Nephropathy In High-risk Patients Research Articles

Effectiveness of edaravone in preventing contrast-induced nephropathy in high-risk patients undergoing coronary angiography: A randomized, double-blind trial.

Contrast-induced nephropathy (CIN) is a serious complication that occurs subsequent to the administration of contrast media for therapeutic angiographic interventions. As of present, no effective therapy exists to prevent its occurrence. This single-center double-blind randomized controlled trial aimed to evaluate the effect of edaravone, an antioxidant, in a group of high-risk patients undergoing coronary angiography. Ninety eligible patients with chronic kidney disease Stages 3-4 were randomly assigned to either the control group (n = 45) or the intervention group (n = 45). In the intervention group, one dosage of edaravone (60 mg) in 1 L of normal saline was infused via a peripheral vein 1 h prior to femoral artery-directed coronary angiography. Patients in the control group received an equal amount of infusion in their last hour before angiography. Both groups received intravenous hydration with 0.9% sodium 1 mL/kg/h starting 12 h before and continuing for 24 h after angiography. The primary outcome measure was the onset of CIN, defined as a 25% increase in serum creatinine levels 120 h after administration of contrast media. The occurrence of CIN was observed in 5.5% (n = 5) of the studied population: 2.2% of patients in the intervention group (n = 1) and 8.9% of controls (n = 4). However, this difference was not statistically significant. Administration of a single dosage of edaravone 1 h prior to infusion of contrast media led to a reduction in the incidence of CIN. Further investigations, employing larger sample sizes, are warranted to gain a comprehensive understanding of its efficacy.

Prospective Randomized Trial of Na/K Citrate for the Prevention of Contrast-Induced Nephropathy in High-risk Patients.

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI) refers to an acute kidney injury (AKI) occurring after exposure to contrast media, commonly used in diagnostic procedures or therapeutic angiographic interventions. Recently, Na/K citrate, used for urine alkalinization, has been assessed for preventing CIN. This experiment evaluated Na/K citrate's efficacy in preventing CIN in high-risk patients undergoing cardiac catheterization. A prospective randomized clinical trial involved 400 patients with moderate- to high-risk factors for CIN undergoing elective percutaneous coronary intervention (PCI). They were randomly assigned to either the control or Na/K citrate groups. The Na/K citrate group (n = 200) received a 5 g Na/K citrate solution diluted in 200 mL water 2 hours before and 4 hours after the first administration, along with intravenous hydration for 2 hours before and 6 hours after the procedure. In contrast, the control group (n = 200) received only intravenous hydration. Serum creatinine (SCr) levels were measured before contrast exposure and 48 hours afterward. CIN was defined as a 25% increase in serum creatinine (SCr) or > 0.5 mg/dL 48 hours after contrast administration. The significance level was set at P ˂ 0.05. CIN was observed in 33 patients (16.5%) in the control group and 6 patients (3%) in the Na/K citrate group. The incidence of CIN was found to have a significant difference between the 2 groups 48 hours after receiving the radiocontrast agent (P < 0.001). Our results show that Na/K citrate is helpful and substantially reduces the incidence of CIN.

SAT-030 CONTRAST INDUCED NEPHROPATHY IN HIGH RISK PATIENTS – MYTH OR REALITY

Contrast induced nephropathy (CIN) is a potential complication of administration of contrast media. CIN is defined as an elevation of serum creatinine (Scr) of more than 25% or ≥0.5 mg/dl (44 μmol/l) from baseline within 48-72 hours in the absence of alternate causes of acute kidney injury (AKI). Incidence of contrast induced acute kidney injury (CI-AKI) in patients undergoing coronary angiography with normal baseline renal function was reported to be < 2%7. However, the incidence of CI-AKI was found to be as high as 50% in chronic kidney disease (CKD) patients undergoing Coronary Angiography. This high incidence reported by studies is mainly due to differences in definition, background renal failure, types and dose of contrast medium used and frequency of other co-existing potential cause of AKI. Recent studies have been published showing that risk of CIN is an ‘overestimated entity” in the literature. The objective of this study is to determine the frequency of CIN in CKD patients with creatinine clearance (CrCl) less than 60ml/min undergoing contrast exposure. We conducted prospective, controlled single center trial in 44 patients with CrCl than 60ml/min who were risk stratified according to Mehran scoring system and underwent coronary angiography or contrast enhanced CT scan and specific protocol for prevention of CIN i.e. IV Hydration with 0.9% Normal Saline was given before procedure and were followed up to 72 hours post procedure. Thirty-three patients out of Forty-Four patients (75%) got adequate hydration as per protocol however eleven patients underwent procedure without hydration as preexisting condition did not allow so. Out of forty-four patients, risk stratification according to Mehran protocol revealed that fifteen out of forty-four patients (34%) were in very high-risk group, sixteen (36%) were in High risk group and thirteen (29%) were in intermediate risk group. Our experience revealed that five Patients out of total Forty-Four patients (11.3%) suffered from Contrast induced Nephropathy and none of them needed hemodialysis. Our study has raised a serious question regarding the incidence of Contrast induced Nephropathy in High risk patients as reported previously. However, more studies are needed on this issue. Till that time, we might consider CIN “a myth rather than a reality”.

