New-onset diabetes after pediatric heart transplantation: A review of the Pediatric Heart Transplant Study

Changes in nutritional status and the development of obesity and metabolic syndrome following pediatric heart transplantation

BACKGROUND

Nutritional status in pediatric patients undergoing heart transplantation (HT) is frequently a focus of clinical management and requires high resource utilization. Pre-operative nutrition status has been shown to affect post-operative mortality but no studies have been performed to assess how nutritional status may change and the risk of developing nutritional comorbidities long-term in the post-transplant period.

METHODS

A single-center retrospective chart review of patients ≥2 years of age who underwent heart transplantation between 1/1/2005 and 4/30/2020 was performed. Patient data were collected at listing, time of transplant, 1-year, and 3-year follow-up post-transplant. Nutrition status was classified based on body mass index (BMI) percentile in the primary analysis. Alternative nutritional indices, namely the nutrition risk index (NRI), prognostic nutrition index (PNI), and BMI z-score, were utilized in secondary analyses.

RESULTS

Of the 63 patients included, the proportion of patients with overweight/obese status increased from 21% at listing to 41% at 3-year follow-up. No underweight patients at listing became overweight/obese at follow-up. Of patients who were overweight/obese at listing, 88% maintained that status at 3-year follow-up. Overweight/obese status at listing, 1-year, and 3-year post-transplantation were significantly associated with developing metabolic syndrome. In comparison to the alternative nutritional indices, BMI percentile best predicted post-transplant metabolic syndrome.

CONCLUSIONS

The results suggest that pediatric patients who undergo heart transplantation are at risk of developing overweight/obesity and related nutritional sequelae (ie, metabolic syndrome). Improved surveillance and interventions targeted toward overweight/obese HT patients should be investigated to reduce the burden of associated comorbidities.

Adult and late adolescent complications of pediatric solid organ transplantation

BACKGROUND

There have been over 51 000 pediatric solid organ transplants since 1988 in the United States alone, leading to a growing population of long-term survivors who face complications of childhood organ failure and long-term immunosuppression.

AIMS

This is an educational review of existing literature.

RESULTS

Pediatric solid organ transplant recipients are at increased risk for risk for cardiovascular and kidney disease, skin cancers, and growth problems, though the severity of impact may vary by organ type. Pediatric recipients often are able to complete schooling, maintain a job, and form family and social networks in adulthood, though at somewhat lower rates than the general population, but face additional challenges related to neurocognitive deficits, mental health disorders, and discrimination.

CONCLUSIONS

Transplant centers and research programs should expand their focus to include long-term well-being. Increased collaboration between pediatric and adult transplant specialists will be necessary to better understand and manage long-term complications.

Early post-transplant hyperglycemia and post-transplant diabetes mellitus following heart transplantation

INTRODUCTION

Heart transplantation is an important treatment for end-stage heart failure. Early post-transplant hyperglycemia (EPTH) and post-transplant diabetes mellitus (PTDM) are common following heart transplantation and are associated with increased morbidity and mortality.

AREAS COVERED

This review summarizes the clinical characteristics, diagnosis, and treatment of EPTH and PTDM in cardiac transplant patients, incorporating findings from non-cardiac solid organ transplant studies where relevant due to limited heart-specific research.

EXPERT OPINION

EPTH following heart transplantation is common yet understudied and is associated with the later development of PTDM. PTDM is associated with adverse outcomes including infection, renal dysfunction, microvascular disease, and an increased risk of re-transplantation and mortality. Risk factors for EPTH include the post-operative immunosuppression regimen, recipient and donor age, body mass index, infections, and chronic inflammation. Early insulin treatment is recommended for EPTH, whereas PTDM management is varied and includes lifestyle modification, anti-glycemic agents, and insulin. Given the emerging evidence on the transplant benefits associated with effective glucose control, and the cardioprotective potential of newer anti-glycemic agents, further focus on the management of EPTH and PTDM within heart transplant recipients is imperative.

Medium-term Outcomes in Pediatric Heart Transplant Recipients Managed Using a Steroid Avoidance Immune Suppression Protocol

BACKGROUND

Short-term outcomes using steroid avoidance immune suppression are encouraging in pediatric heart transplant (HT) recipients at low risk of antibody-mediated rejection. We assessed medium-term outcomes in pediatric HT recipients initiated on a steroid avoidance protocol at our institution using surveillance biopsies.

METHODS

All primary HT recipients during 2006-2020 who did not have a donor-specific antibody were eligible for immune suppression consisting of 5-d Thymoglobulin/steroid induction followed by a tacrolimus-based, steroid-free regimen. We assessed freedom from graft failure (death or retransplant), acute rejection, posttransplant lymphoproliferative disease, and cardiac allograft vasculopathy.

