[Acute kidney injury and renal replacement therapy in victims from out-of-hospital cardiac arrest with administration of contrast agent]

The influence of timing of coronary angiography on acute kidney injury in out-of-hospital cardiac arrest patients: a retrospective cohort study

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 contrast administration for coronary angiography and whether this depends on timing of angiography. 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 deferred 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. As a sensitivity analysis, we repeated the primary analysis using propensity score matching. A multivariable model was built to identify predictors of acute kidney injury.

RESULTS

A total of 2375 patients were included from 2009 until 2018, of which 1148 patients were treated with early coronary angiography and 1227 patients with delayed or no angiography. In the early angiography group 18.5% of patients developed AKI after OHCA and 24.1% 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. The sensitivity analysis using propensity score matching showed accordant results, but no longer non-inferiority of early angiography. The factors time to return of spontaneous circulation (odds ratio [OR] 1.12, 95% CI 1.06-1.19, p < 0.001), the (not) use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (OR 0.20, 95% CI 0.04-0.91, p = 0.04) 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 was not associated with a higher AKI incidence than a deferred 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.

Iodinated contrast medium: Is there a re(n)al problem? A clinical vignette-based review

As we were taught, for decades, that iodinated contrast-induced acute kidney injury should be dreaded, considerable efforts were made to find out effective measures in mitigating the renal risk of iodinated contrast media. Imaging procedures were frequently either downgraded (unenhanced imaging) or deferred as clinicians felt that the renal risk pertaining to contrast administration outweighed the benefits of an enhanced imaging. However, could we have missed the point? Among the abundant literature about iodinated contrast-associated acute kidney injury, recent meaningful advances may help sort out facts from false beliefs. Hence, there is increasing evidence that the nephrotoxicity directly attributable to modern iodinated CM has been exaggerated. Failure to demonstrate a clear benefit from most of the tested prophylactic measures might be an indirect consequence. However, the toxic potential of iodinated contrast media is well established experimentally and should not be overlooked completely when making clinical decisions. We herein review these advances in disease and pathophysiologic understanding and the associated clinical crossroads through a typical case vignette in the critical care setting.

Contrast-associated acute kidney injury in the critically ill: systematic review and Bayesian meta-analysis

PURPOSE

Critically ill patients, among whom acute kidney injury is common, are often considered particularly vulnerable to iodinated contrast medium nephrotoxicity. However, the attributable incidence remains uncertain given the paucity of observational studies including a control group. This study assessed acute kidney injury incidence attributable to iodinated contrast media in critically ill patients based on new data accounting for sample and effect size and including a control group.

METHODS

Systematic review of studies measuring incidence of acute kidney injury in critically ill patients following contrast medium exposure compared to matched unexposed patients. Patient-level meta-analysis implementing a Bayesian nested mixed effects multiple logistic regression model.

RESULTS

Ten studies were identified; only four took into account the baseline acute kidney injury risk, three by patient matching (560 patients). Objective meta-analysis of these three studies (vague and impartial a priori hypothesis concerning attributable acute kidney injury risk) did not find that iodinated contrast media increased the incidence of acute kidney injury (odds ratio 0.95, 95% highest posterior density interval 0.45-1.62). Bayesian analysis demonstrated that, to conclude in favor of a statistically significant incidence of acute kidney injury attributable to contrast media despite this observed lack of association, one's a priori belief would have to be very strongly biased, assigning to previous uncontrolled reports 3-12 times the weight of evidence strength provided by the matched studies including a control group.

CONCLUSIONS

Meta-analysis of matched cohort studies of iodinated contrast medium exposure does not support a significant incidence of acute kidney injury attributable to iodinated contrast media in critically ill patients.