<qa>  What was the baseline serum creatinine?Morning blood samples were received from all volunteers after an 8-h overnight fast. The investigators obtained the blood samples used to measure preoperative serum uric acid, baseline serum creatinine SCr prior to the pre-procedural hydration, blood urea nitrogen BUN, fasting blood glucose, random blood glucose, electrolytes before PCI, serum lipids, albumin, hemoglobin, and other standard clinical parameters. Blood samples were left to clot for one hour and then centrifuged at 1500 ×g for 10 min. Plasma samples were accumulated and stored at 80 C until analysis. 