Heart Transplantation in Children with Turner Syndrome: Analysis of a Linked Dataset

Clinical practice guidelines for the care of girls and women with Turner syndrome

Turner syndrome (TS) affects 50 per 100 000 females. TS affects multiple organs through all stages of life, necessitating multidisciplinary care. This guideline extends previous ones and includes important new advances, within diagnostics and genetics, estrogen treatment, fertility, co-morbidities, and neurocognition and neuropsychology. Exploratory meetings were held in 2021 in Europe and United States culminating with a consensus meeting in Aarhus, Denmark in June 2023. Prior to this, eight groups addressed important areas in TS care: (1) diagnosis and genetics, (2) growth, (3) puberty and estrogen treatment, (4) cardiovascular health, (5) transition, (6) fertility assessment, monitoring, and counselling, (7) health surveillance for comorbidities throughout the lifespan, and (8) neurocognition and its implications for mental health and well-being. Each group produced proposals for the present guidelines, which were meticulously discussed by the entire group. Four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with systematic review of the literature. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with members from the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology, the European Reference Network on Rare Endocrine Conditions, the Society for Endocrinology, and the European Society of Cardiology, Japanese Society for Pediatric Endocrinology, Australia and New Zealand Society for Pediatric Endocrinology and Diabetes, Latin American Society for Pediatric Endocrinology, Arab Society for Pediatric Endocrinology and Diabetes, and the Asia Pacific Pediatric Endocrine Society. Advocacy groups appointed representatives for pre-meeting discussions and the consensus meeting.

Postoperative Morbidity and Interstage Hemodynamics Following Stage I Palliation in Patients with Turner Syndrome and Hypoplastic Left Heart Syndrome

BACKGROUND

Turner syndrome (TS) is associated with left-sided cardiac lesions, including hypoplastic left heart syndrome (HLHS). Mortality as high as 80-90% has been reported following stage I single-ventricle palliation (S1P) in patients with TS and HLHS (TS + HLHS). The specific factors that relate to poor outcomes are not well understood.

METHODS

This is a single-center, retrospective cohort study that includes 197 patients with HLHS who underwent S1P between 2008 and 2022. The clinical outcomes and interstage hemodynamics of TS + HLHS patients (N = 11) were compared with HLHS without TS (TS-HLHS), (N = 186).

RESULTS

Of the 11 TS + HLHS patients, 10 underwent S1P; 4 underwent Glenn and 1 had hemodynamics considered prohibitive for Glenn; only 1 survived to Fontan palliation. Post-S1P mortality was higher in TS + HLHS (60 v 25%, p = 0.017). Following S1P, TS + HLHS had higher rates of postoperative ECMO (70 v 28%, p = 0.006), surgical necrotizing enterocolitis (20 v 3%, p = 0.007), peritoneal drain placement (70 v 31%, p = 0.012), urinary tract infection (30 v 9%, p = 0.035), and ICU readmissions (median 5 v 1, p = 0.035). Interstage hemodynamics demonstrated higher right ventricular end diastolic, (11 v 8mmHg, p = 0.033), mean pulmonary artery (20 v 13mmHg) (p = 0.002), and left atrial pressures (9 v 6mmHg, p = 0.047) in TS + HLHS.

CONCLUSION

High mortality rates are described in TS + HLHS patients following S1P. In our cohort, despite most surviving more than 30 days post-S1P, long-term survival remained poor. Interstage catheterization data suggest poor physiologic candidacy for subsequent stages of single-ventricle palliation. Understanding the clinical and hemodynamic factors related to poor outcomes in TS + HLHS will help inform management for this population.

Hypoplastic Left Heart Syndrome: A Review

Hypoplastic left heart syndrome is a rare and poorly understood congenital disorder featuring a univentricular myocardium, invariably resulting in early childhood death if left untreated. The process to palliate this congenital cardiomyopathy is of high complexity and may include invasive interventions in the first week of life. The preferred treatment strategy involves a staged correction with 3 surgical procedures at different points in time. The Norwood procedure is usually performed within the first weeks of life and aims to increase systemic circulation and relieve pulmonary vascular pressure. This procedure is followed by the bidirectional Glenn and the Fontan procedures in later life, which offer to decrease stress in the ventricular chamber. The prognosis of children with this disease has greatly improved in the past decades; however, it is still largely driven by multiple modifiable and nonmodifiable variables. Novel and clever alternatives have been proposed to improve the survival and neurodevelopment of these patients, although they are not used as standard of care in all centers. The neurodevelopmental outcomes among these patients have received particular attention in the last decade in light to improve this very limiting associated comorbidity that compromises quality of life.

