Outcomes and risk factors for heart transplantation in children with congenital heart disease

Long-term outcomes of heart transplantation in adults with congenital heart disease: The impact of single-ventricle versus biventricular physiology

Objective

Congenital heart disease is a risk factor for mortality after orthotopic heart transplantation; however, the impact of preoperative circulation type and primary congenital heart disease diagnosis remains poorly delineated.

Methods

We retrospectively reviewed patients with adult congenital heart disease aged 16 years or more who underwent orthotopic heart transplantation at our institution between 2008 and 2022. Patients were categorized as having single-ventricle or biventricular circulation. The primary end point was 5-year post-transplant survival.

Results

Sixty-one patients with adult congenital heart disease (single-ventricle: n = 26 [42.6%], biventricular: n = 35 [57.4%]) underwent orthotopic heart transplantation at 33.7 [interquartile range, 19.1-48.7] years. The most common congenital heart disease diagnosis was hypoplastic left heart syndrome (n = 11, 42.3%) in the single-ventricle group and congenitally corrected transposition of the great arteries (n = 7, 20.0%) in the biventricular group. Twenty-four patients previously underwent Fontan palliation. At transplant, patients in the single-ventricle group were younger (18.5 [interquartile range, 17.6-32.3] years vs 45.0 [interquartile range, 33.0-52.2] years, P < .001) and more likely to have biopsy-proven cirrhosis (46.2% vs 14.3%, P = .01) and protein-losing enteropathy (42.3% vs 2.9%, P < .001). Patients in the single-ventricle group also had longer bypass times (223.4 ± 65.3 minutes vs 187.4 ± 59.5 minutes, P = .03) and longer durations of mechanical ventilatory support (3.5 [interquartile range, 2.0-6.0] days vs 1.0 [interquartile range, 1.0-2.0] days, P < .001). Operative mortality was comparable (11.5% vs 8.6%, P = 1). Median follow-up was 6.0 [interquartile range, 2.4-10.0] years. Five-year survival was worse in the single-ventricle group (66.0% ± 10.0% vs 91.3% ± 4.8%, P = .03), as was freedom from major rejection (58.3% ± 10.2% vs 84.0% ± 6.6%, P = .02). In univariable analysis, hypoplastic left heart syndrome and Fontan circulation were risk factors for post-transplant mortality (hypoplastic left heart syndrome: hazard ratio, 5.0, P < .001; Fontan: hazard ratio, 3.5, P = .03).

Conclusions

Adult patients with congenital heart disease undergoing heart transplant with single-ventricle physiology experienced a more complicated post-transplant course, with worse long-term survival and freedom from rejection. Multicenter studies are required to guide orthotopic heart transplantation decision-making in this complex cohort.

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.

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.

Associated Factors and Impact of Persistent Renal Dysfunction in Pediatric Heart Transplantation

BACKGROUND

We evaluated the impact of significant renal dysfunction (SRD) on listing and pediatric heart transplantation (PHT) outcomes.

METHODS

The United Network of Organ Sharing registry was queried. Our cohort included 11,625 children listed for PHT (2000-2020). At listing, 1494 (13%) had SRD, defined as an estimated glomerular filtration rate of <45 mL/min/1.73 m2 and/or dialysis requirement. Characteristics of children with and without SRD were compared. SRD impact on outcomes was examined. Factors associated with waiting list mortality, persistent SRD at PHT, and post-PHT survival with and without simultaneous heart-kidney transplantation were assessed.

