Hydration in contrast-induced acute kidney injury

Contrast-associated acute kidney injury: An update of risk factors, risk factor scores, and preventive measures

As lifespans lengthen, age-related diseases such as cardiovascular disease and diabetes are becoming more prevalent. Correspondingly, the use of contrast agents for medical imaging is also becoming more common, and there is increasing awareness of contrast-associated acute kidney injury (CA-AKI). There is no specific treatment for CA-AKI, and clinicians currently focus on prevention, interventions that alter its pathogenesis, and identification of risk factors. Although the incidence of CA-AKI is low in the general population, the risk of CA-AKI can reach 20% to 30% in patients with multiple risk factors. Many models have been applied in the clinic to assess the risk factors for CA-AKI, enable identification of high-risk groups, and improve clinical management. Hypotonic or isotonic contrast media are recommended to prevent CA-AKI in high-risk patients. Patients with risk factors should avoid using contrast media multiple times within a short period of time. All nephrotoxic drugs should be stopped at least 24 h before the administration of contrast media in high-risk populations, and adequate hydration is recommended for all patients. This review summarizes the pathophysiology of CA-AKI and the progress in diagnosis and differential diagnosis; updates the risk factors and risk factor scoring systems; reviews the latest advances related to prevention and treatment; discusses current problems in epidemiological studies; and highlights the importance of identifying high-risk subjects to control modifiable risk factors and use of a rating scale to estimate the risk and implement appropriate prevention strategies.

Nicorandil for the prevention of contrast-induced nephropathy: A meta-analysis of randomized controlled trials

INTRODUCTION

Nicorandil has been suggested as a preventative strategy against the incidence of contrast-induced nephropathy (CIN). However, results of relevant randomized controlled trials (RCTs) were inconsistent.

AIMS

We performed a meta-analysis of RCTs to evaluate the preventive efficacy of periprocedural treatment of nicorandil against the incidence of CIN.

METHODS

Relevant RCTs were identified via search of PubMed, Embase, and Cochrane's Library databases. Results were pooled using a random-effect model. Subgroup analyses were performed to evaluate the potential influence of administering routes on the efficacy of nicorandil against CIN incidence.

RESULTS

Four RCTs with 709 patients were included. Treatment of nicorandil significantly reduced the incidence of CIN as compared with controls (risk ration [RR]: 0.38, 95% confidence interval [CI]: 0.19 ~ 0.74, P = .005) with moderate heterogeneity (I²  = 33%). Results of subsequent subgroup analysis showed that nicorandil significantly reduced the risk of CIN if orally administered (RR: 0.32, P < .001), but did not if intravenously administered (RR: 0.47, I²  = 68%). Moreover, treatment with nicorandil was associated with significantly less increment of SCr (weight mean difference [WMD]: -3.98%, P < .001) and a tendency of less increment of cystatin C (WMD: -3.86%, P = .08) after 48-hour contrast exposure as compared with controls.

CONCLUSIONS

Periprocedural treatment with nicorandil may be preventative against the incidence of CIN in patients undergoing contrast exposure. The influence of periprocedural nicorandil on clinical outcome in these patients deserves further investigation.

Mehran contrast nephropathy risk score: Is it still useful 10 years later?

BACKGROUND

Nowadays, contrast-induced nephropathy (CIN) is the third cause of acquired acute renal impairment in hospital. CIN is related to increased in-hospital morbidity, mortality, costs of medical care, and long admissions. Because of this, we hypothesized it would be useful to determine the risk of CIN with scores such as the Mehran score. The aim of this study was to validate the Mehran score in a contemporary cohort of Spanish patients with acute coronary syndrome (ACS).

METHODS

We assessed the calibration and discriminatory capacity of Mehran score to predict CIN in a cohort of 1520 patients with a definitive diagnosis of ACS and who underwent coronary angiography between March 2008 and June 2012. We excluded patients on chronic dialysis and those without data of contrast volume. The calibration of the model was assessed with the Hosmer-Lemeshow goodness-of-fit test and discriminatory capacity was assessed by C-statistic, which is equivalent to the area under the receiver-operating characteristic curve.

RESULTS

From the total group, 118 patients (7.8%) developed CIN. They were older, with higher rates of diabetes (DM) and hypertension and worse renal function and anemia (p<0.001). The odds ratios for different score components in Mehran's population versus our study were similar except for DM, hypotension, and intra-aortic balloon pump (1.6%, 2.68%, 2.55% vs 0.9%, 1.89%, and 2.86%, respectively). Calibration and discriminatory capacity of Mehran score were excellent with a Hosmer-Lemeshow p=0.7, C-statistic value >0.8.

CONCLUSIONS

Mehran risk score has been validated in our study as a good score for predicting CIN in patients with ACS who underwent coronary angiography. According to this, we support its use in patients hospitalized for ACS in order to identify the ones at risk, and to optimize CIN prophylactic therapy prior to and after catheterization.

Contrast media controversies in 2015: imaging patients with renal impairment or risk of contrast reaction

OBJECTIVE

The incidence and significance of complications related to intravascular contrast material administration have become increasingly controversial. This review will highlight current thinking regarding the imaging of patients with renal impairment and those at risk for an allergiclike contrast reaction.

CONCLUSION

The risk of contrast-induced acute kidney injury remains uncertain for patients with an estimated glomerular filtration rate (GFR) less than 45 mL/min/1.73 m(2), but if there is a risk, it is greatest in those with estimated GFR less than 30 mL/min/1.73 m(2). In this population, low-risk gadolinium-based contrast agents appear to have a large safety margin. Corticosteroid prophylaxis remains the standard of care in the United States for patients identified to be at high risk of a contrast reaction, but it has an incomplete mitigating effect on contrast reaction rates and the number needed to treat is large.