The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Twenty-fourth pediatric heart transplantation report - 2021; focus on recipient characteristics

Pulmonary Artery Size as a Predictor of Early Post-operative Pediatric and Congenital Heart Transplant Outcomes

Pulmonary artery size has been studied as an outcome predictor for selected congenital heart surgeries but has not been investigated in pediatric and congenital heart transplantation. We sought to evaluate pre-operative pulmonary artery size as a predictor of post-transplant outcomes. This single center retrospective study included all patients transplanted from 2014 to 2023. Echocardiography, computed tomography angiography (CTA), and catheter angiography were used to measure pre-operative pulmonary artery size. Cross-sectional areas were calculated and indexed to calculate Nakata index and lower lobe index. Outcomes included post-transplant cardiovascular and end-organ function, length of stay, and mortality. Statistical analyses included Spearman rank correlations, chi-squared tests, and Mann-Whitney U tests. Included were 68 patients with 37 (54%) having a diagnosis of congenital heart disease. Echocardiogram (n = 68), CTA (n = 52), and catheter angiogram (n = 31) measurements were analyzed. Smaller lower lobe index was associated with longer duration of post-transplant treatment with nitric oxide (p = 0.02). In the congenital heart disease cohort, smaller Nakata index was associated with pulmonary artery reconstruction during transplant (p = 0.003). Indexed pulmonary artery size was otherwise not associated with important outcomes in the entire population or congenital heart disease cohort. While pre-operative pulmonary artery size was associated with prolonged nitric oxide use, it was generally not predictive of other early post-transplant outcomes. No imaging modality was found to have superior predictive value. Use of advanced imaging to guide surgical technique during transplant may negate the impact of smaller pulmonary artery size.

Mechanical circulatory support early after pediatric heart transplantation-an analysis from the Pediatric Heart Transplant Society

BACKGROUND

The use of early mechanical circulatory support (MCS) following pediatric heart transplantation is not well-published. This paper attempts to uncover the incidence, predisposing factors, and outcomes of MCS in a large, international cohort.

METHODS

The Pediatric Heart Transplant Society Database (an international, prospective, event-driven database) was retrospectively analyzed for all cases of primary heart transplant over an 11-year period (2010-2020), dividing the cohort based on need for MCS within 30 days of transplantation.

RESULTS

Of 4,321 primary transplants, 249 (5.8%) required MCS (230 ECMO (Extracoporeal Membranous Oxygenation), 19 ventricular assist device). In a Cox proportional hazard model, congenital heart disease (p = 0.0002), older donor age (p < 0.0001), and longer ischemic time (p = 0.018) were each related to an increased need for MCS; increasing recipient body surface area (p < 0.0001) and increasing donor left ventricular ejection fraction (p = 0.016) were both correlated with less MCS use. One-year survival in those requiring MCS was 54.2%, compared with 94.8% in those who did not need MCS (p < 0.0001). Later survival in patients surviving to 1 year was similar between the groups.

CONCLUSIONS

MCS is used infrequently following pediatric heart transplant and is related to donor, recipient, and transplant factors. Although mortality is high, those surviving the first year post transplant have excellent outcomes. Judicious use in those patients who would otherwise perish is therefore justified.

Severe primary graft failure: Are there lasting impacts? Analysis from the PHTS Database

Background

Primary graft failure (PGF) is a leading cause of early morbidity and mortality after heart transplantation (HTx). PGF is secondary to graft ischemia and ischemia-reperfusion injuries to the cardiomyocytes and vasculature of the donor heart after transplantation. Longer-term outcomes after PGF are not well studied.

Methods

Patients with an HTx (January 1, 2010 to June 30, 2022) were identified using the Pediatric Heart Transplant Society registry. PGF was defined as death, retransplantation, or need for mechanical circulatory support within 72 hours of HTx. Kaplan-Meier analysis and Cox proportional hazard modeling were utilized.

Results

Of the 4,982 patients with a primary HTx, 5.4% (n = 269) met criteria for PGF. Patients with PGF were younger, with higher proportion of congenital heart disease, longer cardiopulmonary bypass and ischemic times (IT), and more likely to be on extracorporeal membrane oxygenation or ventilator at HTx (all p < 0.0001, IT p = 0.0006). PGF resulted in lower overall survival (1 year: 54% vs 94%, p < 0.001). This remained true when conditional survival was examined at 30 and 90 days but not at 1 year (p = 0.1143). Freedom from rejection did not differ between the groups at overall or conditional on 30 days but was slightly higher for those with PGF at 90 and 365 days. There was no difference in freedom from coronary allograft vasculopathy (CAV). PGF was an independent predictor of overall graft loss (hazard ratios [HR] 4.7, p < 0.0001) and conditional survival to 30 days (HR 2.47, p < 0.0001) and 90 days (HR 1.6, p = 0.012) but not beyond 1 year.

Conclusions

Severe PGF is an independent predictor of early mortality post-HTx but subsequently does not further impact long-term survival, overall risk of rejection, or CAV. Understanding the impact of milder forms of PGF on survival and long-term outcomes is still needed. Methods to decrease the risk of PGF, such as alternative preservation and storage techniques, may impact early mortality post-HTx.

Clinical Management and Transplant Considerations in Pediatric Pulmonary Hypertension Due to Left Heart Disease: A Scientific Statement From the American Heart Association

Children with left heart disease are at risk for developing pulmonary hypertension, initially secondary to pulmonary venous hypertension that can progress to include elevated pulmonary vascular resistance, known as combined pre- and postcapillary pulmonary hypertension. Elevated pulmonary vascular resistance may pose a risk to the right ventricle of a newly transplanted heart because of increased afterload and is an important consideration for heart transplant eligibility. However, the epidemiology, pathophysiology, optimal diagnostic and treatment approaches, and thresholds for pulmonary vascular resistance in pulmonary hypertension associated with left heart disease remain unclear because of lack of evidence, particularly in pediatrics. The result is heterogeneity with respect to hemodynamic assessment, use of pulmonary vasodilator therapies, and heart transplant listing. This scientific statement aims to synthesize the available data and highlight areas of general consensus as well as important knowledge gaps.

Multiparametric cardiovascular magnetic resonance is associated with outcomes in pediatric heart transplant recipients

BACKGROUND

Multiparametric cardiovascular magnetic resonance (CMR) has an emerging role in non-invasive surveillance of pediatric heart transplant recipients (PHTR). Higher myocardial T2, higher extracellular volume fraction (ECV), and late gadolinium enhancement (LGE) have been associated with adverse clinical outcomes in adult heart transplant recipients. The purpose of this study was to investigate the prognostic value of CMR-derived T1 and T2 mapping, ECV, and LGE for clinical outcomes in PHTR.

