C-Reactive Protein to Albumin Ratio as a Predictor of Contrast-Induced Nephropathy After Carotid Angiography

Abstract

This study evaluated the role of the C-reactive protein (CRP)/albumin ratio (CAR) in estimating the probability of occurring contrast-induced nephropathy (CIN) after carotid artery angiography (CAAG). Patients (n = 410) who had CAAG for carotid artery stenosis (CAS) were included in this study. A spike in serum creatinine was used to define CIN within 72 h of the procedure (>.5 mg/dL or >25% above baseline). CAR was calculated by dividing the CRP by the albumin level. Patients with CIN had higher numbers of white blood cells ( P = .002), numbers of neutrophils ( P = .007), neutrophil–lymphocyte ratios ( P = .026), high-sensitivity CRP levels ( P < .001), and CAR levels ( P < .001) than those without CIN. They were also older ( P < .001) and more likely to have diabetes mellitus ( P = .006) and hypertension ( P = .016). According to receiver operator characteristic curve (ROC) analysis, the CAR value has a 75% sensitivity and a 68% specificity for identifying CIN at a cutoff of 1.8. Also, NLR and CRP predicted CIN with 71% sensitivity and 67% specificity, 71% sensitivity and 66% specificity at the best cutoff values of 1.96 and 7.91, respectively. According the present study, in patients with CAS, the development of CIN after CAAG is independently correlated with CAR at admission.