Nephrotoxic effects of iodixanol and iopromide in patients with abnormal renal function receiving N-acetylcysteine and hydration before coronary angiography and intervention: a randomized trial

The use of contrast agents during coronary intervention can result in nephropathy, particularly in patients with renal dysfunction. We aimed to determine whether the use of iso-osmolar iodixanol is less nephrotoxic than that of low-osmolar iopromide when patients are adequately prehydrated and have received N-acetylcysteine. We conducted a randomized, double-blind, multicentre study of patients with impaired renal function undergoing a coronary interventional procedure. Primary end-point was the incidence of contrast-induced nephropathy (CIN) on day 2, defined as an increase in serum creatinine concentration of >= 44 mu mol/L (0.5 mg/dL) or by a relative increase of >= 25% from baseline. Secondary end-points included peak increase in serum creatinine between baseline and day 7. Of 191 patients recruited, 15% (95% CI: 8-22) of the patients receiving iopromide and 12% (95% CI: 5-19) of the patients receiving iodixanol developed CIN (95% CI of the difference: 13 to -7, P = 0.56). When including peak serum creatinine on day 7, CIN developed in 23% of patients receiving iopromide and in 27% of patients receiving iodixanol (95% CI of the difference: 8 to -16, P = 0.48). The peak increase in serum creatinine concentration at day 7 was similar in both groups (patients receiving iopromide, 18.4 +/- 24.4 mu mol/L, vs patients receiving iodixanol, 21.9 +/- 24.2 mu mol/L; P = 0.33). There remains a high incidence of CIN despite prehydration and routine use of N-acetylcysteine in patients with pre-existing renal dysfunction undergoing coronary interventional procedures. Although our study is underpowered, iodixanol was not associated with a statistically significant lower incidence of CIN when compared with iopromide.