Wasting or obesity at time of transplant does not predict pediatric heart transplant outcomes: analysis of ISHLT pediatric heart transplant registry

Cardiovascular health in pediatric heart transplant patients

BACKGROUND

Ideal "cardiovascular health" (CVH)-optimal diet, exercise, nonsmoking, BMI, BP, lipids, and glucose-is associated with healthy longevity in adults. Pediatric heart transplant (HT) patients may be at risk for suboptimal CVH.

METHODS

Single-center retrospective study of HT patients 2003-2014 who survived 1 year post-transplant. Five CVH metrics were collected at listing, 1, 3 and 5 years post-transplant (diet and exercise were unavailable). CVH was scored by summing individual metrics: ideal = 2, intermediate = 1, and poor = 0 points; total scores of 8-10 points were considered high (favorable). CVH was compared between HT patients and the US pediatric population (GP) utilizing NHANES 2007-2016. Logistic regression was performed to examine the association of CVH 1 year post-transplant with a composite adverse outcome (death, re-listing, coronary vasculopathy, or chronic kidney disease) 3 years post-transplant.

RESULTS

We included 110 HT patients (median age at HT: 6 years [range 0.1-21]) and 19,081 NHANES participants. CVH scores among HT patients were generally high at listing (75%), 1 (74%), 3 (87%) and 5 (76%) years post-transplant and similar to GP, but some metrics (e.g., glucose) were worse among HT patients. Among HT patients, CVH was poorer with older age and non-Caucasian race/ethnicity. Per 1-point higher CVH score, the demographic-adjusted OR for adverse outcomes was 0.95 (95% CI, 0.7-1.4).

CONCLUSIONS

HT patients had generally favorable CVH, but some metrics were unfavorable and CVH varied by age and race/ethnicity. No significant association was detected between CVH and adverse outcomes in this small sample, but study in a larger sample is warranted.

Association of obesity with mortality and clinical outcomes in children and adolescents with transplantation: A systematic review and meta-analysis

Obesity might be associated with mortality and clinical outcomes following transplantation; however, the direction of this relationship has not been well-recognized in youth. The aim of this systematic review and meta-analysis was to investigate the association of obesity with post-transplant mortality and clinical outcomes in children and adolescents. Following a systematic search of observational studies published by December 2018 in PubMed, Scopus, Embase, and Cochrane library, 15 articles with total sample size of 50,498 patients were included in the meta-analysis. The main outcome was mortality and secondary outcomes included acute graft versus host disease (GVHD), acute rejection, and overall graft loss. The pooled data analyses showed significantly higher odds of long term mortality (OR 1.30, 95% CI 1.15-1.48, P < 0.001, I² = 50.3%), short term mortality (OR 1.79, 95% CI 1.19-2.70, P = 0.005, I² = 59.6%), and acute GVHD (OR 2.13, 95% CI 1.5-3.02, P < 0.001, I² = 1.7%) in children with obesity. There were no significant differences between patients with and without obesity in terms of acute rejection (OR 1.07, 95% CI 0.98-1.16, P = 0.132, I² = 7.5%) or overall graft loss (OR 1.04, 95% CI 0.84-1.28, P = 0.740, I² = 51.6%). This systematic review and meta-analysis has stated higher post-transplant risk of short and long term mortality and higher risk of acute GVHD in children with obesity compared to those without obesity. Future clinical trials are required to investigate the effect of pre-transplant weight management on post-transplant outcomes to provide insights into the clinical application of these findings. This may in turn lead to establish guidelines for the management of childhood obesity in transplantations.

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.

Obesity class does not further stratify outcome in overweight and obese pediatric patients after heart transplantation

The effect of obesity stratification on pediatric heart transplant outcomes is unknown. The UNOS database was queried for patients ≥2-<18 years listed for heart transplant and stratified by BMI: normal (BMI>5%-≤85 percentile), overweight (BMI=86%-95 percentile), class 1 (BMI=100%-120% of 95 percentile), class 2 (BMI=121%-140% of 95 percentile), and class 3 obesity (BMI>140% of 95 percentile). A total of 5056 individuals were listed for transplant, with 71% normal, 13% overweight, 10% class 1, 4% class 2, and 2% class 3 obesity. Waitlist survival was not different between groups. Post-transplant survival was decreased in overweight and combined obese groups vs normal, with no further difference between overweight and obese classes. Overweight and obese patients had higher listing status and were more likely to have ventilator, inotrope, and mechanical circulatory support at listing. After transplant, there was an association of overweight-obese patients with diabetes and rejection requiring hospitalization. Stricter definition of normal weight reveals overweight-obese status was an independent risk factor for poorer post-transplant survival, without further effect by stratification of weight class. However, because there is no difference in waitlist survival, this study does not allow the selection of absolute weight-based criteria regarding transplant listing and suggests the need to look further for modifiable risk factors post-transplant.

