ISHLT consensus statement for the selection and management of pediatric and congenital heart disease patients on ventricular assist devices Endorsed by the American Heart Association

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Development and Validation of a Novel Pediatric Mechanical Circulatory Support Risk Stratification Tool: The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Ventricular Assist Device Score

We sought to develop and validate a new risk stratification score for mortality for children supported with a ventricular assist device (VAD). This retrospective, multicenter study used data from patients undergoing VAD implantation between April 2018 and February 2023 at 44 participating institutions in the Advanced Cardiac Therapies Improving Outcomes (ACTION) network. Multivariable Cox proportional-hazards modeled mortality after VAD implantation. A total of 1,022 patients were enrolled. The 1 year mortality was 19% (95% confidence interval [CI]: 16-23). The multivariable model was used to build the ACTION VADs risk stratification score with four components: ventilation, advanced organ support (dialysis or ECMO), diagnosis, and size (weight ≤5 kg). One point is added for each risk factor. Based on the sum of the risk factors, patients were classified into four classes: class 0-green (4% mortality at 1 year), class 1-yellow (16% mortality at 1 year), class 2-orange (21% mortality at 1 year), and class 3 or higher-red (42% mortality at 1 year). The score performed well, with area under the curve (AUC) of 0.72 and excellent calibration. The ACTION VADs score for mortality can be calculated easily and offers risk stratification and prognostic information for pediatric VAD candidates. This is the first validated risk assessment tool for pediatric mechanical circulatory support.

First North American experience with the Berlin Heart EXCOR Active driver

For smaller pediatric patients on ventricular assist devices, the Berlin Heart EXCOR remains the main form of durable support. It requires a connection to the external IKUS, which has limited portability and battery life. The new EXCOR Active mobile driving unit has a battery life of up to 13 hours. We describe the first North American experience with the EXCOR Active in pediatric patients with a Berlin Heart device. A retrospective chart review was undertaken. Between October 2022 and March 2024, 7 patients were on a Berlin Heart and supported with the EXCOR Active. All patients were initially supported with the IKUS with a median time to transition to the EXCOR Active of 12.0 days (interquartile range [IQR] 9.5, 18.5) and a median time of support with the EXCOR Active of 65.0 days (IQR, 32.0, 81.0). The EXCOR Active posed no significant safety issues, and minimal operating issues were noted. Following the transition from IKUS to the EXCOR Active, there was increased patient and caregiver mobility throughout the hospital. Use of the EXCOR Active has the potential to improve the quality of life in pediatric patients waiting for heart transplantation.

Waitlist Outcomes for Pediatric Heart Transplantation in the Current Era: An Analysis of the Pediatric Heart Transplant Society Database

BACKGROUND

Waitlist mortality (WM) remains elevated in pediatric heart transplantation. Allocation policy is a potential tool to help improve WM. This study aims to identify patients at highest risk for WM to potentially inform future allocation policy changes.

METHODS

The Pediatric Heart Transplant Society database was queried for patients <18 years of age indicated for heart transplantation between January 1, 2010 to December 31, 2021. Waitlist mortality was defined as death while awaiting transplant or removal from the waitlist due to clinical deterioration. Because WM is low after the first year, analysis was limited to the first 12 months on the heart transplant list. Kaplan-Meier analysis and log-rank testing was conducted to compare unadjusted survival between groups. Cox proportional hazard models were created to determine risk factors for WM. Subgroup analysis was performed for status 1A patients based on body surface area (BSA) at time of listing, cardiac diagnosis, and presence of mechanical circulatory support.

RESULTS

In total 5974 children met study criteria of which 3928 were status 1A, 1012 were status 1B, 963 were listed status 2, and 65 were listed status 7. Because of the significant burden of WM experienced by 1A patients, further analysis was performed in only patients indicated as 1A. Within that group of patients, those with smaller size and lower eGFR had higher WM, whereas those patients without congenital heart disease or support from a ventricular assist device (VAD) at time of listing had decreased WM. In the smallest size cohort, cardiac diagnoses other than dilated cardiomyopathy were risk factors for WM. Previous cardiac surgery was a risk factor in the 0.3 to 0.7 m2 and >0.7 m2 BSA groups. VAD support was associated with lower WM other than in the single ventricle cohort, where VAD was associated with higher WM. Extracorporeal membrane oxygenation and mechanical ventilation were associated with increased risk of WM in all cohorts.

CONCLUSIONS

There is significant variability in WM among status-1A patients. Potential refinements to current allocation system should factor in the increased WM risk we identified in patients supported by extracorporeal membrane oxygenation or mechanical ventilation, single ventricle congenital heart disease on VAD support and small children with congenital heart disease, restrictive cardiomyopathy, or hypertrophic cardiomyopathy.

Improving Mechanical Circulatory Support Outcomes in Failing Bidirectional Glenn Physiology

There remains high morbidity and mortality with mechanical circulatory support (MCS) in failing bidirectional Glenn (BDG) physiology. We performed a retrospective analysis of children with BDG physiology supported with MCS before and after 2018. Fourteen patients met inclusion criteria (median age 1.5 years, weight 9 kg). Prior to 2018 (n = 7), with variable anticoagulation and strategies including pulsatile VAD, continuous flow VAD, and extracorporeal membrane oxygenation (ECMO), 3 (43%) of patients were transplanted with a total of 536 patient-days of support (median 59 days). Major hemocompatability-related adverse event (MHRAE) rate was 63 per 100 patient-months. After 2018 (n = 7), using a staged support strategy (ECMO to pulsatile VAD) and bivalirudin anticoagulation, 5 (71%) patients were transplanted with a total of 1260 patient-days of support (median 188 days) and MHRAE rate of 24 per 100 patient-months. Despite challenging physiology, we have observed improved survival and reduced MHRAE despite longer support duration.

