Early Persistent Kidney Injury and Long-Term Outcomes Following Lung Transplantation

Acute kidney injury (AKI) following lung transplantation is associated with long-term outcomes. Although AKI is diagnosed based on absolute creatinine, this level may not reliably reflect kidney function due to reduced muscle mass in this population. Thus, this study investigated persistent kidney injury, defined by early creatinine trajectories, and its association with long-term outcomes regardless of AKI diagnosis.

In this retrospective study of adult lung-transplant recipients, we used linear mixed-effects models to compare first-week creatinine trajectories between patients based on the development of adverse long-term outcomes, specifically 2-year chronic kidney disease (CKD) and major adverse kidney events (MAKE). We also assessed the association between Day 7/Baseline Creatinine Ratio and these outcomes using multivariable logistic regression.

Among 150 recipients, 26% developed postoperative AKI. Although none had preoperative CKD, 60% of AKI patients and 40% of non-AKI patients developed postoperative CKD. Those who developed CKD showed a significantly slower decline in creatinine over the first week compared to patients who did not (difference: 0.17 mg/dL/week, p < 0.001), consistent in patients with and without AKI. Day 7/Baseline Creatinine Ratio was significantly higher in patients with adverse outcomes and independently predicted both 2-year CKD (Adjusted Odds Ratio: 4.54, p = 0.017) and MAKE (Adjusted Odds Ratio: 3.84, p = 0.026).

Early persistent kidney injury was associated with adverse long-term outcomes following lung transplantation, regardless of AKI diagnosis. Day 7/Baseline Creatinine Ratio may serve as an early prognostic marker for risk stratification at the bedside or in clinical research.