Simultaneous hemodialysis during coronary angiography fails to prevent radiocontrast-induced nephropathy in chronic renal failure

Background: Radiocontrast medium- (RM) associated nephrotoxicity continues to be a common cause of acute renal failure and may lead in patients with pre-existing chronic renal insufficiency even to end-stage renal failure requiring chronic dialysis. Since extracorporeal removal of RM after RM administration has been shown to be effective but does not prevent radiocontrast-induced nephropathy, the effect of a simultaneous dialysis during RM administration on renal function is not clear. Methods: In a prospective, randomized and controlled trial, we studied the effect of a 4-hour online dialysis during RM (iomeprol) application in patients with advanced chronic renal failure (serum creatinine ≥ 3 mg/dl) undergoing coronary angiography. All patients received hydration with saline before and after standardized coronary angiography and were randomized to receive a simultaneous high-flux hemodialysis (7 patients, HD group) or to control group (10 patients). 24-hour creatinine clearance (CrCl) was measured in all patients before, 1 week and 8 weeks after coronary angiography. The clinical follow-up comprised 8 weeks after RM application. RM plasma levels were measured in both groups 15, 30, 60 minutes, 2, 4, 12, 24, 48 and 72 hours after application by high-pressure liquid chromatography. Results: At baseline, CrCl (19 ± 10 vs 17 ± 7 ml/min), percentage of diabetics (57 vs 70%) and dose of RM (77 ± 27 vs 86 ± 21 ml) were similar in both groups. Pharmacokinetics: Total clearance of iomeprol was significantly higher (54 ± 15 vs 20 ± 12 ml/min, p < 0.001) and the area under curve (AUC) was significantly lower (23 ± 10 g×h/l vs 94 ± 57 g×h/l, p < 0.001) in the HD group compared to control group. RM peak plasma levels 15 min after application were not different in both groups (3.0 ± 1.1 vs 4.2 ± 1.7 mmol/l, NS), however, significantly lower 60 min (1.6 ± 0.4 vs 3.7 ± 1.5 mmol/l, p < 0.01) and 240 min (0.7 ± 0.3 vs 2.3 ± 0.7 p < 0.001) after angiography. Clinical results: CrCl showed no difference 1 week (24 ± 11 vs 19 ± 9 ml/min, ns) and 8 weeks (24 ± 5 vs 20 ± 9 ml/min, NS) after angiography from baseline or between the groups. In each group, 2 patients developed end-stage renal disease and requested permanent dialysis during the 8-week follow-up. Conclusion: Simultaneous dialysis reduces AUC of iomeprol significantly, however, does not influence plasma peak concentration after angiography. Renal function and incidence of end-stage renal failure were not influenced by online-dialysis.