Renal Resistive Index as a Novel Predictor of Contrast-Induced Acute Kidney Injury in Cirrhosis

Patients with liver cirrhosis undergo repeated contrast-enhanced imaging procedures. We investigated the risk factors for contrast-induced acute kidney injury (CI-AKI) in cirrhotic patients with normal renal function.

A prospective observational cohort study included 110 consecutive patients with cirrhosis who underwent iodinated contrast (IC)-based imaging procedures. Baseline demographic, clinical, and laboratory data and Renal Resistive Index (RRI) were recorded prior to imaging. All patients were assessed for the development of CI-AKI 48-72 hours after contrast administration.

A total of 34 (30.9%) patients developed CI-AKI after contrast administration. Prior history of acute kidney injury (AKI) was seen in 18 (52.9%) patients who developed CI-AKI and 4 (5.3%) patients who did not develop CI-AKI (p < 0.001). Alcohol-related liver disease was the major etiological factor of cirrhosis in 18 (52.9%) patients with CI-AKI as opposed to 23 (30.3%) patients without CI-AKI (p = 0.047). Baseline estimated glomerular filtration rate (eGFR) and serum creatinine levels were not associated with an increased risk of CI-AKI. Higher values of baseline RRI were seen in patients who developed CI-AKI. On univariate analysis, gender, prior history of AKI, grade III ascites, hepatic encephalopathy, Child-Turcotte-Pugh (CTP) score, Model for End-Stage Liver Disease-Sodium (MELD-Na), and Renal Resistive Index (RRI) were found to be significant risk factors for predicting CI-AKI. On multivariate analysis, Renal Resistive Index (RRI), CTP score, and MELD-Na score were associated with an increased risk of CI-AKI. Preprocedural RRI >0.62, CTP score >10, and MELD-Na >24 had significant predictive value for the occurrence of CI-AKI.

Advanced liver cirrhosis was associated with an increased risk of CI-AKI. RRI is an easily available and simple radiologic technique to predict the occurrence of CI-AKI among patients with liver cirrhosis with normal renal function tests.