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A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation
Published on: April 27, 2019
Survival does not differ by annual center transplant volume-A Pediatric Heart Transplant Society Registry study
A Marion Ybarra1, Alicia M Kamsheh1, Matthew J O'Connor2
1Department of Pediatrics, Division of Pediatric Cardiology, Washington University in St. Louis, St. Louis, Missouri, USA.
Insights
Pediatric heart transplant center volume does not impact patient survival or graft loss, even for high-risk congenital heart disease (CHD) patients. Outcomes were similar across centers of all sizes in this large registry study.
Area of Science:
- Pediatric Cardiology
- Transplantation Medicine
- Health Services Research
Background:
- Conflicting data exist on the relationship between pediatric heart transplant center volume and patient outcomes.
- Previous studies may not have adequately addressed case mix differences, particularly in high-risk congenital heart disease (CHD) populations.
- Understanding the impact of center volume on outcomes is crucial for optimizing pediatric heart transplantation.
Purpose of the Study:
- To evaluate the association between pediatric heart transplant center volume and patient outcomes.
- To investigate whether case mix influences the relationship between center volume and outcomes.
Main Methods:
- Retrospective cohort study utilizing the Pediatric Heart Transplant Society (PHTS) Registry (2009-2018).
- Centers categorized into five groups based on average annual heart transplant volume.
- Primary outcome: time to death or graft loss, analyzed using Kaplan-Meier methods.
Main Results:
- Analysis of 4583 pediatric heart transplants across 55 centers revealed no significant difference in survival or graft loss based on center volume.
- This finding held true for the overall cohort, as well as for patients with congenital heart disease (CHD) and cardiomyopathy.
- No volume-outcome relationship was observed for patients undergoing transplantation post-Norwood, Glenn, or Fontan procedures, except for a significant difference in positive crossmatch cases without a clear volume pattern.
Conclusions:
- Pediatric heart transplant outcomes are comparable across centers of all sizes, including for high-risk CHD patients.
- Further research is required to explore patient-specific risk factors and their variation among centers of different volumes.
Background:
There are conflicting data regarding the relationship between center volume and outcomes in pediatric heart transplantation. Previous studies have not fully accounted for differences in case mix, particularly in high-risk congenital heart disease (CHD) groups. We aimed to evaluate the relationship between center volume and outcomes using the Pediatric Heart Transplant Society (PHTS) Registry and explore how case mix may affect outcomes.
Methods:
A retrospective cohort study of all pediatric patients in the PHTS Registry who received a heart transplant from 2009 to 2018 was performed. Centers were divided into 5 groups based on average yearly transplant volume. The primary outcome was time to death or graft loss and outcomes were compared using Kaplan-Meier analysis.
Results:
There were 4583 cases among 55 centers included. There was no difference in time to death or graft loss by center volume in the entire cohort (p = .75), in patients with CHD (p = .79) or in patients with cardiomyopathy (p = .23). There was also no difference in time to death or graft loss by center size in patients undergoing transplant after Norwood, Glenn or Fontan (log rank p = .17, p = .31, and p = .10 respectively). There was a statistically significant difference in outcomes by center size in the positive crossmatch group (p < .0001), though no discernible pattern related to high or low center volume.
Conclusions:
Outcomes are similar among transplant centers of all sizes, including for high-risk patient groups with CHD. Future work is needed to understand how patient-specific risk factors may vary among centers of various sizes and whether this influences patient outcomes.
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