Geographic Distance From Transplant Center Does Not Impact Pediatric Heart Transplant Outcomes.

BACKGROUND: Many pediatric heart transplant recipients live a significant distance from their transplant center. This results in families either traveling long distances or relying on outside physicians to assume aspects of their care. Distance has been implicated to play a role in congenital heart disease outcomes, but its impact on heart transplantation has not been reported. The aim of this study was to assess the impact of distance on pediatric heart transplant outcomes. METHODS: The Scientific Registry of Transplant Recipients database was queried for all pediatric heart transplant recipients from large US children's hospitals (1987-2014). Patients were stratified into 4 groups (<20, 20-50, 50-100, and >100 miles) based on distance. Survival curves were generated and compared using the log-rank test. Cox proportional hazards regression was performed to adjust for differences between groups. RESULTS: A total of 4768 patients were included in the analysis, of which 1435 (30.1%) were <20 miles, 940 (19.7%) were 20 to 50 miles, 806 (16.9%) were 50 to 100 miles, and 1587 (33.3%) were >100 miles from their transplant center. There was no difference in posttransplant survival based on distance after adjusting for patient age, gender, ethnicity, blood type, diagnosis, listing status, and the need for pretransplant ventricular assist device, extracorporeal membrane oxygenation, or ventilator support. CONCLUSION: There is no significant difference in graft survival after pediatric heart transplantation based on patient distance from their transplant center. Our data suggest the current strategy of transitioning some aspects of transplant care to local physicians or management from a distance does not increase posttransplant mortality risk.

The impact of cognitive delay on pediatric heart transplant outcomes.

The presence of CD may be viewed as a relative contraindication to transplantation; however, its impact on pediatric HTx outcomes is poorly characterized. The aim of this study was to assess the impact of CD on pediatric HTx outcomes using academic progress as a surrogate measure of cognitive performance. The OPTN database was queried for all pediatric HTx recipients (2004-2014) with reported academic progress. Multivariable analysis assessed the impact of DGL and the need for SE on post-HTx graft survival. A total of 2245 children were included: 1707 (76%) within grade level, 269 (12%) with DGL, and 269 (12%) who required SE. The need for SE was not a risk factor for post-HTx mortality; however, DGL was an independent risk factor for worse post-HTx outcomes (AHR 1.4, 95% CI 1.02, 1.79, P=.03). Patients who require SE have similar outcomes compared to those without CD, likely secondary to significant parental involvement. Children with DGL demonstrate inferior post-HTx survival, which could result from less parental oversight in children perceived to maintain compliance. Ensuring adequate social support for patients with evidence of CD may help to improve outcomes.

Regional variation in the use of 1A status exceptions for pediatric heart transplant candidates: is this equitable?

The use of status exceptions (SE) was recently publicized as a strategy to reduce waitlist times for children awaiting heart transplant (HTx). The aim of this study was to assess SE use across UNOS regions and compare survival in patients listed using a SE to those listed by standard criteria. The OPTN database was queried for all pediatric patients listed for HTx (2000-2014). SE use was compared across UNOS regions. Survival curves were generated and compared using the log-rank test. 1A SE use is uncommon, being utilized in 108 of 4587 pediatric 1A listings (2.4%). There is significant variability in SE use across UNOS regions (0.7%-16.4% of 1A listings, P < .001). Waitlist survival is significantly higher in candidates listed using a 1A SE compared to those listed by standard criteria (P = .001) and is similar to 1B listings. Regional variation in 1A SE use has the potential to introduce bias into a system designed to be equitable. Waitlist survival in patients listed using a SE is similar to those listed status 1B, suggesting these patients may not require 1A status. Careful review of pediatric heart allocation policies is needed to optimize patient outcomes and ensure a fair and unbiased allocation system.

Expanding the donor pool: regional variation in pediatric organ donation rates.

There are limited published data on pediatric organ donation rates. The aim of this study was to describe the trends in pediatric organ donation over time and to assess the regional variation in pediatric deceased organ donation. OPTN data were utilized to assess the trends in pediatric organ donation over time. The number of deceased pediatric organ donors was indexed using regional mortality data obtained from the National Center for Health Statistics and compared across UNOS regions and two different eras. The number of pediatric deceased organ donors has declined in the recent era, largely driven by fewer adolescent donors. For all age groups, there is significant regional variation in organ donation rates, with identifiable high- and low-performing regions. Expansion of the donor pool may be possible by optimizing organ donation in regions demonstrating lower recruitment of pediatric donors. Using the region with the highest donation rate for each age group as the gold standard, we estimate a potential 24% increase in the number of donors if all regions performed comparably, equating to 215 new pediatric donors annually.

Risk factors for the development of donor-specific antibodies after pediatric heart transplantation.

DSA after HTx may have adverse effects on patient survival. The aim of this study was to assess risk factors for the development of DSA after pediatric HTx. All HTx recipients at our center with serial monitoring of DSA were identified. Cox proportional hazards model was used to estimate donor and recipient characteristics associated with the development of DSA. De novo DSA were detected in 40 (33%) of 121 HTx recipients. Characteristics associated with de novo DSA included older age, African American race, prior operations, prior ECMO, PRA > 10%, longer bypass time, mechanical support at transplant, and donor death from GSW. In a multivariable model, mechanical support (HR 3.23, 95% CI [1.02, 8.87]), African American race (HR 3.36, 95% CI [1.68, 7.32]), and donor death from GSW (HR 4.76, 95% CI [1.62, 14.01]) were significantly associated with DSA. Multiple factors appear to play a role in the development of DSA, knowledge of which may guide the frequency of post-transplant monitoring. DSA develop more frequently in those with prior sensitizing events, suggesting the possibility that these exposures predispose the immune system to respond to donor antigens, even in the presence of a negative cross-match.

Does Body Mass Index Predict Premature Cardiomyopathy Onset for Duchenne Muscular Dystrophy?

Duchenne muscular dystrophy leads to cardiomyopathy. The objective of this study was to estimate the association of body mass index with cardiomyopathy onset. Cardiomyopathy was defined as left ventricular ejection fraction <55% or left ventricular fractional shortening <28%. Overall, 48% met the criteria for cardiomyopathy. We were unable to demonstrate an association between body mass index Z score and age of cardiomyopathy onset (hazard ratio 0.79, 95% confidence interval 0.57-1.11, P = .17) after adjusting for covariates. Duration of corticosteroid use ( P = .01), but not loss of ambulatory ability ( P = .47), was associated with age of cardiomyopathy onset. We were unable to detect a significant difference in median body mass index Z scores in corticosteroid-treated boys compared with corticosteroid-naïve boys (1.11, 95% confidence interval 0.25-1.95, vs 1.05, 95% confidence interval 0.01-1.86, P = .69). No association was detected between the body mass index Z scores of Duchenne muscular dystrophy subjects and age of cardiomyopathy onset.