Prevention of contrast-induced nephropathy with ascorbic acid

Endogenous and Exogenous Antioxidants as Agents Preventing the Negative Effects of Contrast Media (Contrast-Induced Nephropathy)

The use of conventional contrast media for diagnostic purposes (in particular, Gd-containing and iodinated agents) causes a large number of complications, the most common of which is contrast-induced nephropathy. It has been shown that after exposure to contrast agents, oxidative stress often occurs in patients, especially in people suffering from various diseases. Antioxidants in the human body can diminish the pathological consequences of the use of contrast media by suppressing oxidative stress. This review considers the research studies on the role of antioxidants in preventing the negative consequences of the use of contrast agents in diagnostics (mainly contrast-induced nephropathy) and the clinical trials of different antioxidant drugs against contrast-induced nephropathy. Composite antioxidant/contrast systems as theranostic agents are also considered.

Contrast-Induced Nephropathy: A Review of Mechanisms and Risks

Radiological procedures utilizing intravenous iodinated contrast agents are being widely utilized for both therapeutic and diagnostic purposes. This has resulted in an increasing incidence of procedure-related, contrast-induced nephropathy (CIN). CIN is commonly defined as a decline in kidney function occurring in a narrow time window after administration of iodinated contrast agents. Although self-limiting in most cases, CIN carries a risk of more permanent renal insufficiency, dialysis, and death. It remains a common and serious complication among at-risk patients after exposure of contrast agents. Therefore, it is important to identify patients who are at risk during early stages to implement preventative strategies to decrease the incidence of CIN. Minimizing the amount of contrast administered and providing adequate hydration are the cornerstones of an effective preventative approach. This review focuses on the basic concepts of CIN and summarizes the current understanding of its pathophysiology. In addition, it provides practical recommendations with respect to CIN prevention and management.

PrevenTion of contrast-inducEd nephropAThy with urinE alkalinization: the TEATE study design

: Intravascular administration of iodinated contrast media is an essential tool for the imaging of blood vessels and cardiac chambers, as well as for percutaneous coronary and structural interventions. Along with the spreading of diagnostic and interventional procedures, the increasing incidence of contrast-induced nephropathy (CIN) has become an important and prognostically relevant problem. CIN is thought to be largely dependent on oxidative damage, and is a considerable cause of renal failure, being associated with prolonged hospitalization and significant morbidity/mortality. The most effective treatment strategy of this serious complication remains prevention, and several preventive measures have been extensively investigated in the last few years.Preprocedural hydration is the best-known and mostly accepted strategy. The administration of sodium bicarbonate has controversial effects, and is likely to be ineffective when the infused dose is unable to achieve adequate urine alkalinization. Since alkaline pH suppresses the production of free radicals, increasing urine pH would be an attractive goal for CIN prevention.In a prospective randomized controlled, open-label clinical trial we will test the hypothesis that urine alkalinization with either oral or intravenous bicarbonate on top of hydration alone is the main determinant of CIN prevention (primary endpoint) in a population of patients with moderate or severe chronic kidney disease scheduled for coronary angiography and/or angioplasty. If we then demonstrate nonsignificant differences in urine alkalinization and incidence of CIN between the two bicarbonate groups (secondary endpoint), a practical implication will be that oral administration is preferable for practical reasons over the administration of intravenous bicarbonate.

Contrast-associated acute kidney injury: does it really exist, and if so, what to do about it?

For decades, when contrast agents are administrated, physicians have been concerned because of the risk of inducing acute kidney injury (AKI). Recent literature questions the existence of AKI induced by contrast, but animal studies clearly showed harmful effects. The occurrence of contrast-associated AKI was likely overestimated in the past because of confounders for AKI. Several strategies have been investigated to reduce contrast-associated AKI but even for the most important one, hydration, there are conflicting data. Even if the occurrence rate of contrast-associated AKI is low, AKI is related to worse outcomes. Therefore, besides limiting contrast agent usage, general AKI preventive measurements should be applied in at-risk patients.

Pharmacological interventions for the prevention of contrast-induced acute kidney injury in high-risk adult patients undergoing coronary angiography: a systematic review and meta-analysis of randomised controlled trials

Objective

Quantify the efficacy of strategies to prevent contrast-induced acute kidney injury (CI-AKI) in high-risk patients undergoing coronary angiography (CAG) with or without percutaneous coronary intervention (PCI).

