Outcomes of infants with pulmonary atresia with intact ventricular septum listed for heart transplantation: A multi-institutional study.

BACKGROUND: Management of infants with pulmonary atresia/intact ventricular septum (PA/IVS) is variable. Because of higher mortality in more severe forms, heart transplant (HT) is an acceptable approach, but waitlist and post-transplant outcomes are unclear. This study compared outcomes of infants with PA/IVS vs. other single ventricle (SV) anatomies listed for HT. METHODS: Data from the Pediatric Heart Transplant Society (1993-2018) were analyzed for survival and risk factors for mortality. RESULTS: Of 1617 SV infants, 300 had PA/IVS (19%) and 1317 had other SV (81%). Overall, 1-, 5-, and 10-year survival was higher among PA/IVS (74%, 65%, 61%) versus other SV infants (62%, 54%, 50%, p = .004). While waitlist mortality was similar between groups (p = .09), PA/IVS was an independent predictor of improved waitlist survival (HR 0.68, p = .03), and PA/IVS infants had higher incidence of waitlist removal (8% vs. 5.5%, p = .03), most commonly for being "too well." Post-transplant survival was superior among PA/IVS versus other SV infants (1- and 5-year survival 93% and 81% vs. 80% and 71%, p < .0001). Risk factors for PA/IVS waitlist mortality (2008-2018) included extracorporeal membrane oxygenation and mechanical ventilation. Prior aortopulmonary (AP) shunt among PA/IVS infants was associated with improved waitlist survival. CONCLUSIONS: Overall survival among PA/IVS infants listed for HT exceeds that of other SV infants with PA/IVS identified as an independent predictor of improved waitlist and post-transplant survival. Prior AP shunt among listed PA/IVS infants was associated with improved waitlist outcomes, though, which may reflect a listing selection bias.

Cardiac transplantation in children with Noonan syndrome.

NS and related RAS/MAPK pathway (RASopathy) disorders are the leading genetic cause of HCM presenting in infancy. HCM is a major cause of morbidity and mortality in children with Noonan spectrum disorders, especially in the first year of life. Previously, there have been only isolated reports of heart transplantation as a treatment for heart failure in NS. We report on 18 patients with NS disorders who underwent heart transplantation at seven US pediatric heart transplant centers. All patients carried a NS diagnosis: 15 were diagnosed with NS and three with NSML. Sixteen of eighteen patients had comprehensive molecular genetic testing for RAS pathway mutations, with 15 having confirmed pathogenic mutations in PTPN11, RAF1, and RIT1 genes. Medical aspects of transplantation are reported as well as NS-specific medical issues. Twelve of eighteen patients described in this series were surviving at the time of data collection. Three patients died following transplantation prior to discharge from the hospital, and another three died post-discharge. Heart transplantation in NS may be a more frequent occurrence than is evident from the literature or registry data. A mortality rate of 33% is consistent with previous reports of patients with HCM transplanted in infancy and early childhood. Specific considerations may be important in evaluation of this population for heart transplant, including a potentially increased risk for malignancies as well as lymphatic, bleeding, and coagulopathy complications.

Successful hematopoietic cell transplantation following cardiac transplantation in two pediatric patients.

We report two patients who underwent cardiac transplantation at a young age and subsequently required a HCT for varied indications. Despite the challenges associated with HCT following cardiac transplant, including need for altered immunosuppression, toxicities related to chemotherapy exposure, and infection risks, both patients are currently alive and well. There is a paucity of such successful cases documented in the literature, and these cases highlight the critical importance of an experienced, multidisciplinary team when caring for this patient population.

Tacrolimus-associated hemolytic uremic syndrome in a pediatric heart transplant recipient.

HUS is a well-known entity primarily associated with bacterial infection and is characterized by a classic triad of anemia, thrombocytopenia, and kidney injury. Its atypical form has been associated with calcineurin inhibitors and has been extensively discussed in renal transplantation. We present a case of tacrolimus-associated HUS in a pediatric heart transplant recipient, which we believe to be previously unreported in the literature.

