Shock Index-C: A Newfound Spectrum of Shock Index With Great Accuracy to Predict Contrast Induced Nephropathy in Primary Percutaneous Coronary Intervention Cohort

Abstract

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.