RESULTS

Compared with children with an estimated glomerular filtration rate >45 mL/min/1.73 m2, those with SRD had higher waiting list death (37% vs 14%, P < .01) and lower transplantation rate (51% vs 71%, P < .01). On multivariable analysis, SRD was associated with waiting list death (hazard ratio, 3.016; P < .0001). Among 767 children with SRD who received PHT, 361 (47%) had persistent SRD at the time of PHT. On multivariable analysis, factors associated with persistent SRD were older age (odds ratio [OR], 1.147 per year; 95% CI, 1.046-1.258 per year; P = .0035), bilirubin (OR, 1.127 per 1-mg/dL; 95% CI, 1.061-1.197 per 1-mg/dL; P < .0001), dialysis (OR, 1.839; 95% CI, 1.017-3.326; P = .0115), mechanical ventilation (OR, 1.972; 95% CI, 1.336-2.911; P = .0006), extracorporeal membrane oxygenation (OR, 1.747; 95% CI, 1.074-2.842; P = .0247), and not using a ventricular assist device (VAD) (OR, 0.498 [VAD use]; 95% CI, 0.277-0.895 VAD use; P = .0198). Post-PHT survival was 72%, 70%, and 56% (P < .01) at 8 years for PHT alone with improved renal function, simultaneous heart-kidney transplantation (n = 69), and PHT alone with persistent SRD, respectively.

CONCLUSIONS

SRD is associated with high waiting list death and decreased transplantation rate. Timely proper pre-PHT support with VAD could enhance kidney recovery. Simultaneous heart-kidney transplantation neutralized persistent SRD effect on survival and might be considered in high-risk patients such as those on dialysis, mechanical ventilation, or extracorporeal membrane oxygenation support.

Pulmonary hemodynamics before and after pediatric heart transplantation

BACKGROUND

Pulmonary hypertension (PH) may limit the outcome of pediatric heart transplantation (pHTx). We evaluated pulmonary hemodynamics in children undergoing pHTx.

METHODS

Cross-sectional, single-center, observational study analyzing pulmonary hemodynamics in children undergoing pHTx.

RESULTS

Twenty-three children (female 15) underwent pHTx at median (IQR) age of 3.9 (.9-8.2) years with a time interval between first clinical signs and pHTx of 1.1 (.4-3.2) years. Indications for pHTx included cardiomyopathy (CMP) (n = 17, 74%), congenital heart disease (CHD) (n = 5, 22%), and intracardiac tumor (n = 1, 4%). Before pHTx, pulmonary hemodynamics included elevated pulmonary artery pressure (PAP) 26 (18.5-30) mmHg, pulmonary capillary wedge pressure (PCWP) 19 (14-21) mmHg, left ventricular enddiastolic pressure (LVEDP) 17 (13-22) mmHg. Transpulmonary pressure gradient (TPG) was 6.5 (3.5-10) mmHg and pulmonary vascular resistance (Rp) 2.65 WU*m2 (1.87-3.19). After pHTx, at immediate evaluation 2 weeks after pHTx PAP decreased to 20.5 (17-24) mmHg, PCWP 14.5 (10.5-18) mmHg (p < .05), LVEDP 16 (12.5-18) mmHg, TPG 6.5 (4-12) mmHg, Rp 1.49 (1.08-2.74) WU*m2 resp.at last invasive follow up 4.0 (1.4-6) years after pHTx, to PAP 19.5 (17-21) mmHg (p < .05), PCWP 13 (10.5-14.5) mmHg (p < .05), LVEDP 13 (10.5-14) mmHg, TPG 7 (5-9.5) mmHg, Rp 1.58 (1.38-2.19) WU*m2 (p < .05). In CHD patients PAP increased (p < .05) after pHTx at immediate evaluation and decreased until last follow-up (p < .05), while in CMP patients there was a continuous decline of mean PAP values immediately after HTx (p < .05).

CONCLUSIONS

While PH before pHTx is frequent, after pHTx the normalization of PH starts immediately in CMP patients but is delayed in CHD patients.

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.

Not all durations of preheart transplant mechanical ventilation portend inferior post-transplant survival in children

BACKGROUND

Mechanical ventilation prior to pediatric heart transplantation predicts inferior post-transplant survival, but the impact of ventilation duration on survival is unclear.

METHODS

Data from the United Network for Organ Sharing and Pediatric Health Information System were used to identify pediatric (<18 years) heart transplant recipients from 2003 to 2020. Patients ventilated pretransplant were first compared to no ventilation, then ventilation durations were compared across quartiles of ventilation (≤1 week, 8 days-5 weeks, >5 weeks).

