Diagnostic value of cystatin C in contrast-induced acute kidney injury after percutaneous coronary intervention

Abstract

To prospectively evaluate the value of cystatin C ( CysC) in diagnosis of contrast-induced acute kidney injury ( CIAKI) among patients undergoing Percutaneous Cardiovascular Intervention (PCI). Patients who underwent PCI procedures in our hospital were enrolled. Serum creatinine (SCr) and CysC were measured at baseline before, 24 h and 48 h after PCI, respectively. CysC were examined by particle-enhanced turbidimetric immunoassay (PETIA). CIAKI was defined as a relative increase in SCr concentration of at least 25% or an absolute increase more than 44.8 mmol/L (0.5 mg/dl) within 48 h in the absence of other related causes. Results Among 196 patients, 135 were male and 61 female with a mean age of (70.4 +/- 11.3) years old. Twenty-nine (14. 8%) patients developed CIAKI according to the SCr criteria. The area under the ROC curve (AUC) at 24 h and 48 h post PCI were 0. 661 (95% CI 0.548-0.774, P = 0.006) and 0.783 (95% CI 0.701-0.865, P < 0.001), respectively. The diagnostic sensitivities of CysC at 24 h and 48 h were between 6.9% and 48.28%, while, the diagnostic specificities and negative predictive values of CysC were between 85.03%-97.60% and 85.79%-90.45%, respectively. The 15% elevation of 48 h CysC yielded the diagnostic sensitivity of 41.38%, specificity of 92.86%, negative predictive value of 90.17%, corrective rate of 85.28% with Youden Index of 0. 342 4. In this study, CysC presented an excellent diagnostic specificity and negative predictive value in diagnosis of CIAKI. It might be used as a tool for excluding CIAKI in clinical practice. 48 h CysC performed better than 24 h CysC in CIAKI diagnosis, among which a 15% increment achieved relatively the best diagnostic value.