Measures used to treat contrast-induced nephropathy: overview of reviews

Perioperative management of patients undergoing thoracic endovascular repair

Thoracic endovascular aortic repair (TEVAR) is a less invasive method for treating thoracic and some thoracoabdominal aortic aneurysms, dissections of the thoracic aorta and blunt traumatic aortic injury, compared with conventional open surgery. Maximizing the likelihood of a successful outcome requires diligent multidisciplinary (surgical, critical care, nursing, pharmacy, nutrition and physical therapy) perioperative care. In this article, we discuss fundamentals for managing patients after endovascular aortic aneurysm repair. These principles focus on the transition between the operating room and the intensive care unit, prevention and management of spinal cord deficits (SCD), and vital neurological, respiratory, cardiovascular, renal, gastrointestinal and hematological concerns. The better the care team understands the expected postoperative course, the earlier that deviations can be recognized and the more likely that successful rescue can be achieved to reduce the incidence and severity of adverse outcomes. Achieving optimal results after TEVAR requires attention to detail across the preoperative, intraoperative and postoperative phases of care.

Clinical safety evaluation of contrast agents based on real-world evidence

WHAT IS KNOWN AND OBJECTIVE

This study was aimed at comparing the adverse drug reactions (ADRs) arising from the use of iodinated contrast medium (ICM) and gadolinium-based contrast media (GBCM), and to provide a basis for the clinical selection of contrast media.

METHODS

Retrospective data for ADR cases occurring from the use of ICM or GBCM during enhanced scanning in computed tomography and magnetic resonance imaging were collected between June/2013 and May/2020 from Wenling Hospital of Traditional Chinese Medicine. Chi-square tests were performed based on the characteristics of patients and the classification of contrast medium. Bonferroni correction was applied to the statistical analyses with multiple comparisons of proportions.

RESULTS

Among 27,328 patients who were subjected to enhanced CT scanning, 207 cases (0.76%) showed ICM-related ADRs. Among 16,381 patients who were subjected to enhanced MRI scanning, 25 cases (0.15%) showed ADRs related to GBCM. The incidence of ADR induced by GBCM was significantly lower than ICM-induced ADR (p < 0.01). There were no significant differences in the incidence among different types of ICM, including ioversol and iodixanol, as well as iodixanol from different manufacturers (p > 0.05). Interestingly, the ADR incidence of ICM seemed to be associated with gender, with a significantly higher incidence in females than in male patients, and it was also associated with the age, with a lower occurrence in older (>44 years) compared to younger patients.

WHAT IS NEW AND CONCLUSION

With respect to ADR incidence, the safety profile of ICM of different types and different manufacturers was found to be similar in clinical use, warranting no need of specifically choosing imported or more expensive products. While choosing contrast medium type for clinical use, attention should be paid to certain populations, especially to younger and female patients when the patients are about to undergo a contrast-enhanced examination.

Critical care management after open thoracoabdominal aortic aneurysm repair

Thoracoabdominal aortic aneurysm repair is technically demanding for the surgeon and physiologically demanding on the patient. As such, it requires diligent multidisciplinary perioperative care to maximize the likelihood of a successful outcome. In this article, we discuss key principles for managing patients after open thoracoabdominal aortic aneurysm repair, which we have learned over the course of performing more than 3500 of such procedures. These principles address patient handoff between the operating room and Intensive Care Unit, resuscitation, prevention and management of spinal cord deficits, and important neurological, respiratory, cardiovascular, renal, gastrointestinal, and hematological considerations. Understanding the expected postoperative course allows for earlier recognition of deviations from that course and increases the likelihood of successful rescue of patients from adverse outcomes. Achieving positive outcomes after thoracoabdominal aortic aneurysm repair requires attention to detail across the perioperative, intraoperative, and postoperative phases of care.

Contrast-induced nephropathy: Basic concepts, pathophysiological implications and prevention strategies

Contrast-induced nephropathy (CIN) is reversible acute renal failure observed following administration of iodinated contrast media (CM) during angiographic or other medical procedures such as urography. There are various mechanisms through which CM develop their nephrotoxic effects, including oxidative stress and apoptosis. CIN is a real-life, albeit not very rare, entity. Exact pathophysiology remains obscure and no standard diagnostic criteria apply. The Acute Kidney Injury Network criteria was recently employed but its incidence/clinical significance warrants further clarification based on recent methodological advancements, because most published studies to date were contaminated by bias. The current study is a comprehensive review conducted to provide an overview of the basic concepts of CIN and summarize recent knowledge on its pathophysiology and the evidence supporting potential prevention strategies. CIN is expected to increase morbidity, hospital stay and mortality, while all patients scheduled to receive CM should undergo risk assessment for CIN and high-risk patients may be considered candidates for prevention strategies. The value of using compounds with antioxidant properties other than sodium bicarbonate, remains controversial, warranting further clinical investigation.

