Escore de mehran como preditor da injúria renal aguda induzida por contraste: estudo prospectivo

Abstract

Introduction: Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of inhospital acute kidney injury. The Mehran score is a predictive tool that has been used to support preventive interventions against CI-AKI. Objective: To assess the risk of CI-AKI using the Mehran score in hospitalized patients undergoing percutaneous coronary intervention in the context of acute coronary syndrome. Materials and methods: A prospective observational cohort study with a quantitative approach was conducted in a private hospital located in the city of Aracaju, Sergipe, Brazil, from August 2024 to August 2025. Patients aged ≥18 years diagnosed with acute coronary syndrome, who underwent percutaneous coronary intervention and remained hospitalized for more than 24 hours, with available records of baseline and postprocedure serum creatinine in the medical charts for the relevant analyses, were included. Records lacking essential information for specific analyses were excluded only from those analyses, according to the variable evaluated. CI-AKI was defined according to the KDIGO criteria. Data were recorded on the REDCap platform and analyzed using appropriate statistical methods with RStudio® software. Qualitative variables were expressed as absolute and relative frequencies, and quantitative variables as mean and standard deviation or median and interquartile ranges. The significance level adopted was p≤0.05. The discriminatory performance was evaluated by the ROC curve (AUC; 95% CI). Results: The sample consisted of 83 patients, with a mean age of 68.1 years, a predominance of males (66%). The incidence of CI-AKI was 58% (n=48). There was an average increase of 0.31 mg/dL in creatinine and an average percentage increase of 34.36%. The median Mehran score was 4 (IQR 0–8), classifying 65% of patients as low risk. However, among these, 51.9% developed AKI. Comparative analysis between groups with and without AKI revealed a significant difference only in the angina classification (p=0.008). Renal biomarkers, such as the absolute and percentage change in creatinine, were significantly higher in the AKI group (p<0.001). There was no difference between the groups for the other sociodemographic, clinical, and hemodynamic variables. The Mehran score showed limited discriminatory ability, with an AUC of 0.524. Sensitivity was low (41.7%), specificity was moderate (74.3%), and the Kappa coefficient indicated weak agreement (14.9%). Discussion: CI-AKI remains frequent in patients with acute coronary syndrome undergoing percutaneous coronary intervention, especially in populations with multiple comorbidities. The findings indicate that clinical and hemodynamic factors have a greater impact on the development of injury than the type or volume of contrast used. Furthermore, traditional scores have limited predictive ability in complex clinical settings, highlighting the importance of continuous monitoring and individualized preventive strategies conducted by multidisciplinary teams. Conclusion: The Mehran score did not show adequate performance as a predictive tool for CI-AKI under the studied conditions, showing low discriminatory capacity and limited accuracy for risk stratification.