Persistent Renal Damage after Contrast-Induced Acute Kidney Injury: Incidence, Evolution, Risk Factors and Prognosis
Background—The temporal evolution of renal function in patients with acute kidney injury after contrast medium (CI-AKI) is not well known. The aim of this observational study was to evaluate the incidence, risk factors and prognostic implications of persistent renal damage (RD) in patients with pre-existent moderate-to-severe renal dysfunction.
Methods and Results—From June 2003 to March 2008, 3986 patients underwent coronary angiography at our institution; 1490/3986 had an estimated creatinine clearance <60 ml/min and were enrolled. CI-AKI was defined as an absolute increase ≥0.5 mg/dl over baseline serum creatinine within 3 days after the administration of contrast medium (Iodixanol). In patients who developed CI-AKI, persistent RD was defined as a relative decrease of creatinine clearance ≥25% over baseline at 3 months. Patients whose creatinine clearance returned to baseline (or nearly) were classified as transient RD. The overall incidence of CI-AKI was 12.1% and persistent RD occurred in 18.6% of CI-AKI patients. At Cox regression analysis, nephropathy risk score ≥17, left ventricular ejection fraction ≤30% and increased value of serum creatinine ≥1.5 fold from baseline within five days, were found to be significant risk factors for persistent RD. At five years, the incidence of death was significantly higher in patients with persistent RD than both in patients with transient RD (p=.015) and in those without CI-AKI (p=.0001). A similar trend was observed for the combined endpoint of death, dialysis and cardiovascular events.
Conclusions—These results suggest that CI-AKI is not always a transient, benign creatininopathy, but rather a direct cause of worsening renal function. The occurrence of CI-AKI can identify patients at increased risk of cardiovascular events.
- Received December 6, 2011.
- Accepted May 2, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited