Clinical outcomes of contrast-induced nephropathy in patients undergoing percutaneous coronary intervention: a prospective, multicenter, randomized study to analyze the effect of hydration and acetylcysteine.

BACKGROUND: The potential role of hydration in prevention of contrast-induced nephropathy (CIN) still remains to be unclear.

METHODS: Nine-hundred and thirty-six patients scheduled for percutaneous coronary intervention (PCI) were enrolled into the present study, and divided into normal (serum creatinine<1.5 mg/dl) and abnormal (serum creatine> or =1.5 mg/dl) groups according to their baseline serum concentration of creatinine. Each group was further randomly divided into two subgroups: hydration and nonhydration. All patients in abnormal group took twice orally loading dose of 1200 mg acetylcysteine (ATLS) at 12 h before scheduled time for coronary angiogram and immediately after procedure. Creatinine concentration was remeasured at the time of admission (just before catheterization), every day for the following three days. The primary end point during 6-month follow-up included clinical driven revascularization (either PCI or CABG), death from all causes, and requiring emergency renal-replacement therapy.

RESULTS: The incidence of CIN was more commonly in abnormal group that in normal group (6.52% vs. 37.68%, p<0.001). Hydration had potentials in prevention of CIN only in patients with elevated baseline concentration of creatinine. Multivariate analysis demonstrated that the following variables remained to be significant factors correlating with CIN: age> or =70 years (odds ration [OR] 5.27, 95% confidence interval [CI] 1.94 to 13.07, p=0.0007), contrast volume> or =320 ml (OR 3.26, 95% CL 2.14 to 7.58, p=0.01), diabetes mellitus (OR 9.86, 95% CL 5.38 to 31.67, p<0.0001), and peripheral arterial disease (OR 11.25, 95% CL 5.12 to 43.19, p<0.0001). Patients with CIN in abnormal group had worse clinical outcomes, compared to patients with CIN in normal group.

CONCLUSION: Patients with CIN and preexisting renal insufficiency had worse clinical outcomes. Hydration with 0.45% sodium chloride alone had no potential effect on the occurrence of CIN in patients with normal renal function. Combination of hydration with ATLS could reduce the incidence of CIN in patients at high risk.