Evaluation and Management of Chronic Heart Failure in Children and Adolescents With Congenital Heart Disease: A Scientific Statement From the American Heart Association

With continued medical and surgical advancements, most children and adolescents with congenital heart disease are expected to survive to adulthood. Chronic heart failure is increasingly being recognized as a major contributor to ongoing morbidity and mortality in this population as it ages, and treatment strategies to prevent and treat heart failure in the pediatric population are needed. In addition to primary myocardial dysfunction, anatomical and pathophysiological abnormalities specific to various congenital heart disease lesions contribute to the development of heart failure and affect potential strategies commonly used to treat adult patients with heart failure. This scientific statement highlights the significant knowledge gaps in understanding the epidemiology, pathophysiology, staging, and outcomes of chronic heart failure in children and adolescents with congenital heart disease not amenable to catheter-based or surgical interventions. Efforts to harmonize the definitions, staging, follow-up, and approach to heart failure in children with congenital heart disease are critical to enable the conduct of rigorous scientific studies to advance our understanding of the actual burden of heart failure in this population and to allow the development of evidence-based heart failure therapies that can improve outcomes for this high-risk cohort.

Current status and future directions in pediatric ventricular assist device

A ventricular assist device (VAD) is a form of mechanical circulatory support that uses a mechanical pump to partially or fully take over the function of a failed heart. In recent decades, the VAD has become a crucial option in the treatment of end-stage heart failure in adult patients. However, due to the lack of suitable devices and more complicated patient profiles, this therapeutic approach is still not widely used for pediatric populations. This article reviews the clinically available devices, adverse events, and future directions of design and implementation in pediatric VADs.

Mechanical Ventilation and Outcomes of Children Who Undergo Ventricular Assist Device Placement: 2014-2020 Linked Analysis From the Advanced Cardiac Therapies Improving Outcomes Network and Pediatric Cardiac Critical Care Consortium Registries

OBJECTIVES

Placement of a ventricular assist device (VAD) improves outcomes in children with advanced heart failure, but adverse events remain important consequences. Preoperative mechanical ventilation (MV) increases mortality, but it is unknown what impact prolonged postoperative MV has.

DESIGN

Advanced Cardiac Therapies Improving Outcomes Network (ACTION) and Pediatric Cardiac Critical Care Consortium (PC 4 ) registries were used to identify and link children with initial VAD placement admitted to the cardiac ICU (CICU) from August 2014 to July 2020. Demographics, cardiac diagnosis, preoperative and postoperative CICU courses, and outcomes were compiled. Univariable and multivariable statistics assessed association of patient factors with prolonged postoperative MV. Multivariable logistic regression sought independent associations with outcomes.

SETTING

Thirty-five pediatric CICUs across the United States and Canada.

PATIENTS

Children on VADs included in both registries.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred forty-eight ACTION subjects were linked to a matching patient in PC 4 . Median (interquartile) age 7.7 years (1.5-15.5 yr), weight 21.3 kg (9.1-58 kg), and 56% male. Primary diagnosis was congenital heart disease (CHD) in 35%. Pre-VAD explanatory variables independently associated with prolonged postoperative MV included: age (incidence rate ratio [IRR], 0.95; 95% CI, 0.93-0.96; p < 0.01); preoperative MV within 48 hours (IRR, 2.76; 95% CI, 1.59-4.79; p < 0.01), 2-7 days (IRR, 1.82; 95% CI, 1.15-2.89; p = 0.011), and greater than 7 days before VAD implant (IRR, 2.35; 95% CI, 1.62-3.4; p < 0.01); and CHD (IRR, 1.96; 95% CI, 1.48-2.59; p < 0.01). Each additional day of postoperative MV was associated with greater odds of mortality (odds ratio [OR], 1.09 per day; p < 0.01) in the full cohort. We identified an associated greater odds of mortality in the 102 patients with intracorporeal devices (OR, 1.24; 95% CI, 1.04-1.48; p = 0.014), but not paracorporeal devices (77 patients; OR, 1.04; 95% CI, 0.99-1.09; p = 0.115).

CONCLUSIONS

Prolonged MV after VAD placement is associated with greater odds of mortality in intracorporeal devices, which may indicate inadequacy of cardiopulmonary support in this group. This linkage provides a platform for future analyses in this population.

Modifiable risk factor reduction for pediatric ventricular assist devices and the influence of persistent modifiable risk factors at transplant

OBJECTIVES

Ventricular assist devices (VADs) are associated with a mortality benefit in children. Database-driven analyses have associated VADs with reduction of modifiable risk factors (MRFs), but validation with institutional data is required. The authors studied MRF reduction on VAD and the influence of persistent MRFs on survival after heart transplant.

METHODS

All patients at the authors' institution requiring a VAD at transplant (2011-2022) were retrospectively identified. MRFs included renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2), hepatic dysfunction (total bilirubin ≥1.2 mg/dL), total parenteral nutrition dependence, sedatives, paralytics, inotropes, and mechanical ventilation.

