Outcomes of heart transplantation in children with heterotaxy syndrome

OBJECTIVES

End-stage congenital heart disease in children with heterotaxy syndrome might necessitate heart transplantation. Heart transplantation in heterotaxy patients can be associated with several technical (e.g. redo, systemic/pulmonary-venous/situs anomalies, pulmonary artery reconstruction), and extra-cardiac (e.g. ciliary dyskinesia, infections, gastrointestinal) challenges. We aim to examine if heterotaxy syndrome is associated with increased early or late transplantation risks.

METHODS

The United Network for Organ Sharing transplantation database was merged with the Paediatric Health Information System administrative database to identify children with heterotaxy who received heart transplantation. Characteristics and outcomes were compared between children with heterotaxy and contemporaneous non-heterotaxy congenital and non-congenital cardiomyopathy control groups.

RESULTS

After merger, our cohort of 1122 patients was divided to three groups: group heterotaxy (n = 143), group non-heterotaxy congenital (n = 428) and group cardiomyopathy (n = 551). There were differences in the characteristics between the 3 groups, with heterotaxy being comparable to non-heterotaxy congenital group. The waitlist duration was longer for heterotaxy than non-heterotaxy congenital and cardiomyopathy groups (91 vs 63 vs 56 days, p < 0.001). Early post-transplant complications were similar for all groups except for operative mortality that was 1% for cardiomyopathy and 4% for heterotaxy and non-heterotaxy congenital, p < 0.001. Post-transplant stay was shorter for cardiomyopathy (57) compared to non-heterotaxy congenital (99) and heterotaxy (89) days, p < 0.001. While rejection prior to discharge was comparable between heterotaxy and CHD groups, it was higher at 1-year for heterotaxy (22%), than non-heterotaxy congenital (19%) and cardiomyopathy (13%), p < 0.001. Survival at 5 years was superior for cardiomyopathy (87%) compared to heterotaxy (69%) and non-heterotaxy congenital (78%), p < 0.001. For the heterotaxy group, no risk factors affecting survival were identified on multivariable analysis.

CONCLUSIONS

Despite complexity, heart transplantation in selected children with heterotaxy is associated with good mid-term outcomes. Despite early results that are comparable to other patients with congenital heart disease, the increasing rejection rate at one year and the relatively accelerated attrition at mid-term warrant further follow-up. Due to database limitations in defining morphologic and surgical details, further work is warranted to delineate anatomic and surgical variables that could affect survival.

Hemoadsorption Contribution in Failing Fontan Pediatric Heart Transplantation

INTRODUCTION

A systemic inflammatory response is triggered in patients undergoing cardiothoracic surgery with cardiopulmonary bypass (CPB). This response is particularly evident in pediatric patients, especially those of low weight and after undergoing long CPB, and can severely impair the surgical result. Adsorptive blood purification techniques have been proposed to limit this systemic inflammatory response. To test its efficacy, we added the hemoadsorption filter Jafron HA 380 to CPB in a much compromised pediatric patient who underwent heart transplantation.

METHODS

A 10-year-old single ventricle patient previously treated with Fontan operation was listed for heart transplantation due to the evidence of failing Fontan condition. He experienced many episodes of cardiac arrest and underwent heart transplantation in much compromised general and hemodynamic conditions. The hemoadsorption filter Jafron HA 380 was used for all the duration of CPB, and the inflammatory biomarker interleukin 6 (IL-6) was assayed.

RESULTS

Postoperative outcome was uneventful and comparable to that of elective pediatric heart transplantation. IL-6 levels showed an impressive postoperative reduction, and after 2 days, the IL-6 level was comparable with a typical uneventful post-transplant course.

CONCLUSIONS

The use of hemoadsorption filter can contribute to improve the pediatric transplant results, especially in very high-risk patients.

Racial disparity exists in the utilization and post-transplant survival benefit of ventricular assist device support in children

PURPOSE

Children of minority race and ethnicity experience inferior outcomes postheart transplantation (HTx). Studies have associated ventricular assist device (VAD) bridge-to-transplant (BTT) with similar-to-superior post-transplant-survival (PTS) compared to no mechanical circulatory support. It is unclear whether racial and ethnic discrepancies exist in VAD utilization and outcomes.