Preprocedural Prediction Model for Contrast-Induced Nephropathy Patients

Background

Several models have been developed for prediction of contrast‐induced nephropathy (CIN); however, they only contain patients receiving intra‐arterial contrast media for coronary angiographic procedures, which represent a small proportion of all contrast procedures. In addition, most of them evaluate radiological interventional procedure‐related variables. So it is necessary for us to develop a model for prediction of CIN before radiological procedures among patients administered contrast media.

Methods and Results

A total of 8800 patients undergoing contrast administration were randomly assigned in a 4:1 ratio to development and validation data sets. CIN was defined as an increase of 25% and/or 0.5 mg/dL in serum creatinine within 72 hours above the baseline value. Preprocedural clinical variables were used to develop the prediction model from the training data set by the machine learning method of random forest, and 5‐fold cross‐validation was used to evaluate the prediction accuracies of the model. Finally we tested this model in the validation data set. The incidence of CIN was 13.38%. We built a prediction model with 13 preprocedural variables selected from 83 variables. The model obtained an area under the receiver‐operating characteristic (ROC) curve (AUC) of 0.907 and gave prediction accuracy of 80.8%, sensitivity of 82.7%, specificity of 78.8%, and Matthews correlation coefficient of 61.5%. For the first time, 3 new factors are included in the model: the decreased sodium concentration, the INR value, and the preprocedural glucose level.

Conclusions

The newly established model shows excellent predictive ability of CIN development and thereby provides preventative measures for CIN.

Antioxidant and renoprotective effects of sphingosylphosphorylcholine on contrast-induced nephropathy in rats

Contrast induced nephropathy (CIN) is a major cause of morbidity, and increased costs as well as an increased risk of death. This study was evaluated effects of exogenous sphingosylphosphorylcholine (SPC) administration on CIN in rats. Eight animals were included in each of the following eight groups: control, control phosphate-buffered solution (PBS), control SPC 2, control SPC 10, CIN, CIN PBS, CIN SPC 2 and CIN SPC 10. The induced nephropathy was created by injected with 4 g iodine/kg body weight. SPC was administered 3 d at a daily two different doses of 2 μm/mL and 10 μm/mL intraperitoneally. The severity of renal injury score was determined by the histological and immunohistochemical changes in the kidney. Malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) were determined to evaluate the oxidative status in the renal tissue. Treatment with 2 and 10 μM SPC inhibited the increase in renal MDA, NO levels significantly and also attenuated the depletion of SOD in the renal injuryCIN. These data were supported by histopathological findings. The inducible nitric oxide synthase positive cells and apoptotic cells in the renal tissue were observed to be reduced with the 2 and 10 μM SPC treatment. These findings suggested that 2 and 10 μM doses can attenuate renal damage in contrast nephropathy by prevention of oxidative stress and apoptosis. The low and high dose SPC may be a promising new therapeutic agent for CIN.

Sodium Bicarbonate Prevents Contrast-Induced Nephropathy in Addition to Theophylline: A Randomized Controlled Trial

In this study, we investigated whether hydration with sodium bicarbonate is superior to hydration with saline in addition to theophylline (both groups) in the prophylaxis of contrast-induced nephropathy (CIN). It was a prospective, randomized, double-blinded study in a university hospital on 2 general intensive care units (63% of investigations) and normal wards.After approval of the local ethics committee and informed consent 152 patients with screening serum creatinine ≥1.1 mg/dL and/or at least 1 additional risk factor for CIN undergoing intravascular contrast media (CM) exposure were randomized to receive a total of 9 mL/kg bicarbonate 154 mmol/L (group B; n = 74) or saline 0.9% (group S; n = 78) hydration within 7 h in addition to intravenous application of 200 mg theophylline. Serum creatinine was determined immediately before, 24 and 48 h after CM exposure. As primary endpoint we investigated the incidence of CIN (increase of serum creatinine ≥0.5 mg/dL and/or ≥25% within 48 h of CM).Both groups were comparable regarding baseline characteristics. Incidence of CIN was significantly less frequent with bicarbonate compared to sodium hydration (1/74 [1.4%] vs 7/78 [9.0%]; P = 0.035). Time course of serum creatinine was more favorable in group B with decreases in serum creatinine after 24 h (-0.084 mg/dL [95% confidence interval: -0.035 to -0.133 mg/dL]; P = 0.008) and 48 h (-0.093 mg/dL (-0.025 to -0.161 mg/dL); P = 0.007) compared to baseline which were not observed in group S.In patients at increased risk of CIN receiving prophylactic theophylline, hydration with sodium bicarbonate reduces contrast-induced renal impairment compared to hydration with saline.