RESULTS

Thirty-nine patients were identified. At time of VAD implantation, 18 patients had ≥3 MRFs, 21 had 1 to 2 MRFs, and 0 had 0 MRFs. At time of transplant, 6 patients had ≥3 MRFs, 17 had 1 to 2 MRFs, and 16 had 0 MRFs. Hospital mortality occurred in 50% (3 out of 6) patients with ≥3 MRFs at transplant vs 0% of patients with 1 to 2 and 0 MRFs (P = .01 for ≥3 vs 1-2 and 0 MRFs). MRFs independently associated with hospital mortality included paralytics (1.76 [range, 1.32-2.30]), ventilator (1.59 [range, 1.28-1.97]), total parenteral nutrition dependence (1.49 [range, 1.07-2.07]), and renal dysfunction (1.31 [range, 1.02-1.67]). Two late mortalities occurred (3.6 and 5.7 y), both in patients with 1 to 2 MRFs at transplant. Overall posttransplant survival was significantly worse for ≥3 versus 0 MRFs (P = .006) but comparable between other cohorts (P > .1).

CONCLUSIONS

VADs are associated with MRF reduction in children, yet those with persistent MRFs at transplant experience a high burden of mortality. Transplanting VAD patients with ≥3 MRFs may not be prudent. Time should be given on VAD support to achieve aggressive pre-transplant optimization of MRFs.

A single-institutional experience with 36 children less than 5 kilograms supported with the Berlin Heart: Comparison of congenital versus acquired heart disease

OBJECTIVES

We reviewed outcomes in all 36 consecutive children <5 kg supported with the Berlin Heart pulsatile ventricular assist device at the University of Florida, comparing those with acquired heart disease (n = 8) to those with congenital heart disease (CHD) (n = 28).

METHODS

The primary outcome was mortality. The Kaplan-Meier method and log-rank tests were used to assess group differences in long-term survival after ventricular assist device insertion. T-tests using estimated survival proportions were used to compare groups at specific time points.

RESULTS

Of 82 patients supported with the Berlin Heart at our institution, 49 (49/82 = 59.76%) weighed <10 kg and 36 (36/82 = 43.90%) weighed <5 kg. Of 36 patients <5 kg, 26 (26/36 = 72.22%) were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 36 patients <5 kg was [days]: median = 109, range = 4-305.) Eight out of 36 patients <5 kg had acquired heart disease, and all eight [8/8 = 100%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 8 patients <5 kg with acquired heart disease was [days]: median = 50, range = 9-130.) Twenty-eight of 36 patients <5 kg had congenital heart disease. Eighteen of these 28 [64.3%] were successfully bridged to transplantation. (The duration of support with ventricular assist device for these 28 patients <5 kg with congenital heart disease was [days]: median = 136, range = 4-305.) For all 36 patients who weighed <5 kg: 1-year survival estimate after ventricular assist device insertion = 62.7% (95% confidence interval = 48.5-81.2%) and 5-year survival estimate after ventricular assist device insertion = 58.5% (95% confidence interval = 43.8-78.3%). One-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 55.6% (95% confidence interval = 39.5-78.2%) in CHD, P = 0.036. Five-year survival after ventricular assist device insertion = 87.5% (95% confidence interval = 67.3-99.9%) in acquired heart disease and 48.6% (95% confidence interval = 31.6-74.8%) in CHD, P = 0.014.

CONCLUSION

Pulsatile ventricular assist device facilitates bridge to transplantation in neonates and infants weighing <5 kg; however, survival after ventricular assist device insertion in these small patients is less in those with CHD in comparison to those with acquired heart disease.

Malnutrition, sarcopenia, and frailty assessment in pediatric transplantation

Nutrition assessment can be challenging in children with end-stage organ disease and in those requiring an organ transplant. The effect of poor nutrition status can exert long-lasting effects on children with end-stage organ disease requiring transplantation. Malnutrition, sarcopenia, and frailty are conditions that require provision of optimal nutrition to prevent or support the treatment of these conditions. Unfortunately, the literature on the assessment of malnutrition, sarcopenia, and frailty in pediatric end-stage organ disease is scarce, thus leading to confusion on how to effectively identify them. Recently, the addition of a variety of validated nutrition and functional assessment techniques has assisted with appropriate assessment of these conditions. The objective of this narrative review is to provide an overview of the current literature for pediatric assessment of malnutrition, sarcopenia, and frailty in the setting of solid organ transplantation and provide practicing nutrition clinicians a solid foundation for learning how to effectively assess these conditions with the current literature available.

Optimizing the pediatric transplant candidate

PURPOSE OF REVIEW

Advances in pediatric transplant parallel those in adult populations; however, there remain critical unique considerations and differences that require specialized knowledge and a specific skill set to optimize care afforded to the pediatric transplant candidate. We introduce general themes regarding optimization of the transplant candidate that are unique to children.

RECENT FINDINGS

The pathologies leading to pediatric organ transplant candidacy differ from adults and a precise understanding of the physiologies and natural histories of such diseases is critical for optimized care. Regardless of etiology, comorbidities including malnutrition, sarcopenia, and developmental delay are seen and often require disease and organ specific approaches to management. Additionally, an understanding of the concepts of developmental immunology and their relevance to transplant is critical.

SUMMARY

When looking to optimize pretransplant care, awareness of the pediatric-specific challenges by the transplant community in addition to organ- and age-specific management strategies enable the best outcomes for children awaiting solid organ transplantation.

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.

