ATLANTA—Hydration with saline works as well as sodium bicarbonate for preventing contrast-induced nephropathy (CIN) in diabetic patients with impaired renal function, according to study findings released at the 59th annual scientific session of the American College of Cardiology.
CIN is recognized as a risk of exposure to iodine-containing contrast media. The risk can be as high as 50% in patients with risk factors such as CKD and diabetic nephropathy, said investigator Young-Hak Kim, MD, PhD, Associate Professor of Cardiology at University of Ulsan College of Medicine at the Asan Medical Center, Seoul, Republic of Korea.
“Recent small-scale studies had suggested that hydration with sodium bicarbonate may be more protective than sodium chloride alone in the prevention of CIN,” Dr. Kim said. However, a recent meta-analysis (Ann Intern Med. 2009;151:631-638) questioned the effectiveness of sodium bicarbonate due to the heterogeneity in outcomes across studies.
In a study known as PREVENT (Preventive Strategies of Renal Insufficiency in Patients with Diabetes Undergoing Intervention of Arteriography), 382 patients with diabetes and mild-to-moderate chronic stable renal dysfunction (serum creatinine of 1.1 mg/dL or higher and an estimated glomerular filtration rate [eGFR] below 60 mL/min/1.73 m2) who were undergoing coronary or endovascular intervention or angiography were randomized to either open-label sodium chloride or sodium bicarbonate to prevent CIN.
Patients randomized to saline were given 0.9% isotonic solution at 1 mL/kg infused for 12 hours before and after contrast injection; those randomized to sodium bicarbonate were given 154 mEq/L infused at 3 mL/kg for one hour prior to contrast, followed by 1 mL/kg per hour during the procedure and for six hours after completion of the procedure.
The investigators defined CIN as a serum creatinine level greater than 25% or an absolute increase of serum creatinine of 0.5 mg/dL or greater within 48 hours after exposure to contrast.
The rate of CIN was 5.3% with sodium chloride solution infusion compared to 9.0% with sodium bicarbonate solution. The percentage of patients who required dialysis after the procedure, potentially due to CIN, was 2.1% with sodium bicarbonate compared with 1.1% with saline. These differences between the groups were not significant.
In both groups, CIN developed within 48 hours of the coronary procedure more commonly when patients had a contrast load greater than 140 mL. Neither serum creatinine levels nor kidney function, as measured by eGFR, changed significantly in either group when assessed on days 1 and 2 after contrast exposure.
The rates of major adverse events—a composite of myocardial infarction (MI), death, stroke, and need for dialysis—were similar between the groups after one month of follow-up.
The results mirror those of a recent American study (JAMA. 2008:300:1038-1046) in which eGFR decreased by more than 25% in a similar number of patients receiving either sodium bicarbonate or saline. In this study, the rates of death, dialysis, MI, and cerebrovascular events did not differ between the groups at 30 days or six months.