The incidence of clinically significant contrast-induced nephropathy following non-emergent coronary angiography.

Objectives: The primary aim of this study was to assess the incidence of clinically significant contrast-induced nephropathy (CIN) among patients undergoing non-emergent coronary angiography.

Background: Although retrospective analyses have emphasized the association of CIN with adverse patient outcomes, the actual incidence of clinically significant CIN following non-emergent coronary angiography is not clear.

Methods: We prospectively identified patients with baseline estimated glomerular filtration rates (eGFR) < 60 ml/min/1.73 m(2) undergoing non-emergent coronary angiography. We measured serum creatinine 48-96 hr following angiography and assessed the incidence of CIN using two definitions, a rise in Scr > or = 25% and > or = 0.5 mg/dl. We tracked the need for dialysis, hospitalization related to kidney injury, and 30-day mortality to examine the association of CIN with these outcomes.

Results: We enrolled 181 patients with a median eGFR of 52 ml/min/1.73 m(2). Of the 165 patients (91%) with post-procedure Scr data, the incidence of CIN was 6.1-8.5%. One patient required dialysis (0.55%) and one (0.55%) died within 30 days. Although 38 patients required hospital admission, CIN was not associated with the need for hospitalization. Patients with an increase in Scr > or = 25% demonstrated a trend toward increased risk for 30-day mortality (P = 0.09), whereas those with increments in Scr > or = 0.5 mg/dl had a marginally higher risk for dialysis (P = 0.06) and 30-day mortality (P = 0.06), although these associations failed to meet the level of statistical significance.

Conclusions: Biochemically defined CIN occurs in a small, but notable proportion of patients undergoing non-emergent coronary angiography. However, clinically significant CIN is very uncommon.