Patient and parent-reported outcomes in paediatric ventricular assist device support: a multi-center ACTION learning network feasibility and pilot experience

BACKGROUND

Patient- and proxy-reported outcomes (PROs) are an important indicator of healthcare quality and can be used to inform treatment. Despite the widescale use of PROs in adult cardiology, they are underutilised in paediatric cardiac care. This study describes a six-center feasibility and pilot experience implementing PROs in the paediatric and young adult ventricular assist device population.

METHODS

The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) is a collaborative learning network comprised of 55 centres focused on improving clinical outcomes and the patient/family experience for children with heart failure and those supported by ventricular assist devices. The development of ACTION's PRO programme via engagement with patient and parent stakeholders is described. Pilot feasibility, patient/parent and clinician feedback, and initial PRO findings of patients and families receiving paediatric ventricular assist support across six centres are detailed.

RESULTS

Thirty of the thirty-five eligible patients (85.7%) were enrolled in the PRO programme during the pilot study period. Clinicians and participating patients/parents reported positive experiences with the PRO pilot programme. The most common symptoms reported by patients/parents in the first month post-implant period included limitations in activities, dressing change distress, and post-operative pain. Poor sleep, dressing change distress, sadness, and fatigue were the most common symptoms endorsed >30 days post-implant. Parental sadness and worry were notable throughout the entirety of the post-implant experience.

CONCLUSIONS

This multi-center ACTION learning network-based PRO programme demonstrated initial success in this six-center pilot study experience and yields important next steps for larger-scale PRO collection, research, and clinical intervention.

Pulmonary Vasodilator Therapy in Pediatric Patients on Ventricular Assist Device Support: A Single-Center Experience and Proposal for Use

Pediatric precapillary pulmonary hypertension can develop in response to systemic atrial hypertension. Systemic atrial decompression following ventricular assist device (VAD) implantation may not sufficiently lower pulmonary vascular resistance (PVR) to consider heart transplant candidacy. Prostacyclins have been used in adult VAD patients with success, but pediatric data on safety and efficacy in this population are limited. We sought to describe our center's experience to show its safety and to present our current protocol for perioperative use. We reviewed our use of prostacyclin therapy in pediatric patients on VAD support with high PVR from 2016 to 2021. Of the 17 patients who met inclusion, 12 survived to transplant and 1 is alive with VAD in situ . All patients survived posttransplant. With continuous intravenous (IV) epoprostenol or treprostinil therapy, there were no bleeding complications or worsening of end-organ function. A significant reduction was observed in vasoactive inotropic scores by 49% in the first 24 hours post-prostacyclin initiation. The proportion of patients surviving to transplant in this high-risk cohort is favorable. In conclusion, prostacyclins may be safe to use in patients with elevated PVR as part of their VAD and transplant course and may provide a transplant option in those otherwise not candidates.

Expanding use of the HeartMate 3 ventricular assist device in pediatric and adult patients within the Advanced Cardiac Therapies Improving Outcomes Network (ACTION)

BACKGROUND

We report current outcomes in patients supported with the HeartMate 3 (HM3) ventricular assist device in a multicenter learning network.

METHODS

The Advanced Cardiac Therapies Improving Outcomes Network database was queried for HM3 implants between 12/2017 and 5/2022. Clinical characteristics, postimplant course, and adverse events were collected. Patients were stratified according to body surface area (BSA) (<1.4 m2, 1.4-1.8 m2, and >1.8 m2) at device implantation.

RESULTS

During the study period, 170 patients were implanted with the HM3 at participating network centers, with median age 15.3years; 27.1% were female. Median BSA was 1.68 m2; the smallest patient was 0.73 m2 (17.7 kg). Most (71.8%) had a diagnosis of dilated cardiomyopathy. With a median support time of 102.5days, 61.2% underwent transplantation, 22.9% remained supported on device, 7.6% died, and 2.4% underwent device explantation for recovery; the remainder had transferred to another institution or transitioned to a different device type. The most common adverse events included major bleeding (20.8%) and driveline infection (12.9%); ischemic and hemorrhagic stroke were encountered in 6.5% and 1.2% of patients, respectively. Patients with BSA <1.4 m2 had a higher incidence of infection, renal dysfunction, and ischemic stroke.

CONCLUSIONS

In this updated cohort of predominantly pediatric patients supported with the HM3 ventricular assist device, outcomes are excellent with <8% mortality on device. Device-related adverse events including stroke, infection, and renal dysfunction were more commonly seen in smaller patients, highlighting opportunities for improvements in care.

Use of Intracorporeal Durable LVAD Support in Children Using HVAD or HeartMate 3-A EUROMACS Analysis

Purpose: The withdrawal of HVAD in 2021 created a concern for the pediatric population. The alternative implantable centrifugal blood pump HeartMate 3 has since been used more frequently in children. This paper analyses the outcome of children on LVAD support provided with an HVAD or HM3. Methods: A retrospective analysis of the EUROMACS database on children supported with VAD < 19 years of age from 1 January 2009 to 1 December 2021 was conducted. All patients with an LVAD and either an HVAD or HM3 were included. Patients with missing data on VAD status and/or missing baseline and/or follow up information were excluded. Kaplan-Meier survival analysis was performed to evaluate survival differences. Analyses were performed using Fisher's exact test. Results: The study included 150 implantations in 142 patients with 128 implants using an HVAD compared to 28 implants using an HM3. Nine patients (6%) needed temporary right ventricular mechanical support, which was significantly higher in the HM3 group, with 25% (p: 0.01). Patients in the HVAD group were significantly younger (12.7 vs. 14.5 years, p: 0.01), weighed less (45.7 vs. 60 kg, p: <0.000) and had lower BSA values (1.3 vs. 1.6 m2, p: <0.000). Median support time was 204 days. Overall, 98 patients (69%) were discharged and sent home, while 87% were discharged in group HM3 (p: ns). A total of 123 children (86%) survived to transplantation, recovery or are ongoing, without differences between groups. In the HVAD group, 10 patients (8%) died while on support, whereas in 12% of HM3 patients died (p: 0.7). Conclusions: Survival in children implanted with an HM3 was excellent. Almost 90% were discharged and sent home on the device.