Effect of statins in preventing contrast-induced nephropathy: an updated meta-analysis

OBJECTIVE

The effect of statins in preventing contrast-induced nephropathy (CIN) has been reported, with conflicting results. The aim of this study was to carry out an updated meta-analysis to determine whether pretreatment with statins can reduce the risk of CIN and adverse clinical events.

MATERIALS AND METHODS

Systematic database searches of MEDLINE (1950 to December 2013), EMBASE (1966 to December 2013), and the Cochrane Central Register of Controlled Trials (Issue 12, December 2013) were performed. All randomized controlled trials assessing the efficacy of statins on CIN were included.

RESULTS

Seventeen studies with 6323 patients were included. Pretreatment with statins before angiography significantly reduced the risk of CIN [relative risk 0.50; 95% confidence interval (CI) 0.35-0.71; P<0.001] and was associated with significantly lower postprocedural serum creatinine levels (weighted mean difference -0.05 mg/dl; 95% CI -0.09 to -0.02 mg/dl; P=0.005). Meanwhile, the use of statins resulted in trends of reduced risks of renal replacement therapy and all-cause death within 30 days (relative risk 0.44; 95% CI 0.18-1.08; P=0.07). Further analyses indicated that high-dose statins were more effective than low-dose statins in reducing the risk of CIN and that different types of statins showed similar effects in preventing CIN.

CONCLUSION

Pretreatment with statins before angiography is effective in preventing CIN and may reduce the risk of adverse clinical events. However, the optimal dose and duration for statin pretreatment are still unknown.

Evaluation of the protective effect of N-acetylcysteine on contrast media nephropathy

INTRODUCTION

Intravenous contrast agents can cause acute decline in kidney function, especially in patients with risk factors.

OBJECTIVES

In this study, we aimed to examine the ameliorative effect N-acetylcysteine (NAC) to reduce the incidence of contrast nephropathy.

PATIENTS AND METHODS

This study was a prospective, randomized, double-blind clinical trial on 150 patients who underwent coronary angiography. The study was carried out on patients undergoing coronary angiography. Patients were randomly assigned into 2 groups of intervention group and control subjects. Intervention group took NAC 600 mg orally twice a day. It was administered one day before angiography and continued until the second day after angiography. Control subjects received saline only. Serum creatinine was measured before and three days after coronary angiography.

RESULTS

There was no significant difference between intervention and control groups at baseline (P > 0.05). However, there was a significant decline in creatinine level among NAC patients (P = 0.001). Saline group had significantly higher proportion of nephropathy cases than NAC patients Conclusion: We found that the consumption of NAC is useful for contrast induced nephropathy (CIN) prevention.

Renal-related adverse effects of intravenous contrast media in computed tomography

Renal-related adverse effects of intravascular contrast media (CM) include contrast-induced nephropathy in computed tomography and angiography. While large retrospective studies have been published, the exact pathogenesis of this condition is still unknown. We review the main international guidelines, including the American College of Radiology white paper and the guidelines of European Society of Urogenital Radiology, Royal College of Radiologists and Canadian Association of Radiologists, as well as their references, regarding this subject. We present a simplified, concise approach to renal-related adverse effects of CM, taking into consideration the basis for each recommendation in these published guidelines. This will allow the reader to better understand the rationale behind appropriate patient preparation for cross-sectional imaging.

Risk prediction models for contrast induced nephropathy: systematic review

OBJECTIVES

To look at the available literature on validated prediction models for contrast induced nephropathy and describe their characteristics.

DESIGN

Systematic review.

DATA SOURCES

Medline, Embase, and CINAHL (cumulative index to nursing and allied health literature) databases.

REVIEW METHODS

Databases searched from inception to 2015, and the retrieved reference lists hand searched. Dual reviews were conducted to identify studies published in the English language of prediction models tested with patients that included derivation and validation cohorts. Data were extracted on baseline patient characteristics, procedural characteristics, modelling methods, metrics of model performance, risk of bias, and clinical usefulness. Eligible studies evaluated characteristics of predictive models that identified patients at risk of contrast induced nephropathy among adults undergoing a diagnostic or interventional procedure using conventional radiocontrast media (media used for computed tomography or angiography, and not gadolinium based contrast).