Preoperative risk assessment in children undergoing major urologic surgery

BACKGROUND

Preoperative risk assessment is standard in adult surgery, but often these risk assessments cannot be applied to children. Previous studies emphasize the differences between pediatric and adult populations and variability by surgical procedure types.

OBJECTIVE

We investigated preoperative risk factors for several outcomes in children undergoing major urologic surgery using the National Surgical Quality Improvement Program (NSQIP) Pediatric.

STUDY DESIGN

A cohort of 2-18-year-old children who underwent major urologic surgery was identified by Current Procedure Terminology (CPT) codes in the 2012-2013 NSQIP-Pediatric. The NSQIP-Pediatric prospectively collects standardized and validated data from 61 sites on preoperative, operative, and 30-day postoperative variables. Urologic surgeries involving dissection of the peritoneal or extraperitoneal space were included. Patients undergoing pure genitourinary surgery were analyzed separately from those with bowel involvement to improve homogeneity. Postoperative outcomes including hospital length of stay and 30-day infective complications, non-infective complications, unplanned reoperation and readmissions were evaluated by fitting multivariable logistic regression models.

RESULTS

A total of 2601 patients were identified, of whom 399 (15.3%) underwent bowel-involved surgery and 2202 (84.7%) underwent pure genitourinary surgery. Patients in the bowel-involved group were significantly older with more comorbidity. Postoperative complications, unplanned return to operating room, hospital length of stay and readmission rates were all significantly worse in the bowel-involved group. In the pure genitourinary group, older age and white race improved some outcomes, while American Society of Anesthesia (ASA) class ≥ 3, total operation time, obesity, pulmonary risk factors, preoperative renal disease, developmental delay, structural central nervous system abnormality, and supplemental nutrition independently predicted at least one negative outcome (Table).

DISCUSSION

Consistent with previous research on reconstructive surgery, we identified a significant difference in patient age, surgery details, comorbidity, and increased complications for patients undergoing urologic surgery with bowel involvement compared with pure genitourinary surgery. Focusing solely on pure genitourinary surgery, we identified predictors of outcomes. Identification of these factors in pediatric urology is novel and only recently possible with the availability of the NSQIP-Pediatric.

CONCLUSION

Using the NSQIP-Pediatric, we confirmed differences in complication rates for major urologic surgeries, with and without bowel involvement in a national sample. Preoperative risk characteristics were also identified for patients undergoing pure genitourinary surgery. Further investigation into these relationships is necessary to better elucidate their clinical significance with the goal of improving surgical planning, postoperative care, and family counseling.

Impact of Obesity during Pediatric Acute and Critical Illness

Pediatric overweight and obesity rates have reached epidemic proportions and continue to rise globally. Many long-term complications have been described about the impact of obesity; however, little work has been done in the area of acute and critical illness in children. Available evidence suggests that childhood obesity can impact acute and critical illness when compared with normal weight cohorts. This review will discuss the available literature on the impact of pediatric obesity during acute and critical illness.

Differential effect of body mass index on pediatric heart transplant outcomes based on diagnosis

The impact of nutritional status on HTx waitlist mortality in children is unknown, and there are conflicting data regarding the role of nutrition in post-HTx survival. This study examined the influence of nutrition on waitlist and post-HTx outcomes in children. Children 2-18 yr listed for HTx from 1997 to 2011 were identified from the OPTN database and stratified by BMI percentile. Multivariable logistic regression evaluated the influence of BMI on waitlist mortality. Cox proportional hazard regression assessed the impact of BMI on post-HTx mortality. When all 2712 patients were analyzed, BMI did not impact waitlist, one-, or five-yr mortality. However, when stratified by diagnosis, BMI > 95% (AOR 1.96; 95% CI 1.24, 3.09) and BMI < 1% (AOR 2.17; 95% CI 1.28, 3.68) were independent risk factors for waitlist mortality in patients with CM. BMI did not impact waitlist mortality in CHD and did not impact post-HTx outcomes, regardless of diagnosis. BMI > 95% and BMI < 1% are independent risk factors for waitlist mortality in patients with CM, but not CHD. This suggests differing risk factors based on disease etiology, and an individualized approach to risk assessment based on diagnosis may be warranted.