Treatment Strategies for Cardiomyopathy in Children: A Scientific Statement From the American Heart Association

This scientific statement from the American Heart Association focuses on treatment strategies and modalities for cardiomyopathy (heart muscle disease) in children and serves as a companion scientific statement for the recent statement on the classification and diagnosis of cardiomyopathy in children. We propose that the foundation of treatment of pediatric cardiomyopathies is based on these principles applied as personalized therapy for children with cardiomyopathy: (1) identification of the specific cardiac pathophysiology; (2) determination of the root cause of the cardiomyopathy so that, if applicable, cause-specific treatment can occur (precision medicine); and (3) application of therapies based on the associated clinical milieu of the patient. These clinical milieus include patients at risk for developing cardiomyopathy (cardiomyopathy phenotype negative), asymptomatic patients with cardiomyopathy (phenotype positive), patients with symptomatic cardiomyopathy, and patients with end-stage cardiomyopathy. This scientific statement focuses primarily on the most frequent phenotypes, dilated and hypertrophic, that occur in children. Other less frequent cardiomyopathies, including left ventricular noncompaction, restrictive cardiomyopathy, and arrhythmogenic cardiomyopathy, are discussed in less detail. Suggestions are based on previous clinical and investigational experience, extrapolating therapies for cardiomyopathies in adults to children and noting the problems and challenges that have arisen in this experience. These likely underscore the increasingly apparent differences in pathogenesis and even pathophysiology in childhood cardiomyopathies compared with adult disease. These differences will likely affect the utility of some adult therapy strategies. Therefore, special emphasis has been placed on cause-specific therapies in children for prevention and attenuation of their cardiomyopathy in addition to symptomatic treatments. Current investigational strategies and treatments not in wide clinical practice, including future direction for investigational management strategies, trial designs, and collaborative networks, are also discussed because they have the potential to further refine and improve the health and outcomes of children with cardiomyopathy in the future.

Mechanical Circulatory Assistance in Children: Clinical Outcome

BACKGROUND

In countries where organ donation is scarce, mortality in the pediatric heart transplant waiting list is high, and ventricular assist devices (VADs) are therapeutic alternatives in these situations. Berlin Heart EXCOR is currently 1 of the few VADs specific for children.

METHODS

This retrospective study includes pediatric patients who underwent Berlin Heart EXCOR placement in a Brazilian hospital between 2012 and 2021. Clinical and laboratory data at the time of VAD implantation and the occurrence of complications and outcomes (success as a bridge to transplant or death) were analyzed.

RESULTS

Eight patients, from 8 months to 15 years, were included: 6 with cardiomyopathy and 2 with congenital heart disease. Six were on Intermacs 1 and 2 on Intermacs 2. The most common complications observed were stroke and right ventricular dysfunction. Six were transplanted, and 2 died. Those submitted to transplant had a higher mean weight than those who died, with no statistically significant difference. The underlying disease had no impact on the outcome. The group undergoing transplant had lower brain natriuretic peptide and lactate values, but no laboratory variable showed a statistically significant difference in the outcome.

CONCLUSION

A VAD is an invasive treatment with potentially serious adverse effects and is still poorly available in Brazil. However, as a bridge to transplant, it is a useful treatment for children in progressive clinical decline. In this study, we did not observe any clinical or laboratory factor at the time of VAD implantation that implied better outcomes.

Impact of Weight on Ventricular Assist Device Outcomes in Dilated Cardiomyopathy Patients in Pediatric Centers: An ACTION Registry Study

Ventricular assist device (VAD) options vary for children in different weight groups. This study evaluates contemporary device usage and outcomes for children based on weight. Data from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry were examined for patients with dilated cardiomyopathy (DCM) in 4 weight cohorts: <8 kg, 8-20 kg, 21-40 kg, and >40 kg, for devices implanted 3/2013-10/2020. Adverse event rates and ultimate outcome (deceased, alive on device, transplanted, or ventricular recovery) were analyzed. 222 DCM patients were identified with 24% in cohort 1, 23% in cohort 2, 15% in cohort 3, and 38% in cohort 4. Of 272 total implants, paracorporeal pulsatile devices were most common (95%) in cohorts 1 and 2 and intracorporeal continuous devices (81%) in cohorts 3 and 4. Stroke was noted in 17%, 12%, 6%, and 4% of cohorts, respectively (Cohort 1 vs. 4 and 2 vs. 4 - p = 0.01; other comparisons - not significant). Incidences of major bleeding, device malfunction, and infection was not different. All cohorts had >90% positive outcomes. Stroke incidence was higher in smaller cohorts, but other outcomes were similar. Positive outcomes were attained in over 90% across all weight groups, demonstrating excellent outcomes using current VADs in this DCM population.

A Single-Institutional Experience with 36 Children Smaller Than 5 Kilograms Supported with the Berlin Heart Ventricular Assist Device (VAD) over 12 Years: Comparison of Patients with Biventricular versus Functionally Univentricular Circulation

OBJECTIVES

We reviewed outcomes in all 36 consecutive children <5 kg supported with the Berlin Heart pulsatile ventricular assist device (VAD) at the University of Florida, comparing those with univentricular circulation (n  =  23) to those with biventricular circulation (n  =  13).