RESULTS

16 studies were identified, describing 12 prediction models. Substantial interstudy heterogeneity was identified, as a result of different clinical settings, cointerventions, and the timing of creatinine measurement to define contrast induced nephropathy. Ten models were validated internally and six were validated externally. Discrimination varied in studies that were validated internally (C statistic 0.61-0.95) and externally (0.57-0.86). Only one study presented reclassification indices. The majority of higher performing models included measures of pre-existing chronic kidney disease, age, diabetes, heart failure or impaired ejection fraction, and hypotension or shock. No prediction model evaluated its effect on clinical decision making or patient outcomes.

CONCLUSIONS

Most predictive models for contrast induced nephropathy in clinical use have modest ability, and are only relevant to patients receiving contrast for coronary angiography. Further research is needed to develop models that can better inform patient centred decision making, as well as improve the use of prevention strategies for contrast induced nephropathy.

The Effect of Renin-Angiotensin-Aldosterone System Blockade Medications on Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography: A Meta-Analysis

BACKGROUND

Contrast-induced nephropathy (CIN) is the main complication of contrast media administration (CM) in patients undergoing coronary angiography (CAG) and percutaneous coronary intervention (PCI). There are inconsistent results in the literature regarding the effect of renin-angiotensin-aldosterone system (RAAS) blockers (angiotensin-converting enzyme inhibitors [ACEIs] and angiotensin receptor blockers [ARBs]) on CIN. We evaluated the association between the administration of ACEI/ARBs and CIN, as well as the effect of ACEI/ARBs on post-procedural changes in renal function index, in patients undergoing CAG.

METHODS

We searched Pubmed, EMBASE, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for relevant studies. The primary search generated 893 potentially relevant articles. A total of 879 studies were excluded because they did not meet the selection criteria. Finally, 14 studies were eligible for inclusion. There were 7,288 patients that received ACEI/ARBs and 8,159 patients that received placebo or naive to ACEI/ARBs in the study. A random or a fixed effect model was used to calculate the pooled odd ratios (ORs).

RESULTS

The risk of CIN was significantly increased in the ACEI/ARBs group compared to the control group (OR= 1.50, 95%CI: 1.03-2.18, P =0.03). The magnitude of association was significantly reinforced in the observational studies (OR=1.84, 95%CI 1.19-2.85, P=0.006) but not in the randomized controlled trials (OR=0.88, 95%CI 0.41-1.90 P=0.74). The summary adjusted OR of 4 observational studies was 1.56 (95%CI 1.25-1.94, P<0.0001) and was weaker than the unadjusted OR.

CONCLUSIONS

Although there is some evidence to suggest that the administration of RAAS blockers was associated with the increased risk of CIN in patients undergoing CAG, the robustness of our study remains weak. The results are based on small observational studies and need further validation.

Contrast-Induced Nephropathy: Identifying the Risks, Choosing the Right Agent, and Reviewing Effective Prevention and Management Methods

With the rise in the use of intravenous iodinated contrast media for both computed tomography scan and angiographic studies, there is a greater likelihood of complications. One of the most well-known adverse effects is contrast-induced media nephropathy, which is also called contrast-induced acute kidney injury. This is third most common cause of hospital acquired acute renal failure. It is associated with an increase in morbidity, mortality, and greater financial burden on healthcare system. Because of these factors, it is important for the radiologist to not only recognize risk factors, as well as the signs and symptoms, but also to know how to manage patients appropriately.

Statins in the prevention of contrast-induced nephropathy

OPINION STATEMENT

Coronary angiography and percutaneous coronary interventions are common procedures that utilize iodinated contrast medium to visualize the coronary arterial tree and treat stable and unstable ischemic heart syndromes. Exposure to contrast agents can cause acute and persistent worsening of renal function leading to increased morbidity and mortality. Certain patient characteristics such as age, presence of diabetes, congestive heart failure, chronic kidney disease, hemodynamic instability on presentation, and type and volume of contrast used can increase the risk of developing contrast-induced nephropathy (CIN) and its subsequent complications. Despite the lack of a universal definition, CIN is typically defined as an increase in serum creatinine ≥0.5 mg/dL or 25 % above baseline 48 to 72 h after contrast exposure. Previous research has shown the benefits of adequate intravenous hydration with iso-osmolar crystalloids and the importance of limiting the amount of low-osmolar and iso-osmolar contrast used to prevent the development of CIN. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have anti-inflammatory and anti-apoptotic properties with few side effects, making it an attractive therapeutic option for prevention of CIN. A number of trials have examined the benefit of different types of statins, high-dose versus low-dose statins, loading versus chronic dosing of statins, in various clinical presentations including acute coronary syndromes and elective procedures, and in those with associated comorbidities such as anemia and chronic kidney disease. In this review, we will summarize recent data regarding statin therapy for prevention of contrast-induced nephropathy.