Adult Congenital Heart Disease Transplantation: Does Univentricle Physiology Impact Early Mortality?

BACKGROUND: With patients with congenital heart disease increasingly living into adulthood, there is a growing population of patients with adult congenital heart disease (ACHD) who have heart failure. Limited data exist on evaluating heart transplantation in this population. METHODS: A retrospective review was performed of patients with ACHD who underwent heart transplantation from November 1990 to January 2023. Kaplan-Meier, cumulative incidence accounting for competing risk of death, and subgroup analyses comparing those patients with biventricular (BiV) and univentricular (UniV) physiology were performed. Data are presented as median (interquartile range [IQR]) or counts (%). RESULTS: A total of 77 patients with a median age of 36 years (IQR, 27-45 years) were identified, including 57 (74%) BiV and 20 (26%) UniV patients. Preoperatively, UniV patients were more likely to have cirrhosis (9 of 20 [45.0%] vs 4 of 57 [7.0%]; P < .001) and protein losing enteropathy (4 of 20 [20.0%] vs 1 of 57 [1.8%]; P = .015). Multiorgan transplantation was performed in 23 patients (30%) and more frequently in UniV patients (10 [50%] vs 13 [23%]; P = .04). Operative mortality was 6.5%, 2 of 20 (10%) among UniV patients and 2 of 57 (4%) among BiV patients (P = .276). Median clinical follow-up was 6.0 years (IQR, 1.4-13.1 years). Survival tended to be lower among UniV patients compared with BiV patients, particularly within the first year (P = .09), but it was similar for survivors beyond 1 year. At 5 years, the incidence of rejection was 28% (IQR, 17%-38%) and that of coronary allograft vasculopathy was 16% (IQR, 7%-24%). CONCLUSIONS: Underlying liver disease and the need for heart-liver transplantation were significantly higher among UniV patients. Survival tended to be lower among UniV patients, particularly within the first year, but it was similar for survivors beyond 1 year.

Outcomes of fetal listed patients awaiting heart transplantation.

HTx in neonates is mainstay therapy for those with severe cardiomyopathies and congenital heart disease. Fetal listing for HTx has been proposed as a way to increase the potential window for a donor with outcomes predicted to be similar to the neonatal population. Data from the PHTS, a prospective multicenter study, were used to examine the outcomes of fetuses listed between 1993 and 2009. Four thousand three hundred and sixty-five children were listed for HTx during this period. Fetuses comprised 1% and neonates 19.8% of listed patients. In those patients listed as fetus and transplanted, the median wait time from listing to HTx was 55 days (range 4-255), with a median of 25 days (range 0-233) after birth. By six months post-listing, a higher proportion of fetal listed patients had undergone HTx with a lower waitlist mortality when compared with neonate. There was no significant difference in survival following HTx between the two group (p = 0.4). While the results of this study may be less applicable to current practice due to changes in referrals for fetal listing, they do indicate that fetal listing can be a reasonable option. These results are of particular interest at the present time given the ongoing public discourse on the proposed elimination of fetal listing within UNOS.

Optimizing Referral Timing of Patients With Fontan Circulatory Failure for Heart Transplant.

BACKGROUND: There are no criteria guiding the timing of heart transplant referral for Fontan patients, nor are there any characteristics of those deferred or declined listing reported. This study examines comprehensive transplant evaluations for Fontan patients of all ages, listing decisions, and outcomes to inform referral practices. METHODS: Retrospective review of 63 Fontan patients formally assessed by the advanced heart failure service and presented at Mayo Clinic transplant selection committee meetings (TSM) January 2006 to April 2021. The study is compliant with the Helsinki Congress and Declaration of Istanbul and included no prisoners. Statistical analysis was performed with Wilcoxon Rank Sum and Fisher's Exact tests. RESULTS: Median age at TSM was 26 years (17.5, 36.5). Most were approved (38/63 [60%]); 9 of 63 (14%) were deferred and 16 of 63 (25%) were declined. Approved patients more commonly were <18 years old at TSM (15/38 [40%] vs 1/25 [4%], P = .002) compared with those deferred/declined. Complications of Fontan circulatory failure were less common in approved vs deferred/declined patients: ascites (15/38 [40%] vs 17/25 [68%], P = .039), cirrhosis (16/38 [42%] vs 19/25 [76%], P = .01), and renal insufficiency (6/38 [16%] vs 11/25 [44%], P = .02). Ejection fraction and atrioventricular valve regurgitation did not differ between groups. Pulmonary artery wedge pressure was overall high normal (12 mm Hg [9,16]) but higher in deferred/declined vs approved patients, 14.5 (11, 19) vs 10 (8, 13.5) mm Hg, P = .015. Overall survival was significantly lower in deferred/declined patients (P = .0018). CONCLUSION: Fontan patient referral for heart transplant at younger age and before the onset of end-organ complications is associated with increased approval for transplant listing.