METHODS

The primary outcome was mortality. Kaplan-Meier methods and log-rank tests were used to assess group differences in long-term survival after VAD insertion. T-tests using estimated survival proportions and standard errors were used to compare groups at specific time points.

RESULTS

Of all 82 patients ever supported with Berlin Heart at our institution, 49 (49/82  =  59.76%) weighed <10 kg and 36 (36/82  =  43.90%) weighed <5 kg. Of these 36 patients who weighed <5 kg, 26 (26/36  =  72.22%) were successfully bridged to transplantation. Of these 36 patients who weighed <5 kg, 13 (13/36  =  36.1%) had biventricular circulation and were supported with 12 biventricular assist devices (BiVADs) and 1 left ventricular assist device (LVAD) (Age [days]: median  =  67, range  =  17-212; Weight [kilograms]: median  =  4.1, range  =  3.1-4.9), while 23 (23/36  =  63.9%) had univentricular circulation and were supported with 23 single ventricle-ventricular assist devices (sVADs) (Age [days]: median  =  25, range  =  4-215; Weight [kilograms]: median  =  3.4, range  =  2.4-4.9). Of 13 biventricular patients who weighed <5 kg, 12 (12/23  =  92.3%) were successfully bridged to cardiac transplantation. Of 23 functionally univentricular patients who weighed <5 kg, 14 (14/23  =  60.87%) were successfully bridged to cardiac transplantation. For all 36 patients who weighed <5 kg: 1-year survival estimate after VAD insertion  =  62.7% (95% confidence interval [CI]  =  48.5%-81.2%) and 5-year survival estimate after VAD insertion  =  58.5% (95% CI  =  43.8%-78.3%). One-year survival after VAD insertion: 84.6% (95% CI  =  67.1%-99.9%) in biventricular patients and 49.7% (95% CI  =  32.3%-76.4%) in univentricular patients, P  =  0.018. Three-year survival after VAD insertion: 84.6% (95% CI  =  67.1%-99.9%) in biventricular patients and 41.4% (95% CI  =  23.6%-72.5%) in univentricular patients, P  =  0.005.

CONCLUSION

Pulsatile VAD facilitates bridge to transplantation in neonates and infants weighing <5 kg; however, survival after VAD insertion in these small patients is less in those with univentricular circulation in comparison to those with biventricular circulation.

Impact of 2016 UNOS pediatric heart allocation policy changes on VAD utilization, waitlist, and post-transplant survival outcomes in children with CHD versus Non-CHD

AIMS

We analyzed the impact of the revised pediatric heart allocation policy on types of ventricular assist device (VAD) utilization, and waitlist (WL) and post-heart transplant (HT) survival outcomes in congenital heart disease (CHD) versus non-CHD patients before (Era-1) and after (Era-2) pediatric heart allocation policy implementation.

METHODS

We retrospectively reviewed the UNOS database from December 16, 2011, through March 31, 2021, for patients < 18 years old and listed for primary HT. We compared the differences observed between Era-1 and Era-2.

RESULTS

5551 patients were listed for HT, of whom 2447(44%) were in Era-1 and 3104(56%) were in Era-2. CHD patients were listed as status 1A unchanged, but the number of patients listed as status 1B decreased in Era-2, whereas the number of non-CHD patients listed as status 1A decreased, but status 1B increased. In Era-2 compared to Era-1, both temporary (1% to 4%, p < .001) and durable VAD (13.6% to 17.8%, p < .001) utilization increased, and the transplantation rate per 100-patient years increased in both groups. The median WL period for CHD patients increased marginally from 70 to 71 days (p = .06), whereas for non-CHD patients it decreased from 61 to 54 days (p < .001). Adjusted 90-day WL survival increased from 84% to 88%, p = .016 in CHD, but there was no significant change in non-CHD patients (p = .57). There was no significant difference in 1-year post-HT survival in CHD and non-CHD patients between Era-1 and Era-2.

CONCLUSIONS

In summary, after the revised heart allocation policy implementation, temporary and durable VAD support increased, HT rate increased, waitlist duration marginally increased in the CHD cohort and decreased in the non-CHD cohort, and 90-day WL survival probability improved in children with CHD without significant change in 1-year post-HT outcomes. Future studies are needed to identify changes to the policy that may further improve the listing criteria to improve WL duration and post-HT survival.

Reproductive health after thoracic transplantation: An ISHLT expert consensus statement

Pregnancy after thoracic organ transplantation is feasible for select individuals but requires multidisciplinary subspecialty care. Key components for a successful pregnancy after lung or heart transplantation include preconception and contraceptive planning, thorough risk stratification, optimization of maternal comorbidities and fetal health through careful monitoring, and open communication with shared decision-making. The goal of this consensus statement is to summarize the current evidence and provide guidance surrounding preconception counseling, patient risk assessment, medical management, maternal and fetal outcomes, obstetric management, and pharmacologic considerations.

