assist devices: systematic review and meta-analyses

Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients' symptoms, age, and severity of their condition, with heart transplantation required when other treatments are unsuccessful. However, due to lack of fitting donor organs, many patients are left untreated, or their transplant is delayed. In these patients, ventricular assist devices (VADs) are used to bridge to heart transplant. However, VAD support presents various complications in patients. The aim of this study was to compile, review, and analyse the studies reporting risk factors and aetiologies of complications of VAD support in children. Random effect risk ratios (RR) with 95% confidence intervals were calculated to analyse relative risk of thrombosis (RR = 3.53 [1.04, 12.06] I² = 0% P = 0.04), neurological problems (RR = 0.95 [0.29, 3.15] I² = 53% P = 0.93), infection (RR = 0.31 [0.05, 2.03] I² = 86% P = 0.22), bleeding (RR = 2.57 [0.76, 8.66] I² = 0% P = 0.13), and mortality (RR = 2.20 [1.36, 3.55] I² = 0% P = 0.001) under pulsatile-flow and continuous-flow VAD support, relative risk of mortality (RR = 0.45 [0.15, 1.37] I² = 36% P = 0.16) under left VAD and biVAD support, relative risk of thrombosis (RR = 1.72 [0.46, 6.44] I² = 0% P = 0.42), infection (RR = 1.77 [0.10, 32.24] I² = 46% P = 0.70) and mortality (RR = 0.92 [0.14, 6.28] I² = 45% P = 0.93) in children with body surface area < 1.2 m² and > 1.2 m² under VAD support, relative risk of mortality in children supported with VAD and diagnosed with cardiomyopathy and congenital heart diseases (RR = 1.31 [0.10, 16.61] I² = 73% P = 0.84), and cardiomyopathy and myocarditis (RR = 0.91 [0.13, 6.24] I² = 58% P = 0.92). Meta-analyses results show that further research is necessary to reduce complications under VAD support.

Recent and Upcoming Drug Therapies for Pediatric Heart Failure

Pediatric heart failure (HF) is an important clinical condition with high morbidity, mortality, and costs. Due to the heterogeneity in clinical presentation and etiologies, the development of therapeutic strategies is more challenging in children than adults. Most guidelines recommending drug therapy for pediatric HF are extrapolated from studies in adults. Unfortunately, even using all available treatment, progression to cardiac transplantation is common. The development of prospective clinical trials in the pediatric population has significant obstacles, including small sample sizes, slow recruitment rates, challenging endpoints, and high costs. However, progress is being made as evidenced by the recent introduction of ivabradine and of sacubitril/valsartan. In the last 5 years, new drugs have also been developed for HF with reduced ejection fraction (HFrEF) in adults. The use of well-designed prospective clinical trials will be fundamental in the evaluation of safety and efficacy of these new drugs on the pediatric population. The aim of this article is to review the clinical presentation and management of acute and chronic pediatric heart failure, focusing on systolic dysfunction in patients with biventricular circulation and a systemic left ventricle. We discuss the drugs recently approved for children and those emerging, or in use for adults with HFrEF.

Case Report: Low Dose of Valsartan/Sacubitril Leads to Successful Reversal of Acute Heart Failure in Chemotherapy-Induced Cardiomyopathy

Valsartan/sacubitril is a new agent approved for the treatment of chronic heart failure in adults, with a combination of angiotensin receptor inhibitor and neprilysin inhibitor. However, the benefit of valsartan/sacubitril in pediatric patients is unknown. We herein report its clinical benefit in a case of acute decompensated heart failure in chemotherapy-induced cardiomyopathy. This case suggests that in children with acute heart failure refractory to conventional medications, low dose of sacubitril/valsartan may be an effective therapy.

Duchenne Dilated Cardiomyopathy: Cardiac Management from Prevention to Advanced Cardiovascular Therapies

Duchenne muscular dystrophy (DMD) cardiomyopathy (DCM) is characterized by a hypokinetic, dilated phenotype progressively increasing with age. Regular cardiac care is crucial in DMD care. Early recognition and prophylactic use of angiotensin converting enzyme inhibitors (ACEi) are the main stay therapeutic strategy to delay incidence of DMD-DCM. Pharmacological treatment to improve symptoms and left ventricle (LV) systolic function, have been widely implemented in the past years. Because of lack of DMD specific drugs, actual indications for established DCM include current treatment for heart failure (HF). This review focuses on current HF strategies to identify, characterize, and treat DMD-DCM.

