Pre-transplant risk factors for chronic renal dysfunction after pediatric heart transplantation: a 10-year national cohort study.

BACKGROUND: Chronic renal dysfunction may develop after pediatric heart transplantation (PHTx). We examined the incidence of end-stage renal disease (ESRD) and chronic renal insufficiency (CRI) after PHTx, the associated pre-transplant patient characteristics, and impact of renal disease on survival. METHODS: Data sources included the Scientific Registry of Transplant Recipients, Centers for Medicare and Medicaid Services and the Social Security Death Master File. All PHTx recipients (age <18 years) in the USA from 1990 to 1999 who survived >1 year were included. ESRD was defined as long-term dialysis and/or kidney transplant. CRI was defined as creatinine >2.5 mg/dl, including those with ESRD. Relationships between pre-transplant characteristics and time to ESRD and CRI were analyzed using Cox proportional hazards models. The effect of renal disease on survival was analyzed using time-dependent Cox models. RESULTS: During the mean follow-up of 7 years (range 1 to 14 years), 61 of 2,032 (3%) PHTxs developed ESRD. Ten-year actuarial risks for ESRD and CRI were 4.3% and 11.8%, respectively. In a multivariate analysis, significant risk factors for ESRD were: hypertrophic cardiomyopathy; African-American race; intensive care unit (ICU) stay or extracorporeal membrane oxygenation (ECMO) at time of transplant; and pre-transplant diabetes. Risk factors for CRI were: pre-transplant dialysis; hypertrophic cardiomyopathy; African-American race; and previous transplant. Adjusted risk of death in those who developed CRI was 9-fold higher than in those who did not (p < 0.0001). CONCLUSIONS: After PHTx there is an increasing risk for CRI and ESRD over time. Recipients with the characteristics identified in this study may be at greater risk. Development of renal disease significantly increases the risk of post-transplant mortality.

Development and current status of ECD kidney transplantation.

The worsening shortage of donor kidneys for transplant and the aging of both the donor and candidate populations have contributed to the increasing importance of ECD kidney transplantation. While ECD transplants have an increased risk of graft failure, for most candidates patient survival is still improved over remaining on dialysis. Because of this risk, however, ECD kidneys have a high likelihood of discard; significant geographic variation in discard and transplant rates impedes maximum utilization of these kidneys. The ECD allocation system was implemented to help facilitate expeditious placement of ECD kidneys to pre-consented candidates by a simplified allocation algorithm. Under this system, recovery and transplantation of ECD kidneys have increased at rates not seen with non-ECD kidneys and not predicted by preexisting trends. More disappointing has been the lack of effect on the percentage of discards and DGF, despite significant reductions in CIT. The disadvantage in graft survival for ECD kidneys extends equally across the spectrum of recipient characteristics, such that no one group of candidates has a proportionately smaller increase in risk. However, benefit analyses comparing the risk of accepting an ECD kidney versus waiting for a non-ECD kidney demonstrate a significant ECD benefit for older and diabetic candidates in regions with prolonged waiting times. The potential value of an ECD kidney to an individual candidate hinges upon the ability to receive it substantially earlier than a non-ECD kidney. Thus, future allocation efforts may focus on ensuring that is the case. In allocation driven by net benefit, ECD kidneys may become an alternative for those who might not otherwise receive a kidney transplant.