Prehydration Alone is Sufficient to Prevent Contrast-induced Nephropathy after Day-only Angiography Procedures—A Randomised Controlled Trial

Meta-analytic Techniques to Assess the Association Between N-acetylcysteine and Acute Kidney Injury After Contrast Administration: A Systematic Review and Meta-analysis

IMPORTANCE

The most suitable analytic method to systematically analyze numerous trials with contradictory results is unclear. Multiple trials assessing the use of N-acetylcysteine (NAC) for prevention of contrast-induced acute kidney injury (CI-AKI) have had contradictory results with recent trials confirming a lack of benefit.

OBJECTIVE

To systematically review the literature on NAC for the prevention of CI-AKI, and to explore the heterogeneity, publication bias, and small-study effect to determine the most suitable analytic method in a setting where the literature is contradictory.

DATA SOURCES

Medline, Embase, and Cochrane Central Register of Controlled Trials databases were used to find randomized clinical trials (RCTs) comparing NAC with any other prophylactic agent or placebo in adults.

STUDY SELECTION

The search included studies published in English from database inception to January 2020. Two independent reviewers screened the studies, extracted data, and performed the risk of bias assessment.

DATA EXTRACTION AND SYNTHESIS

A meta-analysis was conducted about the effect of NAC on CI-AKI, the need for dialysis, and mortality. Fixed and random effects analyses were also performed. Funnel plots and the trim and fill method were used for assessment of publication bias. Metaregression was performed to explore the heterogeneity and subgroup analysis to examine the association between NAC and CI-AKI when studies were categorized according to sample size and number of events.

RESULTS

A total of 101 trials were included in this meta-analysis. The median sample size was 112 (range, 20 to 4993). Twenty-nine trials had a sample size of 200 or more, and only 3 trials had a sample size of 500 or more. Forty-five trials reported the need for kidney replacement therapy, and 41 trials reported mortality as an outcome. NAC seemed to show a benefit, with a pooled OR of 0.72 (95% CI, 0.63-0.82) using random effects model and a pooled OR of 0.82 (95% CI 0.76-0.90) using a fixed effects model. However, there was significant heterogeneity (I2 = 37.6; P < .001) and significant publication bias, which was reduced only when restricting to large RCTs (N ≥ 500). The clinical outcomes (ie, the need for kidney replacement therapy and mortality) revealed little heterogeneity and no publication bias, and each provided a robust neutral summary result.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, NAC was associated with a benefit in the prevention of CI-AKI. However, because of substantial publication bias and other biases, standard meta-analytic techniques resulted in significant heterogeneity and a spurious, or factitious, association, even when using a random effects model. When the analysis was restricted to RCTs with a large sample size to account for publication bias or restricted to trials with clinical outcomes, this issue was reduced and resulted in more robust and neutral effect sizes.

Comparison of Oral and Intravenous N-acetyl Cysteine in Preventing Contrast Nephropathy

Introduction

Despite high rates of morbidity and mortality in patients with contrast-induced nephropathy (CIN), there is no consensus regarding prevention of this well-known complication of contrast media use. One agent that has been widely used in this regard is N-acetyl cysteine (NAC). Nevertheless, its efficacy is still controversial. The aim of this study was to assess the efficacy of NAC, both in the oral and intravenous forms, for the prevention of CIN.

Methods

This study is a double-blind randomized placebo controlled clinical trial. We randomized 434 adult patients with chronic kidney disease (constant serum creatinine ≥1.5 mg/dL) who were candidates for coronary angiography/plasty. The patients were categorized into three groups. One group received 1,200 mg NAC intravenously half an hour before the procedure and oral placebo starting 3 days before angiography. The second group received oral NAC 600 mg twice daily for 3 days, starting the day before the intervention and intravenous placebo half an hour before intervention. The third group received both oral and intravenous placebo. CIN was defined as a 25% relative increase in serum creatinine from baseline value, 48 h after use of contrast medium.

