Preventive Effects of Sodium Bicarbonate on Contrast-induced Nephropathy in High-risk Patients Undergoing Coronary Angiography: A Randomized Clinical Trial

Contrast agent is widely used in angiography and coronary interventions. Contrast-induced nephropathy (CIN) is the third most common cause of acute renal failure in hospitalized patients, which affects the rate of morbidity and mortality and healthcare costs. The purpose of this study was to determine the preventive effects of sodium bicarbonate on CIN in high-risk patients undergoing coronary angiography. In this clinical trial study, 100 patients with at least one risk factor, such as, congestive heart failure, diabetes mellitus, age>65 years, or renal failure were equally assigned to one of the two groups of bicarbonate or saline. Angiography was performed with Omnipaque (350mg1/ml). Serum levels of creatinine, blood urea, and urine acidity were measured at baseline and 48 hours after angiography. Creatinine clearance was calculated using the Modification of Diet in Renal Disease (MDRD) formula. CIN was defined as a≥25% increase in serum creatinine 48 hours after exposure to the contrast agent. No significant differences were observed between the two groups in baseline clinical laboratory parameters and medications (p>0.05). Forty-eight hours after exposure to the contrast agent, serum creatinine level significantly increased in the saline group (p=0.039), while the increase was not significant in the bicarbonate group (p=0.624). The incidence of CIN was 12% in the bicarbonate group and 14% in the saline group (p=0.7). According to the findings of this study, bicarbonate could be a treatment of choice in the prevention of CIN.