CKD Progression following Acute Kidney Injury: A Secondary Analysis of the STARRT-AKI Trial.

Background: Chronic kidney disease (CKD) is a common complication after acute kidney injury (AKI). We aimed to evaluate whether RRT initiation strategy had an effect on CKD progression. Secondarily, we aimed to identify factors that influenced the development or progression of CKD following severe AKI.

Methods: This secondary analysis of the STARRT-AKI trial included participants with outpatient serum creatinine values available in the year prior to hospitalization and who were alive at 90 days following randomization. Our main analysis focused on patients who had definitive assessment of kidney function at 90 days following randomization. Predictor markers included patient demographics, co-morbidities, markers of acute illness, laboratory values, receipt of renal replacement therapy (RRT), and RRT treatment strategy (accelerated versus standard). The primary outcome was CKD progression, a composite of de novo CKD, defined as new eGFR < 60 ml/min/1.73 m2 if baseline eGFR was ≥ 60 ml/min; a decline in eGFR ≥ 25% if baseline eGFR was < 60 ml/min, or RRT dependence at day 90. The association of RRT treatment strategy with CKD progression was assessed in an unadjusted mixed-effect logistic regression model.

Results: Of the 401 surviving patients with a baseline serum creatinine, 39% experienced CKD progression. RRT initiation strategy had no effect on CKD progression (accelerated arm (41%), vs. the standard arm (38%), Odds ratio 1.13, (95% confidence interval 0.75 to 1.72)). Receipt of RRT and aortic surgery were the most potent risks of CKD progression.

Conclusion: These findings suggest that CKD progression is common after severe AKI. Risk factors for CKD progression included receipt of RRT and aortic surgery, suggested that these individuals should be prioritized for dedicated kidney follow up after hospital discharge.