Results

Of the 434 patients, 149 received intravenous NAC, 145 received oral NAC, and the remaining 140 received placebo. The incidence of CIN in the three groups was 6.1%, 7.6%, and 10.8%, respectively (p = 0.34).

Conclusion

In patients with chronic kidney disease, neither intravenous nor oral NAC is superior to placebo for preventing CIN.

Latest Clinical Evidence About Effect of Acetylcysteine on Preventing Contrast-Induced Nephropathy in Patients Undergoing Angiography: A Meta-Analysis

Contrast-induced nephropathy (CIN) is a serious complication of angiographic procedures. It is the third most common cause of hospital acquired acute renal injury. As there are currently no approved therapies for CIN, prevention could be the best strategy to address this issue. Acetylcysteine may indirectly play an antioxidant role by inducing the synthesis of glutathione. Acetylcysteine can also reduce renal vasoconstriction induced by contrast medium stimulation by stabilizing nitric oxide and acting directly or indirectly on renal cortex and medulla microcirculation. To evaluate the effect of acetylcysteine on the prevention of CIN in patients after angiography, we systematically searched and analyzed the clinical data of patients including the incidence of CIN and change in serum creatinine (SCr) at 48 hours after angiography from selected articles. The result showed that acetylcysteine significantly reduces the incidence of CIN (risk ratios: 0.78, 95% CI: 0.68-0.90, I ² = 37.3%) and the level of SCr (standardized mean difference: -0.53, 95% CI: -0.93 to -0.12, I ² = 91.5%) after angiography compared with the control group. Overall, the use of acetylcysteine in patients after angiography was associated with a significant reduction of CIN and the level of SCr.

Effectiveness of contrast-associated acute kidney injury prevention methods; a systematic review and network meta-analysis

BACKGROUND

Different methods to prevent contrast-associated acute kidney injury (CA-AKI) have been proposed in recent years. We performed a mixed treatment comparison to evaluate and rank suggested interventions.

METHODS

A comprehensive Systematic review and a Bayesian network meta-analysis of randomised controlled trials was completed. Results were tabulated and graphically represented using a network diagram; forest plots and league tables were shown to rank treatments by the surface under the cumulative ranking curve (SUCRA). A stacked bar chart rankogram was generated. We performed main analysis with 200 RCTs and three analyses according to contrast media and high or normal baseline renal profile that includes 173, 112 & 60 RCTs respectively.

RESULTS

We have included 200 trials with 42,273 patients and 44 interventions. The primary outcome was CI-AKI, defined as ≥25% relative increase or ≥ 0.5 mg/dl increase from baseline creatinine one to 5 days post contrast exposure. The top ranked interventions through different analyses were Allopurinol, Prostaglandin E1 (PGE1) & Oxygen (0.9647, 0.7809 & 0.7527 in the main analysis). Comparatively, reference treatment intravenous hydration was ranked lower but better than Placebo (0.3124 VS 0.2694 in the main analysis).

CONCLUSION

Multiple CA-AKI preventive interventions have been tested in RCTs. This network evaluates data for all the explored options. The results suggest that some options (particularly allopurinol, PGE1 & Oxygen) deserve further evaluation in a larger well-designed RCTs.

Effectiveness of N-Acetylcysteine for the Prevention of Contrast-Induced Nephropathy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Conflicting results have been obtained in trials that have evaluated the prophylactic efficacy of N‐acetylcysteine (NAC) pretreatment in the prevention of contrast‐induced nephropathy (CIN). In this meta‐analysis of randomized controlled trials, we aimed to assess the effectiveness of NAC treatment for the prevention of CIN.