METHODS

We performed a single-center, retrospective chart review of consecutive, gadolinium-enhanced CMR studies in PHTR over a 7.5-year period, excluding follow-up studies. Standard CMR ventricular volume and function analysis, T1 mapping with ECV, T2 mapping, and LGE assessment were performed. The composite outcome included cardiac death, non-cardiac death, re-transplantation, and cardiac hospitalization.

RESULTS

Among 113 PHTR, mean age was 13.0 ± 5.1 years, with 6.0 ± 4.0 years since transplant. The indication for CMR was surveillance in 79%. Mean native T1 was 1050 ± 48 ms, T2 49.2 ± 3.9 ms, and ECV 29.7 ± 4.5%. Left ventricular LGE was present in 37% (42/113) and right ventricular LGE in 3.5% (4/113). The mean follow-up time was 2.3 years and median was 1.4 years. Cardiac death occurred in 2% (2/113), re-transplantation in 4% (4/113), and cardiac hospitalization in 22% (25/113). Non-cardiac death did not occur. Using Kaplan-Meier analysis, high T1 (≥1061 ms), T2 (≥50.0 ms), and ECV (≥31.4%) were each associated with decreased freedom from the composite outcome in follow-up. In univariable Cox regression analyses, high T1 was associated with increased risk of the composite outcome (hazard ratios [HR] 4.0, 95% confidence interval [CI] 1.7-9.2, p = 0.001), as were high T2 (HR 2.8, 95% CI 1.1-7.1, p = 0.026), and high ECV (HR 3.5, 95% CI 1.5-8.1, p = 0.004).

CONCLUSION

T1 and T2 mapping are associated with early differences in adverse cardiac events in PHTR. These data suggest a role for a multicenter study with a longer follow-up duration.

Changes in waiting time, need for mechanical circulatory support and outcomes in paediatric heart transplant recipients

AIMS

Heart transplantation is a well-established treatment for end-stage heart failure in paediatric patients, demonstrating excellent long-term outcomes.

METHODS

This retrospective study analyses 35 years of data on 244 paediatric recipients (<18 years) at a single institution from 1986 to 2022. The analysis explores changes in diagnoses, survival, waiting times and mechanical circulatory support (MCS) over three decades (1991-2000, 2001-2010 and 2011-2020).

RESULTS

Survival outcomes significantly improved over the study period, with 1-year survival rates increasing from 79.3% (1991-2000) to 92.3% (2011-2020, P = 0.041). The median overall survival was 18.0 years, and median conditional survival to 1 year post-transplant was 20.9 years. Survival differences were noted among age groups, with infants under 1 year of age experiencing higher early mortality, and adolescents (aged 11-17 years) facing increased long-term risks, possibly linked to adult donor characteristics. Waiting times for heart transplantation increased, especially for younger age groups (0-5 and 6-10 years), reflecting the growing demand for donor organs. The use of MCS, including ventricular assist devices (VAD), surged, with 67% of recipients in the most recent decade receiving pre-transplant VAD support. Importantly, despite prolonged waiting times and increased VAD use, overall survival continued to be favourable.

CONCLUSIONS

Early and long-term results after paediatric heart transplantation have been continuously improving over the past decades. Despite an increased demand for donor organs and the growing reliance on VAD as bridge to transplantation, post-transplantation survival is not compromised.

Socioeconomic Status and Major Adverse Transplant Events in Pediatric Heart Transplant Recipients

Importance

Low socioeconomic status (SES) has been associated with higher risk of rejection and graft loss in pediatric heart transplant (HT) recipients. The association of SES with other posttransplant morbidities is unknown.

Objective

To assess whether low SES is associated with higher risk of a major adverse transplant event (MATE) among pediatric HT recipients.

Design, Setting, and Participants

Retrospective single-center cohort study at a children's hospital in Boston with consecutive primary HT recipients from 2006 to 2019 and follow-up through 2022. Data were analyzed from June 2023 to March 2024.

Exposure

Very low or low, moderate, and high or very high Childhood Opportunity Index (COI) for neighborhood (census tract) of patient residence.

Main Outcomes and Measures

Primary outcome was 3-year MATE-6 score assessed in 6-month survivors as cumulative burden of acute cellular rejection, antibody-mediated rejection, coronary vasculopathy, lymphoproliferative disease, kidney dysfunction, and infection, each as an ordinal score from 0 to 4 (24 for death or retransplant). Secondary outcomes were freedom from rejection during first 6 months, freedom from death or retransplant, MATE-3 score for events 1 to 3 (under immune suppression) and events 4 to 6 (chronic immune suppression effects), and each MATE component.

Results

Of 153 children analyzed, the median (IQR) age at HT was 7.2 (1.5-14.8) years, 99 (65%) were male, 16 (10%) were Black, 17 (11%) were Hispanic, and 106 (69%) were White. Fifty patients (33%) lived in very low or low, 17 (11%) in moderate, and 86 (56%) in high or very high COI neighborhoods. There was no significant group difference in mean (SD) 3-year MATE-6 score (very low or low COI, 3.4 [6.5]; moderate COI, 2.4 [6.3]; and high or very high COI, 4.0 [6.9]). Furthermore, there was no group difference in mean (SD) MATE-3 scores for underimmune suppression (very low or low COI, 1.9 [3.5]; moderate COI, 1.2 [3.2]; and high or very high COI, 2.2 [3.6]), chronic immune suppression effects (very low or low COI, 1.6 [3.3]; moderate COI, 1.1 [3.2]; and high or very high COI, 1.8 [3.6]), individual MATE components, rejection during the first 6 months, or death or retransplant.

Conclusions and relevance

In this cohort study of pediatric HT recipients, there was no difference in posttransplant outcomes among recipients stratified by SES, a notable improvement from prior studies. These findings may be explained by state-level health reform, standardized posttransplant care, and early awareness of outcome disparities.

Paediatric HeartMate 3™, the Uneventful 22-Month Journey to Transplantation of a 14-Year-Old-Patient-Time for Prolonged LVAD Support in Children?