Additional furosemide treatment beyond saline hydration for the prevention of contrast-induced nephropathy: a meta-analysis of randomized controlled trials

OBJECTIVES

There have been conflicting results on the clinical utility of furosemide in preventing contrast-induced nephropathy (CIN). This study aimed to elucidate the effect of additional furosemide treatment beyond saline hydration on CIN post radiologic procedures by a meta-analysis of randomized controlled trials (RCTs).

METHODS

The Medline, EMBASE, and Cochrane databases were systematically searched. Two reviewers independently determined the eligibility of studies that randomly assigned patients undergoing radiologic procedure to receive additional peri-procedural furosemide injection or intravenous saline hydration alone. Combined results were presented as risk ratios (RR) with 95% confidence intervals (CI) by random-effect models.

RESULTS

We identified 5 RCTs including 1330 patients. Of them 659 received peri-procedural furosemide injection in addition to saline hydration, and 671 only received intravenous saline hydration (the control). Relatively small total number of dialysis events and heart failure events were reported in the included studies (n = 18 across 5 trials, n = 24 across 3 trials, respectively). Compared to the control, additional furosemide treatment did not significantly increase the incidence of CIN (RR = 1.18; 95% CI, 0.50-2.78; P = 0.71) and the risk of dialysis (RR = 1.03; 95% CI, 0.41-2.57; P = 0.95) post radiologic procedure. Furthermore, furosemide treatment appeared to decrease the occurrence of heart failure (RR = 0.35; 95% CI, 0.14-0.88; P = 0.02).

CONCLUSIONS

Peri-procedural furosemide treatment in addition to saline hydration did not provide significantly prophylactic effect on CIN after radiologic procedure. Nevertheless, the process seemed likely to decrease the risk of heart failure post saline hydration.

Comparison between theophylline, N-acetylcysteine, and theophylline plus N-acetylcysteine for the prevention of contrast-induced nephropathy

BACKGROUND

Few studies compared the efficacy of theophylline with N-acetylcysteine or evaluated the efficacy of combination therapy in the prevention of contrast-induced nephropathy (CIN). We compared the efficacy of theophylline, N-acetylcysteine, and the combination of these agents in the prevention of CIN.

METHODS

This randomized controlled trial was conducted on 96 patients referring consecutively to the Shahid Chamran University Hospital in Isfahan, Iran, for elective coronary angiography (with our without angioplasty). Patients with at least moderate risk for CIN were included and were randomized to receive theophylline (200 mg), N-acetylcysteine (600 mg), or theophylline + N-acetylcysteine, twice a day, from 24 h before to 48 h after administration of the contrast material. A non-ionic, low-osmolar contrast material was used. Serum creatinine was measured before and 48 h after contrast material injection.

RESULTS

Serum creatinine was increased by 6.83 ± 15.32% with theophylline, 13.09 ± 14.63% with N-acetylcysteine, and 5.45 ±1 3.96% with theophylline + N-acetylcysteine after contrast material injection (between group P = 0.072). Controlling for Mehran risk score, baseline serum creatinine, and contrast volume, the change in serum creatinine level was lower with theophylline compared with N-acetylcysteine (F = 4.79, P = 0.033), and with theophylline + N-acetylcysteine compared with N-acetylcysteine (F = 5.78, P = 0.020). CIN (increase in creatinine of ≥ 0.5 mg/dl or ≥ 25% from the baseline) was occurred in 20%, 21.9%, and 7.1% of patients in the theophylline, N-acetylcysteine, and theophylline + N-acetylcysteine groups, respectively (P = 0.260).

CONCLUSION

Theophylline is superior to N-acetylcysteine in preventing contrast-induced renal dysfunction, but the combination with N-acetylcysteine is not superior to theophylline alone in this regard. Further trials with larger sample of patients are warranted.

[Iodinated contrast agents used in Radiology]

Iodinated contrast media are widely used in Radiology practices with a very low rate of adverse effects, being contrast-induced nephropathy the most serious one. In the majority of cases it is temporary and reversible, even though it can increase the inhospital morbidity and mortality in patients with risk factors. We will describe the various measures of prevention, being hydration and use of non-ionic contrast low osmolality those which have demonstrated greater effectiveness. Precautions to be taken in some risk situations, as patients treated with metformin or with impaired renal function, are also discussed.

Do intravenous N-acetylcysteine and sodium bicarbonate prevent high osmolal contrast-induced acute kidney injury? A randomized controlled trial

BACKGROUND

N-acetylcysteine (NAC) or sodium bicarbonate (NaHCO3), singly or combined, inconsistently prevent patients exposed to radiographic contrast media from developing contrast-induced acute kidney injury (CI-AKI).