Safety of a Noninvasive Expandable Electromagnetic Prosthesis with an In Situ Ventricular Assist Device: A Case Report.

CASE: An 8-year-old girl was diagnosed with osteosarcoma of the distal femur. She underwent chemotherapy and wide resection with implantation of a noninvasive electromagnetic expandable distal femur prosthesis. Ninety-three days after chemotherapy, she developed anthracycline-induced cardiomyopathy with heart failure for which a ventricular assist device was placed. Device compatibility was tested, and she was successfully lengthened. CONCLUSION: Expandable prostheses allow limb length maintenance in skeletally immature patients who undergo limb salvage. Chemotherapy for osteosarcoma involves anthracyclines with a dose-dependent side effect of cardiotoxicity. Patients can be successfully and safely lengthened with expandable electromagnetic prostheses with in situ ventricular assist devices.

1p36 Deletion Syndrome and Left Ventricular Non-compaction Cardiomyopathy-Two Cases Report.

1p36 deletion is the most common terminal deletion syndrome in humans. Herein, we report two cases, a 5-month-old female and a 14.5-year-old female, both with 1p36 deletion and left ventricular non-compaction cardiomyopathy. They presented with severely depressed left ventricle function and underwent heart transplantation with excellent outcomes. Given the incidence of heart defects and cardiomyopathy in 1p36 deletion syndrome, it should be recommended that children with this genetic condition have screening for cardiac disease. These cases add to the current literature by demonstrating the potential therapeutic options for non-compaction in 1p36 deletion syndrome and showed the favorable outcomes.

Clinical and hemodynamic characteristics of the pediatric failing Fontan.

AIM: To describe the clinical and hemodynamic characteristics of Fontan failure in children listed for heart transplant. METHODS: In a nested study of the Pediatric Heart Transplant Society, 16 centers contributed information on Fontan patients listed for heart transplant between 2005and 2013. Patients were classified into four mutually exclusive phenotypes: Fontan with abnormal lymphatics (FAL), Fontan with reduced systolic function (FRF), Fontan with preserved systolic function (FPF), and Fontan with "normal" hearts (FNH). Primary outcome was waitlist and post-transplant mortality. RESULTS: 177 children listed for transplant were followed over a median 13 (IQR 4-31) months, 84 (47%) were FAL, 57 (32%) FRF, 22 (12%) FNH, and 14 (8%) FPF. Hemodynamic characteristics differed between the 4 groups: Fontan pressure (FP) was most elevated with FPF (median 22, IQR 18-23, mmHg) and lowest with FAL (16, 14-20, mmHg); cardiac index (CI) was lowest with FRF (2.8, 2.3-3.4, L/min/m2). In the entire cohort, 66% had FP >15 mmHg, 21% had FP >20 mmHg, and 10% had CI <2.2 L/min/m2. FRF had the highest risk of waitlist mortality (21%) and FNH had the highest risk of post-transplant mortality (36%). CONCLUSIONS: Elevated Fontan pressure is more common than low cardiac output in pediatric failing Fontan patients listed for transplant. Subtle hemodynamic differences exist between the various phenotypes of pediatric Fontan failure. Waitlist and post-transplant mortality risks differ by phenotype.