Background

CI-AKI remains a common problem. The renoprotective efficacy of existing pharmacological agents remains uncertain in high-risk populations.

Methods

Systematic review and meta-analysis of randomised controlled trials (RCTs) to compare different strategies versus hydration in patients with chronic kidney disease (CKD) undergoing CAG±PCI. Primary outcome was incident CI-AKI. Fixed-effects meta-analyses estimated ORs, 95% CIs and heterogeneity.

Results

Forty-eight RCTs were included. Seven pharmacological strategies were evaluated by multiple RCTs and 10 by one RCT each. These had varying risk of bias; >25% of trials were at high risk of performance bias. Five strategies significantly reduced the odds of CI-AKI: N-acetylcysteine (NAC) (27 trials, 5694 participants; OR=0.77, 95% CI 0.65 to 0.91, p=0.002, I²=36%), ascorbic acid (four trials, 759 participants; OR=0.59, 95% CI 0.39 to 0.89, p=0.01, I²=0%), statin (two trials, 3234 participants; OR=0.59, 95% CI 0.39 to 0.89, p=0.75, I²=0%), trimetazidine (two trials, 214 participants; OR=0.27, 95% CI 0.10 to 0.71, p=0.01, I²=0%) and nicorandil (two trials, 389 participants; OR=0.47, 95% CI 0.23 to 0.94, p=0.03, I²=52%). Theophylline had a similar, but non-significant, effect. A subgroup analysis found that the benefit of NAC was highest in patients requiring a high-contrast dose.

Conclusions

Several drugs are renoprotective in patients with CKD undergoing CAG±PCI. The evidence is strongest for NAC. We recommend that NAC should be used when a high dose of contrast is anticipated.

Trial registration number

PROSPERO registration CRD42014014704.

Open Science Framework link: https://osf.io/vxg7d/?view_only=62bad0404b18405abd39ff2ead2575a8

Selenium, Vitamin C and N-Acetylcysteine do not Reduce the Risk of Acute Kidney Injury after Off-Pump CABG: a Randomized Clinical Trial

Objective

The aim of this study was to investigate the impact of perioperative administration of N-acetylcysteine, selenium and vitamin C on the incidence and outcomes of acute kidney injury after off-pump coronary bypass graft surgery.

Methods

291 patients requiring elective off-pump coronary bypass graft surgery were randomized to receive either N-acetylcysteine, vitamin C and selenium 600 mg, 1500 mg, 0.5 mg, and nothing orally twice a day, respectively, from the day before to 2 days after surgery. They were assessed for the development of acute kidney injury using Acute Kidney Injury Network criteria, time of onset, its severity and duration, duration of mechanical ventilation, intensive care unit and hospital length of stay, and in-hospital mortality.

Results

272 patients completed the study. The total incidence of acute kidney injury was 22.1% (n=60) with 14 (20.9%), 15 (22.1%), 21 (31.8%), and 10 (14.1%) patients in the vitamin C, NAC, selenium, and control groups, respectively (P=0.096). We did not register significant differences in the incidence, the time of occurrence, the severity and the duration of acute kidney injury, as well as the duration of mechanical ventilation, the intensive care unit and hospital length of stay, and the in-hospital mortality among the four groups.

Conclusion

We found that perioperative administration of N-acetylcysteine, vitamin C and selenium were not effective in preventing acute kidney injury and associated morbidity and mortality after off-pump coronary bypass graft surgery.

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.

Vitamins for Prevention of Contrast-induced Acute Kidney Injury: A Systematic Review and Trial Sequential Analysis

BACKGROUND

To date, universally accepted preventive measures for contrast-induced acute kidney injury (CI-AKI) do not exist, and they warrant further research.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of vitamins, including vitamin C and E, for prevention of CI-AKI.

METHODS

We electronically searched the MEDLINE, EMBASE, and Cochrane databases. The outcome of interest was the incidence of CI-AKI.