Hypoalbuminemia and poor growth predict worse outcomes in pediatric heart transplant recipients

Children with end-stage cardiac failure are at risk of HA and PG. The effects of these factors on post-transplant outcome are not well defined. Using the PHTS database, albumin and growth data from pediatric heart transplant patients from 12/1999 to 12/2009 were analyzed for effect on mortality. Covariables were examined to determine whether HA and PG were risk factors for mortality at listing and transplant. HA patients had higher waitlist mortality (15.81% vs. 10.59%, p = 0.015) with an OR of 1.59 (95% CI 1.09-2.30). Survival was worse for patients with HA at listing and transplant (p ≤ 0.01 and p = 0.026). Infants and patients with congenital heart disease did worse if they were HA at time of transplant (p = 0.020 and p = 0.028). Growth was poor while waiting with PG as risk factor for mortality in multivariate analysis (p = 0.008). HA and PG are risk factors for mortality. Survival was worse in infants and patients with congenital heart disease. PG was a risk factor for mortality in multivariate analysis. These results suggest that an opportunity may exist to improve outcomes for these patients by employing strategies to mitigate these risk factors.

Nutrition management after pediatric solid organ transplantation

Survival rates for pediatric transplant recipients and organ grafts have increased due to improvements in surgical techniques and with immunosuppressant treatment therapies. Interdisciplinary management after pediatric organ transplantation is essential to assist not only with the complex medical issues and complications that can result from immunosuppressant therapy but also with the achievement of normal growth and development. Impaired growth is a complication frequently experienced by pediatric transplant patients. The presence or absence of impaired growth is affected by the length of illness prior to transplant, graft function, the use of corticosteroids, and the development of infectious complications after surgery. A review of posttransplant nutrition assessment, nutrition requirements, and nutrition goals is provided. In addition, a case series of experiences with nutrition management of pediatric solid organ transplant recipients is described.

Long-term outcomes of children after solid organ transplantation

Solid organ transplantation has transformed the lives of many children and adults by providing treatment for patients with organ failure who would have otherwise succumbed to their disease. The first successful transplant in 1954 was a kidney transplant between identical twins, which circumvented the problem of rejection from MHC incompatibility. Further progress in solid organ transplantation was enabled by the discovery of immunosuppressive agents such as corticosteroids and azathioprine in the 1950s and ciclosporin in 1970. Today, solid organ transplantation is a conventional treatment with improved patient and allograft survival rates. However, the challenge that lies ahead is to extend allograft survival time while simultaneously reducing the side effects of immunosuppression. This is particularly important for children who have irreversible organ failure and may require multiple transplants. Pediatric transplant teams also need to improve patient quality of life at a time of physical, emotional and psychosocial development. This review will elaborate on the long-term outcomes of children after kidney, liver, heart, lung and intestinal transplantation. As mortality rates after transplantation have declined, there has emerged an increased focus on reducing longer-term morbidity with improved outcomes in optimizing cardiovascular risk, renal impairment, growth and quality of life. Data were obtained from a review of the literature and particularly from national registries and databases such as the North American Pediatric Renal Trials and Collaborative Studies for the kidney, SPLIT for liver, International Society for Heart and Lung Transplantation and UNOS for intestinal transplantation.

Abnormal nutrition affects waitlist mortality in infants awaiting heart transplant

BACKGROUND

Although nutritional status affects survival after heart transplant (HTx) in adults and older children, its effect on outcomes in young children is unknown. This study aimed to assess the effect of pre-HTx nutrition on outcomes in this population.

METHODS

Children aged 0 to 2 years old listed for HTx from 1997 to 2011 were identified from the Organ Procurement and Transplantation Network database. Nutritional status was classified according to percentage of ideal body weight at listing and at HTx. Logistic regression analysis evaluated the risk of waitlist mortality. Cox proportional hazard models assessed the effect of nutrition on post-HTx survival.

