Age, glomerular filtration rate, ejection fraction, and the AGEF score predict contrast-induced nephropathy in patients with acute myocardial infarction undergoing primary PCI

Background: In patients undergoing primary percutaneous coronary interventions(PCI) for ST-segment elevation myocardial infarction (STEMI), the occurrence of Contrast-Induced Nephropathy (CIN) has a pronounced impact both on morbidity and mortality. We investigated the variables associated with CIN development in the setting of primary PCI and evaluated the predictive value of a 3-variable clinical risk score (the AGEF score) based on age, left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate (eGFR). Methods: 481 consecutive patients with STEMI who were undergoing primary PCI were prospectively enrolled. CIN was defined as an absolute increase in serum creatinine ≥0.5mg/dL or an increase ≥25% from baseline within 72 hours after theadministration of contrast medium. AGEF score was calculated by adding 1 point to the Age/EF(%) ratio if the eGFR was <60 mL/min per 1.73 m2. Results: Overall, the incidence of CIN was 5.2%. As expected, in-hospital mortality was higher in patients with CIN than in those without (16% Vs 1.3%, p=0.001). At multivariable analysis age (OR 1.08, p=0.038, AUC 0.78), eGFR (OR 0.95, p=0.002, AUC 0.88), LVEF (OR 0.94, p=0.033, AUC 0.69) and post-procedural TIMI flow grade (OR 0.30, p=0.01, AUC 0.57) were independent predictors of CIN. AGEF score was an accurate (OR 5.19, p<0.0001, AUC 0.88) and calibrated (Hosmer-Lemeshow χ2=6.24, p=0.62) predictor of CIN (Figure). Conclusions: Advanced age, depressed LVEF and reduced eGFR are independent predictors of CIN development after primary PCI for STEMI. In our model, the pre-procedural individual patient risk can be assessed by calculating the AGEF score by solving this exponential equation: Risk = e [AGEF score × 1.65 - -6.26]/(1 + e [AGEF score × 1.65 – 6.26]).