Support with Single Ventricle-Ventricular Assist Device (sVAD) in Patients with Functionally Univentricular Circulation Prior to Fontan Operation

Some patients with functionally univentricular circulation develop cardiac failure refractory to maximal management and are supported with a ventricular assist device (VAD). The purpose of this manuscript is to summarize our previous publications related to single ventricle-ventricular assist device (sVAD) support in patients with functionally univentricular circulation and to describe our current institutional approach at University of Florida to sVAD support in neonates, infants, and children prior to Fontan. Our programmatic philosophy at University of Florida is to strive to identify the minority of neonates with functionally univentricular circulation who are extremely high-risk prior to initiating staged palliation and to stabilize these neonates with primary preemptive sVAD in preparation for cardiac transplantation; our rationale for this approach is related to the challenges associated with failed staged palliation and subsequent bail-out sVAD support and transplantation. A subset of extremely high-risk neonates and infants with functionally univentricular ductal-dependent circulation undergo primary preemptive sVAD insertion and subsequent cardiac transplantation. Support with VAD clearly facilitates survival on the waiting list during prolonged wait times and optimizes outcomes after Norwood (Stage 1) by providing an alternative pathway for extremely high-risk patients. Therefore, the selective utilization of sVAD in extremely high-risk neonates facilitates improved outcomes for all patients with functionally univentricular ductal-dependent circulation. At University of Florida, our programmatic approach to utilizing sVAD support as a bridge to transplantation in the minority of neonates with functionally univentricular circulation who are extremely high-risk for staged palliation is associated with Operative Mortality after Norwood (Stage 1) Operation of 2.9% (2/68) and a one-year survival of 91.1% (82/90) for all neonates presenting with hypoplastic left heart syndrome (HLHS) or HLHS-related malformation with functionally univentricular ductal-dependent systemic circulation. Meanwhile, at University of Florida, for all 82 consecutive neonates, infants, and children supported with pulsatile paracorporeal VAD: Kaplan-Meier survival estimated one year after VAD insertion = 73.3% (95% confidence interval [CI] = 64.1-83.8%), and Kaplan-Meier survival estimated five years after VAD insertion = 68.3% (95% CI = 58.4-79.8%). For all 48 consecutive neonates, infants, and children at University of Florida with biventricular circulation supported with pulsatile paracorporeal VAD: Kaplan-Meier survival estimated one year after VAD insertion = 82.7% (95% CI = 72.4-94.4%), and Kaplan-Meier survival estimated five years after VAD insertion = 79.7% (95% CI = 68.6-92.6%). For all 34 consecutive neonates, infants, and children at University of Florida with functionally univentricular circulation supported with pulsatile paracorporeal sVAD: Kaplan-Meier survival estimated one year after VAD insertion = 59.7% (95% CI = 44.9-79.5%), and Kaplan-Meier survival estimated five years after VAD insertion = 50.5% (95% CI = 35.0-73.0%). These Kaplan-Meier survival estimates for patients supported with pulsatile paracorporeal VAD are better in patients with biventricular circulation in comparison to patients with functionally univentricular circulation both one year after VAD insertion (P=0.026) and five years after VAD insertion (P=0.010). Although outcomes after VAD support in functionally univentricular patients are worse than in patients with biventricular circulation, sVAD provides a reasonable chance for survival. Ongoing research is necessary to improve the outcomes of these challenging patients, with the goal of developing strategies where outcomes after sVAD support in functionally univentricular patients are equivalent to the outcomes achieved after VAD support in patients with biventricular circulation.

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.

An Up-to-Date Literature Review on Ventricular Assist Devices Experience in Pediatric Hearts

Ventricular assist devices (VAD) have gained popularity in the pediatric population during recent years, as more and more children require a heart transplant due to improved palliation methods, allowing congenital heart defect patients and children with cardiomyopathies to live longer. Eventually, these children may require heart transplantation, and ventricular assist devices provide a bridge to transplantation in these cases. The FDA has so far approved two types of device: pulsatile and continuous flow (non-pulsatile), which can be axial and centrifugal. Potential eligible studies were searched in three databases: Medline, Embase, and ScienceDirect. Our endeavor retrieved 16 eligible studies focusing on five ventricular assist devices in children. We critically reviewed ventricular assist devices approved for pediatric use in terms of implant indication, main adverse effects, and outcomes. The main adverse effects associated with these devices have been noted to be thromboembolism, infection, bleeding, and hemolysis. However, utilizing left VAD early on, before end-organ dysfunction and deterioration of heart function, may give the patient enough time to recuperate before considering a more long-term solution for ventricular support.

Palliated Hypoplastic Left Heart Syndrome Patients Experience Superior Waitlist and Comparable Post-Heart Transplant Survival to Non-Single Ventricle Congenital Heart Disease Patients

Congenital heart disease (CHD) is a well-established risk factor for inferior waitlist and post-heart transplant survival in children. Differences in outcomes between CHD subgroups are understudied. The present study compared outcomes for palliated hypoplastic left heart syndrome (HLHS) patients to other non-single ventricle CHD (non-SVCHD) and non-CHD patients. United Network for Organ Sharing was used to identify children (age < 18) listed for heart transplant in the United States between 2016 and 2021. CHD sub-diagnoses were only available for United Network for Organ Sharing status 1a after 2015, thereby defining the cohort. Waitlist outcomes were studied using competing-risk time-to-event analysis for transplantation, mortality/decompensation, and alive-on-waitlist. Multivariable Cox proportional hazards regression analyses were used to identify factors associated with inferior post-transplant survival. Patients included: palliated-HLHS (n = 477), non-SVCHD (n = 686), and non-CHD (n = 1261). At listing, Palliated-HLHS patients were older than non-SVCHD (median 2-year [IQR 0-8] vs median 0-year [0-3], respectively) and younger than non-CHD (median 7-year [0-14]) (P < 0.001 vs both), and were more likely to be white (P < 0.01 vs both). Upon time-to-event analysis, rates of waitlist mortality/decompensation rates were greater among non-SVCHD than palliated-HLHS. Post-transplant survival was comparable between palliated-HLHS and non-SVCHD (P = 0.920) but worse compared to non-CHD (P < 0.001). Both palliated-HLHS (HR 2.40 [95% CI 1.68-3.42]) and non-SVSCHD (2.04 [1.39-2.99]) were independently associated with post-transplant mortality. Palliated-HLHS patients with heart failure experience significantly worse post-transplant outcomes than non-CHD but, compared to other CHD patients, experience superior waitlist and comparable post-transplant survival. While a high-risk cohort, HLHS patients can achieve gratifying waitlist and post-transplant survival.