Methods and Results

PubMed, EMBASE, and the Cochrane Library were electronically searched from inception to January 2016 for all relevant studies. The weighted relative risk (RR) and corresponding 95% CI for incident CIN were estimated using random effects models. Standard methods for assessing statistical heterogeneity and publication bias were used. The study included 11 480 participants and 1653 cases of CIN. The incidence of CIN was 12.8% in the NAC group versus 16.0% in the control group (RR: 0.76, 95% CI: 0.66–0.88, P=0.0002). In the patients undergoing coronary angiography, the incidence of CIN in the NAC group versus the control group was 13.7% versus 17.2% (RR: 0.74, 95% CI: 0.63–0.87, P=0.0002); in those undergoing peripheral angiography, the incidence was 6.4% versus 5.8% (RR: 1.00, 95% CI: 0.42–2.40, P=1.00); in those undergoing computed tomography, the incidence was 7.7% versus 14.8% (RR: 0.51, 95% CI: 0.29–0.89, P=0.02).

Conclusions

Our meta‐analysis showed an inverse and significant association between NAC supplementation and risk of CIN in patients undergoing coronary angiography and computed tomography, while a protective role for NAC in patients undergoing peripheral angiography was not obvious.

Should acetylcysteine be used to prevent contrast induced nephropathy?

Diagnostic and therapeutic procedures that require the infusion of iodine containing contrast solutions are associated with the risk of contrast-induced nephropathy, a condition that can cause significant morbidity. Acetylcysteine has been proposed as a measure to prevent this condition. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified 20 systematic reviews including 64 randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded that even though acetylcysteine might not cause important adverse effects, it does not decrease need for dialysis, mortality or other important outcomes.

Intravenous N-acetylcysteine for prevention of contrast-induced nephropathy: a meta-analysis of randomized, controlled trials

Background

Contrast-induced nephropathy (CIN) is one of the common causes of acute renal insufficiency after contrast procedures. Whether intravenous N-acetylcysteine (NAC) is beneficial for the prevention of contrast-induced nephropathy is uncertain. In this meta-analysis of randomized controlled trials, we aimed to assess the efficacy of intravenous NAC for preventing CIN after administration of intravenous contrast media.

Study Design

Relevant studies published up to September 2012 that investigated the efficacy of intravenous N-acetylcysteine for preventing CIN were collected from MEDLINE, OVID, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and the conference proceedings from major cardiology and nephrology meetings. The primary outcome was CIN. Secondary outcomes included renal failure requiring dialysis, mortality, and length of hospitalization. Data were combined using random-effects models with the performance of standard tests to assess for heterogeneity and publication bias. Meta-regression analyses were also performed.

Results

Ten trials involving 1916 patients met our inclusion criteria. Trials varied in patient demographic characteristics, inclusion criteria, dosing regimens, and trial quality. The summary risk ratio for contrast-induced nephropathy was 0.68 (95% CI, 0.46 to 1.02), a nonsignificant trend towards benefit in patients treated with intravenous NAC. There was evidence of significant heterogeneity in NAC effect across studies (Q = 17.42, P = 0.04; I² = 48%). Meta-regression revealed no significant relation between the relative risk of CIN and identified differences in participant or study characteristics.

Conclusion

This meta-analysis showed that research on intravenous N-acetylcysteine and the incidence of CIN is too inconsistent at present to warrant a conclusion on efficacy. A large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of CIN is required to more adequately assess the role for intravenous NAC in CIN prevention.

The Role of N--Acetylcysteine in the Prevention of Contrast-Induced Nephropathy in Patients Undergoing Peripheral Angiography

Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired acute kidney injury (AKI). N-acetylcysteine (NAC) was proposed as an effective preventative measure. As data in relation to the use of NAC for the prevention of CIN in peripheral angiography are lacking, a systematic review and meta-analysis were undertaken. A comprehensive search for the published and unpublished data was performed. Data were extracted from the eligible studies. Pooled odds ratios (ORs) were used to calculate the effect of NAC on CIN incidence. Pooled effect size estimates were used to calculate the effect of NAC on serum creatinine (SCr) postcontrast. Our results showed that NAC did not reduce CIN incidence (pooled OR 1.05; 95% confidence interval [CI] 0.38-2.88; P = .92) or the mean SCr levels (pooled weighted mean difference, 4.38; 95% CI 10.4-1.65; P = .15). In conclusion, insufficient evidence exists to recommend NAC for the prevention of CIN in patients undergoing peripheral angiography.

