GW24-e3759 Effect of N-acetylcysteine for prevention contrast agent associated renal injury in elderly patients with coronary heart disease

Objectives In the field of coronary intervention, the contrast agent associated renal injury has become another major challenge that is cardiovascular doctors must face. Contrast agent associated renal injury not only prolong hospital stay and increase medical costs, but also increase hospital mortality and be associated with long-term adverse events. Now lack exact effective prevention measures. Elderly people usually have several diseases, such as high blood pressure, high uric acid, high cholesterol, diabetes, renal arteriosclerosis, so they are more susceptible to the contrast agent induced renal injury. We aimed to evaluate the protective effect of N-acetylcysteine against contrast agent associated renal injury in elderly patients with coronary heart disease. Methods 182 elderly patients (>60 years) with coronary heart disease undergoing coronary artery angiography randomised to an N-acetylcysteine (NAC) or control group. The patients in two groups respectively received NAC 1200 mg or placebo twice daily 24 hours before and after contrast administration. At 24h, 48h and 5 days after contrast agent administration, the renal glomerular and tubular function were measured including serum cystatin C, urea nitrogen, creatinine, creatinine clearance rate, urine β2-microglobulin, and urine N-acetyl-β-glucosaminidase (NAG). Results In both groups, the contrast agents obviously affected the renal functions of the patients (P < 0.05). At 24h after contrast administration, the levels of serum cystat in C, urine β2-microglobulin and urine NAG were significantly lower in NAC group than control group (1.22 ± 0.41 vs 1.51 ± 0.58, P< 0.05, 198 ± 85.7 vs 230.5 ± 94, P< 0.05, 15.6 ± 5.0 vs 22.1 ± 5.9, P< 0.05), but the other functional parameters showed no significant difference. At 48h after contrast administration, the glomerular and tubular functional parameters were all superior in NAC group (cystatin C 1.02 ± 0.45 vs 1.33 ± 0.42, P< 0.05, urea nitrogen 8.4 ± 3.3 vs 9.9 ± 3.9, P< 0.05, creatinine 104.5 ± 29.7 vs 122.4 ± 42.3, P< 0.05, creatinine clearance rate 91.2 ± 25.2 vs 73.0 ± 45.4, P< 0.05, urine β2-microglobulin 227.9 ± 104.8 vs 269.2 ± 101.7, P< 0.05, urine NAG 18.8 ± 3.4 vs 21.7 ± 4.6 , P < 0.05). At 5 days, the two groups showed significant differences in such glomerular and tubular functional parameters as urea nitrogen, creatinine, creatinine clearance rate, urine β2-microglobulin, and urine NAG (7.1 ± 3.0 vs 8.3 ± 3.7, P< 0.05, 84.4 ± 24.8 vs 93.0 ± 37.2, P< 0.05, 93.5 ± 33.3 vs 82.2 ± 29.0, P< 0.05, 209.8 ± 90.2 vs 243.5 ± 92.1, P< 0.05, 17.0 ± 4.9 vs 19.6 ± 6.7, P< 0.05), but not in serum cystatin C level. The incidence of contrast agent-induced nephropathy was significantly lower in NAC group than control group (4/ 92 vs 10/ 90, P < 0.05). Conclusions N-acetylcysteine offers protection against contrast agent associated renal injury in elderly patients with coronary heart disease.