We report on a 14-year-old patient who was supported for nearly two years with an ic-LVAD and managed to complete his journey to transplantation without a single complication. Although mechanical assist device support is available for children up to 20 kg in body weight, availability is limited to paracorporeal devices. Intracorporal (ic) left ventricular assist devices (LVADs) for infants in the suitable weight class are a viable option as a bridge-to-transplant, where they make up more than 50% of transplant candidates in their category. A teenager with 59 kg body weight was newly diagnosed with DCM and listed for heart transplantation. After initially being on VA-ECMO, an Abbott HeartMate 3 LVAD with postoperative temporary RVAD support was initialised. RV-support was maintained for 10 days. The further postoperative course was uneventful, and he was discharged on day 98. He was seen regularly in the outpatient department and integrated into school routine again, following the extensive training of his classmates and the responsible school staff. After a total of 672 days on support, he was successfully transplanted. There were no unplanned admissions, thrombotic nor bleeding events, as well as no driveline infection, even though the patient participated in sport classes at school.

Critical care therapies pre- and post-heart transplant and their impact: Analysis from the Pediatric Cardiac Critical Care Consortium

BACKGROUND

Few studies highlighting the critical care management of patients after heart HTx (HTx) have been published to date. This analysis provides a contemporary representation of pre- and post-HTx critical care in various patient cohorts and outlines the impact of intensive care unit (ICU) therapies on outcomes.

METHODS

Data from PC4 Collaborative Registry were analyzed for pediatric patients undergoing HTx between August 2014 and April 2022.

RESULTS

A total of 1877 HTx in 1857 patients were reported from 42 centers; 56.5% had congenital heart disease (CHD). Patients with CHD were younger, smaller, more likely male, White race, and publicly insured. CHD patients had higher need for catheterization, increased likelihood of inotropic support and mechanical ventilation and lower VAD rates. Their operative courses were significant for longer bypass and cross-clamp times. Postoperatively, CHD patients required more CPR , utilized more ICU therapies and had higher hospital mortality (7.8% vs. 1.8% for non-CHD patients, p<0.0001). Longer cardiopulmonary bypass, longer deep hypothermic circulatory arrest times and delayed sternal closure were independent risk factors for hospital mortality. Lastly, center transplant volume but not surgical volume was associated with transplant outcomes.

CONCLUSIONS

A diagnosis of CHD before HTx is associated with a greater use of ICU-specific therapies compared non-CHD cohort. Operative factors, particularly in patients with CHD, are independently associated with higher hospital mortality as was low transplant volume at the center. The study provides basis for further investigating ICU and operative factors that can be modified to improve transplant outcomes.

Left ventricular assist device temporary explantation as a strategy for infection control in a pediatric patient

We report a case of temporary Berlin Heart EXCOR® explantation in a pediatric patient with idiopathic dilated cardiomyopathy who suffered an uncontrollable inflow cannulation site infection while on bridge-to-transplantation. Despite failure to thrive and catheter-related infections, once free of the device, the patient was cured of infection using systemic antibiotics and surgical debridement. The patient underwent EXCOR® reimplantation after four months, and is awaiting heart transplantation in stable condition. A life-threatening ventricular assist device-related infection may require device explantation under conditions that may not fulfill conventional explantation criteria despite risks. Temporary explantation can be an effective strategy if isolated systolic dysfunction is managed carefully.

Pediatric continuous-flow total artificial heart with rotor axial position tracking technology: First report of in vivo assessment

Background

The pediatric continuous-flow total artificial heart (P-CFTAH) is a novel double-ended centrifugal pump designed with the intent to provide circulatory support for pediatric heart failure. To enable continuous monitoring of pump hemodynamics, Hall effect sensors (HES) were embedded inside the P-CFTAH design to track both axial movement and position of the pump rotor postimplantation. Herein, we report an early in vivo evaluation of the P-CFTAH with HES, implanted in small-sized ovine models.

Methods

Five healthy lambs were used for the P-CFTAH implantation via a full median sternotomy and cardiopulmonary bypass support. Successful evaluation of the P-CFTAH was achieved in 4 out of 5 (n = 4, 20.9 ± 1.3 kg). The hemodynamics and operating conditions were continuously recorded with varying pump speeds (2,800-5,000 rpm), systemic/pulmonary vascular resistance ratio, and high- and low-volume conditions. Among the 4 cases, P-CFTAH with HES embedded in the rotor was used in 2 cases.

Results

All surgical procedures were uneventful, and the optimal anatomical fit of the pump was shown in the chest. Differences between the left and right atrial pressures were mostly maintained within the intended limit of ±10 mm Hg throughout the design range of systemic and pulmonary vascular resistance. The HES accurately traced the rotor position, showing a positive correlation with atrial pressure differences.

Conclusions

The findings suggest that the P-CFTAH has the potential to provide self-balancing circulatory support for pediatric heart failure patients. The study contributes to the development of a pediatric-sized total artificial heart with improved monitoring.

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.

Impact of prolonged ischemic time on pediatric heart transplantation outcomes: Improved outcomes in the most recent era

BACKGROUND

Impacts of ischemic time (IT) on pediatric heart transplant outcomes are multifactorial. We aimed to analyze the effect of prolonged IT on graft loss after pediatric heart transplantation. We hypothesized that graft survival with prolonged IT has improved across eras.

METHODS

Patients <18 years old in the Pediatric Heart Transplant Society database were included (N=6,765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, retransplant, or need for mechanical circulatory support in the first 7 days post-transplant. Descriptive statistical methods were used to compare differences between patient characteristics and IT. Kaplan-Meier survival analysis compared freedom from graft loss, rejection, and infection. Multivariable analysis was performed for graft loss and SGF (hazard and logistic regression modeling, respectively).

RESULTS

Diagnoses were cardiomyopathy (N = 3,246) and congenital heart disease (CHD; N = 3,305). CHD were younger, more likely to have an IT ≥4.5 hours, and more likely to require extracorporeal membrane oxygenation or mechanical ventilation at transplant (all p < 0.001). Median IT was 3.6 hours (interquartile range 2.98-4.31; range 0-10.5). IT was associated with early graft loss (HR 1.012, 95% CI 1.005-1.019), but not when analyzed only in the most recent era. IT was associated with SGF (OR 1.016 95%CI 1.003-1.030).

CONCLUSIONS

Donor IT was independently associated with an increased risk of graft loss, albeit with a small effect relative to other risk factors. Graft survival with prolonged IT has improved in the most recent era but the risk of SGF persists.