METHODS

The United Network for Organ Sharing (UNOS) database was used to identify 6,121 children (<18 years) listed for HTx between 2006 and 2021: black (B-22% of cohort), Hispanic (H-21%), and white (W-57%). VAD utilization, outcomes, and PTS were compared between race/ethnicity groups. Multivariable Cox proportional analyses were used to study the association of race and ethnicity on PTS with VAD BTT, using backward selection for covariates.

RESULTS

Black children were most ill at listing, with greater proportions of UNOS status 1A/1 (p < 0.001 vs H & W), severe functional limitation (p < 0.001 vs H & W), and greater inotrope requirements (p < 0.05 vs H). Non-white children had higher proportions of public insurance. VAD utilization at listing was: B-11%, H-8%, W-8% (p = 0.001 for B vs H & W). VAD at transplant was: B-24%, H-21%, W-19% (p = 0.001 for B vs H). At transplant, all VAD patients had comparable clinical status (functional limitation, renal/hepatic dysfunction, inotropes, mechanical ventilation; all p > 0.05 between groups). Following VAD, hospital outcomes and one-year PTS were equivalent but long-term PTS was significantly worse among non-whites-(p < 0.01 for W vs B & H). On multivariable analysis, black race independently predicted mortality (hazard ratio 1.67 [95% confidence interval 1.22-2.28]) while white race was protective (0.54 [0.40-0.74]).

CONCLUSIONS

Pediatric VAD use is, seemingly, equitable; the most ill patients receive the most VADs. Despite similar pretransplant and early post-transplant benefits, non-white children experience inferior overall PTS after VAD BTT.

Association of MICA and AT1R antibodies with antibody-mediated rejection and cardiac allograft vasculopathy in a pediatric heart transplant recipient

BACKGROUND

Recipient antibodies against mismatched donor-specific human leukocyte antigens (HLA) are known to be associated with antibody-mediated rejection (AMR), posing increased risks of cardiac allograft vasculopathy (CAV), graft dysfunction, and graft loss after heart transplant (HTx). However, the impact of non-HLA antibodies on HTx outcome is not yet well defined.

CASE DESCRIPTION

Here we report a case of a pediatric patient, who was retransplanted after developing CAV in his first heart allograft. Five years post 2nd HTx, the patient presented with graft dysfunction and mild rejection (ACR 1R, AMR 1H, C4d Neg) in the cardiac biopsy in the absence of HLA donor-specific antibodies (DSAs). We detected strong antibodies against non-HLA antigens, including angiotensin II receptor type 1 (AT1R) and donor-specific MHC class I chain-related gene A (MICA), in the patient's serum that were implicated in the AMR and accelerated CAV of his second allograft, and likely played a role in the loss of his first allograft as well.

CONCLUSION

This case report underscores the clinical relevance of non-HLA antibodies in heart transplantation and highlights the value of incorporating these tests in the immunological risk assessment and post-transplant monitoring of HTx recipients.

Echocardiography Provides a Reliable Estimate of Total Cardiac Volume for Pediatric Heart Transplantation

BACKGROUND

Donor-to-recipient size matching for heart transplantation typically involves comparing donor and recipient body weight; however, weight is not linearly related to cardiac size. Attention has shifted toward the use of computed tomography- (CT-) derived total cardiac volume (TCV), that is, CT-TCV, to compare donor and recipient heart organ size. At this time, TCV size matching is near impossible for most centers due to logistical limitations. To overcome this impediment, echocardiogram-derived TCV (ECHO-TCV) is an attractive, alternative option to estimate CT-TCV. The goal of this study is to test whether ECHO-TCV is an accurate and reliable surrogate for TCV measurement compared with the gold standard CT-TCV.

METHODS

ECHO-TCV and CT-TCV were measured in a cohort spanning the neonatal to young adult age range with the intention to simulate the pediatric heart transplant donor pool. ECHO-TCV was measured using a modified Simpson's summation-of-discs method from the apical 4-chamber (A4C) view. The gold standard of CT-TCV was measured from CT scans using three-dimensional reconstruction software. The relationship between ECHO-TCV and CT-TCV was evaluated and compared with other anthropometric and image-based markers that may predict CT-TCV. Inter-rater reliability of ECHO-TCV was tested among 4 independent observers. Subanalyses were performed to identify imaging views and timing that enable greater accuracy of ECHO-TCV.

