Effects of allopurinol pretreatment on the risk of contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention: A meta-analysis of randomized controlled trials .

BACKGROUND: Treatment with allopurinol has been suggested to reduce the incidence of contrast-induced acute kidney injury (CI-AKI). However, results of previous randomized controlled trials (RCTs) are not consistent. We performed a meta-analysis to evaluate the influence of allopurinol on the risk of CI-AKI. MATERIALS AND METHODS: Related RCTs were identified via systematic search of electronic databases including PubMed, Embase, and Cochrane's Library. The influence of allopurinol on the incidence of CI-AKI was defined as the primary outcome. Results were pooled using a random-effects model or a fixed-effects model according to the heterogeneity. RESULTS: Five RCTs with 754 patients who underwent percutaneous coronary intervention (PCI) were included. All patients received preprocedural hydration therapy with intravenous normal saline. Pooled results showed that allopurinol significantly reduced the incidence of CI-AKI (risk ratio (RR): 0.37, p = 0.01). Subgroup analyses demonstrated that allopurinol significantly reduced the incidence of CI-AKI in high-risk patients (incidence of CI-AKI >/= 30%, RR: 0.10, p = 0.04) but not in low-risk patients (incidence of CI-AKI < 30%, RR: 0.67, p = 0.14). Moreover, allopurinol significantly prevented the increment of serum creatinine (weighted mean difference (WMD): -0.13 mg/dL, p < 0.001) and attenuated the loss of estimated glomerular filtration rate (WMD: 4.78 mL/min, p = 0.04). However, serum uric acids were not significantly affected (WMD: -0.26 mg/dL, p = 0.72). CONCLUSION: Pretreatment with allopurinol reduces the incidence of CI-AKI in patients undergoing contrast exposure in PCI. The benefits of allopurinol on CI-AKI may be more remarkable in high-risk patients.