A randomized trial of saline hydration to prevent contrast-induced nephropathy in patients on regular captopril or furosemide therapy undergoing percutaneous coronary intervention.

Contrast-induced nephropathy (CIN) is characterized by acute deterioration of renal function that occurs after parenteral administration of contrast media in the absence of other causes. Although no definite proof has been obtained yet, the risk of diuretics or angiotensin-converting enzyme inhibitors (ACEI) to exacerbate CIN has been reported because of their effects on renal perfusion. This study was conducted to assess the protective effect of hydration alone in the prevention of CIN after percutaneous coronary intervention (PCI) in patients on diuretics or ACEI. This randomized clinical trial was conducted at the Chamran Hospital, Isfahan University of Medical Sciences, Iran, during the years 2006-2007. The study patients were divided into four groups, each group containing 60 patients. Patients in groups A and B were on regular treatment with ACEI (captopril) and patients in groups C and D were on regular diuretic (furosemide) therapy. About 36 h before PCI, captopril in group A and furosemide in group C were discontinued. The serum creatinine (Cr) levels were measured at the time of performing PCI and 24 h and 48 h after PCI in all patients. All patients received 1 mL/kg/h normal saline (0.9%) 12 h before and 24 h after PCI. The occurrence of CIN after PCI was diagnosed based on the following formula: Cr level after PCI - Cr level before PCI. If this value was greater than 0.5 mg/dL, it was coded as one and if the value was less than 0.5 mg/dL, it was coded as zero. The mean difference was analyzed and compared among the four groups by the ANOVA test. Three patients (5%) in group A, two patients (3.3%) in group B, two patients (3.3%) in group C and one patient (1.6%) in group D had a >0.5 mg/dL difference in serum Cr. The difference seen between these groups was not statistically significant (P > 0.05). This study shows that although furosemide and captopril can exacerbate CIN by impairment of renal perfusion, this can be prevented by hydration and discontinuation of furosemide and captopril may not be required.