Pathology of explanted pediatric hearts: An 11-year study. Population characteristics and implications for outcomes

BACKGROUND

As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT.

METHODS

Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors.

RESULTS

In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases.

CONCLUSIONS

Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.

Impact of ventricular assist device use on pediatric heart transplant waitlist mortality: Analysis of the scientific registry of transplant recipients database

BACKGROUND

Children awaiting heart transplant (Tx) have a high risk of death due to donor organ scarcity. Historically, ventricular assist devices (VADs) reduced waitlist mortality, prompting increased VAD use. We sought to determine whether the VAD survival benefit persists in the current era.

METHODS

Using the Scientific Registry of Transplant Recipients, we identified patients listed for Tx between 3/22/2016 and 9/1/2020. We compared characteristics of VAD and non-VAD groups at Tx listing. Cox proportional hazards models were used to identify risk factors for 1-year waitlist mortality.

RESULTS

Among 5054 patients, 764 (15%) had a VAD at Tx listing. The VAD group was older with more mechanical ventilation and renal impairment. Unadjusted waitlist mortality was similar between groups; the curves crossed ~90 days after listing (p = .55). In multivariable analysis, infant age (HR 2.77, 95%CI 2.13-3.60), Black race (HR 1.57, 95%CI 1.31-1.88), congenital heart disease (HR 1.23, 95%CI 1.04-1.46), renal impairment (HR 2.67, 95%CI 2.19-3.26), inotropes (HR 1.28, 95%CI 1.09-1.52), and mechanical ventilation (HR 2.23, 95%CI 1.84-2.70) were associated with 1-year waitlist mortality. VADs were not associated with mortality in the first 90 waitlist days but were protective for those waiting ≥90 days (HR 0.43, 95%CI 0.26-0.71).

CONCLUSIONS

In the current era, VADs reduce waitlist mortality, but only for those waitlisted ≥90 days. The differential effect by race, size, and VAD type is less clear. These findings suggest that Tx listing without VAD may be reasonable if a short waitlist time is anticipated, but VADs may benefit those expected to wait >90 days.

The pig as an optimal animal model for cardiovascular research

Cardiovascular disease is a worldwide health problem and a leading cause of morbidity and mortality. Preclinical cardiovascular research using animals is needed to explore potential targets and therapeutic options. Compared with rodents, pigs have many advantages, with their anatomy, physiology, metabolism and immune system being more similar to humans. Here we present an overview of the available pig models for cardiovascular diseases, discuss their advantages over other models and propose the concept of standardized models to improve translation to the clinical setting and control research costs.

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.

Cardiac magnetic resonance assessment of acute rejection and cardiac allograft vasculopathy in pediatric heart transplant

BACKGROUND

In pediatric heart transplant (PHT), cardiac catheterization with endomyocardial biopsy (EMB) is standard for diagnosing acute rejection (AR) and cardiac allograft vasculopathy (CAV) but is costly and invasive.

OBJECTIVES

To evaluate the ability of cardiac magnetic resonance (CMR) to noninvasively identify differences in PHT patients with AR and CAV.

METHODS

Patients were enrolled at three children's hospitals. Data were collected from surveillance EMB or EMB for-cause AR. Patients were excluded if they had concurrent diagnoses of AR and CAV, CMR obtained >7days from AR diagnosis, they had EMB negative AR, or could not undergo contrasted, unsedated CMR. Kruskal-Wallis test was used to compare groups: (1) No AR or CAV (Healthy), (2) AR, (3) CAV. Wilcoxon rank-sum test was used for pairwise comparisons.

RESULTS

Fifty-nine patients met inclusion criteria (median age 17years [IQR 15-19]) 10 (17%) with AR, and 11 (19%) with CAV. AR subjects had worse left ventricular ejection fraction compared to Healthy patients (p = 0.001). Global circumferential strain (GCS) was worse in AR (p = 0.054) and CAV (p = 0.019), compared to Healthy patients. ECV, native T1, and T2 z-scores were elevated in patients with AR.

CONCLUSIONS

CMR was able to identify differences between CAV and AR. CAV subjects had normal global function but abnormal GCS which may suggest subclinical dysfunction. AR patients have abnormal function and tissue characteristics consistent with edema (elevated ECV, native T1 and T2 z-scores). Characterization of CMR patterns is critical for the development of noninvasive biomarkers for PHT and may decrease dependence on EMB.

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.

Durable left ventricular assist device explantation following recovery in paediatric patients: Determinants and outcome after explantation

OBJECTIVES

Myocardial recovery in children supported by a durable left ventricular assist device is a rare, but highly desirable outcome because it could potentially eliminate the need for a cardiac transplant and the lifelong need for immunosuppressant therapy and the risk of complications. However, experience with this specific outcome is extremely limited.

METHODS

All patients < 19 years old supported by a durable left ventricular assist device from the European Registry for Patients with Mechanical Circulatory Support database were included. Participating centres were approached for additional follow-up data after explantation. Associated factors for explantation due to myocardial recovery were explored using Cox proportional hazard models.

RESULTS

The incidence of recovery in children supported by a durable left ventricular assist device was 11.7% (52/445; median duration of support, 122.0 days). Multivariable analyses showed body surface area (hazard ratio 0.229; confidence interval 0.093-0.565; P = 0.001) and a primary diagnosis of myocarditis (hazard ratio 4.597; confidence interval 2.545-8.303; P < 0.001) to be associated with recovery. Left ventricular end-diastolic diameter in children with myocarditis was not associated with recovery. Follow-up after recovery was obtained for 46 patients (88.5%). Sustained myocardial recovery was reported in 33/46 (71.7%) at the end of the follow-up period (28/33; >2 year). Transplants were performed in 6/46 (11.4%) (in 5 after a ventricular assist device was reimplanted). Death occurred in 7/46 (15.2%).

CONCLUSIONS

Myocardial recovery occurs in a substantial portion of paediatric patients supported with durable left ventricular assist devices, and sustainable recovery is seen in around three-quarters of them. Even children with severely dilated ventricles due to myocarditis can show recovery. Clinicians should be attentive to (developing) myocardial recovery. These results can be used to develop internationally approved paediatric weaning guidelines.

