A COMPARISON BETWEEN IONIC AND NONIONIC CONTRAST NEPHROPATHY AMONG HIGH RISK PATIENTS CANDIDATE FOR CORONARY ANGIOGRAPHY

Among the causes of nephrotoxic acute renal failure, the increase use of contrast agents has caused the contrast nephropathy to come second after aminoglycosides. The aim of this study is comparison of nephrotoxicity of ionic (Urografin) and nonionic (Omnipaque, Ultravist) contrast agents in high risk patients candidate for coronary angiography. In this study 82 high risk patients who were candidate for coronary angiography in a 6 months period in the year 2004 in Golestan hospital of Ahwaz were randomly divided into two equall groups – ionic and nonionic contrast agents – and the prevalence of contrast nephropathy in each group was determined. Electrolyte changes ( Na, K ) of these patients were also assessed. Plasma level of BUN, Cr, Na and K were measured before and 24 to 48 h after angiography and it was accounted as contrast nephropathy if Cr level has raised at least 0.5 mg.

Among 41 patients who undergone angiography with nonionic agents (Omnipaque, Ultravist), 2 patients (5%) were affected by contrast nephropathy while this complication was seen in 6 patients (14.6%) among those who undergone angiography with ionic contrast agent (Urografin). No significant changes were seen in electrolyte concentration (Na, K) before and after angiography. Noting the fact that the predictive value of this finding is 0.132 (P>0.05), the statistical value of this is not proved. Therfore, there is no diffrence in nephrotoxicity between ionic and non-ionic contrast nephropathy in high risk patients. The most common risk factors of this complication were diabetes mellitus (DM) 50%, age≥65, 50% and chronic renal failure 25%. Relative risk (RR) of DM was 1.16, for old age 1.1 and it was 1.49 for chronic renal failure (CRF). The results of this study were similar to the results of American college of cardiology metaanalysis, Shwab study in USA and Esnalt study in France.