Preventing radiocontrast-induced nephropathy in chronic kidney disease patients undergoing coronary angiography

Radiocontrast-induced nephropathy (RCIN) is an acute and severe complication after coronary angiography, particularly for patients with pre-existing chronic kidney disease (CKD). It has been associated with both short- and long-term adverse outcomes, including the need for renal replacement therapy, increased length of hospital stay, major cardiac adverse events, and mortality. RCIN is generally defined as an increase in serum creatinine concentration of 0.5 mg/dL or 25% above baseline within 48 h after contrast administration. There is no effective therapy once injury has occurred, therefore, prevention is the cornerstone for all patients at risk for acute kidney injury (AKI). There is a small but growing body of evidence that prevention of AKI is associated with a reduction in later adverse outcomes. The optimal strategy for preventing RCIN has not yet been established. This review discusses the principal risk factors for RCIN, evaluates and summarizes the evidence for RCIN prophylaxis, and proposes recommendations for preventing RCIN in CKD patients undergoing coronary angiography.

Acetylcysteine for prevention of renal outcomes in patients undergoing coronary and peripheral vascular angiography: main results from the randomized Acetylcysteine for Contrast-induced nephropathy Trial (ACT)

BACKGROUND

It remains uncertain whether acetylcysteine prevents contrast-induced acute kidney injury.

METHODS AND RESULTS

We randomly assigned 2308 patients undergoing an intravascular angiographic procedure with at least 1 risk factor for contrast-induced acute kidney injury (age >70 years, renal failure, diabetes mellitus, heart failure, or hypotension) to acetylcysteine 1200 mg or placebo. The study drugs were administered orally twice daily for 2 doses before and 2 doses after the procedure. The allocation was concealed (central Web-based randomization). All analysis followed the intention-to-treat principle. The incidence of contrast-induced acute kidney injury (primary end point) was 12.7% in the acetylcysteine group and 12.7% in the control group (relative risk, 1.00; 95% confidence interval, 0.81 to 1.25; P=0.97). A combined end point of mortality or need for dialysis at 30 days was also similar in both groups (2.2% and 2.3%, respectively; hazard ratio, 0.97; 95% confidence interval, 0.56 to 1.69; P=0.92). Consistent effects were observed in all subgroups analyzed, including those with renal impairment.

CONCLUSIONS

In this large randomized trial, we found that acetylcysteine does not reduce the risk of contrast-induced acute kidney injury or other clinically relevant outcomes in at-risk patients undergoing coronary and peripheral vascular angiography.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT00736866.

Does oral N-acetylcysteine reduce contrast-induced renal injury in patients with peripheral arterial disease undergoing peripheral angiography? A randomized-controlled study

The nephroprotective role of N-acetylcysteine (NAC) against contrast-induced nephropathy (CIN) in patients undergoing peripheral arterial angiography remains unclear. A total of 40 patients undergoing peripheral arterial angiography were randomized to receive intravenous (iv) hydration only (group 1) or oral NAC in addition to iv hydration (group 2; ISRCTN: 35882618). Primary outcome was reduction in the elevation of urinary retinol binding protein (RBP), albumin-creatinine ratio (ACR), and serum creatinine (serC). Groups 1 and 2 had equivocal percentage reduction in RBP and ACR levels from baseline (P = .80 and .30). A significant reduction in serC was, however, observed with NAC by third postprocedure day (P = .04). One patient in the treatment arm developed CIN compared with 3 patients in the control group (P = .33). Equivocal changes in RBP and ACR levels by both treatments seem to indicate that either is equally effective in affording renal protection.

