Protective effect of allopurinol in preventing contrast-induced nephropathy among patients undergoing percutaneous coronary intervention: a systematic review and meta-analysis.

Introduction: Contrast-induced nephropathy (CIN) is the third most common cause of iatrogenic acute renal failure and is triggered by administration of radiopaque contrast media. Periprocedural hydration is imperative in prevention of CIN, and uric acid has been recognized to have an integral role in development of renal disease. The aim of our study is to understand the efficacy of allopurinol in preventing CIN among patients undergoing percutaneous coronary intervention. Material and methods: A literature search was performed on PubMed (Medline), Science Direct and Cochrane Library using a combination of Mesh terms. We limited our search to randomized controlled trials (RCTs) and articles published in the English language. The PRISMA protocol was utilized to conduct this meta-analysis. Results: Six studies were included in the final analysis. All included studies were clinical trials conducted between 2013 and 2019. A total of 853 patients were included. There was a significant reduction in the risk of CIN among patients who were pretreated with adequate hydration plus allopurinol (100 to 600 mg) compared to hydration only before undergoing percutaneous coronary angiography (RR = 0.39, 95% CI: 0.21-0.73). A sensitivity analysis of studies using 300 mg of allopurinol only reported a significant reduction in CI-AKI compared to hydration alone (RR = 0.26, 95% CI: 0.11-0.57). Conclusions: Our study demonstrates that Allopurinol is effective in preventing contrast-induced nephropathy in patients undergoing percutaneous coronary intervention. Larger clinical trials are warranted to better understand this effect.