RESULTS

Overall, 150 of 181 primary HT recipients were eligible for steroid avoidance regimen. Their median age was 8.7 y, 41% had congenital heart disease, 23% were sensitized, and 35% were on a mechanical support. The median follow-up was 6.1 y. Eleven patients (8%) were on maintenance steroids at discharge and 13% at 1 y. Graft survival was 94% at 1 y and 87% at 5 y. Freedom from rejection was 73% at 1 y and 64% at 5 y. Freedom from posttransplant lymphoproliferative disease was 96% at 1 y and 95% at 5 y. Freedom from moderate cardiac allograft vasculopathy was 94% at 5 y. Eight patients developed diabetes. Estimated glomerular filtration rate was <60 mL/min/1.73 m 2 in 5% of the cohort at 5 y.

CONCLUSIONS

Pediatric HT recipients at low risk of antibody-mediated rejection have excellent medium-term survival and relatively low incidence of posttransplant morbidities when managed using a steroid avoidance immune suppression protocol.

Racial and Ethnic Disparities in Incidence and Prognosis of Perioperative Stroke Among Pediatric Cardiac Transplant Recipients

Background

In the general population, Black children have a higher incidence of stroke and all‐cause mortality after stroke than White children. Beginning 6 months following cardiac transplantation, Black children have higher mortality than White children. However, whether there are racial and ethnic disparities in incidence and all‐cause mortality following perioperative stroke among pediatric cardiac transplant recipients is unknown.

Methods and Results

Using the Scientific Registry of Transplant Recipients, we studied children who underwent their first heart transplant in the United States between January 1994 and September 2019. Using multivariable logistic regression, we assessed the association between race and ethnicity and perioperative stroke. We used multivariable piecewise Cox regression to examine the association between race and ethnicity and mortality among survivors of perioperative stroke. Among 8224 children who had a first cardiac transplant, 255 (3%) had a perioperative stroke. Black children had 32% lower odds of perioperative stroke compared with White children (adjusted odds ratio, 0.68 [95% CI, 0.46–0.996]). Following perioperative stroke, mortality rates were similar for Black and White children in the first 6 months (adjusted hazard ratio [HR], 0.99 [95% CI, 0.44–2.26]). However, Black children had a higher mortality rate than White children beyond 6 months (adjusted HR, 3.36 [95% CI, 1.22–9.22]).

Conclusions

Among pediatric cardiac transplant recipients, Black children have a lower incidence of perioperative stroke than White children. Among survivors of perioperative stroke, mortality is initially similar by race and ethnicity, but beyond 6 months, Black children have over a 3‐fold higher mortality rate than White children. Identifying and intervening on potential differences in care is essential to addressing these disparities.

Post-Transplantation Diabetes Mellitus in Pediatric Patients

More than 80% of pediatric solid organ transplant (SOT) recipients now survive into young adulthood and many encounter transplant-related complications. Post-transplantation diabetes mellitus (PTDM), sometimes also referred to as post-transplant diabetes or new onset diabetes after transplant, occurs in 3-20% of pediatric SOT recipients depending upon the organ transplanted, age at transplantation, immunosuppressive regimen, family history, and time elapsed since transplant. To diagnose PTDM, hyperglycemia must persist beyond the initial hospitalization for transplantation when a patient is on stable doses of immunosuppressive medications. Though standard diagnostic criteria used by the American Diabetes Association (ADA) to diagnose diabetes are employed, clinicians need to be aware of the limitations of using these criteria in this unique patient population. Management of PTDM parallels strategies used for type 2 diabetes (T2D), while also carefully considering comorbidities and potential interactions with immunosuppressive medications in these patients. In caring for patients with PTDM, it is important to be familiar with these interactions and comorbidities in order to coordinate care with the transplant team and optimize outcomes for these patients.

An ethical analysis of obesity as a determinant of pediatric heart transplant candidacy

BACKGROUND

Inclusion of BMI as criterion in the determination of heart transplant candidacy in children is a clinical and ethical challenge. Childhood obesity is increasing and children with heart disease are not spared. Currently, many adult heart transplant centers consider class II obesity and higher (BMI > 35 kg/m² ) to be a relative contraindication for transplantation due to risk of poor outcome after transplant. No national guidelines exist regarding consideration of BMI in pediatric heart transplant and outcomes data are limited. This leaves decisions about transplant candidacy in obese pediatric patients to individual institutions or on a case-by-case basis, allowing for bias and inequity.

METHODS

We review (a) the prevalence of childhood obesity, including among heart transplant candidates, (b) the lack of existing BMI guidelines, and (c) relevant literature on BMI and pediatric heart transplant outcomes. We discuss the ethical considerations of using obesity as a criterion using the principles of utility, justice, and respect for persons.

RESULTS

Existing transplant outcomes data do not show that obese children have different or poor enough outcomes compared to non-obese children to warrant exclusion. Moreover, obesity in the United States is unequally distributed by race and socioeconomic status. Children already suffering from health disparities are therefore doubly penalized if obesity denies them access to life-saving transplant.

CONCLUSION

Insufficient data exist to support using any BMI cutoff as an absolute contraindication for heart transplant in children. Attention should be paid to health equity issues when considering excluding a patient for transplant based on obesity.