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

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

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

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.

The effect of prophylactic oral vitamin C use on DNA double-strand breaks after abdominal contrast-enhanced CT: A preliminary study

PURPOSE

To investigate the protective effect of oral Vitamin C on DNA double-strand breaks (DSBs) after abdominal contrast-enhanced CT examination.

MATERIALS AND METHODS

Sixty patients undergoing abdominal multiphase contrast-enhanced CT were divided into control group (n = 30) and prevention group (n = 30). Patients in the prevention group were orally administered 1 g Vitamin C 30-120 minutes prior to CT examination. Blood samples were obtained prior to and 5 min following CT examination for each subject. γ-H2AX foci representing DSBs in the nucleus of lymphocytes were marked by fluorescent markers. Change in γ-H2AX foci/cell was compared through Student t-tests or ANOVA testing. The relationship between physical parameters and increase in γ-H2AX foci was analyzed through Pearson or Spearman correlation analysis.

RESULTS

The mean increase in γ-H2AX was 0.49 foci /cell in the control group and 0.19 foci/cell in the prevention group (p < 0.001), corresponding to a 61% reduction in the mean increase in γ-H2AX foci in the prevention group compared to the control group. In the prevention group, increase in γ-H2AX foci/cell positively correlated with dose length product and volume CT dose index (r = 0.449 and 0.403, respectively; both p < 0.05). No difference in the increase in γ-H2AX foci/cell was found between the different time interval subgroups of 30, 60, and 120 min between Vitamin C administration and CT examination (p > 0.05).

CONCLUSION

Oral Vitamin C can significantly reduce the level of DSBs after abdominal contrast-enhanced CT examination and is a simple and effective method to decrease DNA damage.

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.

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.

A Bayesian network meta-analysis of preventive strategies for contrast-induced nephropathy after cardiac catheterization

BACKGROUND

The optimal preventive strategy for contrast induced acute kidney injury (CIAKI) in patients undergoing cardiac catheterization remains uncertain.

OBJECTIVE

We conducted Bayesian network meta-analysis (NMA) to compare different preventive strategies for CIAKI in these cohorts.

METHODS

Forty-nine randomized controlled trials were extracted using MEDLINE, EMBASE and CENTRAL data bases (inception-1st December 2017). We calculated median of the odds ratio (OR) with the corresponding 95% credible interval (CrI). The ranking probability of each treatment was based on SUCRA (surface under the cumulative ranking curve).

RESULTS

In NMA of 28,063 patients [normal saline (NS: 9716 patients), sodium bicarbonate (NaHCO3: 4484 patients), statin (2542 patients), N-acetylcysteine (NAC: 3006 patients), NAC + NaHCO3 (774 patients), NS + NAC (3807 patients), NS + NaHCO3 (135 patients) and placebo (3599 patients)], statins reduced the relative risk of CIAKI compared with NS (OR: 0.50; 95% CrI, 0.25-0.99), and placebo (OR: 0.44; 95% CrI, 0.24-0.83). Subgroup analyses showed that in patients receiving low osmolar contrast, statins reduced the relative risk of CIAKI by 58% versus NS, and 51% versus placebo. There were no significant differences across all the treatments in terms of risk of hemodialysis or all-cause mortality. Statins had the highest probability for reducing the risk of CIAKI (SUCRA, 0.86), risk of hemodialysis (SUCRA, 0.88) and all-cause mortality (SUCRA, 0.81).

CONCLUSION

Statins were the superior preventive strategy for reducing the risk of CIAKI compared with NS alone and placebo.

The impact of N-acetylcysteine and ascorbic acid in contrast-induced nephropathy in critical care patients: an open-label randomized controlled study

BACKGROUND

The aim was to investigate whether the use of N-acetylcysteine and ascorbic acid reduce contrast-induced nephropathy incidence in critical care patients.

METHODS

This was a one-center, two-arm, prospective, randomized, open-label, controlled trial in the Intensive Care Unit of the University Hospital of Larissa, Greece. Patients with stable renal function, who underwent non urgent contrast-enhanced computed tomography for diagnostic purposes, were included in the study. Patients in the treatment group (NacA, n = 60) received intravenously N-acetylcysteine (1200 mg) and ascorbic acid (2 g) dissolved separately in 100 ml of normal saline 2 hours before, and at 10 hours and 18 hours following the infusion of contrast agent, while control group patients (CG, n = 64) received only normal saline. All patients received additional hydration. Contrast-induced nephropathy was defined as relative increase by 25% of the baseline values of serum creatinine.

RESULTS

Contrast-induced nephropathy in NacA and CG were 18.33% and 15.6%, respectively (p = 0.81). The percentage change median (interquartile range (IR)) of serum cystatin-C (mg/L) from baseline in patients who underwent contrast-induced tomography, were 37.23% (28.53) and 93.20% (46.90) in NacA and in CG, respectively (p = 0.03). The 8-isoprostane serum levels in NacA were significantly lower compared to CG at 2 hours (p = 0.012) and 24 hours (p = 0.006) following radiocontrast infusion. Multivariate analysis revealed that contrast-induced nephropathy was independently associated with a higher baseline ratio of serum urea/creatinine (odds ratio, 1.02; 95 CI%, 1.00-1.05) and with the use of nephrotoxic medications (odds ratio, 0.24; 95 CI%, 0.06-0.94).

CONCLUSION

Intravenous administration of N-acetylcysteine and ascorbic acid failed to reduce contrast-induced nephropathy in critically ill patients who underwent contrast-enhanced computed tomography, despite a significant reduction of 8-isoprostane levels in treated patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01017796 . Registered on 20 November 2009.

