Relation of uric acid and contrast-induced nephropathy in patients undergoing primary percutaneous coronary intervention in the ED

Objectives: To investigate the predictive role of serum uric acid (SUA) levels measured in the emergency department (ED) to monitor contrast-induced nephropathy (CIN) and correlation with severity of nephropathy in patients undergoing primary percutaneous coronary intervention (PCI). Method: The patients who were admitted to our ED and underwent primary PCI were enrolled retrospectively. Their baseline characteristics including SUA and creatinine levels in the ED and their creatinine levels 48 hours after PCI were noted. Nephropathy was graded as follows: grade 0, Delta Cr <= 25% and <= 0.5 mg/dL; grade 1, Delta Cr > 25% but <= 0.5 mg/dL; and grade 2, Delta Cr > 0.5 mg/dL. A multiple logistic regression analysis was used to define the independent predictors of CIN. Results: Of a total of 744 patients, CIN was observed in 12.5% (n = 93). Serum uric acid levels were significantly higher in the CIN (+) group compared with the CIN (-) group (6.09 +/- 2.01 mg/dL vs 4.89 +/- 1.32 mg/dL, respectively; P < .001). Patients with grade 0 CIN had significantly lower SUA levels than did those with grades 1 and 2 (4.89 +/- 1.32 mg/dL vs 5.88 +/- 1.99 and 6.41 +/- 2.02 mg/dL, respectively; P < .001), but there was no significant difference between grade 1 and grade 2 CIN cases in terms of SUA levels (5.88 +/- 1.99 mg/dL vs 6.41 +/- 2.02 mg/dL, P = .10). The cutoff value for SUA was 5.05 mg/dL for the prediction of CIN (area under the curve, 0.685; P < .001; sensitivity, 66%; specificity, 60%) in the population. Conclusions: The SUA level is a simple independent early predictor of CIN in patients who underwent primary PCI, and early detection may help prevent the progression of CIN. (C) 2013 Elsevier Inc. All rights reserved.