The Influence of Timing of Coronary Angiography on Acute Kidney Injury in Out-of-Hospital Cardiac Arrest Patients: A Retrospective Cohort Study.

Abstract Background: Acute kidney injury (AKI) is a frequent complication in cardiac arrest survivors and associated with adverse outcome. It remains unclear whether the incidence of AKI increases after the post-cardiac arrest administration of contrast for coronary angiography and whether this depends on timing of contrast administration. Aim of this study was to investigate whether early angiography is associated with increased development of AKI compared to deferred angiography in out-of-hospital cardiac arrest (OHCA) survivors.Methods: In this retrospective multicenter cohort study we investigated whether early angiography (within 2 h) after OHCA was non-inferior to delayed/no angiography regarding the development of AKI. We used an absolute difference of 5% as the non-inferiority margin. Primary non-inferiority analysis was done by calculating the risk difference with its 90% confidence interval (CI) using a generalized linear model for a binary outcome and the identity link-function. As a sensitivity analysis we repeated the primary analysis using propensity score matching.Results: A total of 2151 patients were included in the study from 2009 until 2018, of which 1062 patients were treated with early coronary angiography and 1089 patients with delayed or no angiography. The proportion that developed AKI after OHCA was 17.8% in the early angiography group and 21.5% in the deferred angiography group. Risk difference was -3.7% with 90% CI ranging from -6.7% to -0.7%, indicating non-inferiority of early angiography at the prespecified margin of 5%. As sensitivity analysis we repeated the primary analysis using propensity score matching, which accordingly showed non-inferiority of early angiography. A multivariable model was built to identify predictors of acute kidney injury. The factors time to return of spontaneous circulation (odds ratio [OR] 1.10, 95% CI 1.05–1.15, p<0.001) and baseline creatinine (OR 1.05, 95% CI 1.03–1.07, p<0.001) were found to be independently associated with the development of AKI.Conclusions: Although AKI occurred in approximately 20% of OHCA patients, we found that early angiography had an equal AKI incidence as a delayed or no angiography strategy. The present results implicate that it is safe to perform early coronary angiography with respect to the risk of developing AKI after OHCA.