OBJECTIVE

We asked whether intravenous isotonic saline and either NaHCO3 in 5% dextrose or else a high dose of NAC in 5% dextrose prevent CI-AKI in outpatients exposed to high-osmolal iodinated contrast medium more than does saline alone.

METHODS

This completed prospective, parallel, superiority, open-label, controlled, computer-randomized, single-center, Brazilian trial (NCT01612013) hydrated 500 adult outpatients (214 at high risk of developing CI-AKI) exposed to ioxitalamate during elective coronary angiography and ventriculography. From 1 hour before through 6 hours after exposure, 126 patients (group 1) received a high dose of NAC and saline, 125 (group 2) received NaHCO3 and saline, 124 (group 3) received both treatments, and 125 (group 4) received only saline.

RESULTS

Groups were similar with respect to age, gender, weight, pre-existing renal dysfunction, hypertension, medication, and baseline serum creatinine and serum cystatin C, but diabetes mellitus was significantly less prevalent in group 1. CI-AKI incidence 72 hours after exposure to contrast medium was 51.4% (257/500), measured as serum creatinine > (baseline+0.3 mg/dL) and/or serum cystatin C > (1.1 · baseline), and 7.6% (38/500), measured as both serum creatinine and serum cystatin C > (baseline+0.3 mg/dL) or > (1.25 · baseline). CI-AKI incidence measured less sensitively was similar among groups. Measured more sensitively, incidence in group 1 was significantly (p<0.05) lower than in groups 2 and 3 but not group 4; adjustment for confounding by infused volume equalized incidence in groups 1 and 3.

CONCLUSION

We found no evidence that intravenous isotonic saline and either NaHCO3 or else a high dose of NAC prevent CI-AKI in outpatients exposed to high osmolal iodinated contrast medium more than does saline alone.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01612013.

Short term high dose atorvastatin for the prevention of contrast-induced nephropathy in patients undergoing computed tomography angiography

BACKGROUND

Statins are shown effective by some studies in preventing contrast-induced nephropathy (CIN). We evaluated the effectiveness of atorvastatin in the prevention of CIN in computed tomography angiography (CTA) candidates.

METHODS

This study was conducted on patients referring for elective CTA with normal renal function. Patients received atorvastatin (80 mg/day) or placebo from 24 h before to 48 h after administration of the contrast material. Serum creatinine was measured before and 48 h after contrast material injection. CIN was defined as an increase in serum creatinine level of ≥ 0.5 mg/dl or ≥ 25% of the baseline creatinine.

RESULTS

A total of 236 patients completed the study; 115 atorvastatin, 121 placebo, mean age = 58.40 ± 9.80 year, 68.6% male. Serum creatinine increased after contrast material injection in both the atorvastatin (1.00 ± 0.16-1.02 ± 0.15 mg/dl, P = 0.017) and placebo groups (1.03 ± 0.17-1.08 ± 0.18 mg/dl, P < 0.001). Controlling for age, gender, comorbidities, drug history, and baseline serum creatinine level, patients who received atorvastatin experienced less increase in serum creatinine after contrast material injection (beta = 0.127, P = 0.034). However, there was no difference between the atorvastatin and placebo groups in the incidence of CIN (4.3 vs. 5.0%, P = 0.535).

CONCLUSION

In patients undergoing CTA, a short-term treatment with high dose atorvastatin is effective in preventing contrast-induced renal dysfunction, in terms of less increase in serum creatinine level after contrast material injection. Further trials including larger sample of patients and longer follow-ups are warranted.

Accuracy of point-of-care serum creatinine devices for detecting patients at risk of contrast-induced nephropathy: a critical overview

Contrast-induced nephropathy (CIN) is a common event in hospitals, with reported incidences ranging from 1 to 30%. Patients with underlying kidney disease have an increased risk of developing CIN. Point-of-care (POC) creatinine devices are handheld devices capable of providing quantitative data on a patient's kidney function that could be useful in stratifying preventive measures. This overview aims to synthesize the current evidence on diagnostic accuracy and clinical utility of POC creatinine devices in detecting patients at risk of CIN. Five databases were searched for diagnostic accuracy studies or clinical trials that evaluated the usefulness of POC devices in detecting patients at risk of CIN. Selected articles were critically appraised to assess their individual risk of bias by the use of standard criteria; 13 studies were found that addressed the diagnostic accuracy or clinical utility of POC creatinine devices. Most studies incurred a moderate to high risk of bias. Overall concordance between POC devices and reference standards (clinical laboratory procedures) was found to be moderate, with 95% limits of agreement often lying between -35.4 and +35.4 µmol/L (-0.4 and +0.4 mg/dL). Concordance was shown to decrease with worsening kidney function. Data on the clinical utility of these devices were limited, but a significant reduction in time to diagnosis was reported in two studies. Overall, POC creatinine devices showed a moderate concordance with standard clinical laboratory creatinine measurements. Several biases could have induced optimism in these estimations. Results obtained from these devices may be unreliable in cases of severe kidney failure. Randomized trials are needed to address the clinical utility of these devices.