Paediatric heart transplantation: life-saving but not yet a cure

In the 1980s, heart transplantation was the first successful treatment for infants born with hypoplastic left heart syndrome. Infants who have required heart transplantation benefit from immunologic "advantages," including long-term survival free from cardiac allograft vasculopathy. Currently ∼ 90% of children undergoing a heart transplant are reaching their first-year anniversary and the clinical practices of paediatric heart transplantation have dramatically improved. These successes are largely attributed to research sponsored by the Pediatric Heart Transplant Study Group, the International Society of Heart and Lung Transplantation and, more recently, the Non-profits Enduring Hearts and Additional Ventures. Despite these successes, the field is challenged to increase progress to achieve long-term survival into adulthood. The wait-list mortality, especially among infants, is unacceptably high often leading to palliative measures that can increase post-transplant mortality. Cardiac allograft vasculopathy remains a major cause for progressive graft loss of function and sudden death. The relative tolerance seen in immature recipients has not been translated to modifying older recipients' post-transplant outcomes. The modifiable cause(s) for the increased risks of transplantation in children of different ethnicities and races require definition. Addressing these challenges faces the reality that for-profit research favours funding adult recipients, with ∼ 10-fold greater numbers, and their more modest longevity goals. Advocacy for funding "incentives" such as the Orphan Drug rules in the United States and upholding principles of equity and inclusion are critical to addressing the challenges of paediatric heart transplant recipients worldwide.

Echocardiographic assessment of pediatric heart transplantation: A single-center experience in China

BACKGROUND

Pediatric heart transplant (HT) has become the standard of care for end-stage heart failure in children worldwide. Serial echocardiographic evaluations of graft anatomy and function during follow-up are crucial for post-HT management. However, evolution of cardiac structure and function after pediatric HT has not been well described, especially during first year post-HT. This study aimed to characterize the evolution of cardiac structure and function after pediatric HT and investigate the correlation between biventricular function with adverse clinical outcomes.

METHODS

A single-center retrospective study of echocardiographic data obtained among 99 pediatric HT patients was conducted. Comprehensive echocardiographic examination was performed in all patients at 1-, 3-, 6-, 9- and 12-months post-HT. We obtained structural, functional and hemodynamic parameters from both left- and right-side heart, such as left ventricular stroke volume (LVSV), left ventricular ejection fraction (LVEF), right ventricular fractional area change (RVFAC), etc. The cardiac evolution of pediatric HT patients during first post-HT year was described and compared between different time points. We also explored the correlation between cardiac function and major adverse transplant events (MATEs).

RESULTS

1) Evolution of left heart parameters: left atrial length, mitral E velocity, E/A ratio, LVSV and LVEF significantly increased while mitral A velocity significantly decreased over the first year after HT (P < .05). Compared with 1 month after HT, interventricular septum (IVS) and left ventricular posterior wall (LVPW) decreased at 3 months but increased afterwards. (2) Evolution of right heart parameters: right ventricular base diameter and mid-diameter; right ventricular length diameter, tricuspid E velocity, E/A ratio, tricuspid annular velocity e' at free wall, and RVFAC increased, while tricuspid A velocity decreased over the first year after HT (P < .05). (3) Univariate logistic regression model suggests that biventricular function parameters at 1-year post-HT (LVEF, RVFAC, tricuspid annular plane systolic excursion and tricuspid lateral annular systolic velocity) were associated with MATEs.

CONCLUSION

Gradual improvement of LV and RV function was seen in pediatric HT patients within the first year. Biventricular function parameters associated with MATEs. The results of this study pave way for designing larger and longer follow-up of this population, potentially aiming at using multiparameter echocardiographic prediction of adverse events.

Increasing donor-recipient weight mismatch in infant heart transplantation is associated with shorter waitlist duration and no increased morbidity or mortality

OBJECTIVES

Infants awaiting paediatric heart transplantation (PHT) experience long waitlist duration and high mortality due to donor shortage. Using the United Network for Organ Sharing database, we explored if increasing donor-recipient weight ratio (DRWR) >2.0 (recommended cutoff) was associated with adverse outcomes.

METHODS

Between 2007 and 2020, 1392 infants received PHT. We divided cohort into 3 groups: A (DRWR ≤1.0, n = 239, 17%), B (DRWR 1.0-2.0, n = 947, 68%), C (DRWR >2.0, n = 206, 15%). Group characteristics and PHT outcomes were analysed.

RESULTS

DRWR ranged between 0.5 and 4.1. Underlying pathology (congenital versus cardiomyopathy), gender, race, renal function and mechanical circulatory support were comparable between groups. Group C patients were more likely to be ventilated, to receive ABO blood group (ABO)-incompatible heart and to have longer donor ischaemic time. Waitlist duration was significantly shorter for group C (33 vs 50 days, P < 0.1). Early outcomes for groups A, B and C were the following (respectively): operative death (6%, 4%, 3%, P = 0.29), primary graft dysfunction (5%, 3%, 3%, P = 0.30), renal failure (10%, 7%, 7%, P = 0.42) and stroke (3%, 4%, 1%, P = 0.36). The DRWR group was not associated with operative death in either congenital (odds ratio (OR) = 0.819, 95% confidence interval (CI) = 0.523-1.282) or cardiomyopathy (OR = 1.221, 95% CI = 0.780-1.912) patients and only significant factor was pre-PHT extracorporeal membrane oxygenation (OR = 4.400, 95% CI = 2.761-7.010). Additionally, survival at 1 year (87%, 87%, 85%, P = 0.80) and 5 years (76%, 78%, 77%, P = 0.80) was comparable between the DRWR groups.

CONCLUSIONS

Infants who received PHT with DRWR >2.0, up to 4.1, experienced shorter waitlist duration with no demonstrable increase in peri-transplant complications, operative or late mortality. Historic practice to avoid DRWR > 2.0 due to complications (e.g. hypertension-related stroke, graft dysfunction, death) is not currently supported in infants and stretching DRWR acceptance criteria would decrease PHT waitlist duration and potentially improve waitlist complications and mortality.

Repeat pediatric heart transplantation: A united network for organ sharing database analysis

BACKGROUND

A history of congenital heart disease and previous transplantation are each independently associated with worse survival following pediatric heart transplantation. This study aimed to evaluate the characteristics and outcomes of children undergoing repeat heart transplantation in the United States based on the underlying diagnosis.

METHODS

The United Network for Organ Sharing database was used to identify 8111 patients aged <18 years undergoing isolated heart transplantation from 2000 to 2021, including 435 (5.4%) repeat transplants. Restricted cubic spline analysis assessed the non-linear relationship between inter-transplant interval and the primary outcome of all-cause mortality or re-transplantation. Multivariable Cox regression assessed the impact of re-transplantation on the primary outcome. Median follow-up was 5.0 (interquartile range 1.9-9.9) years.