RESULTS

A total of 19 studies were included in this meta-analysis. Pooled analysis showed that vitamin C plus saline [relative risk (RR) = 0.63, 95% confidence interval (CI) 0.49-0.82, p = 0.0005] and vitamin E plus saline (RR = 0.39, 95% CI 0.24-0.62, p < 0.0001) significantly reduced the incidence of CI-AKI compared to saline alone. The effect of vitamin C plus saline was further confirmed by trial sequential analysis (TSA). However, TSA indicated that more trials are required to confirm the efficacy of vitamin E plus saline. There was no significant difference in preventing CI-AKI between vitamin C and N-acetylcysteine (NAC) (RR = 0.90, 95% CI 0.47-1.71, p = 0.75), between vitamin C plus NAC and saline (RR = 0.62, 95% CI 0.30-1.30, p =  0.20), as well as between vitamin C plus NAC and NAC (RR = 0.97, 95% CI 0.49-1.92, p = 0.93).

CONCLUSIONS

Vitamin C plus saline administration is effective at reducing the risk of CI-AKI. Evidence for the use of vitamin E plus saline in this context is encouraging, but more trials are required. Furthermore, this meta-analysis and TSA indicated insufficient power to draw a definitive conclusion on the effect of vitamin C plus NAC, versus saline or NAC alone, which needs to be explored further.

Post-contrast acute kidney injury. Part 2: risk stratification, role of hydration and other prophylactic measures, patients taking metformin and chronic dialysis patients : Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

OBJECTIVES

The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. AREAS COVERED IN PART 2: Topics reviewed include stratification of PC-AKI risk, the need to withdraw nephrotoxic medication, PC-AKI prophylaxis with hydration or drugs, the use of metformin in diabetic patients receiving contrast medium and the need to alter dialysis schedules in patients receiving contrast medium.

KEY POINTS

• In CKD, hydration reduces the PC-AKI risk • Intravenous normal saline and intravenous sodium bicarbonate provide equally effective prophylaxis • No drugs have been consistently shown to reduce the risk of PC-AKI • Stop metformin from the time of contrast medium administration if eGFR < 30 ml/min/1.73 m 2 • Dialysis schedules need not change when intravascular contrast medium is given.

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.

Ascorbic acid ameliorates renal injury in a murine model of contrast-induced nephropathy

BACKGROUND

Contrast induced nephropathy (CIN) is the commonest cause of iatrogenic renal injury and its incidence has increased with the advent of complex endovascular procedures. Evidence suggests that ascorbic acid (AA) has a nephroprotective effect in percutaneous coronary interventions when contrast media are used. A variety of biomarkers (NGAL, NGAL:creatinine, mononuclear cell infiltration, apoptosis and RBP-4) in both the urine and kidney were assayed using a mouse model of CIN in order to determine whether AA can reduce the incidence and/or severity of renal injury.

METHODS

Twenty-four BALB/c mice were divided into 4 groups. Three groups were exposed to high doses of contrast media (omnipaque) in a well-established model of CIN, and then treated with low or high dose AA or placebo (saline). CIN severity was determined by measurement of urinary neutrophil gelatinase-associated lipocalin (NGAL):creatinine at specific time intervals. Histological analysis was performed to determine the level of mononuclear inflammatory infiltration as well as immunohistochemistry to determine apoptosis in the glomeruli by staining for activated caspase-3 and DNA nicking (TUNEL assays). Reverse transcriptase PCR (rtPCR) of mRNA transcripts prepared from mRNA extracted from mouse kidneys was also performed for both lipocalin-2 (Lcn2) encoding NGAL and retinol binding protein-6 (RBP4) genes. NGAL protein expression was also confirmed by ELISA analysis of kidney lysates.

RESULTS

Urinary NGAL:creatinine ratio was significantly lower at 48 h with a 44% and 62% (204.3μg/mmol versus 533.6μg/mmol, p = 0.049) reduction in the low and high dose AA groups, respectively. The reduced urinary NGAL:creatinine ratio remained low throughout the time period assessed (up to 96 h) in the high dose AA group. In support of the urinary analysis ELISA analysis of NGAL in kidney lysates also showed a 57% reduction (12,576 ng/ml versus 29,393 ng/ml) reduction in the low dose AA group. Immunohistochemistry for apoptosis demonstrated decreased TUNEL and caspase-3 expression in both low and high dose AA groups.

