Kiris T, et al. - In this study with 1,010 acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), the value of the blood urea nitrogen-to-left ventricular ejection fraction ratio (BUNEFr) in predicting contrast-induced nephropathy (CIN) was assessed. They defined contrast-induced nephropathy as an absolute increase of 0.3 mg/dL or a relative increase of 25% from baseline serum creatinine within 48–72 hours of contrast medium exposure. CIN developed in 74 patients (7.3%), who were older and had a higher BUNEFr vs those without CIN. The identified independent predictors of CIN in multivariate analysis included age, hypotension or positive inotrope support, history of stroke, contrast volume, and BUNEFr. A multivariable model that included hypotension or positive inotrope support, history of stroke, and contrast volume generated an AUC 0.813 for the development of CIN. An improved risk classification was obtained when BUNEFr was added to a multivariable model. Overall, BUNEFr may be valuable in predicting CIN in ACS patients treated with PCI.