Important Considerations in Pediatric Heart Failure

PURPOSE OF REVIEW

The goal of this paper is to provide an overview of contemporary knowledge specific to the causes, management, and outcome of heart failure in children.

RECENT FINDINGS

While recently there have been subtle improvements in heart failure outcomes in children, these improvements lag significantly behind that of adults. There is a growing body of literature suggesting that pediatric heart failure is a unique disease process with age- and disease-specific myocardial adaptations. In addition, the heterogenous etiologies of heart failure in children contribute to differential response to therapies and challenge the ability to obtain meaningful results from prospective clinical trials. Consideration of novel clinical trial designs with achievable but clinically relevant endpoints and focused study of the mechanisms underlying pediatric heart failure secondary to cardiomyopathies and structural heart disease are essential if we hope to advance care and identify targeted and effective therapies.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Energy Balance-Related Behaviors and Body Mass Index in Asian School-Aged Children With Congenital Heart Disease

BACKGROUND

Overweight/obesity is a substantial global public health concern, which can be caused by genetic factors and energy balance-related behaviors (EBRBs). If it occurs in children with congenital heart disease (CCHD), it can yield an extra burden on their health. Most studies on CCHD have taken place in Western societies, leaving Asian populations understudied, especially children.

OBJECTIVE

We sought (1) to determine body mass index distribution among school-aged CCHD in Taiwan, (2) to ascertain whether the body mass index of CCHD differs from that of the general population, (3) to describe EBRBs in CCHD, and (4) to identify factors associated with underweight and overweight/obesity among CCHD.

METHODS

In this cross-sectional study, 97 child-parent dyads (53.6% boys; mean age, 9.73 years; 25.8% moderate-to-severe heart conditions) were enrolled. Self-administered questionnaires were used to collect demographics, medical factors, food frequency, physical activity, and sedentary behaviors. Anthropometric measurements were taken in the hospital. Independent predictors of EBRBs and health conditions were calculated through logistic regression analysis.

RESULTS

Among Taiwanese CCHD, 19.6% were underweight and 14.4% were overweight/obese. Children with moderate-to-severe heart defects were more often underweight. Body mass index did not differ between CCHD and children in the general population. More complex heart defects and asthma were associated with being underweight, whereas sedentary behaviors, cardiomegaly, and the New York Heart Association classification II to IV were associated with being overweight/obese.

CONCLUSIONS

Sedentary lifestyle is seemingly the only EBRB correlated with being overweight. Physical activity programs for children may help prevent and treat overweight or obesity in Asian CCHD, similar to Western countries.

A critical appraisal of the tafazzin knockdown mouse model of Barth syndrome: what have we learned about pathogenesis and potential treatments?

Pediatric heart failure remains poorly understood, distinct in many aspects from adult heart failure. Limited data point to roles of altered mitochondrial functioning and, in particular, changes in mitochondrial lipids, especially cardiolipin. Barth syndrome is a mitochondrial disorder caused by tafazzin mutations that lead to abnormal cardiolipin profiles. Patients are afflicted by cardiomyopathy, skeletal myopathy, neutropenia, and growth delay. A mouse model of Barth syndrome was developed a decade ago, which relies on a doxycycline-inducible short hairpin RNA to knock down expression of tafazzin mRNA (TAZKD). Our objective was to review published data from the TAZKD mouse to determine its contributions to our pathogenetic understanding of, and potential treatment strategies for, Barth syndrome. In regard to the clinical syndrome, the reported physiological, biochemical, and ultrastructural abnormalities of the mouse model mirror those in Barth patients. Using this model, the peroxisome proliferator-activated receptor pan-agonist bezafibrate has been suggested as potential therapy because it ameliorated the cardiomyopathy in TAZKD mice, while increasing mitochondrial biogenesis. A clinical trial is now underway to test bezafibrate in Barth syndrome patients. Thus the TAZKD mouse model of Barth syndrome has led to important insights into disease pathogenesis and therapeutic targets, which can potentially translate to pediatric heart failure.