Risk of acute kidney injury after contrast-enhanced computerized tomography: a systematic review and meta-analysis of 21 propensity score–matched cohort studies

Abstract

Objectives Intravenous application of contrast media is part of a wide spectrum of diagnostic procedures for better imaging quality. Clinical avoidance of contrast-enhanced imaging is an ever-present quandary in patients with impaired kidney function. The objective of this study was to estimate the risk for acute kidney injury (AKI), dialysis and mortality among patients undergoing contrast-enhanced CT compared to propensity score–matched controls (i.e. contrast-unenhanced CT). Selected cohort studies featured high-risk patients with advanced kidney disease and critical illness. Methods This review was designed to conform to the Preferred Reporting Items in Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed was searched from August 2021 to November 2021 for all-language articles without date restriction. A random-effects model (DerSimonian and Laird method) was used for meta-analysis. Results Twenty-one articles were included, comprising data of 169,455 patients. The overall risk of AKI was similar in the contrast-enhanced and unenhanced groups (OR: 0.97 [95% CI: 0.85; 1.11], p = 0.64), regardless of baseline renal function and underlying disease. Substantial heterogeneity was detected (I2 = 90%, p ≤ 0.0001). Multivariable logistic regression identified hypertension (p = 0.03) and estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m2 (p = 0.0001) as factors associated with greater risk of post-contrast AKI. Conclusions Based on propensity score–matched pairs obtained from 21 cohort studies, we found no evidence for increased risk for AKI, dialysis or mortality after contrast-enhanced CT among patients with eGFR ≥ 45 mL/min/1.73 m2. In congruence with the emerging evidence in the literature, caution should be exercised in patients with hypertension and eGFR ≤ 30 mL/min/1.73 m2. Key Points • The application of contrast media for medical imaging is not associated with higher odds for AKI, induction of renal replacement therapy, or mortality. Many comorbidities traditionally associated with greater risk for acute kidney injury do not appear to predispose for renal decline after contrast media exposure. • Underlying hypertension and eGFR less than or equal to 30 mL/min/1.73 m2seem to predispose for post-contrast acute kidney injury. • Propensity score matching cannot account for unmeasured influences on AKI incidence, which needs to be addressed in the interpretation of results.

Repeated Dose of Contrast Media and the Risk of Contrast-Induced Acute Kidney Injury in a Broad Population of Patients Hospitalized in Cardiology Department

“…In the meta-analysis by Obed et al [ 15 ] comprising the data of 169,455 patients, computed tomography with CM usage was not associated with a higher risk of AKI (OR: 0.97, 95%CI: 0.85–1.11, p = 0.64). Only hypertension and an eGFR of ≤30 mL/min/1.73 m 2 predisposed patients to the development of CI-AKI.…”

Current applications of algorithmic artificial intelligence in interventional radiology: A review of the literature

“…58 However, several radiology organisations are revising how contrast-enhanced studies are implicated in acute kidney injury. 59,60…”

Revised Swedish guidelines on intravenous iodine contrast medium-induced acute kidney injury 2022: A summary

“…Due to new information in these studies, the 2018 Swedish guidelines regarding CI-AKI following CT were revised during 2022. This revision is based on: A 2022 systematic review and meta-analysis of 21 retrospective propensity score-matched controlled studies regarding the risk of AKI after contrast medium (CM)-enhanced and unenhanced CT (2) revealed the following: (i) an increased risk of AKI after CM-enhanced CT compared with controls undergoing unenhanced CT in patients with an estimated glomerular filtration rate eGFR) <30 mL/min/1.73 m 2 (odds ratio [OR] = 1.68, 95% confidence interval [CI] = 1.29–2.19; P = 0.0001) with an absolute risk increase of 4%; and (ii) no evidence of an increased risk of AKI, dialysis, or mortality after CM-enhanced CT in patients with an eGFR ≥45 mL/min/1.73 m 2 , without comments regarding the eGFR interval of 30–44 mL/min/1.73 m 2 . A 2021 multicenter emergency department propensity score-matched study (3) of approximately 68,000 patients revealed the following: (i) an increased risk of AKI withing 48–72 h and dialysis within one month after CM-enhanced CT in patients with eGFR <45 mL/min/1.73 m 2 compared with the non-enhanced CT group; and (ii) no evidence of an increased risk of AKI or dialysis after CM-enhanced CT in patients with an eGFR ≥45 mL/min/1.73 m 2 . A systematic review performed by the Radiological Society of the Netherlands graded retrospective propensity score-matched controlled CT studies as low evidence due to risk of selection bias between the CM-enhanced and non-enhanced group (4). Thus, the scientific evidence is still uncertain regarding toxicity of intravenous CM. The total post-CM-induced incidence of AKI in four randomized hydration protocol studies (Tables 1 and 2) of elective examinations (95% outpatients) including CT (n = 1613), and peripheral and coronary angiography and interventions (n = 289).…”

“…A 2022 systematic review and meta-analysis of 21 retrospective propensity score-matched controlled studies regarding the risk of AKI after contrast medium (CM)-enhanced and unenhanced CT (2) revealed the following: (i) an increased risk of AKI after CM-enhanced CT compared with controls undergoing unenhanced CT in patients with an estimated glomerular filtration rate eGFR) <30 mL/min/1.73 m 2 (odds ratio [OR] = 1.68, 95% confidence interval [CI] = 1.29–2.19; P = 0.0001) with an absolute risk increase of 4%; and (ii) no evidence of an increased risk of AKI, dialysis, or mortality after CM-enhanced CT in patients with an eGFR ≥45 mL/min/1.73 m 2 , without comments regarding the eGFR interval of 30–44 mL/min/1.73 m 2 .…”