RESULTS

At transplant, 11% (511/4506) of patients required ventilation. Ventilated patients were younger, had more congenital heart disease, more urgent listing-status, and greater rates of nephropathy, TPN-dependence, and inotrope and ECMO requirements (p < .001 for all). Post-transplant, previously ventilated patients experienced longer ventilation durations, ICU and hospital stays, and inferior survival (all p < .001). Hospital outcomes and survival worsened with longer pretransplant ventilation. One-year and overall survival were similar between the no-ventilation and ≤1 week groups (p = .703 & p = .433, respectively) but were significantly worse for ventilation durations >1 week (p < .001). On multivariable analysis, ventilation ≤1 week did not predict mortality (HR 0.98 [95% CI 0.85-1.43]), whereas ventilation >1 week did (HR: 1.18 [1.01-1.39]).

CONCLUSIONS

Longer pretransplant ventilation portends worse outcomes, although only ventilation >1 week predicts mortality. These findings can inform pretransplant prognostication.

Infants Who Require Total Parenteral Nutrition and Paralytics at Time of Heart Transplant Experience Inferior Post-Transplant Mortality

Background: Infants experience the worst one-year post-heart transplant (HTx) survival of any other pediatric group. Although mechanical ventilatory (MV) requirement at the time of transplant is an established predictor of post-transplant mortality, the impacts of commonly co-utilized support modalities such as total parenteral nutrition (TPN)-dependence and paralytics are understudied. Methods: All infant HTx recipients from 2003 to 2020 in both the United Network for Organ Sharing and Pediatric Health Information System databases were identified (n = 1344) and categorized depending upon support requirement at the time of transplant—none (59%), MV-only (10%), MV + Paralytics (2%), TPN-dependence-only (15%), MV + TPN (10%), and MV + Paralytics + TPN (4%). The primary study aim was to characterize the impact of TPN-dependence and paralytics on one-year post-transplant survival (PTS). Results: Compared to no-support, supported infants were generally at higher risk and more ill at transplant, with greater rates of congenital heart disease, renal and hepatic dysfunctions, and inotrope requirements. Post-transplant hospital outcomes were inferior among supported patients; all support groups experienced longer post-transplant MV, intensive care unit, and hospital lengths of stay (all P < .05 vs no-support). Upon multivariable analysis, each support modality independently predicted 1-year mortality (MV vs no-MV: 1.54 [1.10-2.14]; MV + Paralytics vs neither: 2.02 [1.25-3.27]; TPN vs no-TPN: 1.53 [1.10-2.13]; P < .01 for all), whereas no-support was protective (HR 0.66 [95% CI 0.48-0.91]). Conclusions: Infants who require paralytics and/or who are TPN-dependent at the time of HTx experience worse one-year PTS. Such knowledge can assist in risk-stratification, and the identification of patients who would benefit from pretransplant optimization.

Successful bridge to transplantation with long-term support using Berlin heart EXCOR in a child with failing Fontan

A 2-year-old girl underwent the Fontan operation for aortic valve stenosis, mitral valve stenosis, a hypo-plastic left ventricle, and a non-compacted right ventricle. The patient's cardiac function reduced gradually thereafter, mainly due to systemic ventricular dysfunction. A Berlin Heart EXCOR (BHE) ventricular assist device with a 10-mL pump was implanted at 4 years of age. After 465 days, BHE support without major complications, the patient underwent heart transplantation. A safe and long-term BHE support was achieved with proper case selection and repeated examinations.