RESULTS

Banked imaging data of 136 subjects with both echocardiogram and CT were identified. ECHO-TCV demonstrated a linear relationship to CT-TCV with a Pearson correlation coefficient of r = 0.96 (95% CI, 0.95-0.97; P < .0001) and mean absolute percent error of 8.6%. ECHO-TCV correlated most strongly with CT-TCV in the subset of subjects <4 years of age (n = 33; r = 0.98; 95% CI, 0.96-0.99; P < .0001). The single-score intraclass correlation coefficient across all 4 raters is 0.96 (interquartile range, 0.93-0.98). ECHO-TCV measured from a standard A4C view at end diastole with the atria in the plane of view had the strongest correlation to CT-TCV.

CONCLUSIONS

ECHO-TCV by the A4C view was found to be both an accurate and reliable alternative measurement of CT-TCV and is derived from readily available donor ECHO images. The ECHO-TCV findings in this study make the ECHO method an attractive means of direct donor-to-recipient TCV size matching in pediatric heart transplantation.

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.

Pediatric heart transplantation in infants and small children under 3 years of age: Single center experience - "Early and long-term results"

OBJECTIVES

We analyzed the early and long-term survival after ABO-compatible heart transplantation in children under 3 years of age from 1991 to 2021 at our center. This retrospective and descriptive study aimed to identify serious adverse events associated with mortality after pediatric heart transplantation.

PATIENTS AND METHODS

46 patients with congenital heart failure (37%) in end-stage heart failure have undergone a pediatric heart transplantation. Primary outcome of interest was survival at follow-up time.

RESULTS

Median (IQR) follow-up time (y), age (y), body-weight (kg) and BMI (kg/cm²) were 13.2 (5.7-19.5), 0.9 (0.2-2.0), 6.8 (4.3-10.0) and 14.2 (12.3-15.7). Twenty-four (52%) patients were male. 15 patients (33%) had a single ventricle physiology. At 30- days survival rate was 94 ± 4%. Survival rate at 1, 5, 10 and 15 years post HTx was 87 ± 5%, 84 ± 6%, 79 ± 6% and 63 ± 8%. One child underwent re-transplantation after 4 years, and another one after 11 years - in both cases due to graft failure. Higher early mortality in patients under 3 months of age and in patients with single ventricle physiology. Transplant free survival at 15 years was in children with cardiomyopathy better (71 ± 10%) than in those with congenital heart disease (50 ± 13%). One or more previous heart surgeries prior to HTx (n = 21) were associated to more mortality.

CONCLUSION

Pediatric heart transplantation has acceptable long-term results and is still the best therapeutic option in children with end-stage cardiac failure. Underlying anomalies and single ventricle physiology, age below 3 months had a significant impact on survival.

Multi-parametric cardiovascular magnetic resonance with regadenoson stress perfusion is safe following pediatric heart transplantation and identifies history of rejection and cardiac allograft vasculopathy

BACKGROUND

The progressive risk of graft failure in pediatric heart transplantation (PHT) necessitates close surveillance for rejection and coronary allograft vasculopathy (CAV). The current gold standard of surveillance via invasive coronary angiography is costly, imperfect and associated with complications. Our goal was to assess the safety and feasibility of a comprehensive multi-parametric CMR protocol with regadenoson stress perfusion in PHT and evaluate for associations with clinical history of rejection and CAV.

METHODS

We performed a retrospective review of 26 PHT recipients who underwent stress CMR with tissue characterization and compared with 18 age-matched healthy controls. CMR protocol included myocardial T2, T1 and extracellular volume (ECV) mapping, late gadolinium enhancement (LGE), qualitative and semi-quantitative stress perfusion (myocardial perfusion reserve index; MPRI) and strain imaging. Clinical, demographics, rejection score and CAV history were recorded and correlated with CMR parameters.