RESULTS

Repeat transplant patients were older (median age 12 vs. 4 years; p < .001), and less likely to be in UNOS status 1A (66.0%, n = 287 vs. 81.0% n = 6217; p < .001) than primary transplant patients. Freedom from the primary outcome was 51.4% (95% confidence interval [CI] 45.5-57.2) among repeat transplants and 70.5% (95% CI 69.2-71.8) among primary transplants at 10 years (p < .001). Among repeat transplant patients, the relative hazard of the primary outcome became non-significant when the inter-transplant interval >3.6 years. Congenital heart disease was an independent predictor of mortality among primary (HR 1.8, 95% CI 1.6-1.9) but not repeat transplant (HR 1.1, 95% CI .8-1.6) patients.

CONCLUSIONS

Long-term outcomes remain poor for patients undergoing repeat heart transplantation, particularly those with an inter-transplant interval <3.6 years. Underlying diagnosis does not impact outcomes after repeat transplantation, after accounting for other risk factors.

Recurrent Mild Acute Rejections and Donor-specific Antibodies as Risk Factors for Cardiac Allograft Vasculopathy in a National Pediatric Heart Transplant Cohort

Background

Immune-mediated factors such as acute cellular rejections and donor-specific antibodies (DSAs) are risk factors for cardiac allograft vasculopathy (CAV). We studied a national cohort with a unified setting and thorough protocol endomyocardial biopsy (EMB) data for an association between cellular rejections, especially when mild and recurrent, and DSAs with CAV in pediatric heart transplant (HTx) patients.

Methods

This is a retrospective, national cohort study of 94 pediatric HTxs performed between 1991 and 2019 and followed until December 31, 2020. Diagnosis of CAV was based on reevaluation of angiographies. Protocol and indication EMB findings with other patient data were collected from medical records. Associations between nonimmune and immune-mediated factors and CAV were analyzed with univariable and multivariable Cox regression analyses.

Results

Angiographies performed on 76 patients revealed CAV in 23 patients (30%). Altogether 1138 EMBs (92% protocol biopsies) were performed on 78 patients (83%). During the first posttransplant year, grade 1 rejection (G1R) appeared in 45 patients (58%), and recurrent (≥2) G1R findings in 14 patients (18%). Pretransplant DSAs occurred in 13 patients (17%) and posttransplant DSAs in 37 patients (39%). In univariable analysis, pretransplant DSAs, appearance and recurrence of G1R findings, and total rejection score during the first posttransplant year, as well as recurrent G1R during follow-up, were all associated with CAV. In multivariable analysis, pretransplant DSAs and recurrent G1R during the first posttransplant year were found to be associated with CAV.

Conclusions

Our results indicate that pretransplant DSA and recurrent G1R findings, especially during the first posttransplant year, are associated with CAV after pediatric HTx.

Selection and Interpretation of Molecular Diagnostics in Heart Transplantation

The number of heart transplants performed annually in the United States and worldwide continues to increase, but there has been little change in graft longevity and patient survival over the past 2 decades. The reference standard for diagnosis of acute cellular and antibody-mediated rejection includes histologic and immunofluorescence evaluation of endomyocardial biopsy samples, despite invasiveness and high interrater variability for grading histologic rejection. Circulating biomarkers and molecular diagnostics have shown substantial predictive value in rejection monitoring, and emerging data support their use in diagnosing other posttransplant complications. The use of genomic (cell-free DNA), transcriptomic (mRNA and microRNA profiling), and proteomic (protein expression quantitation) methodologies in diagnosis of these posttransplant outcomes has been evaluated with varying levels of evidence. In parallel, growing knowledge about the genetically mediated immune response leading to rejection (immunogenetics) has enhanced understanding of antibody-mediated rejection, associated graft dysfunction, and death. Antibodies to donor human leukocyte antigens and the technology available to evaluate these antibodies continues to evolve. This review aims to provide an overview of biomarker and immunologic tests used to diagnose posttransplant complications. This includes a discussion of pediatric heart transplantation and the disparate rates of rejection and death experienced by Black patients receiving a heart transplant. This review describes diagnostic modalities that are available and used after transplant and the landscape of future investigations needed to enhance patient outcomes after heart transplantation.

Human fitting of pediatric and infant continuous-flow total artificial heart: visual and virtual assessment

Background

This study aimed to determine the fit of two small-sized (pediatric and infant) continuous-flow total artificial heart pumps (CFTAHs) in congenital heart surgery patients.

Methods

This study was approved by Cleveland Clinic Institutional Review Board. Pediatric cardiac surgery patients (n = 40) were evaluated for anatomical and virtual device fitting (3D-printed models of pediatric [P-CFTAH] and infant [I-CFTAH] models). The virtual sub-study consisted of analysis of preoperative thoracic radiographs and computed tomography (n = 3; 4.2, 5.3, and 10.2 kg) imaging data.

Results

P-CFTAH pump fit in 21 out of 40 patients (fit group, 52.5%) but did not fit in 19 patients (non-fit group, 47.5%). I-CFTAH pump fit all of the 33 patients evaluated. There were critical differences due to dimensional variation (p < 0.0001) for the P-CFTAH, such as body weight (BW), height (Ht), and body surface area (BSA). The cutoff values were: BW: 5.71 kg, Ht: 59.0 cm, BSA: 0.31 m². These cutoff values were additionally confirmed to be optimal by CT imaging.

Conclusions

This study demonstrated the range of proper fit for the P-CFTAH and I-CFTAH in congenital heart disease patients. These data suggest the feasibility of both devices for fit in the small-patient population.

Current treatment outcomes of congenital heart disease and future perspectives

China has the largest number of individuals with congenital heart disease (CHD) in the world and a heavy burden of CHD. Therefore, understanding current CHD treatment outcomes and patterns in China will contribute to global progress in CHD treatment and be a valuable experience. Generally, CHD treatment in China has satisfactory outcomes owing to the joint efforts by all relevant stakeholders across the country. However, efforts are needed to overcome the remaining challenges: management of mitral valve disease and paediatric end-stage heart failure needs to be improved; cohesive paediatric cardiology teams should be established and collaboration between hospitals enhanced; CHD-related medical resources need to be more accessible and equitable; and nationwide CHD databases should be enhanced. In the second paper of this Series, we aim to systematically summarise the current CHD treatment outcomes in China, discuss potential solutions, and provide future perspectives.

