External Multicenter Validation of the Mehran Risk Score for Contrast Induced Acute Kidney Injury

Background: Contrast induced acute kidney injury (CIAKI) is a known complication of percutaneous coronary intervention (PCI). Mehran Risk Score (MR score) has been previously shown to predict CIAKI, renal replacement therapy (RRT), and one-year mortality in patients undergoing PCI. The purpose of our study was to externally validate the MR score. Methods: To examine the utility of the MR score we reviewed records of 931 adult patients who underwent PCI in 2005 at 3 academic medical centers. Patients with acute myocardial infarction, end stage renal disease and contrast exposure within one week of PCI were excluded. MR score was calculated for each patient and stratified into 4 groups: MR score 0-5 (group 1), 6-10 (group 2), 11-15 (group 3), ≥ 16 (group 4). CIAKI was defined as an increase in serum creatinine of 25% or 0.5 mg/dl over baseline 48 hours post PCI. Need for hemodialysis was assessed within 1 month after PCI. All-cause mortality was assessed 1 year after PCI. Likelihood ratio was calculated to assess the MR score discrimination for our data as well as Mehran, et al. Results: The overall incidence of CIAKI, hemodialysis and mortality were 12.2%, 0.4%, and 9.0% respectively. A higher MR score was strongly associated with development of CIAKI and mortality (p < 0.01 for trend). There was no difference in the rate of CIAKI overall or in each MR score group when the 2 populations were compared, however, the risk of death was higher in our population (RR 1.58, CI 1.371.89, p < 0.001). Conclusion: In conclusion, we were able to externally validate the MR score as a useful tool to predict CIAKI and one-year all-cause mortality post PCI.