Objectives: Contrast induced nephropathy (CIN) is a common complication and found to be associated with increased morbidity and mortality after primary percutaneous coronary intervention (PCI). The objective of this study was to validate the Mehran Risk Score (MRS) for the risk stratification of CIN in patients undergone primary PCI. Methodology: A cohort of consecutive patients undergone primary PCI at a tertiary care cardiac center were included for this study. Patients in Killip class IV at presentation, patents history of any PCI, and chronic kidney diseases were excluded from this study. MRS was calculated at baseline and post procedure serum creatinine level increase of either 25% or 0.5 mg/dL was taken as CIN. Results: A total of 547 patients were included, of which 79.3%(434) were male. CIN after primary PCI was observed in 62(11.3%) patients. The area under the curve (AUC) for the MRS was 0.712 [0.641 to 0.783]. Cut-off value of ≥6.5 had sensitivity of 61.3% [48.1%-73.4%] with positive predictive value of 21.2% [17.5%-25.6%] and specificity of 70.9% [66.7%-74.9%] with negative predictive value of 93.5% [91.3%-95.2%]. MRS ≥6.5 was found to be an independent predictor on multivariable analysis with adjusted odds ratios (OR) of 3.86 [2.23-6.68] along with multi-vessel diseases with OR of 2.31 [1.27-4.19]. Conclusion: MRS has shown to have a good discriminating power. However low positive predictive value of the optimal cutoff value of ≥6.5 for prediction of CIN suggests need of modification to the MRS to improve its clinical utility in the modern era of primary PCI.

Objectives: This study was conducted to assess the predictive value of Shock Index-Creatinine Clearance (SI-C) for the risk stratification of contrast induced nephropathy (CIN) in patients after primary percutaneous coronary intervention (PPCI). Methodology: 1150 consecutive patients of STEMI and candidates of PPCI presenting at our tertiary care cardiac center were included in this study. Patients with significant hemodynamic instability, allergic reaction to contrast agent or having exposure to contrast agent within a week prior to PPCI and those requiring renal replacement therapy were excluded from this study. SI-C and Mehran risk scores were calculated and the rise in post procedure serum creatinine level by 0.5 mg/dL or up to 25% from baseline was characterized as CIN. The predictive power of both SIC and Mehran risk score was assessed with help of receiver operating characteristic (ROC) curve analysis. Results: Out of 1150 participants, 960 were male with a mean age of 55.64 ± 11.45 years. Out of which 113 (9.8%) patients developed CIN.  Area under the cure (AUC) for the prediction of CIN was 0.702 [95% confidence interval (CI): 0.651 to 0.753] for SI-C as against 0.633 [95% CI: 0.574 to 0.692] for Mehran score. SIC also retained its statistical significance as independent predictor of CIN with adjusted odds ratio of 1.01 [95% CI: 1.01 to 1.02] on multivariable regression analysis. Conclusion: SI-C has demonstrated strong discriminative power to determine the risk of CIN in PPCI setting when compared with Mehran risk score.