End-stage care for children after heart transplant

Heart transplant is performed annually in over 600 children worldwide to treat life-limiting cardiac disease. Conversations regarding waitlist mortality, post-transplant morbidity and mortality, and goals of care are commonplace pre-transplant. However, there is a void of information and resources for providers and families when end-stage disease recurs in the long-term transplant recipient. The purpose of this review is to discuss the care of the pediatric heart transplant recipient with chronic cardiac dysfunction occurring years after a successful transplant. This includes a need for transplant providers to have education and training related both to palliative care and medical ethics to improve shared decision making with patients and families.

Genetic Evaluation and Screening in Cardiomyopathies: Opportunities and Challenges for Personalized Medicine

Cardiomyopathy is a major cause of heart failure caused by abnormalities of the heart muscles that make it harder for it to fill or eject blood. With technological advances, it is important for patients and families to understand that there are potential monogenic etiologies of cardiomyopathy. A multidisciplinary approach to clinical genetic screening for cardiomyopathies involving genetic counseling and clinical genetic testing is beneficial for patients and families. With early identification of inherited cardiomyopathy, patients can initiate guideline-directed medical therapies earlier, resulting in a greater likelihood of improving prognoses and health outcomes. Identifying impactful genetic variants will also allow for cascade testing to determine at-risk family members through clinical (phenotype) screening and risk stratification. Addressing genetic variants of uncertain significance and causative variants that may change in pathogenicity is also important to consider. This review will dive into the clinical genetic testing approaches for the various cardiomyopathies, the significance of early detection and treatment, the value of family screening, the personalized treatment process associated with genetic evaluation, and current strategies for clinical genetic testing outreach.

Stroke Diagnosis Protocol for Children With Ventricular Assist Devices

Ventricular assist devices (VADs) are increasingly used for end-stage heart failure in children. VAD-associated neurologic dysfunction, including stroke and intracranial hemorrhage, occurs in more than 20% of patients. Starting in 2019, we implemented a protocol to diagnose stroke in relation to VAD to facilitate treatment. A multidisciplinary approach was implemented including targeted education for providers. VAD goals, structured neurologic exam, and frequency of neuromonitoring were incorporated into daily rounds, tailored to patient's phase of recovery. A protocolized neurocritical team assessment was implemented. A VAD-specific stroke algorithm and order set were implemented to facilitate rapid neuroimaging. We performed a pre- and postimplementation analysis from 2015 to 2020. Forty-six patients had VADs placed, 25 preintervention, and 21 postintervention. We compared the number of patients evaluated for stroke, time to imaging, and documentation of last known normal exam. Preintervention, time to imaging was 7 hours, and documentation was inconsistent. Postintervention, time to imaging decreased to 2.8 hours ( p = 0.038) with universal documentation of last known normal ( p = 0.009). The use of head computerized tomographies decreased from 11 preintervention to three postintervention. Development of a VAD protocol decreased time to imaging for suspected stroke and reduced unnecessary imaging. Further studies are required to validate these data.

Cardiac xenotransplantation: from concept to clinic

For many patients with terminal/advanced cardiac failure, heart transplantation is the most effective, durable treatment option, and offers the best prospects for a high quality of life. The number of potentially life-saving donated human organs is far fewer than the population who could benefit from a new heart, resulting in increasing numbers of patients awaiting replacement of their failing heart, high waitlist mortality, and frequent reliance on interim mechanical support for many of those deemed among the best candidates but who are deteriorating as they wait. Currently, mechanical assist devices supporting left ventricular or biventricular heart function are the only alternative to heart transplant that is in clinical use. Unfortunately, the complication rate with mechanical assistance remains high despite advances in device design and patient selection and management, and the quality of life of the patients even with good outcomes is only moderately improved. Cardiac xenotransplantation from genetically multi-modified (GM) organ-source pigs is an emerging new option as demonstrated by the consistent long-term success of heterotopic (non-life-supporting) abdominal and life-supporting orthotopic porcine heart transplantation in baboons, and by a recent 'compassionate use' transplant of the heart from a GM pig with 10 modifications into a terminally ill patient who survived for 2 months. In this review, we discuss pig heart xenotransplantation as a concept, including pathobiological aspects related to immune rejection, coagulation dysregulation, and detrimental overgrowth of the heart, as well as GM strategies in pigs to prevent or minimize these problems. Additional topics discussed include relevant results of heterotopic and orthotopic heart transplantation experiments in the pig-to-baboon model, microbiological and virologic safety concepts, and efficacy requirements for initiating formal clinical trials. An adequate regulatory and ethical framework as well as stringent criteria for the selection of patients will be critical for the safe clinical development of cardiac xenotransplantation, which we expect will be clinically tested during the next few years.

Palliative Care Across the Life Span for Children With Heart Disease: A Scientific Statement From the American Heart Association

AIM

This summary from the American Heart Association provides guidance for the provision of primary and subspecialty palliative care in pediatric congenital and acquired heart disease.

METHODS

A comprehensive literature search was conducted from January 2010 to December 2021. Seminal articles published before January 2010 were also included in the review. Human subject studies and systematic reviews published in English in PubMed, ClinicalTrials.gov, and the Cochrane Collaboration were included. Structure: Although survival for pediatric congenital and acquired heart disease has tremendously improved in recent decades, morbidity and mortality risks remain for a subset of young people with heart disease, necessitating a role for palliative care. This scientific statement provides an evidence-based approach to the provision of primary and specialty palliative care for children with heart disease. Primary and specialty palliative care specific to pediatric heart disease is defined, and triggers for palliative care are outlined. Palliative care training in pediatric cardiology; diversity, equity, and inclusion considerations; and future research directions are discussed.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

The experiences of children with a cardiac transplant, their families and health care providers in the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic has had deleterious impacts on pediatric patients and families, as well as the healthcare providers who have attended to their care needs.

METHODS

In this qualitative study, children with a cardiac transplant, as well as their families and healthcare providers were interviewed to explore the impact of the COVID-19 pandemic on pediatric care, as well as on patients' and their families' daily lives. Participants were recruited from a children's hospital in western Canada. Fifteen caregiving parents of transplanted children, 2 young patients, and 8 healthcare providers participated in interviews.