In vivo evaluation of bioprinted cardiac patches composed of cardiac-specific extracellular matrix and progenitor cells in a model of pediatric heart failure

Pediatric patients with congenital heart defects (CHD) often present with heart failure from increased load on the right ventricle (RV) due to both surgical methods to treat CHD and the disease itself. Patients with RV failure often require transplantation, which is limited due to lack of donor availability and rejection. Previous studies investigating the development and in vitro assessment of a bioprinted cardiac patch composed of cardiac extracellular matrix (cECM) and human c-kit + progenitor cells (hCPCs) showed that the construct has promise in treating cardiac dysfunction. The current study investigates in vivo cardiac outcomes of patch implantation in a rat model of RV failure. Patch parameters including cECM-inclusion and hCPC-inclusion are investigated. Assessments include hCPC retention, RV function, and tissue remodeling (vascularization, hypertrophy, and fibrosis). Animal model evaluation shows that both cell-free and neonatal hCPC-laden cECM-gelatin methacrylate (GelMA) patches improve RV function and tissue remodeling compared to other patch groups and controls. Inclusion of cECM is the most influential parameter driving therapeutic improvements, with or without cell inclusion. This study paves the way for clinical translation in treating pediatric heart failure using bioprinted GelMA-cECM and hCPC-GelMA-cECM patches.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89-1.40, p = 0.34), 1.03 for HF (0.7-1.51, p = 0.88), 0.70 for Arrhythmias (0.39-1.24, p = 0.22), 0.46 for PB (0.08-2.72, p = 0.39), and 5.81 for CKD (1.70-19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99-3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Systemic Venous Reconstructions During Pediatric Heart Transplantation

BACKGROUND

Congenital heart disease continues to be an important indication for pediatric heart transplantation (HT) and is often complicated by systemic venous anomalies. The need for reconstruction, surgical technique used, as well as the outcomes of these have limited documentation.

METHODS

Descriptive, retrospective study of patients transplanted at Emory University between 2006 and 2017. We reviewed surgical data, follow-up, and interventions for patients necessitating venous reconstruction during transplantation.

RESULTS

A total of 179 transplants were performed during the time period of which 74 (41%) required systemic venous reconstruction. Mean age at transplant was 6.3 (±6.16) years, and 74.3% of these patients carried a diagnosis of single ventricle; 51 (68.9%) of 74 patients required pulmonary artery reconstruction at the time of HT. Forty patients required superior vena caval reconstruction, while 22 patients required inferior vena caval reconstruction due to prior palliation or anomaly. Venous anomalies along with other anatomic features necessitated biatrial transplantation in four patients. Posttransplant evaluation revealed systemic venous stenosis in 14 (18.9%) of 74 patients. Eight (10.8%) patients required 12 interventions for the systemic veins. Patients with bilateral Glenn anastomosis prior to transplant were at high risk for the development of stenosis and needing interventions. Systemic venous complications were uncommon in those with native systemic veins without Glenn or Fontan procedure.

CONCLUSION

Systemic venous reconstruction needs are high in pediatric HT. Posttransplant stenosis and the need for interventions are relatively common. Current techniques for systemic venous reconstruction for complex congenital heart disease patients may deserve further review to optimize these outcomes.

Transplantation for Congenital Heart Disease: Focus on the Impact of Functionally Univentricular Versus Biventricular Circulation

BACKGROUND

Varying single center data exist regarding the posttransplant outcomes of patients with single ventricle circulation, particularly following the Fontan operation. We sought to better elucidate these results in patients with congenital heart disease (CHD) through combining two national databases.

METHODS

The United Network for Organ Sharing (UNOS) transplantation database was merged with the Pediatric Health Information System (PHIS), an administrative database with 71% of UNOS patients matched. Patients undergoing transplantation at a PHIS hospital from 2006 to 2017 were categorized as single ventricle or biventricular strategy based on their diagnoses and procedures in 90% of patients. When known, single ventricle patients were further analyzed by their palliative stage post-Glenn or post-Fontan (known in 31%).

