Effects of allopurinol and vitamin E on renal function in patients with cardiac coronary artery bypass grafts

Abstract

Background: Acute renal failure is a common complication of cardiac surgery, with oxidants found to play an important role in renal injury. We therefore assessed whether the supplemental antioxidant vitamin E and the inhibitor of xanthine oxidase allopurinol could prevent renal dysfunction after coronary artery bypass graft (CABG) surgery.

Methods: Of 60 patients with glomerular filtration rate (GFR) < 60 mL/min scheduled to undergo CABG surgery, 30 were randomized to treatment with vitamin E and allopurinol for 3-5 days before surgery and 30 to no treatment. Serum creatinine levels and potassium and creatinine clearances were measured preoperatively and daily until day 5 after surgery.

Results: The patients consisted of 31 males and 29 females, with a mean age of 63 +/- 9 years. After surgery, there were no significant differences in mean serum creatinine (1.2 +/- 0.33 vs 1.2 +/- 0.4 mg/dL; p = 0.43) concentrations, or creatinine clearance (52 +/- 12.8 vs 52 +/- 12.8 mL/min; p = 0.9). The frequency of acute renal failure did not differ in treatment group compared with control (16% vs 13%; p = 0.5). Length of stay in the intensive care unit (ICU) was significantly longer in the control than in the treated group (3.9 +/- 1.5 vs 2.6 +/- 0.7 days; p < 0.001).

Conclusion: Prophylactic treatment with vitamin E and allopurinol had no renoprotective effects in patients with pre-existing renal failure undergoing CABG surgery. Treatment with these agents, however, reduces the duration of ICU stay.

Keywords: antioxidants; coronary artery bypass; prevention and control; renal function.