Effect of renin-angiotensin system blockers on contrast-induced acute kidney injury in patients with normal or mild-to-moderate reduced kidney function undergoing coronary angiography: A systematic review and meta-analysis

Introduction: Contrast-induced acute kidney injury (CI-AKI) is a major complication after coronary angiography (CAG) or percutaneous coronary intervention (PCI) and is associated with increased morbidity and mortality. It remains controversial whether renin-angiotensin system (RAS) blockers increase or decrease CI-AKI. In this meta-analysis, we investigated the association between RAS blockers and CI-AKI in patients with normal kidney function or mildto- moderate chronic kidney disease (CKD). Materials and methods: We performed a systematic search of PubMed, EMBASE, clinicaltrials. gov, and the Cochrane Library up to December 2019 for studies that assessed the association between RAS blockers and CI-AKI events after CAG/PCI. The primary outcome was the development of CI-AKI. Odds ratios (ORs) with corresponding 95% confidence interval (CI) were synthesized. Results: Five randomized controlled trials (RCTs) and five observational studies were included, accounting for a total of 7, 420 patients. Unstratified, RAS blocker administration was significantly associated with an increased risk of CI-AKI (pooled OR = 1.63, 95% CI 1.19 - 2.25, p = 0.003). However, the effect was not observed in RCTs (pooled OR = 1.22, 95% CI 0.54 - 2.74, p = 0.63). Sensitivity analysis in observational studies showed significant association (pooled OR = 1.77, 95% CI 1.22 - 2.55, p = 0.003) with high heterogeneity and evidence of publication bias. Conclusion: In patients with relatively-preserved renal function, the association of RAS blockers with an increased risk of CI-AKI after contrast media exposure was inconclusive, as sensitivity analysis showed conflicting results and bias. Although this study did not demonstrate significant evidence, it indicated that clinicians need to be vigilant in assessing the potential risk for RAS blockers to cause CI-AKI in low-risk patients.