RESULTS

A total of 1,517 CHD transplantations were identified, 67% with single ventricle strategy (1,016). Single ventricle, biventricular, and indeterminate patients had similar survival (log-rank P > .1). Risk factors for mortality in patients with CHD were extracorporeal membrane oxygenation (ECMO) support at transplant (hazard: 2.27), ABO blood type incompatibility (hazard: 1.61), African American recipient (hazard 1.42), and liver dysfunction (hazard 1.29). A total of 130 confirmed Fontan and 185 confirmed bidirectional Glenn patients underwent transplantation, each with survival equivalent to biventricular patients (log-rank P > .500). For Fontan patients, renal dysfunction (hazard: 5.40) and transplant <1 year after Fontan (hazard 2.82) were found to be associated with mortality.

CONCLUSIONS

Single ventricle patients, as a group, experience similar outcomes as biventricular patients with CHD undergoing transplantation, and this extends to Fontan patients. Risk factors for mortality correlate with end-organ dysfunction as well as race and ABO blood type incompatibility in the CHD population.

Risk Factors for Red Blood Cell Transfusions in Children Undergoing Cardiac Catheterization

OBJECTIVE

To identify risk factors associated with risk of red blood cell transfusions (RBCTs) following pediatric cardiac catheterizations.

STUDY DESIGN

We performed a review of all pediatric cardiac catheterizations from 2012 to 2017. The primary endpoint was RBCT within 72 hours of pediatric cardiac catheterization. Patient and procedural factors were reviewed. Generalized linear modelling was performed to describe interactions among relevant risk factors.

RESULTS

In total, 831 RBCTs occurred within 72 hours of 6028 pediatric cardiac catheterizations (13.8%). Univariate analysis revealed that the prevalence of RBCT was highest among infants (37.6% incidence of RBCT) and among those with higher estimated blood loss as a percent of blood volume (P = .03). Among infants, multivariate analysis revealed that weight (OR 0.72; 95% CI 0.63-0.81), complex 2-ventricle (OR 3.14, 95% CI 2.18-4.57), and single ventricle status (OR 5.21, 95% CI 3.42-8.01) were associated with risk of RBCT. Inpatient infants from intensive care (OR 4.74; 95% CI 3.49-6.49) or stepdown units (OR 2.33; 95% CI 1.58-3.46) were at higher risk. Length of procedure (OR 2.57; 95% CI 2.03-3.26) and oxygen saturation (OR 0.98; 95% CI 0.97-0.99; P < .01) were also associated with RBCTs.

CONCLUSIONS

Hospitalized infants with single ventricle or complex 2-ventricle anatomy are at highest risk of RBCT. Length of procedure, blood loss, and oxygen saturations are additional risk factors associated with RBCT. Operators should consider these factors when planning pediatric cardiac catheterizations, particularly when exposure to RBCT is undesirable.

The reality of limping to pediatric heart transplantation

OBJECTIVE

Improvements in surgical technique, critical care, and early repair for congenital heart disease (CHD) have led to improved outcomes with heart transplantation, often used as a salvage procedure after failed palliation, especially in infants. These patients, however, often have several risk factors for poor posttransplant survival. We aimed to identify the reality of survival after heart transplantation in patients "limping to transplant" with common risk factors.

METHODS

All heart transplant recipients younger than 18 years were identified from the UNOS data set from 2000 to 2017. Modifiable risk factors (MRFs) of mechanical ventilation, renal dysfunction, and liver dysfunction at transplant and nonmodifiable risk factors of infancy at listing or CHD were examined. One-year posttransplant survival was analyzed with logistic regression.

RESULTS

Of 4101 transplants, 1459 patients (36%) had 1 or more MRFs. There was a decrease in 1-year survival with additional MRFs up to a 9.1-times increased risk of death in an infant with CHD. A noninfant without CHD and no MRFs had a 95% 1-year survival, in contrast to an intubated patient with CHD without other end-organ dysfunction, who had 1-year survival of 76%, which decreased to 58% if they were an infant and also had renal dysfunction.

CONCLUSIONS

Patients "limping to transplant" with multiple risk factors demonstrates decreasing early survival relative to those without other end-organ dysfunction. It is imperative that we have transparent discussions about expected outcomes with these families and identify ways to optimize patients' conditions through other supportive avenues to improve posttransplant outcomes.

