Contrast-induced nephropathy: Definition, epidemiology, and patients at risk

Radiological procedures utilizing intravascular iodinated contrast media injections are being widely applied for both diagnostic and therapeutic purposes. This has resulted in an increasing incidence of procedure-related contrast-induced nephropathy (CIN). The definition of CIN includes absolute (≥0.5 mg/dl) or relative increase (≥25%) in serum creatinine at 48-72 h after exposure to a contrast agent compared to baseline serum creatinine values, when alternative explanations for renal impairment have been excluded. Although the risk of renal function impairment associated with radiological procedures is low (0.6-2.3%) in the general population, it may be very high in selected patient subsets (up to 20%), especially in patients with underlying cardiovascular disease. This review provides information on the known risk factors for the development of CIN, and completes with describing user-friendly CIN risk score based on the readily available information.