The Prevention of Contrast-Induced Nephropathy

Objective: Contrast-induced nephropathy (CIN) is a complication which may develop after exposure to iodinated contrast media. The resulting acute kidney injury (AKI) is associated with an increase in both short- and long-term morbidity and mortality, increased hospital length of stay, and greater health care costs. The pathophysiological mechanism associated with the development of CIN remains unknown. This narrative review summarizes the pathophysiology, risk factors, and current evidence for the prevention of CIN. Data Sources: A MEDLINE literature search (2004-May 2014) was performed using search terms contrast-induced nephropathy and prevention. Additional references were identified from literature citations, review articles, and meta-analyses. Study Selection and Data Extraction: Abstracts of English-language human clinical trials that examined therapies for the prevention of CIN were evaluated. Studies that did not investigate a preventative intervention for CIN were excluded. Emphasis was placed on recent publications. Data Synthesis: A multitude of therapies focused on the prevention of CIN have been investigated. Unfortunately, many of these studies have produced negative and/or inconsistent results. There is a paucity of adequately designed clinical studies evaluating strategies for the prevention of CIN. However, the best data supports use of preprocedural hydration with isotonic solution as the standard of care for prophylaxis. Conclusion: Given the poor prognosis associated with CIN, there is need for improved methods to prevent it. At present, the best tools to protect patients from unnecessary risk for CIN are careful assessment of renal function, judicious use of procedures that utilize contrast media, and adequate hydration with isotonic solution.

Nonpharmacological strategies to prevent contrast-induced acute kidney injury

Contrast-induced AKI (CI-AKI) has been one of the leading causes for hospital-acquired AKI and is associated with independent risk for adverse clinical outcomes including morbidity and mortality. The aim of this review is to provide a brief summary of the studies that focus on nonpharmacological strategies to prevent CI-AKI, including routine identification of at-risk patients, use of appropriate hydration regimens, withdrawal of nephrotoxic drugs, selection of low-osmolar contrast media or isoosmolar contrast media, and using the minimum volume of contrast media as possible. There is no need to schedule dialysis in relation to injection of contrast media or injection of contrast agent in relation to dialysis program. Hemodialysis cannot protect the poorly functioning kidney against CI-AKI.

Pharmacological strategies to prevent contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is the most common iatrogenic cause of acute kidney injury after intravenous contrast media administration. In general, the incidence of CI-AKI is low in patients with normal renal function. However, the rate is remarkably elevated in patients with preexisting chronic kidney disease, diabetes mellitus, old age, high volume of contrast agent, congestive heart failure, hypotension, anemia, use of nephrotoxic drug, and volume depletion. Consequently, CI-AKI particularly in high risk patients contributes to extended hospitalizations and increases long-term morbidity and mortality. The pathogenesis of CI-AKI involves at least three mechanisms; contrast agents induce renal vasoconstriction, increase of oxygen free radicals through oxidative stress, and direct tubular toxicity. Several strategies to prevent CI-AKI have been evaluated in experimental studies and clinical trials. At present, intravascular volume expansion with either isotonic saline or sodium bicarbonate solutions has provided more consistent positive results and was recommended in the prevention of CI-AKI. However, the proportion of patients with risk still develops CI-AKI. This review critically evaluated the current evidence for pharmacological strategies to prevent CI-AKI in patients with a risk of developing CI-AKI.

Nephropathy after administration of iso-osmolar and low-osmolar contrast media: evidence from a network meta-analysis

BACKGROUND/OBJECTIVES

Contrast-induced nephropathy (CIN) may be a severe complication to the administration of iodine-based contrast media for diagnostic or interventional procedure using radiation exposure. Whether there is a difference in nephrotoxic potential between the various agents is uncertain. We aimed to perform a systematic review and network meta-analysis of randomized trials on iodine-based contrast agents.

METHODS

Randomized trials of low-osmolar or iso-osmolar contrast media were searched in CENTRAL, Google Scholar, MEDLINE/PubMed, and Scopus. Risk of CIN was appraised within a hierarchical Bayesian model computing absolute rates (AR) and odds ratios (OR) with 95% credibility intervals, and probability of being best (Pbest) for each agent.

