UCSF

Background & aims

Renal dysfunction increases risk of death for patients with cirrhosis. We investigated whether mortality differs significantly among patients with acute kidney injury (AKI), chronic kidney disease (CKD), and both.

Methods

We performed a retrospective analysis of all non-status 1 adults on the waitlist for liver transplantation for at least 90 days, collected from the Organ Procurement and Transplantation Network registry from July 1, 2007 through July 1, 2014. We assigned patients to groups of AKI (an increase of ≥0.3 mg/dL or ≥50% in serum creatinine in the last 7 days or fewer than 72 days of hemodialysis), CKD (an estimated glomerular filtration rate <60 ml/min/1.73 m² for 90 days with a final rate ≥30 ml/min/1.73 m² or ≥72 days of hemodialysis), AKI and CKD (meet both definitions), or normal (meet neither definition). We performed competing risk analyses to associate patterns of renal dysfunction with waitlist mortality, accounting for liver transplantation, with renal pattern as a time-dependent covariate. Logistic regression for 6-month mortality determined the added benefit of including renal function pattern in the assessment.

Results

There were 22,680 patients in the cohort; they spent a median 1.6 years (range, 0.7-3.1 years) on the waitlist and a median 5 years (range, 2-9 years) undergoing assessments of renal function. In competing risk analysis, even after adjusting for confounders including final model for end-stage liver disease sodium (MELD-Na) scores, the pattern of renal function was significantly associated with waitlist mortality: AKI and CKD (subhazard ratio [SHR], 2.86; 95% CI, 2.65-3.10), AKI (SHR, 2.42; 95% CI 2.22-2.64), CKD (SHR, 1.56; 95% CI, 1.45-1.67) compared with normal. The area under the curve values, based on MELD-Na score at time of placement on the waitlist, were 0.80 with renal function pattern and 0.71 without (P < .001).

Conclusion

In competing risk analysis, even after adjusting for confounders including final MELD-Na score, we found the pattern of renal dysfunction to associate with mortality in patients with cirrhosis. Including information on type of renal dysfunction could improve risk analysis.