CONCLUSIONS

Ascorbic acid reduced the frequency and severity of renal injury in this murine model of CIN. Further work is required to establish whether AA can reduce the incidence of CIN in humans undergoing endovascular procedures.

Strategies Preventing Contrast-Induced Nephropathy After Coronary Angiography: A Comprehensive Meta-Analysis and Systematic Review of 125 Randomized Controlled Trials

This systematic review with meta-analysis sought to determine the strength of evidence for the effects of hydration (sodium bicarbonate [SB] and normal saline [NS]), supplementations ( N-acetylcysteine [NAC] and vitamin C), and some common drugs (adenosine antagonists [AAs], statins, loop diuretics, and angiotensin-converting enzyme inhibitors [ACEIs]) on the incidence of contrast-induced nephropathy (CIN) and requirement for hemodialysis after coronary angiography. After screening, a total of 125 trials that reported outcomes were identified. Pooled analysis indicated beneficial effects of SB versus NS (odds ratio [OR] = 0.73; 95% confidence interval [CI]: 0.56-0.94; P = .01), NAC (OR = 0.79; 95% CI: 0.70-0.88; P = .001), vitamin C (OR = 0.64; 95% CI: 0.45-0.89; P = .01), statins (OR = 0.45; 95% CI: 0.35-0.57; P = .001), AA (OR = 0.28; 95% CI: 0.14-0.47; P = .001), loop diuretics (OR = 0.97; 95% CI: 0.33-2.85; P = .9), and ACEI (OR = 1.06; 95% CI: 0.69-1.61; P = .8). Overall, hydration with SB, use of supplements, such as NAC and vitamin C, and administration of statins and AA should always be considered for the prevention of CIN after coronary angiography.

Acute kidney injury in China

China has a large population and bears a heavy burden of kidney diseases. Acute kidney injury (AKI) is increasingly prevalent in China and is associated with severe morbidity and mortality. The inadequacies of early diagnosis and management remain the major challenges to Chinese nephrologists. There is an urgent need for a nationwide, or even a global effort to increase an awareness of the devastating effects of AKI, to develop professional preventive strategies, as well as to achieve early diagnosis and early intervention. In this article, we review the increasing incidence of AKI and complexity behind prevention and management, focusing on differences in various clinical settings in China.

Pharmacologic Prophylaxis for Contrast-Induced Acute Kidney Injury

In the effort to prevent contrast-induced acute kidney injury (CI-AKI), several pharmacologic agents have been tested for their single or combined nephroprotective properties. To date, however, no drug has been officially approved for this aim. This article focuses on the three agents that have been most extensively studied: statins, N-acetylcysteine, and ascorbic acid. Particular attention is paid to the impact of these drugs on the CI-AKI prevention and improved prognosis.

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.

The effect of intravenous vitamin C infusion on periprocedural myocardial injury for patients undergoing elective percutaneous coronary intervention

BACKGROUND

This small study has determined the effect of vitamin C on myocardial reperfusion in patients undergoing elective percutaneous coronary intervention (PCI). This study was to explore whether antioxidant vitamin C infusion before the procedure is able to affect the incidence of periprocedural myocardial injury (PMI) in patients undergoing PCI.

METHODS

In this prospective single-centre randomized study, 532 patients were randomized into 2 groups: the vitamin C group, which received a 3-g vitamin C infusion within 6 hours before PCI, and a control group, which received normal saline. The primary end point was the troponin I-defined PMI, and the second end point was the creatine kinase (CK)-MB-defined PMI. Separate analyses using both end points were performed. PMI was defined as an elevation of cardiac biomarker values (CK-MB or troponin I) > 5 times the upper limit of normal (ULN), alone or associated with chest pain or ST-segment or T-wave changes.

RESULTS

After PCI, the incidence of PMI was reduced, whether defined by troponin or by CK-MB, compared with the control group (troponin I, 10.9% vs 18.4%; P = 0.016; CK-MB, 4.2% vs 8.6%; P = 0.035). Logistic multivariate analysis showed that preprocedure use of vitamin C is an independent predictor of PMI either defined by troponin I (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.33-0.97; P = 0.037) or by CK-MB (OR, 0.37; 95% CI, 0.14-0.99; P = 0.048).