Risk of nephropathy is not increased by the administration of larger volume of contrast during coronary angiography

It is proposed that contrast-induced nephropathy (CN) correlates with the use of increasing contrast volumes during coronary angiography. This supposition has led to the current recommendation to limit the dose of contrast in patients at high risk for renal dysfunction. Limits in contrast dosing may negatively impact the evaluation of patients undergoing cardiac catheterization for myocardial infarction and acute coronary syndrome. The objective of this study was to empirically assess, in a large population, the presence and strength of this correlation. Baseline blood samples and clinical information were obtained from 5256 consenting patients hospitalized for coronary angiography. Levels of serum creatinine were measured pre- and postcatheterization, and the total change in serum creatinine was calculated. Nephropathy was defined as a change of > or =0.5 mg/dL. The total volume of contrast dye (iopamidol, nonionic) used during the angiography procedure was recorded. Logistic regression was used for the primary analysis.The average age was 64 +/- 14 years, and 67% of patients were male. Paradoxically, the incidence of CN was inversely related to the volume in the overall population: 16%, 14%, 8%, and 7% for quartile (Q) 1 (<115 mL), Q2 (115-160 mL), Q3 (161-225 mL), and Q4 (>225 mL) of contrast, respectively (P-trend <0.001). In multivariable regression, this trend toward lower CN remained (Q1 (referent) OR = 1.0, Q2: 1.02, Q3: 0.60, Q4: 0.53, P < 0.001). Other predictors included age, left ventricular ejection fraction, diabetes, and baseline creatinine level (all P < 0.001). For patients at high risk, with a baseline creatinine >2.0 mg/dL (n = 415), contrast volume (Q1: <75 mL, Q2: 75-120 mL, Q3: 121-170 mL, Q4: >170 mL) did not predict either increased or decreased risk of CN (48%, 42%, 49%, 43%, respectively, P-trend = 0.76). This lack of predictive value remained after multivariable adjustment.In this large population, no association was found between the amount of contrast used during angiography and the incidence of CN in patients at initial high risk. The apparent inverse relation of risk with volume in the overall population is likely explained by clinical practice bias. If confirmed, these results may have important clinical implications.

Intravenous N-acetylcysteine with saline hydration improves renal function and ameliorates plasma total homocysteine in patients undergoing cardiac angiography

Proinflammatory cytokines and hyperhomocysteinemia are associated with clinically relevant restenosis in coronary artery disease. N-acetylcysteine (NAC) can decrease proinflammatory cytokines and plasma homocystine as well as reduce contrast-induced nephropathy. The aim of this study, therefore, was to compare normal saline hydration with and without intravenous NAC in terms of changes in renal function, proinflammatory cytokines, inflammatory markers, and plasma total homocysteine during coronary angiography. Forty-six patients who underwent coronary angiography and/or stent implantation for unstable angina were enrolled and assigned to NAC or NS treatment groups based on normal saline hydration with or without intravenous NAC, respectively. The NS group had lower serum creatinine (Cre: p = 0.02) and plasma total homocysteine (tHcy; p < 0.001) and increased glomerular filtration rate (GFR; p = 0.003) after angiography. In the NAC group, the serum blood urea nitrogen (BUN; p = 0.001), Cre (p < 0.001), and plasma tHcy (p < 0.001) were lower, and the GFR (P = 0.013) was increased after angiography. There were no statistically significant differences in serum high-sensitivity C reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), or interleukin-10 (IL-10) before and after angiography in the NS and NAC groups. Intergroup comparison revealed that plasma tHcy level was lower for the NAC-treated patients (p = 0.002), with lower plasma tHcy level before and after treatment in this group (p < 0.001). Normal saline hydration can improve renal function and decrease plasma tHcy after coronary angiography with or without NAC; however, the combination of the two decreases plasma tHcy more than normal saline hydration alone.

A meta-analysis of N-acetylcysteine in contrast-induced nephrotoxicity: unsupervised clustering to resolve heterogeneity

BACKGROUND

Meta-analyses of N-acetylcysteine (NAC) for preventing contrast-induced nephrotoxicity (CIN) have led to disparate conclusions. Here we examine and attempt to resolve the heterogeneity evident among these trials.