RESULTS

Findings highlighted how families and their healthcare providers experienced pandemic-related shifts. Themes highlighted experiences, which entailed (1) initially hearing about the COVID-19 pandemic; (2) learning about their new reality; (3) adjusting to the pandemic; (4) adjusting to shifts in pediatric services; (5) evolving a view on the future, and (6) offering recommendations for cardiac care in a pandemic.

CONCLUSIONS

Study implications emphasize the need to critically reflect on, and advance, methods of helping young patients and their families in pandemic circumstances, and supporting healthcare providers.

The Dutch national paediatric heart transplantation programme: outcomes during a 23-year period

BACKGROUND

Since 1998, there has been a national programme for paediatric heart transplantations (HT) in the Netherlands. In this study, we investigated waiting list mortality, survival post-HT, the incidence of common complications, and the patients' functional status during follow-up.

METHODS

All children listed for HT from 1998 until October 2020 were included. Follow-up lasted until 1 January 2021. Data were collected from the patient charts. Survival, post-operative complications as well as the functional status (Karnofsky/Lansky scale) at the end of follow-up were measured.

RESULTS

In total, 87 patients were listed for HT, of whom 19 (22%) died while on the waiting list. Four patients were removed from the waiting list and 64 (74%) underwent transplantation. Median recipient age at HT was 12.0 (IQR 7.2-14.4) years old; 55% were female. One-, 5‑, and 10-year survival post-HT was 97%, 95%, and 88%, respectively. Common transplant-related complications were rejections (50%), Epstein-Barr virus infections (31%), cytomegalovirus infections (25%), post-transplant lymphoproliferative disease (13%), and cardiac allograft vasculopathy (13%). The median functional score (Karnofsky/Lansky scale) was 100 (IQR 90-100).

CONCLUSION

Children who undergo HT have an excellent survival rate up to 10 years post-HT. Even though complications post-HT are common, the functional status of most patients is excellent. Waiting list mortality is high, demonstrating that donor availability for this vulnerable patient group remains a major limitation for further improvement of outcome.

Pediatric heart transplantation: The past, the present, and the future

Heart transplantation (HTx) has a storied past, with origins dating back to the early twentieth century and the first pediatric orthotopic heart transplant performed in 1967 on a neonate with Ebstein abnormality. Today, approximately 500 pediatric HTx are performed annually, with survival times now measured in decades rather than days or weeks. In large part, advances in immunosuppression, critical care, dedicated transplant teams and mechanical circulatory support have paved the way for improvements in waitlist mortality and post-transplant survival, with future directions including the development of intracorporeal ventricular assist devices (VADs) for small children, expanding/standardizing donor criteria, and xenotransplantation.

The Role of Purinergic Signaling in Heart Transplantation

Heart transplantation remains the optimal treatment option for patients with end-stage heart disease. Growing evidence demonstrates that purinergic signals mediated by purine nucleotides and nucleosides play vital roles in heart transplantation, especially in the era of ischemia-reperfusion injury (IRI) and allograft rejection. Purinergic signaling consists of extracellular nucleotides and nucleosides, ecto-enzymes, and cell surface receptors; it participates in the regulation of many physiological and pathological processes. During transplantation, excess adenosine triphosphate (ATP) levels are released from damaged cells, and driver detrimental inflammatory responses largely via purinergic P2 receptors. Ecto-nucleosidases sequentially dephosphorylate extracellular ATP to ADP, AMP, and finally adenosine. Adenosine exerts a cardioprotective effect by its anti-inflammatory, antiplatelet, and vasodilation properties. This review focused on the role of purinergic signaling in IRI and rejection after heart transplantation, as well as the clinical applications and prospects of purinergic signaling.

Heart transplant indications, considerations and outcomes in Fontan patients: Age-related nuances, transplant listing and disease-specific indications

In the current era, 5-10% of Fontan patients die or need a transplant in childhood, and approximately 50% will experience the same fate by age 40 years. Heart transplant (HTx) can be successful for selected children and adults with Fontan circulatory failure (FCF) of any mechanism, with a 1-year post-transplant survival approaching 90% in children and 80% in the largest single-centre adult Fontan HTx experience. Protein losing enteropathy and plastic bronchitis can be expected to resolve post-transplant and limited data suggests patients with FALD who survive HTx can expect improvement in liver health. Early Fontan failure, within 12 months of Fontan completion, is not easily rescued by HTx and late referrals / failure to refer adult patients remains problematic. Very little is known about the numbers of patients not referred, turned down following assessment for HTx, or dying on the waiting list which are needed to understand the complete picture of HTx in the Fontan population and to identify where best to focus quality improvement efforts. Recent revisions to listing prioritization in Canada with considerations specific to the Fontan population aim to mitigate the fact that the status listing criteria are not tailored to the congenital heart population. Transplanting high-risk children prior to Fontan completion, developing ACHD transplant centres of expertise which can also offer combined heart-liver transplant when appropriate, and improving single ventricle mechanical support options and criteria for both adults and children may help mitigate the early post-listing mortality.

The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-eighth adult lung transplantation report - 2021; Focus on recipient characteristics

For over 30 years, the International Society for Heart and Lung Transplantation (ISHLT) International Thoracic Organ Transplant (TTX) Registry has gathered data regarding transplant procedures, donor and recipient characteristics, and outcomes from a global community of transplant centers. Almost 70,000 adult lung transplant procedures have been reported to the Registry since its inception, each one providing an opportunity for a recipient with end-stage lung disease to regain quality of life and longevity. With each year's report, we provide more detailed analyses on a particular focus theme important to recipient outcomes. Since 2013, these have been donor and recipient age; retransplantation; early graft failure; indication for transplant; allograft ischemic time; multiorgan transplantation; and donor and recipient size matching.^1-7 In response to a changing regulatory environment, the ISHLT TTX Registry is undergoing an update in data acquisition, and the patient cohort examined in this report is therefore derived from the same data source or datasets as that examined in the 2019 annual reports.^2,8-10 We refer the reader to the 2019 and prior reports for a detailed description of the baseline characteristics of the cohort, and additional core analyses not directly related to the focus explored in this year's report. To complement the 2020 report which focussed on donor characteristics, the goal of this year's report was to focus entirely on changes in recipient factors over the past 3 decades and to identify important recipient characteristics and transplant processes that may influence post-transplant outcomes. Due to small numbers, heart-lung transplant recipient characteristics and transplant outcomes have not been included. This 38th annual adult lung transplant report is hence based on data submitted to the ISHLT TTX Registry on 67,493 adult recipients of deceased recipient transplants between January 1, 1992 and June 30, 2018.