RESULTS

Mean age at transplant was 9.3 ± 5.5 years and median duration since transplant was 5.1 years (IQR 7.5 years). One patient had active rejection at the time of CMR, 11/26 (42%) had CAV 1 and 1/26 (4%) had CAV 2. Biventricular volumes were smaller and cardiac output higher in PHT vs. healthy controls. Global T1 (1053 ± 42 ms vs 986 ± 42 ms; p < 0.001) and ECV (26.5 ± 4.0% vs 24.0 ± 2.7%; p = 0.017) were higher in PHT compared to helathy controls. Significant relationships between changes in myocardial tissue structure and function were noted in PHT: increased T2 correlated with reduced LVEF (r = - 0.57, p = 0.005), reduced global circumferential strain (r = - 0.73, p < 0.001) and reduced global longitudinal strain (r = - 0.49, p = 0.03). In addition, significant relationships were noted between higher rejection score and global T1 (r = 0.38, p = 0.05), T2 (r = 0.39, p = 0.058) and ECV (r = 0.68, p < 0.001). The presence of even low-grade CAV was associated with higher global T1, global ECV and maximum segmental T2. No major side effects were noted with stress testing. MPRI was analyzed with good interobserver reliability and was lower in PHT compared to healthy controls (0.69 ± - 0.21 vs 0.94 ± 0.22; p < 0.001).

CONCLUSION

In a PHT population with low incidence of rejection or high-grade CAV, CMR demonstrates important differences in myocardial structure, function and perfusion compared to age-matched healthy controls. Regadenoson stress perfusion CMR could be safely and reliably performed. Increasing T2 values were associated with worsening left ventricular function and increasing T1/ECV values were associated with rejection history and low-grade CAV. These findings warrant larger prospective studies to further define the role of CMR in PHT graft surveillance.

Use of induction therapy in pediatric heart transplant recipients in Switzerland - Analysis of the Swiss national database

BACKGROUND

Data on individualized immunosuppressive protocols for the pediatric heart recipients are missing in Europe. To contribute to this very small but specialized field, we describe the use of induction therapy (IT) in pediatric heart transplant patients in Switzerland and the retrospective outcomes.

METHOD

This is a retrospective national database analysis of children <19 years of age at time of heart transplantation (HT) from 05/2008-01/2018. Use of IT or no IT, use of steroids, calculated panel reactive antibodies (cPRA) and outcomes (Mortality, post-transplant lymphoproliferative disease (PTLD), rejection rates) were studied within a mean follow-up period of 2.9 years (0.2-8.1 years).

RESULTS

All 32 patients (12♂, 20♀), median age at HT of 6.4 years (24 days - 18 years) received IT using either polyclonal antibodies (ATG; 72%) or interleukin-2 receptor antagonist (anti-IL-2R mAb; 28%). Length of treatment was median of 4 (1-63) days. At time of HT all patients received steroids, while at discharge 32% and one year after HT 19%. Kaplan-Meier analysis of survival revealed a one-year survival of 86%. Three out of 7 patients with elevated cPRA (43%) died. Median time to first treated rejection was 19.4 months (±60.5 SD) without significant difference if treated with anti-IL-2R mAb or ATG (p:0.5). No development of PTLD, chronic renal failure needing ongoing renal replacement therapy or diabetes mellitus were recorded.

DISCUSSION

This is the first report of the national practice use of IT within Switzerland. It reveals a high use of IT, no development of PTLD and a low use of steroids at one-year post HT.

Pediatric heart transplantation: how to manage problems affecting long-term outcomes?

Since the initial International Society of Heart Lung Transplantation registry was published in 1982, the number of pediatric heart transplantations has increased markedly, reaching a steady state of 500-550 transplantation annually and occupying up to 10% of total heart transplantations. Heart transplantation is considered an established therapeutic option for patients with end-stage heart disease. The long-term outcomes of pediatric heart transplantations were comparable to those of adults. Issues affecting long-term outcomes include acute cellular rejection, antibody-mediated rejection, cardiac allograft vasculopathy, infection, prolonged renal dysfunction, and malignancies such as posttransplant lymphoproliferative disorder. This article focuses on medical issues before pediatric heart transplantation, according to the Korean Network of Organ Sharing registry and as well as major problems such as graft rejection and cardiac allograft vasculopathy. To reduce graft failure rate and improve long-term outcomes, meticulous monitoring for rejection and medication compliance are also important, especially in adolescents.

