Heart-Kidney Transplants Linked to Better Outcomes Compared to Heart-Only Transplants in Children with Non-Dialysis-Dependent Advanced Chronic Kidney Disease

TL;DR

Heart-kidney transplants in children with advanced kidney disease lead to better survival than heart-only transplants.

Contribution

Demonstrates improved outcomes with simultaneous heart-kidney transplants in pediatric CKD patients.

Findings

Heart-kidney recipients had significantly higher patient survival compared to heart-only recipients.

Heart graft survival was also significantly better in heart-kidney transplant recipients.

Results were derived from a propensity-score-weighted analysis of pediatric transplant data.

Abstract

Background
Chronic kidney disease (CKD) significantly contributes to morbidity and mortality in children awaiting a heart transplant. The optimal approach to managing advanced CKD (stage 3b or higher) in children with heart failure—whether simultaneous heart-kidney transplant or heart-only transplant—remains unclear.
Method
Using the Scientific Registry of Transplant Recipients (SRTR), we identified all pediatric heart transplant recipients (age ≤ 18 years) with an estimated glomerular filtration rate (eGFR) of < 45 mL/min/1.73 m² at the time of transplant. We then divided the cohort into simultaneous heart-kidney recipients (n = 21) and heart-only recipients (n = 839). To evaluate patient and graft survival, we created a weighted comparison group of heart-only recipients using covariate-balancing propensity scores. Characteristics that were balanced included year of transplant, age at transplant, sex, race, HLA mismatch, cause of heart disease, previous heart transplant, and immunosuppression. We compared patient and heart graft survival between simultaneous heart-kidney and weighted heart-only groups using weighted Cox regression.
Results
We observed significantly higher patient survival (HR: 0.29; 95% CI: 0.1–0.81; p = 0.02) and heart graft survival (HR: 0.24; 95% CI: 0.08–0.67; p = 0.002) in simultaneous heart-kidney recipients compared to propensity-score-weighted heart-only recipients.
Conclusions
Compared to heart-only transplants, simultaneous heart-kidney transplants are associated with higher patient and heart graft survival in children with non-dialysis-dependent CKD stage 3b or higher.