Solid Organ Transplantation for Children with Neurodevelopmental Disabilities – Ethical Considerations and a Call for Clarity

Pediatric transplant centers are faced with the difficult task of maximizing the benefit of organs donated for transplantation while also ensuring that all patients undergoing transplant evaluation are fairly considered for this life-saving therapy. Children with neurodevelopmental disabilities are a complex patient population that on occasion may face the need for a solid organ transplant. Several concerns exist regarding transplantation in this population, yet standard transplant inclusion and exclusion criteria do not exist. Here we explore important factors regarding organ transplantation for children with neurodevelopmental disorders, including patient outcomes, quality of life considerations, and the fundamental ethical principles underlying this complex medical decision-making.

Mid-Term Outcomes of Heart Transplantation in Children with Genetic Disorders

BACKGROUND

Many congenital heart diseases (CHD) are associated with genetic defects. Children with complex CHD often develop heart failure, requiring heart transplant. Given the broad spectrum of genetic pathologies and dearth of transplants performed in these children, little is known regarding their outcomes.

METHODS

We conducted a retrospective review of heart transplants performed at a high-volume center from 2007-2021. Patients were separated into pathogenic molecular and copy number variants, aneuploidies, and variants of uncertain significance, and compared to those without known genetic diagnoses. Variables included genetic diagnoses, bridge-to-transplant approach, preoperative comorbidities, operative characteristics, and postoperative complications. Outcomes included ICU-free days to 28 days, hospital mortality, survival, rejection, re-transplantation, and educational status at latest follow-up.

RESULTS

223 patients were transplanted over the study period: 9.9% (22/223) had pathogenic molecular variants, 4.5% (10/223) had copy number variants, 1.8% (4/223) had aneuploidies, and 9.0% (20/223) had variants of uncertain significance. The most common anomalies were Turner syndrome (n=3) and 22q11.2 deletion syndrome (n=2). Children with aneuploidies had higher rates of hepatic dysfunction and hypothyroidism, while those with pathogenic copy number variants had higher rates of preoperative gastrostomy and stroke. Children with aneuploidies were intubated longer post-transplant, with greater need for re-intubation, and had the fewest ICU-free days. Mortality and mean survival did not differ. At median follow-up of 4.4 (1.9-8.8) years, 89.7% (26/29) of survivors with pathogenic anomalies were attending or had graduated school.

CONCLUSIONS

Despite more preoperative comorbidities, mid-term outcomes following heart transplant in children with genetic syndromes and disorders are promising.

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.

Turner syndrome: mechanisms and management

Turner syndrome is a rare condition in women that is associated with either complete or partial loss of one X chromosome, often in mosaic karyotypes. Turner syndrome is associated with short stature, delayed puberty, ovarian dysgenesis, hypergonadotropic hypogonadism, infertility, congenital malformations of the heart, endocrine disorders such as type 1 and type 2 diabetes mellitus, osteoporosis and autoimmune disorders. Morbidity and mortality are increased in women with Turner syndrome compared with the general population and the involvement of multiple organs through all stages of life necessitates a multidisciplinary approach to care. Despite an often conspicuous phenotype, the diagnostic delay can be substantial and the average age at diagnosis is around 15 years of age. However, numerous important clinical advances have been achieved, covering all specialty fields involved in the care of girls and women with Turner syndrome. Here, we present an updated Review of Turner syndrome, covering advances in genetic and genomic mechanisms of disease, associated disorders and multidisciplinary approaches to patient management, including growth hormone therapy and hormone replacement therapy.

Expanding analytic possibilities in pediatric solid organ transplantation through linkage of administrative and clinical registry databases

Database linkage is a common strategy to expand analytic possibilities. Our group recently completed a linkage between the SRTR and PHIS databases for pediatric heart transplant recipients. The aim of this project was to expand the linkage between SRTR and PHIS to include liver, kidney, lung, heart-lung, and small bowel transplants. All patients (<21 years) who underwent liver, kidney, lung, heart-lung, or small bowel transplant were identified from the PHIS database using APR-DRG codes (2002-2018). Linkage was performed in a stepwise approach using indirect identifiers. Hospital costs were estimated based on hospital charges and cost-to-charge ratios, inflated to 2018 dollars and described by transplant type. A total of 14 061 patients overlapped between databases. Of these, 13 388 (95.2%) were uniquely linked. Linkage success ranged from 92.6% to 97.8% by organ system. A total of 12 940 (92%) patients had complete cost data. Hospitalization costs were greatest for patients undergoing small bowel transplantation with a median cost of $734 454 (IQR $336 174 - $1 504 167), followed by heart $565 386 (IQR $352 813 - $999 216), heart-lung $471 573 (IQR $328 523 - 992 438), lung $303 536 (IQR $215 383 - $612 749), liver $200 448 (IQR $130 880 - $357 897), and kidney transplant $94 796 (IQR $73 157 -$131 040). We report a robust linkage between the SRTR and PHIS databases, providing an invaluable tool to assess resource utilization in solid organ transplant recipients. Our analysis provides contemporary cost data for pediatric solid organ transplantation from the largest US sample reported to date. It also provides a platform for expanded analyses in the pediatric transplant population.