Comparison of inhospital outcomes of pediatric heart transplantation between single ventricle congenital heart disease and cardiomyopathy

Data investigating the impact of household income and other factors on SV patient status-post-Fontan palliation after heart transplantation are lacking. We aim to evaluate factors affecting outcomes after OHT in this population. The PHIS database was interrogated for either SV or myocarditis/primary CM who were 4 years or older who underwent a single OHT. There were 1599 patients with a median age of 13.2 years (IQR: 9.3-16.1). Total hospital costs were significantly higher in the SV group ($408 000 vs $294 000, P < 0.0001), but as median household income increased, the risk of inhospital mortality, post-transplant LOS, and LOS-adjusted total hospital costs all decreased. The risk of inhospital mortality increased 6.5% per 1 year of age increase at the time of transplant. Patients in the SV group had significantly more diagnoses than those in the CM group (21 vs 15, P < 0.0001) and had longer total hospital LOSs as a result of longer post-transplant courses (25 days vs 15, P < 0.0001). Increased median household income and younger age are associated with decreased resource utilization and improved inhospital mortality in SV CHD patients who undergo OHT. In conclusion, earlier consideration of OHT in this population, coupled with improved selection criteria, may increase survival in this population.

Chronotropic incompetence in paediatric heart transplant recipients with prior congenital heart disease

BACKGROUND

Cardiopulmonary exercise testing has been used to measure functional capacity in children who have undergone a heart transplant. Cardiopulmonary exercise testing results have not been compared between children transplanted for a primary diagnosis of CHD and those with a primary diagnosis of cardiomyopathy despite differences in outcomes. This study is aimed to compare cardiopulmonary exercise testing performance between these two groups.

METHODS

Patients who underwent heart transplant with subsequent cardiopulmonary exercise testing at least 6 months after transplant at our institution were identified. They were then divided into two groups based on primary cardiac diagnosis: CHD or cardiomyopathy. Patient characteristics, echocardiograms, cardiac catheterisations, outcomes, and cardiopulmonary exercise test results were compared between the two groups.

RESULTS

From the total of 35 patients, 15 (43%) had CHD and 20 (57%) had cardiomyopathy. Age at transplant, kidney disease, lung disease, previous rejection, coronary vasculopathy, catheterisation, and echocardiographic data were similar between the groups. Mean time from transplant to cardiopulmonary exercise testing, exercise duration, and maximum oxygen consumption were similar in both groups. There was a difference in heart rate response with CHD heart rate response of 63 beats per minute compared to cardiomyopathy group of 78 (p = 0.028). Patients with CHD had more chronotropic incompetence than those with cardiomyopathy (p = 0.036).

CONCLUSION

Primary diagnosis of CHD is associated with abnormal heart rate response and more chronotropic incompetence compared to those transplanted for cardiomyopathy.

Comparison of 10-year graft failure rates after induction with basiliximab or anti-thymocyte globulin in pediatric heart transplant recipients-The influence of race

BACKGROUND/OBJECTIVE

The impact of induction therapy in pediatric heart transplantation has been uncertain. Given the risk of poor outcomes in black pediatric heart transplant recipients, we evaluated the effect on graft survival of ATG and BAS induction in black and non-black pediatric recipients.

METHODS

This was a retrospective analysis of pediatric candidates (aged ≤18 years) who underwent heart transplantation from 2000 to 2016 identified from the UNOS database. Primary outcome was 10-year graft survival.

RESULTS

This study included 654 patients receiving BAS, 2385 patients receiving ATG, and 2425 receiving no induction. Ten-year survival was similar for the following groups: non-black BAS (57%), non-black ATG (66%), and black ATG (51%). The black BAS group had a 10-year graft survival of 39% which was inferior on pairwise comparison to the other groups (all P values < 0.001). On multivariate analysis, ATG was associated with decreased risk of graft failure when compared to no induction (HR 0.86, 95% CI 0.76-0.97, P = 0.011) and had an association approaching statistical significance when compared to BAS induction (0.84, 0.7-1.01, P = 0.069). This association was seen in black recipients in whom ATG was strongly associated with decreased risk of graft failure when compared to either no induction (0.65, 0.5-0.83, P = 0.001) or BAS (0.64, 0.46-0.89, P = 0.008) but was not seen in non-black recipients.

