Preventive efficacy of oxygen therapy against contrast-associated acute kidney injury in patients undergoing coronary angiography: a systematic review and meta-analysis of randomized controlled trials

Contrast‑associated acute kidney injury (CA-AKI) is a common and serious complication of coronary angiography. Supplemental oxygen therapy has been proposed as a simple strategy to reduce CA-AKI by improving renal oxygenation, but existing trial results are inconsistent. This systematic review and meta-analysis evaluated the efficacy of oxygen therapy in preventing CA-AKI among patients undergoing coronary angiography. We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines, searching PubMed, Google Scholar, Scopus, Web of Science, and Embase from inception to December 2025. Studies evaluating post-angiography serum creatinine levels and the incidence of CA-AKI were included. Data were analyzed using random-effects models to account for between-study variability. Continuous outcomes were pooled as mean differences (SMDs) using the generic inverse variance method, while dichotomous outcomes were summarized as risk ratios (RRs). Heterogeneity among studies was assessed using the I² statistic, We screened 9,676 potential articles, and included five randomized controlled trials. Oxygenation therapy was associated with a significant reduction in serum creatinine levels at 48 h post-procedure, with a mean difference of − 0.10 mg/dL (95% CI − 0.16 to − 0.04; P = 0.001) and moderate heterogeneity among studies (I² = 61%). Additionally, the therapy significantly lowered the risk of CA-AKI, with a pooled risk ratio of 0.39 (95% CI 0.18–0.88; P = 0.02), although substantial heterogeneity was observed across trials (I² = 75%). Oxygenation therapy significantly reduces post-procedural serum creatinine levels and the risk of CA-AKI. Further large-scale randomized trials are warranted to confirm these findings given the observed heterogeneity.