Major Adverse Events One Year After Acute Kidney Injury After Contrast-Enhanced Computed Tomography

Recent studies have demonstrated that a single episode of acute kidney injury from a number of causes can increase the risk of severe long-term outcomes, including major cardiovascular events and death. We tested the hypothesis that patients who develop acute kidney injury consistent with contrast-induced nephropathy after contrast-enhanced computed tomography (CT) imaging are at increased risk of major adverse events at 1 year.

We followed a prospective, heterogeneous cohort of consecutive emergency department patients undergoing contrast-enhanced CT for the outcomes of acute kidney injury consistent with contrast-induced nephropathy and major adverse events, defined as the combined outcome of death (all cause), renal failure, myocardial infarction, and stroke or other arterial vascular events, in any anatomic territory, requiring invention within 1 year. The primary outcome, major adverse events, was determined by the consensus of 2 of 3 blinded adjudicators.

We followed 633 patients undergoing contrast-enhanced CT, of whom 11% developed acute kidney injury consistent with contrast-induced nephropathy and 15% (95/633; 95% confidence interval [CI] 12% to 18%) experienced at least 1 major adverse event within 1 year, including 7% (46/633; 95% CI 5% to 9%) who died. The development of acute kidney injury after contrast-enhanced CT was associated with an increased risk of 1-year major adverse event: the incident risk ratio was 4.01 (95% CI 2.61 to 6.05) and was 2.36 (95% CI 1.49 to 3.75) after adjusting for age, existing coronary artery disease, active malignancy, and 1 or more additional exposures to intravascular iodinated contrast media.

The development of acute kidney injury after contrast-enhanced CT was associated with a 2-fold increase in 1-year major adverse events. Further research is needed to validate this observation.