Practical Risk Stratification Score for Prediction of Contrast-Induced Nephropathy After Primary Percutaneous Coronary Intervention in Patients With Acute ST-Segment Elevation Myocardial Infarction

BACKGROUND: Contrast-induced nephropathy (CIN) is a common complication of percutaneous coronary intervention (PCI). This study aimed to develop a new risk stratification score that is simpler and more practical than the standard Mehran risk score (MRS) in prediction of CIN after primary PCI in ST-segment elevation myocardial infarction (STEMI) patients. METHODS: A prognostic prediction research with clinical risk score development was conducted. All STEMI patients who underwent primary PCI at the Central Chest Institute from June 1, 2017 to June 30, 2018 were included. Multivariable logistic regression analysis was used to identify independent predictors of CIN with a significant P value < 0.05. Logistic coefficients of each predictor were used for score weighting and transformation. Predictive performance was validated and compared between newly-derived risk score and the MRS by non-parametric receiver operating characteristic (ROC) regression. RESULTS: A total of 217 patients, 43 (19.8%) with CIN and 174 (80.2%) without CIN, were included for score derivation. A total of 13 potential predictors were explored under multivariable logistic regression model and were subsequently eliminated. The new risk score was based on three final predictors which were ejection fraction of less than 40%, triple-vessel disease as findings from angiogram, and the use of intra-aortic balloon pump (IABP). With only three predictor variables, the score predicted the risk of CIN with good discriminative ability (area under the receiver operating characteristic curve (AuROC): 0.83, 95% confidence interval (CI): 0.76 - 0.90) which was higher than that of the MRS (AuROC: 0.78, 95% CI: 0.69 - 0.87). The score was categorized into low-risk (positive predictive value (PPV): 9.9, 95% CI: 5.4 - 14.4) and high-risk (PPV: 56.5, 95% CI: 42.4 - 70.8) groups at the cut-off point of 2. CONCLUSIONS: The newly developed score was proved to have good predictive performance with fewer numbers of predictors and could be practically applied for risk stratification of CIN in STEMI patients who required emergent primary PCI.