Association of the blood urea nitrogen-to-left ventricular ejection fraction ratio with contrast-induced nephropathy in patients with acute coronary syndrome who underwent percutaneous coronary intervention.

AIM: We investigated the predictive value of the blood urea nitrogen-to-left ventricular ejection fraction ratio (BUNEFr) to evaluate the risk of contrast-induced nephropathy (CIN) in acute coronary syndrome (ACS) patients who were treated with percutaneous coronary intervention (PCI).

METHODS: A total of 1010 ACS patients undergoing PCI were included in this study. The serum creatinine level was measured before and within 48-72 h of contrast medium administration. Contrast-induced nephropathy was defined as an absolute increase of 0.3 mg/dL or a relative increase of 25% from baseline serum creatinine within 48-72 h of contrast medium exposure. To evaluate the relation between BUNEFr and CIN, the patients were divided into a CIN group and a no-CIN group.

RESULTS: A total of 74 patients developed CIN (7.3%). Patients with CIN were older and had a higher BUNEFr than those without. Multivariate analysis showed that age, hypotension or positive inotrope support, history of stroke, contrast volume, and BUNEFr (OR 10.59, 95% CI 2.803-40.070, p = 0.001) were independent predictors of CIN. For the development of CIN, the AUC of a multivariable model that included hypotension or positive inotrope support, history of stroke, and contrast volume was 0.813 (95% CI 0.758-0.857, p < 0.001). When BUNEFr was added to a multivariable model, the AUC was 0.859 (95% CI 0.814-0.894, z = 3.204, difference p = 0.0014). Moreover, the addition of BUNEFr to a multivariable model was associated with a significant net reclassification improvement estimated at 49.4% (p < 0.001) and an integrated discrimination improvement of 0.044 (p = 0.0138).

CONCLUSION: The BUNEFr may be a useful new predictor of CIN in ACS patients treated with PCI. The inclusion of BUNEFr in a multivariable model could allow improved risk classification in these patients regarding the development of CIN.