METHODS

Two reviewers independently extracted and graded the data. Limiting studies to randomized, controlled trials with adequate outcome data yielded 22 reports with 2746 patients.

RESULTS

Significant heterogeneity was detected among these trials (I2 = 37%; p = 0.04). Meta-regression analysis failed to identify significant sources of heterogeneity. A modified L'Abbé plot that substituted groupwise changes in serum creatinine for nephrotoxicity rates, followed by model-based, unsupervised clustering resolved trials into two distinct, significantly different (p < 0.0001) and homogeneous populations (I2 = 0 and p > 0.5, for both). Cluster 1 studies (n = 18; 2445 patients) showed no benefit (relative risk (RR) = 0.87; 95% confidence interval (CI) 0.68-1.12, p = 0.28), while cluster 2 studies (n = 4; 301 patients) indicated that NAC was highly beneficial (RR = 0.15; 95% CI 0.07-0.33, p < 0.0001). Benefit in cluster 2 was unexpectedly associated with NAC-induced decreases in creatinine from baseline (p = 0.07). Cluster 2 studies were relatively early, small and of lower quality compared with cluster 1 studies (p = 0.01 for the three factors combined). Dialysis use across all studies (five control, eight treatment; p = 0.42) did not suggest that NAC is beneficial.

CONCLUSION

This meta-analysis does not support the efficacy of NAC to prevent CIN.

European Society of Urogenital Radiology guidelines on contrast media application

PURPOSE OF REVIEW

The present review covers the European Society of Urogenital Radiology guidelines for safe use of contrast media of importance for referring urologists.

RECENT FINDINGS

During the recent years contrast medium-induced nephropathy has become a hot topic. It is of importance to reduce its incidence. First of all, the patients at risk should be identified prior to the administration of a contrast medium, so that appropriate measures can be taken. Before intravenous administration of an iodinated agent but not before gadolinium-based and ultrasound agents, all patients should be questioned about the potential renal dysfunction at the time of referral, and only those who answer affirmative to at least one question should have their serum creatinine level determined. Before intraarterial injection, the serum creatinine should always be measured. In case of an abnormal level, another imaging procedure should be considered. If impossible, hydration should be instituted and administration of nephrotoxic drugs should be stopped. After administration, delayed reactions such as nephrogenic systemic fibrosis, thyreotoxicosis, skin rash, etc. may be seen. Interaction with isotope studies and biochemical analysis occurs too.

SUMMARY

The awareness regarding the potential adverse reactions due to contrast media and the necessary precautions to be taken are of utmost importance both for radiologists and referring physicians. This is the only way to reduce their incidence.

Contrast-induced nephropathy: preventive and protective effects of melatonin

Infusion of contrast agents increases osmotic load, viscosity, hypoxemia of the renal medulla and renal free radical production through post-ischemic oxidative stress. The present experimental study sought to determine whether melatonin, because of its anti-oxidant properties might have a preventive and protective role against the development of contrast-induced nephropathy (CIN). Twenty-four adult male rats were divided into four experimental groups: healthy control rats (CR), rats with CIN (CINR), rats with CIN pretreated with melatonin (CINR1M), and rats with CIN pre- and post-treated with melatonin (CINR2M). In CINR, both serum creatinine (Cr) level and fractional excretion of sodium (FE-Na) significantly increased, whereas Cr clearance decreased at post-CIN compared with pre-CIN period. Rats in CINR1M did not show any improvement in renal function. Cr clearance decreased, whereas both serum Cr level and FE-Na increased in rats pretreated with melatonin. In contrast, significant improvements were observed in CINR2M. Serum Cr and Cr clearance did not change, whereas FE-Na significantly reduced in rats pre- and post-treated with melatonin. In conclusion, the present experimental study clearly demonstrated the preventive and protective role of melatonin against the development of CIN.