Updates in the management of congenital heart disease in adult patients

INTRODUCTION

Adults with congenital heart disease represent a highly diverse, ever-growing population. Optimal approaches to management of problems such as arrhythmia, sudden cardiac death, heart failure, transplant, application of advanced therapies and unrepaired shunt lesions are incompletely established. Efforts to strengthen our understanding of these complex clinical challenges and inform evidence-based practices are ongoing.

AREAS COVERED

This narrative review summarizes evidence underpinning current approaches to congenital heart disease management while highlighting areas requiring further investigation. A search of literature published in 'Medline,' 'EMBASE,' and 'PubMed' using search terms 'congenital heart disease,' 'arrhythmia,' 'sudden cardiac death,' 'heart failure,' 'heart transplant,' 'advanced heart failure therapy,' 'ventricular assist device (VAD),' 'mechanical circulatory support (MSC),' 'intracardiac shunt' and combinations thereof was undertaken.

EXPERT OPINION

Application of novel technologies in the diagnosis and management of arrhythmia has and will continue to improve outcomes in this population. Sudden death remains a prevalent problem with many persistent unknowns. Heart failure is a leading cause of morbidity and mortality. Improved access to specialist care, advanced therapies and cardiac transplant is needed. The emerging field of cardio-obstetrics will continue to define state-of-the-art care for the reproductive health of women with heart disease.

Pulmonary Artery Banding for Dilated Cardiomyopathy in Children: Returning to the Bench from Bedside

Current treatment paradigms for end-stage dilated cardiomyopathy (DCM) in children include heart transplantation and mechanical support devices. However, waitlist mortality, shortage of smaller donors, time-limited durability of grafts, and thrombo-hemorrhagic events affect long-term outcomes. Moreover, both these options are noncurative and cannot preserve the native heart function. Pulmonary artery banding (PAB) has been reinvented as a possible “regenerative surgery” to retrain the decompensated left ventricle in children with DCM. The rationale is to promote positive ventricular–ventricular interactions that result in recovery of left ventricular function in one out of two children, allowing transplantation delisting. Although promising, global experience with this technique is still limited, and several surgical centers are reluctant to adopt PAB since its exact biological bases remain unknown. In the present review, we summarize the clinical, functional, and molecular known and supposed working mechanisms of PAB in children with DCM. From its proven efficacy in the clinical setting, we described the macroscopic geometrical and functional changes in biventricular performance promoted by PAB. We finally speculated on the possible underlying molecular pathways recruited by PAB. An evidence-based explanation of the working mechanisms of PAB is still awaited to support wider adoption of this surgical option for pediatric heart failure.

Patient and Device Selection in Pediatric MCS: A Review of Current Consensus and Unsettled Questions

The field of pediatric ventricular assist device (VAD) support has expanded significantly over the past 20 years, with one third of pediatric heart transplant recipients currently being bridged to transplant with a VAD. Despite increased pediatric VAD utilization, however, there remains little formalized guidance for patient or device selection. The population of children with advanced heart failure is quite heterogeneous, and the available data suggest that VAD outcomes vary significantly based upon patient size, anatomy, level of illness, and type of device implanted. In an effort to better understand current practice patterns and identify populations for whom there does not appear to be a consensus approach to achieving optimal VAD outcomes, the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) has surveyed clinical decision-making among member sites and conducted a review of the available literature regarding patient population-specific VAD outcomes and center-specific practices related to patient and device selection. Rather than aiming to provide clinical guidelines, this document offers an overview of contemporary approaches to patient and device selection, highlighting specific populations for whom there is not a consensus approach to achieving reliably good VAD outcomes, as these populations may benefit most from future research and quality improvement efforts directed toward identifying best practice.

Ventricular assist device support in neonates and infants with a failing functionally univentricular circulation

Some neonates with functionally univentricular hearts are at extremely high risk for conventional surgical palliation. Primary cardiac transplantation offers the best option for survival of these challenging neonates; however, waitlist mortality must be minimized. We have developed a comprehensive strategy for the management of neonates with functionally univentricular hearts that includes the selective use of conventional neonatal palliation in standard-risk neonates, hybrid approaches in neonates with elevated risk secondary to a noncardiac etiology, and neonatal palliation combined with insertion of a single ventricular assist device (VAD) in neonates with elevated risk secondary to a cardiac etiology. Here we describe our selection criteria, technical details, management strategies, pitfalls, and current outcomes for neonates with functionally univentricular hearts supported with a VAD. Our experience shows that extremely high-risk neonates with functionally univentricular hearts who are poor candidates for conventional palliation can be successfully stabilized with concomitant palliation and pulsatile VAD insertion while awaiting cardiac transplantation.