Original ArticleAllopurinol Administration for the Prevention of Contrast-Induced Nephropathy A Network Meta-analysis With Trial Sequential AnalysisBellos, Ioannis MD; Iliopoulos, Dimitrios C. MD, PhD; Perrea, Despina N. MD, PhDAuthor Information Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, Athens University Medical School, National and Kapodistrian University of Athens, Athens, Greece. Reprints: Ioannis Bellos, MD, Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, Athens University Medical School, National and Kapodistrian University of Athens, 15Β, Ag. Thoma Str, Athens 115 27, Greece (e-mail: firstname.lastname@example.org). The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcvp.org). Received November 17, 2018 Accepted January 21, 2019 Journal of Cardiovascular Pharmacology: May 2019 - Volume 73 - Issue 5 - p 307-315 doi: 10.1097/FJC.0000000000000663 Buy SDC Metrics Abstract Abstract: Contrast-induced nephropathy represents a major source of morbidity in patients undergoing coronary angiography. Various preventive measures have been proposed, although the optimal one remains still unknown. The aim of the present meta-analysis is to accumulate current literature knowledge and evaluate the renoprotective effects of allopurinol administration before contrast medium exposure. To achieve this, MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and Google Scholar databases were searched from inception to November 8, 2018. Statistical meta-analysis was conducted with Review Manager 5.3, TSA 0.9.5.5 and R-3.4.3. Six studies were included with a total of 918 patients. Quantitative synthesis revealed that allopurinol leads to significantly reduced incidence of contrast-induced nephropathy compared with hydration alone [odds ratio: 0.29, 95% confidence interval: (0.09–0.90)]. Trial sequential analysis suggested that Z-curve crossed the O'Brien–Fleming significance boundaries, although required information size was not reached. Network meta-analysis indicated that allopurinol had the highest probability (81.2%) to rank as the most effective intervention compared with hydration and N-acetyl cysteine; however, significant overlap with the rest treatments was noted. In conclusion, the present meta-analysis suggests that allopurinol may represent a promising measure for the prevention of acute kidney injury after coronary angiography. Future large-scale randomized controlled trials should verify this finding, while combinations of allopurinol with other novel interventions should be evaluated to define the most effective strategy to be implemented in the clinical setting. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.