Prevention of Radiocontrast-induced Nephropathy with N-acetylcysteine after Cardiac Angiography in Diabetic Patients with Renal Dysfunction

Abstract

Purpose. To examine the effects of N-acetylcysteine (NAC) in a homogeneous high-risk population. Methods. This is a prospective randomized single-blinded placebo-controlled clinical study. Diabetic patients with pre-existing renal insufficiency (serum creatinine concentration (SCC) above 1.6mg/dL, or estimated creatinine clearance (CCR) less than 40mL/min) who had received moderate to large amounts of non-ionic low osmolar contrast medium, Omnipaque (iohexol), during a diagnostic or interventional procedure were eligible to participate. All patients were adequately hydrated with half-saline (1mL/(kg•h) from 12 hours before to 12 hours after the procedure). They were randomized into one of two groups. Patients in the NAC group were given NAC 600mg orally twice a day, 4 doses in total; the first dose was given one day before the procedure. Patients in the control group were given placebo orally twice a day, 4 doses in total; the first dose was given one day before the procedure. SCC was assessed before hydration, 2 days after the procedure, and 5 days after the procedure. Radiocontrast-induced nephropathy (RCIN) was defined as a 25% rise from baseline or an absolute increase of 0.5mg/dL in SCC after the procedure. The primary end-point was risk of developing RCIN. Results. Twenty patients completed the study. There were no significant differences in age, sex, body mass index, blood pressure, duration of angiography, or mean volume of dye infused between the two groups. CCR did not change significantly in either group 2 days after angiography (NAC group 24.5±10.3 vs 29.6±10.6mL/min, N=11, p=0.34; control group 27.4±10.3 vs 29.6±10.6mL/min, N=9, p=0.57), or 5 days after angiography (NAC group 24.5±10.3 vs 27.4±11.8mL/min, N=11, p=0.40; control group 27.4±10.3 vs 24.2±8.8mL/min, N=9, p=0.43). None of the patients in the NAC group and five patients in the control group developed RCIN. The incidence of RCIN was lower in the NAC group (0% vs 56%, p=0.006, N=20). The average length of hospitalization was shorter in the NAC group (5.2 vs 8.1 days, p=0.04, N=20). None of the patients who developed RCIN required dialysis. Conclusion. NAC protects diabetic patients with renal dysfunction from iohexol-related RCIN after cardiac angiographic procedures.