Preventive Efficacy of Oxygenation on Contrast-Associated Acute Kidney Injury in Chronic Kidney Disease (stages 3-5) Patients Undergoing Elective Coronary Angiography ± Revascularisation: An Open Label Bicentric Randomised Controlled Trial.

Aim: Contrast-associated acute kidney injury (CA-AKI) has higher mortality in coronary artery disease (CAD) with chronic kidney disease (CKD), undergoing coronary angiography ± revascularisation (CAG ± R). We conducted a clinical superiority trial with dichotomous outcomes to evaluate the impact of renal hypoxia mitigation with oxygen therapy (OT) on CA-AKI incidence.

Methods: CKD stages 3-5 patients undergoing CAG ± R were assigned to the OT group (OTG) and the control therapy group (CTG). CTG received hydration only, whereas OTG received 2 L/min of pure oxygen in addition to hydration. The primary endpoint was the incidence of CA-AKI at 48 h. Secondary endpoints included patient and renal survival (doubling of serum creatinine or dialysis dependency) at 30 days, as well as intervention complications.

Results: Of the 395 patients, 321 patients qualified for the per-protocol analysis (OTG: 160 and CTG: 161). CA-AKI incidence was 5.6%, and OTG observed an effective prevention (1.25% vs. 9.93%, CTG, p = 0.004). Renal and patient survival at 30 days was 100%. Three CTG patients required dialysis and were dialysis-independent at 30 days. The risk of CA-AKI incidence was high among ages > 65 years (p = 0.007), previous acute myocardial infarction (p = 0.02), CKD stage-3 (p = 0.01) and avoidance of OT use (p = 0.02). OTG had a favourable serum creatinine trend (p = 0.05). Absolute risk reduction of CA-AKI with OT was 8.7%, and the number needed to treat was 12. Interventional complications were zero.

Conclusion: Oxygen supplementation and saline hydration effectively prevented CA-AKI in CKD stages 3-5 patients undergoing elective CAG ± R. Hence, oxygen therapy should be a standard CA-AKI protective strategy during CAG ± R and radiocontrast-related procedures.