Long-term impact of dialysis-requiring AKI during the perioperative period of liver transplantation on postdischarge outcomes

Hospital readmission for acute kidney injury is independently associated with de novo end-stage renal disease after liver transplantation

End-stage renal disease (ESRD) after liver transplantation (LT) is associated with high morbidity and mortality. The consequences of hospitalizations for post-LT acute kidney injury (AKI) are poorly understood. Using linked Medicare claims and transplant registry data, we analyzed adult liver alone recipients not receiving pretransplant dialysis between January 1, 2007, and December 31, 2016. Covariate-adjusted Cox proportional hazards models stratified by center evaluated factors associated with AKI readmission during the first post-LT year, and whether AKI readmission was associated with de novo early (<1 y) or late (≥1 y) ESRD post-LT. The cohort included 10,559 patients and was 64.5% male, 72.5% White, 8.1% Black, and 14.0% Hispanic with median age 62 years. Overall, 2875 (27.2%) patients had ≥1 AKI hospitalization during the first year. Estimated glomerular filtration rate at LT was associated with AKI readmission (adjusted HR: 1.16 per 10 mL/min/1.73m 2 decrease; p <0.001). The adjusted HR for early ESRD in patients with ≥1 AKI readmission <90 days post-LT was 1.90 ( p <0.001). The adjusted HRs for late ESRD with 1 and ≥2 prior AKI readmissions were 1.57 and 2.80, respectively ( p <0.001). AKI readmissions in the first post-LT year impact over one-quarter of recipients. These increase the risk of subsequent ESRD, but may represent an opportunity to intervene and mitigate further renal dysfunction.

The type, duration, and severity of pretransplant kidney injury predict prolonged kidney dysfunction after liver transplantation

Chronic kidney disease (CKD) is a major complication of liver transplantation (LT) associated with substantial morbidity and mortality. Knowing the drivers of post-LT kidney dysfunction-with a granular focus on the type, duration, and severity of pre-LT kidney disease-can highlight intervention opportunities and inform dual-organ allocation policies. We retrospectively analyzed predictors of safety net kidney after liver transplant (KALT) eligibility and kidney replacement therapy (KRT) for > 14 days after LT. Among 557 recipients of adult deceased-donor LT, 49% had normal kidney function, 25% had acute kidney injury (AKI), and 25% had CKD±AKI at the time of LT. A total of 36 (6.5%) qualified for KALT and 63 (11%) required KRT > 14 days. In univariable analysis, factors associated with KALT eligibility and KRT > 14 days, respectively, included stage 3 AKI (OR 7.87; OR 7.06), CKD±AKI (OR 4.58; OR 4.22), CKD III-V duration (OR 1.10 per week; OR 1.06 per week), and increasing CKD stage (stage III: OR 3.90, IV: OR 5.24, V: OR 16.8; stage III: OR 2.23, IV: OR 3.62, V: OR 19.4). AKI stage I-II and AKI duration in the absence of CKD were not associated with the outcomes. Pre-LT KRT had a robust impact on KALT eligibility (OR 4.00 per week) and prolonged post-LT KRT (OR 5.22 per week), with 19.8% of patients who received any pre-LT KRT ultimately qualifying for KALT. Eligibility for KALT was similar between those who received 0 days and ≤ 14 days of KRT after LT (2.1% vs. 2.9%, p = 0.53). In conclusion, the type, duration, and severity of pre-LT kidney dysfunction have unique impacts on post-LT kidney-related morbidity, and future research must use these novel classifications to study mitigation strategies.

Impact of Renal Replacement Therapy on Rejection among Liver Transplant Recipients

Introduction: Renal dysfunction in liver transplant recipients is associated with an increased risk of morbidity and mortality, with an even higher risk among patients requiring renal replacement therapy. There is limited data evaluating rejection outcomes in patients requiring renal replacement therapy after liver transplant. Program evaluation aims: To evaluate the incidence of biopsy-proven acute rejection, recipient and graft survival, infection, renal dysfunction, and immunosuppression practices. Design: This was a single-center, retrospective, cohort study. To be eligible, patients were deceased donor liver transplant recipients ≥18 year of age transplanted between January 2017 and August 2019 who received steroid-only induction and tacrolimus as part of their initial immunosuppression regimen. Results: Recipients that required renal replacement therapy (N  =  86) were compared to those who received no renal replacement therapy (N  =  158). Biopsy-proven acute rejection at 1-year posttransplant was significantly higher among those requiring renal replacement therapy (36% vs 13%, P < .001). Patient survival at 12 months was 77% for those requiring renal replacement therapy and 94% for those not requiring renal replacement therapy (P < .001). Infection (HR 3.8, 95% CI 1.6-8.8; P < .001), but not rejection (HR 0.7, 95% CI 0.3-1.7; P  =  .5) was an independent predictor of mortality. The use of renal replacement therapy after liver transplant necessitated careful titration of immunosuppression to balance the detrimental risks of infection versus rejection in this high-risk population.

Modelling kidney outcomes based on MELD eras - impact of MELD score in renal endpoints after liver transplantation

Background

Acute kidney injury is a common complication in solid organ transplants, notably liver transplantation. The MELD is a score validated to predict mortality of cirrhotic patients, which is also used for organ allocation, however the influence of this allocation criteria on AKI incidence and mortality after liver transplantation is still uncertain.

Methods

This is a retrospective single center study of a cohort of patients submitted to liver transplant in a tertiary Brazilian hospital: Jan/2002 to Dec/2013, divided in two groups, before and after MELD implementation (pre-MELD and post MELD). We evaluate the differences in AKI based on KDIGO stages and mortality rates between the two groups.

Results

Eight hundred seventy-four patients were included, 408 in pre-MELD and 466 in the post MELD era. The proportion of patients that developed AKI was lower in the post MELD era (p 0.04), although renal replacement therapy requirement was more frequent in this group (p < 0.01). Overall mortality rate at 28, 90 and 365 days was respectively 7%, 11% and 15%. The 1-year mortality rate was lower in the post MELD era (20% vs. 11%, p < 0.01). AKI incidence was 50% lower in the post MELD era even when adjusted for clinically relevant covariates (p < 0.01).

Conclusion

Liver transplants performed in the post MELD era had a lower incidence of AKI, although there were more cases requiring dialysis. 1-year mortality was lower in the post MELD era, suggesting that patient care was improved during this period.

Pediatric length-of-stay index following liver transplantation

BACKGROUND

PELD scores are used to reduce waitlist mortality, but they do not accurately predict likelihood of prolonged length-of-stay or higher costs associated with it. This study aims to create a pediatric length-of-stay (LOS) index to predict increased risk of prolonged stay following liver transplantation.

METHODS

The scoring system generated predicts length-of-stay following pediatric liver transplantation. With univariate and multivariate analyses on data from 5669 pediatric liver transplant recipients, independent recipient/donor risk factors for prolonged stay (>30 days) were identified. Multiple imputations accounted for missing variables.

RESULTS

The most significant factors were ICU admission (OR 2.92, CI 2.27-3.75), recipient bilirubin >32 (OR 2.35, CI 1.70-3.25), and hemodialysis 1 week before transplantation (OR 2.27, CI 1.57-3.27). The LOS index assigns weighted scoring points to factors to predict prolonged stay (C-statistic of .72). The index demonstrated discrimination across the population after dividing it into quartiles for prolonged stay.

CONCLUSIONS

The pediatric LOS index, utilizing 13 donor/recipient factors, can assess the risk for pediatric liver transplantation prolonged stay. Important predictive factors are hemodialysis, ICU admission, recipient weight and bilirubin, and recipient life support status.