Cardiac allograft vasculopathy: Differences of absolute and relative intimal hyperplasia in children versus adults in optical coherence tomography

BACKGROUND

Intracoronary imaging enables an early detection of intimal changes. To what extend the development of absolute and relative intimal hyperplasia in intracoronary imaging differs depending on age and post-transplant time is not known.

METHODS

Aim of our retrospective study was to compare findings between 24 pediatric (cohort P) and 21 adult HTx patients (cohort A) using optical coherence tomography (OCT) at corresponding post-transplant intervals (≤5 years: P1 (n = 11) and A1 (n = 10); >5 and ≤ 10 years: P2 (n = 13) and A2 (n = 11),. Coronary intima thickness (IT), media thickness (MT) and intima to media ratio (I/M) were assessed per quadrant. Maximal IT >0.3 mm was considered absolute, I/M > 1 relative intimal hyperplasia.

RESULTS

Compared to A1, I/M was significantly higher in P1 (maximal I/M: P1: 5.41 [2.81-13.39] vs. A1: 2.30 [1.55-3.62], p = 0.005), whereas absolute IT values were comparable. In contrast, I/M was comparable between P2 and A2, but absolute IT were significantly higher in A2 (maximal IT: P2: 0.16 mm [0.11-0.25] vs. A2: 0.40 mm [0.30-0.71], p < 0.001). A2 presented with higher absolute IT (maximal: A1: 0.16 mm [0.12-0.44] vs. A2: 0.40 mm [0.30-0.71], p = 0.02) and I/M (maximal I/M A1: 2.30 [1.55-3.62] vs. A2: 3.79 [3.01-5.62], p = 0.04).

CONCLUSION

Our results suggest an age- and time-dependent difference in the prevalence of absolute and relative intimal hyperplasia in OCT, with an early peak in children and a progressive increase in adults.

Motor outcome, executive functioning, and health-related quality of life of children, adolescents, and young adults after ventricular assist device and heart transplantation

OBJECTIVE

The aim of the current study is to measure long-term executive function, motor outcome, and QoL in children, adolescents, and young adults after VAD and Htx.

METHODS

Patients were examined during routine follow-up. Investigation tools were used as follows: Examination for MND of motor outcomes, Epitrack^® for attention and executive functioning, and Kidscreen-52 and EQ-5D-5L questionnaires for QoL. Additional data were retrospectively obtained by an analysis of patient medical records.

RESULTS

Out of 145 heart transplant recipients at the department of pediatric cardiology of the University Hospital Munich, 39 were implanted with a VAD between 1992 and 2016. Seventeen (43.6%) patients died before or after Htx; 22 (56.4%) patients were included in our study. Mean age at transplant was 9.52 years (range: 0.58-24.39 years, median 9), and the mean follow-up time after Htx was 6.18 years (range: 0.05-14.60 years, median 5.82). MND examination could be performed in 13 patients (normal MND: n = 11, simple MND: n = 1, complex MND: n = 1). Executive functioning was tested in 15 patients. Two (13.3%) patients had good results, six (40%) average results, three (20%) borderline results, and four (26.7%) impaired results. QoL (Kidscreen n = 7, EQ-5D-5L n = 8) was similar to a healthy German population.

CONCLUSION

Motor outcome, executive functioning and QoL in survivors of VAD bridging therapy and Htx can be good, though underlying diseases and therapies are associated with a high risk of cerebral ischemic or hemorrhagic complications.

Application of modified bicaval technique for pediatric heart transplant with oversized donor heart

Whereas bicaval technique is an effective surgical method, standard bicaval technique for younger age and donor/recipient caval mismatch was reported to have a risk of superior vena caval obstruction. Between 2016 and 2019, three patients with dilated cardiomyopathy aged 10 years or younger underwent orthotropic heart transplantation with modified bicaval technique at our institute. Donor/recipient body weight and height ratios were 2.36, 0.77, and 2.61 and 1.37, 0.94, and 1.51, respectively. All patients were preoperatively supported by a left ventricular assist device: Excor Pediatric in two patients and Jarvik 2000 in one. Duration of LVAD support was 180, 238, and 220 days. One patient required revision of pulmonary anastomosis during the operation; accordingly, the chest was closed 3 days later. There was no mortality. Caval obstructions were not observed. Three months after the operation, tricuspid regurgitation was mild in two patients and trivial in one.

