Renal replacement therapy for prevention of contrast-induced acute kidney injury: a meta-analysis of randomized controlled trials.

BACKGROUND Contrast-induced acute kidney injury (CI-AKI) is an important cause of acute renal injury. Several clinical trials using renal replacement therapy (RRT) for prevention of CI-AKI yielded conflicting results. We performed a meta-analysis to assess the efficacy of prophylactic RRT on CI-AKI. METHODS Randomized controlled trials on CI-AKI using RRT were identified without language restriction in Cochrane library, Pubmed and Embase. Data extracted from literature were analyzed with Review manager and Stata software. RESULTS Nine randomized controlled trials involving 751 patients were included. Heterogeneity was found across trials (p < 0.00001). A random effect model was used to combine the data. RRT reduced the risk of CI-AKI by 26% compared with the control group, but statistical significance was not reached (risk ratio (RR) 0.74, 95% CI 0.35-1.60, p = 0.45). Subgroup analysis of modality indicated that hemodialysis was ineffective in reducing the risk of CI-AKI (RR 1.21, 95% CI 0.63-2.32, p = 0.57), while CRRT decreased the incidence of CI-AKI (RR 0.22, 95% CI 0.07-0.64, p = 0.006). Subgroup analysis according to the CKD stage did not record heterogeneity across trials. RRT increased the odds of CI-AKI in CKD stage 3 patients (RR 1.53, 95% CI 0.07-0.64, p = 0.01), but decreased the occurrence of CI-AKI in patients with CKD stage higher than 3 (RR 0.74, 95% CI 0.35-1.60, p = 0.45). The pooled RR of the need for permanent dialysis demonstrated an insignificant trend towards benefit in patients treated with RRT (RR 0.61, 95% CI 0.26-1.40, p = 0.24). RRT reduced in-hospital mortality compared with control group (RR 0.33, 95% CI 0.14-0.77, p = 0.01). CONCLUSION RRT fails to reduce the incidence of CI-AKI in CKD stage 3 patients, but may be beneficial in patients with more advanced renal function. CRRT is more effective than hemodialysis for prevention of CI-AKI. RRT is effective in reducing the in-hospital mortality of CI-AKI patients.