CONCLUSIONS

Black pediatric heart transplant recipients who received ATG induction had an improved long-term graft survival compared to those who received BAS induction or no induction.

Effects of luteolin on regulatory proteins and enzymes for myocyte calcium circulation in hypothermic preserved rat heart

Heart transplantation has been applied in the clinic as an optimal solution for patients with end stage cardiac failure for a number of years. However, hypothermic preservation of the heart remains limited to 4–6 h and calcium accumulation over time is an important factor resulting in cell death. To provide longer and safer storage for donor hearts, it was demonstrated in our previous study that luteolin, a traditional Chinese medicine used to treat cardiovascular diseases, inhibits cell death and L-type calcium currents during hypothermic preservation. In the current study, the protective role of luteolin in modulating cardiomyocyte calcium cycling was further investigated. Intracellular calcium overload has already been implicated in hypothermia-induced dysfunction of cardiomyocytes. University of Wisconsin (UW) solution supplemented with 7.5, 15 or 30 µmol/l luteolin was used to preserve fresh isolated cardiomyocytes at 4°C. The results demonstrated that all three doses of luteolin supplementation attenuated calcium overload over a 6 h preservation period. Luteolin also suppressed the accumulation of important regulatory proteins and enzymes for cardiomyocyte calcium circulation, mitochondria Ca²⁺ uniporter and calmodulin, which are normally induced by cold storage in UW solution. Protein Kinase A activity was also suppressed in cardiomyocytes preserved in luteolin supplemented UW solution, while Ca²⁺-Mg²⁺-ATPase activity was increased. The results demonstrated that luteolin confers a cardioprotective effect through inhibiting the changes of calcium regulators during cold storage and therefore ameliorates Ca²⁺ overload in rat cardiomyocytes.

Mortality Risk Stratification in Fontan Patients Who Underwent Heart Transplantation

The number of patients who require orthotopic heart transplantation (OHT) for failing Fontan physiology continues to grow; however, the methods and tools to evaluate risk of OHT are limited. This study aimed to identify a set of preoperative variables and characteristics that were associated with a greater risk of postoperative mortality in patients who received OHT for failing Fontan physiology. Thirty-six Fontan patients were identified as having undergone OHT at University of California-Los Angeles Medical Center from 1991 to 2014. Data were collected retrospectively and analyzed. The primary end point was designated as postoperative mortality. After an average follow-up time of 3.5 years, 17 (44%) patients suffered postoperative mortality. Patient characteristics including (1) age <18 years at the time of OHT, (2) Fontan-OHT interval of <10 years, (3) systemic ventricular ejection fraction <20%, (4) moderate-to-severe atrioventricular valve insufficiency, (5) an elevated Model of End-stage Liver Disease, eXcluding INR score, or (6) need for advanced mechanical support before surgery were associated with an increased incidence of postoperative mortality. Using these risk factors, we present a theoretical framework to stratify risk of postoperative death in failing Fontan patients after OHT. In conclusion, a method such as this may aid in the transplantation evaluation and listing process of patients with failing Fontan physiology.

Current Therapy for Hypoplastic Left Heart Syndrome and Related Single Ventricle Lesions