Serial Changes in Right Ventricular Systolic Function Among Rejection-Free Children and Young Adults After Heart Transplantation

BACKGROUND

Evolution of right ventricular (RV) systolic function after pediatric heart transplantation (HT) has not been well described.

METHODS

We analyzed echocardiograms performed over the first year after HT among children and young adults who remained rejection-free. Ninety-six patients (median age 7.1 [0.1-24.4] years at HT) were included: 22 infants (≤1 year) and 74 noninfants (>1 year). Two-dimensional tricuspid annular plane systolic excursion (TAPSE), tissue Doppler-derived tricuspid annular systolic velocity (S'), fractional area change (FAC), myocardial performance index (MPI), and two-dimensional speckle-tracking-derived RV global longitudinal (GLS) and free wall strain (FWS) were assessed.

RESULTS

All measures of RV function were impaired immediately after HT and significantly improved over the first year: TAPSE z-score (-8.15 ± 1.88 to -3.94 ± 1.65, P < .0001), S' z-score (-4.30 ± 1.36 to -2.28 ± 1.33, P < .0001), FAC (24.37% ± 7.71% to 42.02% ± 7.09%, P < .0001), MPI (0.96 ± 0.47 to 0.41 ± 0.22, P < .0001), GLS (-10.37% ± 3.86% to -21.05% ± 3.41%, P < .0001), and FWS (-11.2% ± 4.08% to -23.66% ± 4.13%, P < .0001). By 1 year post-HT, TAPSE, S', GLS, and FWS, remained abnormal, whereas FAC and MPI nearly normalized. Patients transplanted during infancy demonstrated better recovery of RV systolic function.

CONCLUSIONS

Although RV systolic function improved over the first year after HT in children and young adults without rejection, measures that assess longitudinal contractility remained abnormal at 1 year post-HT. These findings contribute to our understanding of RV myocardial contractility after HT in children and young adults and improve our ability to assess function quantitatively in this population.

Strategies to Prevent Cast Formation in Patients with Plastic Bronchitis Undergoing Heart Transplantation

Plastic bronchitis, a rare complication after Fontan palliation, carries a high morbidity and mortality risk. Heart transplantation is an effective treatment option, but casts may occur in the early post-operative period. We present a case series detailing peri-operative management strategies to minimize morbidity and mortality related to plastic bronchitis in patients undergoing heart transplantation. Patient 1 received no treatment pre-, intra-, or post-transplant for prevention of bronchial casts and developed severe respiratory acidosis 18 h following transplant. Emergent bronchoscopy was performed and a large obstructive cast was removed. The patient recovered and received inhaled tissue plasminogen activator (tPA) for 5 days. Patient 2 received inhaled tPA before, during, and for 5 days after transplantation and no bronchial casts developed. Patient 3 underwent intraoperative bronchoscopy just prior to implantation revealing no casts. The patient underwent non-urgent, preemptive bronchoscopy on post-transplant days 1, 3, and 4, removing several partially obstructive bronchial blood clots/casts, with no casts thereafter. Heart transplantation results in eventual resolution of plastic bronchitis. Residual bronchial casts can still be problematic in the peri-operative period. Airway clearance with inhaled tPA or bronchoscopy may prevent the need for prolonged mechanical ventilation and reduce post-operative morbidity in this unique population.

Persistent Epstein-Barr viral load in Epstein-Barr viral naïve pediatric heart transplant recipients: Risk of late-onset post-transplant lymphoproliferative disease

AIM

To examine the risk of late-onset post-transplant lymphoproliferative disorder (PTLD) in the presence of persisting high Epstein-Barr virus (EBV) in EBV naïve pediatric heart transplant (HT) recipients.

METHODS

A retrospective review of the medical records of the 145 pediatric HT recipients who had serial EBV viral load monitoring at our center was performed. We defined EBV naive patients whose EBV serology either IgM or IgG in the blood were negative at the time of HT and excluded passive transmission from mother to child in subjects less than 6 mo of age.