CONCLUSIONS

In patients undergoing elective PCI, preprocedure intravenous treatment with vitamin C is associated with less myocardial injury.

Role of dongchongxiacao (Cordyceps) in prevention of contrast-induced nephropathy in patients with stable angina pectoris

OBJECTIVE

To study the preventative effects of Dongchongxiacao (Cordyceps) on contrast-induced nephropathy (CIN) in patients with stable angina pectoris (SAP).

METHODS

One-hundred and three SAP inpatients were divided randomly into two groups: basic treatment (n = 51) and Dongchongxiacao (Cordyceps) treatment (n = 52); corbrin capsules (3 g; t.d.s.) were used 3 days before angioplasty and 3 days after angioplasty). Serum creatinine (Scr) was assessed at the time of hospital admission and 1, 2, and 3 days after angioplasty. Values of kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and interleukin (IL) 18 in the kidney were detected before angioplasty and 1 day after angioplasty in the patients of both groups. The prevalence of CIN between the two groups was then compared.

RESULTS

CIN occurred in 9 of 103 patients (8.74%). The prevalence of CIN in the Dongchongxiacao (Cordyceps) treatment group was lower than that of the basic treatment group (5.77% vs 11.76%) but the difference was not significant (P > 0.05). The post-procedure mean peak of Scr, post-procedure increase in Scr levels from baseline, and urine levels of KIM-1, NGAL and IL18 after the procedure in the Dongchongxiacao (Cordyceps) treatment group were significantly lower than those in the basic treatment group (P < 0.05).

CONCLUSION

Prophylactic treatment with Dongchongxiacao (Cordyceps) in SAP patients who undergo coronary angiography or coronary intervention could prevent contrast-induced renal impairment.

Radiographic contrast-media-induced acute kidney injury: pathophysiology and prophylactic strategies

Contrast-induced acute kidney injury (CI-AKI) is one of the most widely discussed and debated topics in cardiovascular medicine. With increasing number of contrast-media- (CM-) enhanced imaging studies being performed and growing octogenarian population with significant comorbidities, incidence of CI-AKI remains high. In this review, pathophysiology of CI-AKI, its relationship with different types of CM, role of serum and urinary biomarkers for diagnosing CI-AKI, and various prophylactic strategies used for nephroprotection against CI-AKI are discussed in detail.

Does ascorbic acid protect against contrast-induced acute kidney injury in patients undergoing coronary angiography: a systematic review with meta-analysis of randomized, controlled trials

OBJECTIVES

This study sought to perform a systematic review with meta-analysis of randomized controlled trials comparing the use of ascorbic acid with placebo or other treatment options for the treatment of contrast induced-acute kidney injury (CI-AKI) in patients undergoing coronary angiography.

BACKGROUND

CI-AKI remains the most widely discussed and debated topic in cardiovascular medicine, with its incidence increasing due to an increasing number of contrast media-enhanced radiological procedures being performed.

METHODS

MEDLINE, Embase, and Cochrane central databases were searched from inception to May 2013, without language restrictions. For a study to be selected, it had to report the incidence of CI-AKI as an outcome measure. Studies were excluded if at least 1 study arm did not have ascorbic acid administered alone or with saline solution hydration. Data were extracted by 1 author, and random checks were made by another author.

RESULTS

Nine randomized, controlled trials reported data on the incidence of CI-AKI in 1,536 patients who had completed the trial and were included in the final analysis. Patients receiving ascorbic acid had 33% less risk of CI-AKI compared with patients receiving placebo or an alternate pharmacological treatment (risk ratio by random-effects model: 0.672; 95% confidence interval, 0.466 to 0.969; p = 0.034).

CONCLUSIONS

Ascorbic acid provides effective nephroprotection against CI-AKI and may form a part of effective prophylactic pharmacological regimens.

Comparison of diagnostic accuracy of Doppler USG and contrast-enhanced magnetic resonance angiography and selective renal arteriography in patients with atherosclerotic renal artery stenosis

Background

There are many systemic complications of conventional selective renal arteriography (SRA), such as contrast-mediated nephropathy. Contrast-enhanced magnetic resonance angiography (CE-MRA) and renal artery Doppler ultrasonography (DUSG) have been used increasingly for renal artery stenosis (RAS). The aim of this study was to evaluate the accuracy of CE-MRA and DUSG as used for diagnosis of RAS.

