Objectives To observe the level of Cystatin C(Cys C) in patients underwent coronary angiography (CAG) and / or percutaneous coronary intervention (PCI) before and after operation and to explore Cys C value in predicting of contrast-induced nephropathy (CIN). To observe the incidence of CIN in three groups: the basic treatment group, the Vitamine C group and the prostaglandin E1 group and to explore the effective prevention method of CIN.

Methods All patients underwent CAG and / or PCI were from the department of Cardiology, Affiliated Hospital of Xuzhou Medical College from March 2011 to September 2011. 200 cases were randomly divided into three groups. The basic treatment group (66 cases) were given 0.9% sodium chloride with the speed of 1 ml/(kg·h) 6h before and 12h after operation, atorvastatin 20mg was given before and after operation. The prostaglandin E1 group (67 cases) were given prostaglandin E1 20μg Qd, 1 day before and 2 consecutive days after operation on the basis of the treatment group. The Vitamin C group (67 cases) were given Vitamine C 3.0 g by intravenous infusion 2∼4 h before operation and oral Vitamin C 1.0 g on day 1, 2 respectively after operation on the basis of the treatment group, the total dose of the Vitamine C is 5 g.

The renal function of all patients were accessed before and 1-2 days after operation. The eGFR were calculated by the model of MDRD formula modified to suit the operational practice of Chinese people. Cystatin C level was unified to be determined by Enzyme-linked immunosorbent assay (ELISA).

Results The groups were well matched for baseline characteristics, the average amount of contrast medium during operation and the operation duration. Of the 200 patients, there were 23 cases of CIN. The incidence of CIN was 16.7% (11/66) in basic treatment group while 3.0% (2/67) in prostaglandin E1 group and 14.9% (10/67) in Vitamine C group. There was a significant difference in the incidence of CIN between three groups (P<0.05). The prevalence of CIN was much lower in prostaglandin E1 group than in basic treatment group and Vitamine C group but there was no a significant difference between basic treatment group and Vitamine C group

There was a significant difference (P <0.05) between the urine Cystatin C level of 12h, 24h, 48h (196.83 ± 43.05, 302.15 ± 70.60, 130.84 ± 30.99) ng/ml after operation and before operation (47.45 ± 17.02). There was no a significant difference between the Scr level at 24h after operation and before the operation. CIN can be diagnosed by urine Cystatin C at least 24h ahead of the level of Scr.

Conclusions Urinary Cystatin C might be a better and earlier biomarker for prediction of CIN. Hydration and statin with prostaglandin E1 is more effective in reducing the prevalence of CIN in patients underwent CAG and/or PCI. Vitamine C besides hydration and statin in the short time can not further reduce the prevalence of CIN.