[Vitamin C+sodium bicarbonate versus sodium bicarbonate alone in preventing contrast-induced nephropathy]

INTRODUCTION

Contrast-induced nephropathy (CIN) is a common and severe complication in interventional cardiology.

OBJECTIVE

The aim of our study was to compare the incidence of contrast-induced nephropathy in two accelerated hydration protocols: the first one by the serum bicarbonate and the second combining the serum bicarbonate and oral vitamin C.

METHODS

This is a multicenter prospective, randomized study conducted between October 2012 and May 2013, including 160 patients.

RESULTS

The mean age of our study population was 60.8±9.3 years (36-83 years). The two study groups were comparable in terms of cardiovascular risk factors, concomitant medication, and baseline serum creatinine. The CIN incidence was 6.3% in the vitamin C group and 10% in the control group (P=0.38). No significant difference was observed in terms of CIN incidence between the different subgroups analyzed.

CONCLUSION

According to our study, ascorbic acid administered orally as part of an accelerated hydration protocol does not reduce the incidence of CIN.

Contrast-Induced Nephropathy: A Fact or Fiction in Lower Limb Revascularization?

INTRODUCTION

Contrast-induced nephropathy (CIN) is defined as an increase >25% of serum creatinine from baseline, occurring in 24-48 hours after exposure to contrast, while alternative explanations for renal impairment have been excluded. The volume administered directly relates to risk, increasing by 12% per 100 mL of contrast. According to the series, its incidence varies between 3.3% and 8% in patients without renal damage and 12-50% in patients with chronic kidney disease (CKD) and/or diabetes mellitus (DM). The purpose of this study is to determine the incidence of CIN in endovascular revascularization of lower limbs in our center, where we apply the ALARA concept (As Low As Reasonably Achievable) to the use of contrast.

MATERIAL AND METHODS

163 patients who underwent endovascular revascularization procedures in lower limbs were included in this prospective observational study between February 2013 and April 2015. They were classified according to clinical stage and presence of DM and/or CKD. Data included serum creatinine values preoperative and postoperative, type and volume of contrast used. Patients on hemodialysis and those without sufficient analytical data were excluded. Chi-squared test and Student t-test were used for data analysis. P < 0.05 was considered statistically significant.

RESULTS

109 patients were enrolled, with 67% of DM and 31.5% of CKD. CIN incidence was 3.7% in patients without DM neither CKD, in DM was 6.8% and 12.5% in CKD. Mean creatinine presurgery was 97.96 and postsurgery 97.07, finding no significant differences between them (P = 0.753). Medium-contrast volume was 37.43 mL ± 22.3. The worsening variable (creatinine postsurgery minus creatinine presurgery) was evaluated according to clinical stage, DM, or CKD, being not significant in either group.

CONCLUSIONS

In our experience, the dose administered of contrast was not related to the existence of postprocedure CIN, due to the policy of optimizing the use of contrast.

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.

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.

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.

Antioxidant effect of Phyllanthus emblica extract prevents contrast-induced acute kidney injury

Background

Contrast-induced acute kidney injury (CI-AKI) occurs after the administration of intravenous iodinated contrast agents. Oxidative stress has been proposed as one of the most important mechanisms in the pathogenesis of CI-AKI. The objective of this study was to investigate the antioxidant effect of the extract from Phyllanthus emblica (PE) in preventing CI-AKI.

Methods

Male Sprague Dawley rats were subjected into eight groups, were given water (control) or PE extract (125 or 250 or 500 mg/kg/day) for 5 days before the induction of CI-AKI. Renal function and oxidative stress markers; malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activity were determined in plasma and renal tissue. Kidney sections were performed for histopathological examination.

Results

In the contrast media (CM) group, increases in blood urea nitrogen and serum creatinine were demonstrated which correlated with severity of tubular necrosis, peritubular capillary congestion and interstitial edema. Moreover, an increase in MDA and a decrease in TAC SOD and CAT activity in CM group were significantly changed when compared with the control (P < 0.05). In contrast, CI-AKI-induced rats administrated with PE extract 250 and 500 mg/kg/day significantly preserved renal function and attenuated the severity of pathological damage (P < 0.05) as well as significantly lower MDA and higher TAC, SOD and CAT than the CM group (P < 0.05).

Conclusions

This study demonstrated the protective role of PE extract against 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.

Contrast-induced nephropathy in aged critically ill patients

Background. Aging is associated with renal structural changes and functional decline. The attributable risk for renal dysfunction from radiocontrast agents in critically ill older patients has not been well established. Methods. In this prospective study, we assessed the incidence of contrast-induced nephropathy (CIN) in critically ill patients with stable renal function who underwent computed tomography with intravenous contrast media. Patients were categorized into two age groups: <65 (YG) or ≥65 years old (OG). CIN was defined as 25% or greater increase from baseline of serum creatinine or as an absolute increase by 0.5 mg/dL until the 5th day after the infusion of contrast agent. We also evaluated the alterations in oxidative stress by assessing serum 8-isoprostane. Results. CIN occurred in 5 of 13 OG patients (38.46%) whereas no YG patient presented CIN (P = 0.015). Serum creatinine kinetics in older patients demonstrated a rise over five days following contrast infusion time while a decline was observed in the YG (P = 0.005). Conclusions. Older critically ill patients are more prone to develop renal dysfunction after the intravenous infusion of contrast agent in relation to their younger counterparts.

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.