Material/Methods

We divided 130 consecutive patients investigated for resistant hypertension into 2 groups based on age: group 1 was patients <60 years old and group 2 was patients >60 year. DUSG, CE-MRA, and SRA were performed in group 1 and group 2 patients.

Results

Seventy-two patients (24 males [M], 48 females [F]) in group 1, and 58 patients (26 M, 32 F) in group 2 were included in the study. In the evaluation of clinically significant renal artery stenosis with DUSG, in group 1 the overall sensitivity was 83.33% and overall specificity was 81.82%, and in group 2 they were 69.23% and 0%, respectively, when compared with SRA. In the evaluation of clinically significant renal artery stenosis with CE-MRA, the overall sensitivity and specificity were 92.31% and 36.36%, respectively, in group 1 and 100.00% and 73.33%, respectively in group 2, when compared with SRA.

Conclusions

CE-MRA is an accurate, non-invasive method for the diagnosis of RAS in patients above 60 years of age and DUSG may be the choice of diagnostic method for RAS in patients under 60 years of age.

Serum neutrophil gelatinase-associated lipocalin and cystatin C are early biomarkers of contrast-induced nephropathy after coronary angiography in patients with chronic kidney disease

We had previously reported on serum neutrophil gelatinase-associated lipocalin (NGAL) as an earlier biomarker of contrast-induced nephropathy (CIN) than serum creatinine (SCr) in 100 patients with chronic kidney disease undergoing coronary angiography.(1) We then compared serum NGAL to serum cystatin C (CysC) in the same group of patients. The SCr, estimated glomerular filtration rate, serum NGAL, and serum CysC were measured at baseline and various time points as appropriate postprocedure. The frequency of CIN was 11% (n = 11). Serum NGAL increased ≥25% from baseline at 24 hours in 7 patients with CIN (P = .04). Serum CysC increased ≥25% from baseline at 24 hours in 4 patients with CIN (P = .008). Changes in serum NGAL and serum CysC from baseline at 24 hours (▵ values) could diagnose CIN 24 hours earlier than SCr with serum NGAL showing a superior performance.

Ascorbic Acid: Prevention of Contrast-Induced Nephropathy

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .

Efficacy of ascorbic acid, N-acetylcysteine, or combination of both on top of saline hydration versus saline hydration alone on prevention of contrast-Induced nephropathy: a prospective randomized study

BACKGROUND

Antioxidant drugs such as N-acetylcysteine (NAC) and ascorbic acid have been evaluated in interventional studies to prevent contrast-induced nephropathy (CIN), however, there are limited data on comparing either or both, with background of standard intravenous saline hydration versus the standard intravenous saline hydration alone in preventing CIN.

METHODS

We conducted a single-center randomized trial among patients undergoing coronary angiography or percutaneous coronary intervention who had serum creatinine ≥ 1.3 mg/dL or were on diabetes mellitus medication. Eligible patients were randomly assigned to one of the following 4 groups: (1) NAC, (2) ascorbic acid, (3) combination of both drugs, and (4) control group. Additionally, all the groups received the standard intravenous saline hydration. Creatinine was measured 4-5 days after procedure.

RESULTS

A total of 243 patients were randomized; 62 to NAC, 57 to ascorbic acid, 58 to both drugs, and 66 to placebo. The development of 0.5 mg/dL absolute increase of serum creatinine, 25% relative decrease of creatinine clearance, or either (CIN) were measured in the ascorbic acid group (3.6% for all), NAC group (6.8%, 3.4%, 8.5%, respectively), combined group (5.5%, 5.5%, 9.1%, respectively), and control group (6.2%, 6.2%, 7.7%, respectively). None of these differences were significant (P = 0.896 for serum creatinine, P = 0.863 for creatinine clearance, and P = 0.684 for CIN).

CONCLUSIONS

In a cohort of patients at risk of developing CIN, we could not detect any significant benefit of the use of ascorbic acid, NAC, or a combination of both drugs over the standard hydration regimen in preventing CIN.