Heart-kidney transplants linked to better outcomes compared to heart-only transplants in children with non-dialysis-dependent advanced chronic kidney disease.

BACKGROUND

Chronic kidney disease (CKD) causes significant morbidity and mortality among children with heart failure. Although the survival benefit of a simultaneous heart-kidney transplant has been demonstrated in children with heart failure undergoing dialysis [1], the optimal intervention, simultaneous heart-kidney transplant or heart-only transplant, in those with advanced CKD but not requiring dialysis remains uncertain (Choudhry et al. Pediatr Transplant 26:e14149, 2022).

METHODS

Using the Scientific Registry of Transplant Recipients (SRTR), we identified all pediatric heart transplant recipients (age ≤ 18 years) who were transplanted between 1989 and 2022 with an estimated glomerular filtration rate (eGFR) of less than 45 mL/min/1.73 m2 at the time of transplant. We categorized the cohort into simultaneous heart-kidney (n = 21) and heart-only recipients (n = 839). To compare patient and graft survival between these groups, we created a weighted comparison group of heart-only recipients using covariate-balancing propensity scores. The characteristics balanced included the year of transplant, age at transplant, sex, race, HLA mismatch, cause of heart disease, previous heart transplant, and immunosuppression. Survival was analyzed 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

In children awaiting a heart transplant with advanced non-dialysis-dependent CKD (eGFR < 45 ml/min/1.73 m2), a simultaneous heart-kidney transplant is associated with higher patient and heart graft survival compared to a heart-only transplant.