RESULTS

A total of 42 trials (10048 patients) were included focusing on 7 different iodine-based contrast media. Risk of CIN was similarly low with iodixanol (AR=5.7% [2.2%-13.9%], Pbest=18.8%), iomeprol (AR=6.0% [2.2%-15.4%], Pbest=24.8%), iopamidol (AR=6.1% [2.2%-15.5%], Pbest=21.5%), and ioversol (AR=6.0% [2.1%-16.4%], Pbest=31.3%). Conversely, CIN was twice as common with iohexol (AR=11.2% [4.1%-29.5%], Pbest=0.1%) and ioxaglate (AR=11.0% [4.0%-26.9%], Pbest<0.1%), with both proving less safe than iodixanol (respectively OR=2.18 [1.22-3.92] and 2.05 [1.26-3.29]), iomeprol (OR=2.08 [1.04-4.17] and 1.96 [1.06-3.48]) and iopamidol (OR=2.04 [1.15-3.85] and 1.92 [1.06-3.45]). Data on iopromide were less conclusive (AR=6.9% [2.6%-17.1%], Pbest=3.6%).

CONCLUSIONS

Iodixanol, iomeprol, iopamidol and ioversol are iodine-based contrast media with a similar renal safety profile. Iohexol and ioxaglate have a poorer renal safety profile, whereas further data may be required on iopromide.

Ameliorative effect of melatonin against contrast media induced renal tubular cell injury

BACKGROUND AND OBJECTIVE

Reactive oxygen species (ROS) is a mediator of renal damage. Melatonin is a potent-free radical scavenger. Our objective was to test whether melatonin would protect against the nephrotoxicity of contrast media.

METHODS

In an experimental study 40 adult male Wistar rats were randomly divided into four equal groups including: 1) Control group (No drug), 2) Contrast media group (10 ml/kg iodixanol i.v. single dose), 3) Contrast media and melatonin (first 10 ml/kg iodixanol then 10 ml/kg/day melatonin by i.p. injection on days 3, 4 and 5) and 4) Contrast media and melatonin pretreatment group (melatonin 10 ml/ kg/day by i.p. injection on 1, 2 and 3 days, then 10 ml/kg iodixanol by i.v. injection on third day. The blood creatinine and BUN as well as the histological changes were evaluated for severity of renal injury (degeneration, vacuolization of tubular renal cells, dilatation of tubular lumen and presence of debris in the lumens), by scoring from one to four.

RESULTS

Contrast media significantly increased the creatinine and BUN and renal injury (p<0.05). Melatonin prevented and reversed the injury induced by contrast media (P<0.05). Pretreatment with melatonin reduced the renal injury induced by contrast media (P<0.05).

CONCLUSION

Melatonin is an effective drug to prevent contrast-induced renal injury. Therefore its usage (especially pretreatment) might be beneficial in patients who are planning to use contrast media agents.

Effect of remote ischaemic conditioning on contrast-induced nephropathy in patients undergoing elective coronary angiography (ERICCIN): rationale and study design of a randomised single-centre, double-blind placebo-controlled trial

Background

Contrast-induced nephropathy (CIN), an acute kidney injury resulting from the administration of intravascular iodinated contrast media, is an important cause of morbidity/mortality following coronary angiographic procedures in high-risk patients. Despite preventative measures intended to mitigate the risk of CIN, there remains a need for an effective intervention. Remote ischaemic conditioning (RIC), where non-injurious ischaemia is applied to an arm prior to the administration of contrast, has shown promise in attenuating CIN but its effectiveness in preserving long-term renal function is unknown, which will be studied as part of the effect of remote ischaemic conditioning against contrast-induced nephropathy (ERICCIN) trial. (http://Controlled-trials.com Identifier: ISRCTN49645414.)

Methods

The ERICCIN trial is a single-centre, randomised double-blinded placebo-controlled trial which plans to recruit 362 patients who are at risk of CIN, defined by pre-existent renal impairment (estimated glomerular filtration rate <60 ml/min/1.73 m²), over a period of 2 years. Patients will be randomised to either control or RIC consisting of 4, 5 min 200 mmHg balloon-cuff inflation/deflations, to the upper arm. The primary endpoint will be the development of CIN (>25 % of eGFR, or rise of creatinine of >44 μmol/l) at 48 h. A key secondary endpoint will be whether RIC impacts upon persistent renal impairment over the 3-month follow-up period. Additional secondary endpoints include the measurement of serum neutrophil gelatinase-associated lipocalin and urinary albumin at 6, 48 h and 3 months following administration of contrast.

Implications

Findings from ERICCIN trial will potentially demonstrate that RIC attenuates contrast-induced acute and chronic kidney injury and influence future clinical practice guidelines in at-risk patients undergoing coronary angiographic procedures.