Universally fatal only 4 decades ago, the progress in the 3-stage palliation of hypoplastic left heart syndrome and related single right ventricular lesions has drastically improved the outlook for these patients. Although the stage II operation (hemi-Fontan or bidirectional Glenn) and stage III Fontan procedure have evolved into relatively low-risk operations, the stage I Norwood procedure remains one of the highest-risk and costliest common operations performed in congenital heart surgery. Yet, despite this fact, experienced centers now report hospital survivals of >90% for the Norwood procedure. This traditional 3-stage surgical palliation has seen several innovations in the past decade aimed at improving outcomes, particularly for the Norwood procedure. One significant change is a renewed interest in the right ventricle-to-pulmonary artery shunt as the source of pulmonary blood flow, rather than the modified Blalock-Taussig shunt for the Norwood. The multi-institutional Single Ventricle Reconstruction trial randomly assigned 555 patients to one or the other shunt, and these subjects continue to be followed closely as they now approach 10 years postrandomization. In addition to modifications to the Norwood procedure, the hybrid procedure, a combined catheter-based and surgical approach, avoids the Norwood procedure in the newborn period entirely. The initial hybrid procedure is then followed by a comprehensive stage II, which combines components of both the Norwood and the traditional stage II, and later completion of the Fontan. Proponents of this approach hope to improve not only short-term survival, but also potentially longer-term outcomes, such as neurodevelopment, as well. Regardless of the approach, traditional surgical staged palliation or the hybrid procedure, survivals have vastly improved, and large numbers of these patients are surviving not only through their Fontan in early childhood, but also into adolescence and young adulthood. As this population grows, it becomes increasingly important to understand the longer-term outcomes of these Fontan patients, not only in terms of survival, but also in terms of the burden of disease, neurodevelopmental outcomes, psychosocial development, and quality of life.

The Long-Term Management of Children and Adults with a Fontan Circulation: A Systematic Review and Survey of Current Practice in Australia and New Zealand

Although long-term survival is now the norm, Fontan patients face significant morbidity and premature mortality. Wide variation exists in long-term Fontan management. With an aim of improving their long-term management, we conducted a systematic review to identify best available evidence and gaps in knowledge for future research focus. We also surveyed cardiologists in Australia and New Zealand managing Fontan patients, to determine the alignment of current local practice with best available evidence. A systematic review was conducted using strict search criteria (PRISMA guidelines), pertaining to long-term Fontan management. All adult congenital and paediatric cardiologists registered with The Australia and New Zealand Fontan Registry were invited to respond to an online survey. Reasonable quality evidence exists for non-inferiority of aspirin over warfarin for thromboprophylaxis in standard-risk Fontan patients. No strong evidence is currently available for the routine use of ACE inhibitors, beta blockers or pulmonary vasodilators. Little evidence exists regarding optimal arrhythmia treatment, exercise restriction/prescription, routine fenestration closure, elective Fontan conversion and screening/management of liver abnormalities. Although pregnancy is generally well tolerated, there are high rates of miscarriage and premature delivery. Thirty-nine out of 78 (50 %) cardiologists responded to the survey. Heterogeneity in response was demonstrated with regard to long-term anti-coagulation, other medication use, fenestration closure and pregnancy and contraception counselling. Substantial gaps in our knowledge remain with regard to the long-term management of Fontan patients. This is reflected in the survey of cardiologists managing these patients. We have identified a number of key areas for future research.

End-stage ischemic heart failure and Williams-Beuren syndrome: A unique scenario for pediatric heart transplantation

WBS is a rare disorder caused by mutations in the chromosomal sub-band 7q11.23 involving the elastin gene. The clinical features (craniofacial, developmental, and cardiovascular abnormalities) are variable. The association with cardiac anomalies is a well-recognized feature, and SVAS is the most common cardiac defect found. End-stage ischemic heart disease is unusual in this setting but when it occurs, OHT remains the final therapeutic option. This decision can be difficult to determine, and it must be tailored to the individual patient based on the clinical status and concomitant cardiovascular and multisystem lesions. To date, no cases of OHT in patients with WBS have been described. We present a 14-month-old patient with WBS who developed severe LV dysfunction secondary to ischemia following a complex staged surgery for SVAS repair. He underwent successful OHT with no post-operative complications, and at three-month follow-up, he remains asymptomatic on standard immunosuppressive therapy. This case constitutes the first demonstration that OHT may be indicated for extended survival in selected children with WBS and we discuss the basic principles for extending the indication for OHT to this scenario as well as the particularities for post-transplant care.