RESULTS

PTLD was diagnosed in 8 out of 145 patients (5.5%); 6/91 (6.5%) in those who were EBV seropositive and 2/54 (3.7%) in the EBV naïve group at the time of HT (P = 0.71). We found 32/145 (22%) patients with persistently high EBV load during continuing follow-up; 20/91 (22%) in EBV seropositive group vs 12/54 (22%) in EBV naïve group (P = 0.97). There was no significant association between pre-HT serostatus and EBV load after transplant (P > 0.05). In the EBV seropositive group, PTLD was diagnosed in 15% (3/20) of patients with high EBV vs 4.2% (3/71) of patients with low or undetectable EBV load (P = 0.14) whereas in EBV naïve patients 8.3% (1/12) of those with high EBV load and 2.3% (1/42) with low or undetectable EBV load (P = 0.41). There was a highly significant association between occurrence of PTLD in those with high EBV load and duration of follow up (4.3 ± 3.9 years) after HT by Cochran-Armitage test for the entire cohort (P = 0.005). At least one episode of acute rejection occurred in 72% (23/32) of patients with high EBV vs 36% (41/113) patients with low or undetectable EBV after HT (P < 0.05).

CONCLUSION

There is an association between persistently high EBV load during post-HT follow up and the occurrence of late-onset PTLD in pediatric HT recipients irrespective of serostatus at the time of transplant. The occurrence of allograft rejection increased in patients with high EBV load presumably due to reduction in immunosuppression.

Left ventricular noncompaction: A rare indication for pediatric heart transplantation

Isolated left ventricular noncompaction is a rare congenital cardiomyopathy, characterized morphologically by a dilated left ventricle, prominent trabeculations and deep intertrabecular recesses in the ventricular myocardium, with no other structural heart disease. It is thought to be secondary to an arrest of normal myocardial compaction during fetal life. Clinically, the disease presents with heart failure, embolic events, arrhythmias or sudden death. Current diagnostic criteria are based on clinical and imaging data and two-dimensional and color Doppler echocardiography is the first-line exam. There is no specific therapy and treatment is aimed at associated comorbidities. Cases refractory to medical therapy may require heart transplantation. The authors describe a case of severe and refractory heart failure, which was the initial presentation of isolated left ventricular noncompaction in a previously healthy male child, who underwent successful heart transplantation.

Orthotopic heart transplantation in patients with univentricular physiology

Parallel advancements in surgical technique, preoperative and postoperative care, as well as a better understanding of physiology in patients with duct-dependent pulmonary or systemic circulation and a functional single ventricle, have led to superb results in staged palliation of most complex congenital heart disease (CHD) [1]. The Fontan procedure and its technical modifications have resulted in markedly improved outcomes of patients with single ventricle anatomy [2,3,4]. The improved early survival has led to an exponential increase of the proportion of Fontan patients surviving long into adolescence and young adulthood [5]. Improved early and late survival has not yet abolished late mortality secondary to myocardial failure, therefore increasing the referrals for cardiac transplantation [6]. Interstage attrition [7] is moreover expected in staged palliation towards completion of a Fontan-type circulation, while Fontan failure represents a growing indication for heart transplantation [8]. Heart transplantation has therefore become the potential “fourth stage” [9] or a possible alternative to a high-risk Fontan operation [10] in a strategy of staged palliation for single ventricle physiology. Heart transplant barely accounts for 16% of pediatric solid organ transplants [11]. The thirteenth official pediatric heart transplantation report- 2010 [11] indicates that pediatric recipients received only 12.5% of the total reported heart transplants worldwide. Congenital heart disease is not only the most common recipient diagnosis, but also the most powerful predictor of 1-year mortality after OHT. Results of orthotopic heart transplantations (OHT) for failing single ventricle physiology are mixed. Some authors advocate excellent early and mid-term survival after OHT for failing Fontan [9], while others suggest that rescue-OHT after failing Fontan seems unwarranted [10]. Moreover, OHT outcome appears to be different according to the surgical staging towards the Fontan operation and surgical technique of Fontan completion [12].

The focus of this report is a complete review of the recent literature on OHT for failing single ventricles, outlining the clinical issues affecting Fontan failure, OHT listing and OHT outcome. These data are endorsed reporting our experience with OHT for failing single ventricle physiology in recent years.