Clinical Investigation
Mortality, Resource Utilization, and Inpatient Costs Vary Among Pediatric Heart Transplant Indications: A Merged Data Set Analysis From the United Network for Organ Sharing and Pediatric Health Information Systems Databases

https://doi.org/10.1016/j.cardfail.2018.11.014Get rights and content

Highlights

  • Children with congenital heart disease require substantially greater hospital resource utilization and have significantly worse outcomes during the first year after heart transplantation compared with other indications.

  • Specifically, transplant recipients with single-ventricle disease have a 12-fold increase in 1-year post-transplantation mortality compared with cardiomyopathy.

  • Using data from this merged cohort, further work is aimed at identifying modifiable pre-transplantation risk factors, such as pre-transplantation conditioning with ventricular assist device support and cardiac rehabilitation, to improve post-transplantation outcomes and reduce resource utilization in this complex population.

ABSTRACT

Background

Merging United Network for Organ Sharing (UNOS) and Pediatric Health Information Systems databases has enabled a more granular analysis of pediatric heart transplant outcomes and resource utilization. We evaluated whether transplant indication at time of transplantation was associated with mortality, resource utilization, and inpatient costs during the first year after transplantation.

Methods and Results

We analyzed transplant outcomes and resource utilization from 2004 to 2015. Patients were categorized as congenital (CHD), myocarditis, or cardiomyopathy based on UNOS-defined primary indication. CHD complexity subgroup analyses (single-ventricle, complex, and simple biventricular CHD) were also performed. Of 2251 transplants (49% CHD, 5% myocarditis, 46% cardiomyopathy), CHD recipients were younger (2 [IQR 0–10], 6 [IQR 0–12], and 7 [IQR 1–14] years, respectively; P < .001) and less likely to have a ventricular assist device (VAD) at transplantation (3%, 27%, and 13%, respectively; P < .001). Patients with single-ventricle CHD had the longest time on the waitlist and were least likely to receive a VAD before transplantation. After adjusting for patient-level factors, transplant recipients with single-ventricle CHD had the greatest mortality during transplantation admission and within 1 year (odds ratio [OR] 11.8 [95% confidence interval (CI) 5.9–23.6] and OR 6.0 [95% CI 3.6–10.2], respectively, vs cardiomyopathy). Mortality was similar between patients with myocarditis and cardiomyopathy. Post-transplantation length of stay (LOS) was longer in transplant recipients with CHD than myocarditis or cardiomyopathy (25 [interquartile range [IQR] 15–45] vs 21 [IQR 12–35] vs 16 [IQR 12–25] days; P < .001), related in part to longer duration of intensive care unit–level care (ICU LOS 8 [IQR 4–20] vs 6 [IQR 4–13] vs 5 [IQR 3–8] days; P < .001). Similarly, patients with CHD had higher median post-transplantation costs than myocarditis or cardiomyopathy ($415K [IQR $201K–503K] vs $354K [IQR $179K–390K] vs $284K [IQR $145K–319K]; P < .001) that persisted after adjusting for patient-level factors (adjusted cost ratio 1.4 [95% CI 1.4–1.5], CHD vs cardiomyopathy) and was primarily driven by longer LOS. More than 50% were readmitted during the first year after transplantation, although readmission rates were similar across transplant indications (P = .42).

Conclusions

Children with CHD, particularly single-ventricle patients, require substantially greater hospital resource utilization and have significantly worse outcomes during the first year after heart transplantation compared with other indications. Further work is aimed at identifying modifiable pre-transplantation risk factors, such as pre-transplantation conditioning with VAD support and cardiac rehabilitation, to improve post-transplantation outcomes and reduce resource utilization in this complex population.

Section snippets

Data Source

Data were obtained from a merged UNOS-PHIS cohort of pediatric transplant recipients at participating centers from 2004 to 2015. UNOS is a nonprofit organization that collects data on every organ transplantation since 1987 in the United States. Information collected in UNOS includes detailed pre- and post-transplantation demographic and clinical information for donors and recipients, such as primary diagnosis, severity status, and follow-up information regarding mortality. PHIS is an

Patient and Center Characteristics

A total of 2251 pediatric heart transplantations (49% CHD, 5% myocarditis, 46% cardiomyopathy) from 26 US centers were included in the analysis. Among recipients with CHD, 22% had single-ventricle disease and 55% simple biventricular CHD. The majority (86%) of transplantations occurred in medium- to high-volume centers, defined as >10 transplants per year, owing to center volume homogeneity among participating PHIS institutions. Pre-transplantation characteristics of the recipients and donors

Discussion

This merged UNOS-PHIS data set has enabled a comprehensive evaluation of both pre-transplantation characteristics and post-transplantation outcomes and resource utilization among heart transplant indications in more than 2,200 pediatric heart transplantations in 26 US centers over the past decade. As hypothesized, CHD has greater resource utilization and inpatient costs despite poorer outcomes compared with other transplant indications, even after adjusting for pre-transplantation patient-level

Study Limitations

This study has several limitations. It is a retrospective observational analysis from a large multicenter cohort. Although patient-level factors were adjusted for in our analyses, there may be factors that were not captured and thus could not be included in our analysis. We identified that most transplantations in our cohort occurred at moderate- to large-volume transplant centers based on the represented centers participating in PHIS. We think that our findings are valid for centers of similar

Conclusion

Children with CHD, particularly single-ventricle disease, have poorer outcomes despite increased resource utilization and costs during the first year after transplantation compared with children with cardiomyopathy and myocarditis. Data from this merged database—UNOS combined with PHIS, an administrative hospital database—have enabled more granular pre- and post-transplantation analysis of patient- and center-level factors in children. Further work is aimed at identifying modifiable

Disclosures

None.

Previous Presentation

This study was presented at the 67th Annual Meeting and Scientific Session of the American College of Cardiology, Orlando, Florida, March 10–12, 2018, and the 38th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation, Nice, France, April 11–14, 2018.

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