RESULTS

Of 1,653 children evaluated, 899 (54%) had normal nutrition at listing, 445 (27%) were mildly wasted, 203 (12%) were moderate or severely wasted, and 106 (6%) had an elevated weight-to-height (W:H) ratio. Moderate or severe wasting (adjusted odds ratio, 1.9; 95% confidence interval, 1.3-2.7) and elevated W:H (adjusted odds ratio, 1.7; 95% confidence interval, 1.1-2.6) were independent risk factors for waitlist mortality. HTx was performed in 1,167 patients, and 1,016 (87%) survived to 1-year post-HTx. Nutritional status at listing or at HTx was not associated with increased post-HTx mortality. Nutritional status did not affect the need for early reoperation, dialysis, or the incidences of infection, stroke, or rejection before hospital discharge.

CONCLUSIONS

Moderate or severe wasting and an elevated W:H are independent risk factors for waitlist mortality in patients aged < 2 years but do not affect post-HTx mortality. Optimization of pre-HTx nutritional status constitutes a strategy to reduce waitlist mortality in this age range.

Influence of obesity on clinical outcomes in hospitalized children: a systematic review

IMPORTANCE

Obesity is prevalent among hospitalized children. Knowledge of the relationship between obesity and outcomes in hospitalized children will enhance nutrition assessment and provide opportunities for interventions.

OBJECTIVE

To systematically review the existing literature concerning the impact of obesity on clinical outcomes in hospitalized children.

EVIDENCE ACQUISITION

PubMed, Web of Science, and EMBASE databases were searched for studies of hospitalized children aged 2 to 18 years with identified obesity and at least 1 of the following clinical outcomes: all-cause mortality, incidence of infections, and length of hospital stay. Cohort and case-control studies were included. Cross-sectional studies, studies of healthy children, and those without defined criteria for classifying weight status were excluded. The Newcastle-Ottawa Scale was used to assess study quality.

RESULTS

Twenty-eight studies (26 retrospective; 24 cohort and 4 case-control) were included. Of the 21 studies that included mortality as an outcome, 10 reported a significant positive relationship between obesity and mortality. The incidence of infections was assessed in 8 of the 28 studies; 2 reported significantly more infections in obese compared with nonobese patients. Of the 11 studies that examined length of stay, 5 reported significantly longer lengths of hospital stay for obese children. Fifteen studies (53%) had a high quality score. Larger studies observed significant relationships between obesity and outcomes. Studies of critically ill, oncologic or stem cell transplant, and solid organ transplant patients showed a relationship between obesity and mortality.

CONCLUSIONS AND RELEVANCE

The available literature on the relationship between obesity and clinical outcomes is limited by subject heterogeneity, variations in criteria for defining obesity, and outcomes examined. Childhood obesity may be a risk factor for higher mortality in hospitalized children with critical illness, oncologic diagnoses, or transplants. Further examination of the relationship between obesity and clinical outcomes in this subgroup of hospitalized children is needed.

Anthropometric growth and utilization of enteral feeding support in pediatric heart transplant recipients

We sought to outline trends in anthropometric growth before and after cardiac transplantation and to document our experience with the use of EFS in this population. A total of 130 patients (59% male) were enrolled and followed for a median of 4.4 yr after transplantation. Negative changes over time in weight z-score (EST: -0.256 [0.160] z/yr, p = 0.01), height z-score (EST: -0.214 [0.096] z/yr, p = 0.03), and BMI z-score (EST: -0.287 [0.161] z/yr, p = 0.07) were observed prior to transplantation. Significant increases in weight z-score (EST: +0.342 [0.143] z/yr, p < 0.001) and BMI z-score (EST: +0.396 [0.140] z/yr, p = 0.005) were seen in the first 18 months following transplantation. No further increases in height, weight, or BMI z-score were seen beyond this. Forty-two (32%) patients received EFS. Prior to transplantation, it was not found to be associated with change in anthropomorphic growth. Post-transplantation exposure to EFS was associated with a faster increase in weight z-score (EST: +0.480 [0.231] z/yr, p = 0.04) and height z-score over time (EST: +0.366 [0.141] z/yr, p = 0.01). Normalization of weight and height z-scores was not achieved during the study follow-up period. This study suggests that further investigation into the role of EFS is warranted to identify strategies to improve growth in pediatric heart transplant recipients.