The clinical and renal consequences of contrast-induced nephropathy.

Contrast-induced nephropathy (CIN), an impairment of renal function following intravascular injection of contrast media, is commonly defined as an increase in the baseline serum creatinine concentration of >25% or 0.5 mg/dl (44 micromol/l). The incidence of CIN does not appear to have changed appreciably in the last three decades, and it continues to be the third leading cause of hospital-acquired acute renal failure (ARF). In the general population, the incidence of CIN is estimated to be 1-2%. However, the risk for developing CIN may be as high as 50% in some high-risk patient subgroups, such as those with diabetes mellitus and pre-existing renal impairment. Patients who develop CIN after percutaneous coronary intervention sustain an increase in both short- and long-term mortality whether or not chronic kidney disease was present prior to contrast exposure. The diminished long-term survival in patients with CIN has been observed for both, those whose ARF is not severe enough to require dialysis as well as those requiring dialysis. Treatment is limited to supportive measures while awaiting the resolution of the renal impairment. At times, this does not occur. Because of the lack of treatment options and because CIN is associated with serious short- and long-term sequelae, emphasis needs to be directed at preventative measures, identification of high-risk patients and education of all physicians involved in the care of these patients in order to reduce the incidence of CIN.