Single-Center Prospective Study to Investigate the Difference in the Incidence of Contrast-Induced Nephropathy in High-Risk Patients With the Use of the Dye-Vert Plus System

Single-Center Prospective Study to Investigate the Difference in the Incidence of Contrast-Induced Nephropathy in High-Risk Patients With the Use of the Dye-Vert Plus System

Efficacy of nicorandil treatment for prevention of contrast-induced nephropathy in high-risk patients undergoing cardiac catheterization: A prospective randomized controlled trial

Contrast-induced nephropathy (CIN) remains to be a potentially serious complication of radiographic procedures and is the third leading cause of the acute kidney injury (AKI) among hospitalized patients. This clinical trial was performed to assess the preventive effect of oral nicorandil on CIN in high-risk patients undergoing cardiac catheterization. In this prospective, randomized, controlled trial, 128 patients with at least two risk factors for CIN undergoing elective percutaneous coronary intervention (PCI) were randomly assigned to either the nicorandil group or the control group. Patients in the nicorandil group (n = 64) received 10 mg nicorandil, daily from 30 min before and up to 3 days after procedure and intravenous hydration for 2 h before and 6 h after the procedure, whereas patients in the control group (n = 64) just received intravenous hydration. Serum creatinine (SCr) was measured before contrast exposure and at 72 h. CIN was defined as an increase of 25% in SCr or > 0.5 mg/dL 72 h after contrast administration. Contrast-induced nephropathy occurred in 14 out of 64 (21.9%) patients in the control group and in 3 out of 64 (4.7%) patients in the nicorandil group. There was a significant difference in the incidence of CIN between the two groups at 72 h after administering the radiocontrast agent (p = 0.008). Moreover, there were significant differences between the two groups in SCr and estimated glomerular filtration rate 72 h after radiocontrast administration (p < 0.05). The findings revealed that oral nicorandil had substantial efficacy over hydration protocol for the development of CIN in high-risk patients undergoing cardiac catheterization.

Efficacy of Atorvastatin in Prevention of Contrast-induced Nephropathy in High-risk Patients Undergoing Angiography: A Double-blind Randomized Controlled Trial

Objective:To evaluate the efficacy and safety of atorvastatin (ATN) 80 mg in the prevention of contrast medium- induced nephropathy (CIN) in high risk patients undergoing angiograph.Materials and Methods:This was a prospective, double-blind, two-arm, parallel group RCT. A total of 216 patients undergoing coronary angiography were screened, and 188 eligible patients were randomized to two treatment arms. Patients in Group A received tablet N-acetylcysteine (NAC) 1200 mg once daily, and patients in Group B received tablet atorvastatin 80 mg + NAC 1200 mg once daily, for 3 days before, and 2 days after angiography.Results:A total of 160 patients completed the trial. Postprocedure, nine and two CIN cases were found in Group A and B, respectively. The mean change in serum creatinine was 0.086 ± 0.168 in Group A and 0.021 ± 0.083 in Group B, which was statistically significant (P = 0.0289). Postprocedure, the estimated glomerular filteration rate was reduced by 19.52 in Group A and 13.55 in Group B (P = 0.003).Conclusion:This trial indicates the positive role of statins in preventive strategy against CIN along with NAC.

Prophylactic hydration to prevent contrast-induced nephropathy: much ado about nothing?

Clinical guidelines recommend prophylactic hydration to reduce the risk of contrast-induced nephropathy in high-risk patients, including those with chronic kidney disease. A recent single-center randomized trial showed no significant difference inthe incidence of contrast-induced nephropathy in ambulatory patients with stage3 chronic kidney disease who were randomized to no prophylactic hydration versusnormal saline hydration. While these results may identify patients who areless likely to benefit from prophylactic hydration, nephrologists and interventionalists should carefully consider the generalizability of these results toindividual patients.

Nephroprotective potential of carnitine against glycerol and contrast-induced kidney injury in rats through modulation of oxidative stress, proinflammatory cytokines, and apoptosis.

Contrast media (CM) are a major cause of nephropathy in high-risk patients. The aim of this study was to examine the effects of carnitine (CAR) in advanced nephrotoxicity due to CM administration in rats with glycerol-induced renal functional disorder. 40 rats were divided randomly into five groups (n = 8): (1) healthy group; (2) glycerol only (GLY); (3) glycerol and CM (GLY + CM); (4) glycerol, CM and 200 mg kg(-1) carnitine (CAR200, Carnitene(®); Sigma-tau/Santa Farma, Istanbul, Turkey); and (5) glycerol, CM and 400 mg kg(-1) carnitine (CAR400). Kidney injury was induced with a single-dose, intramuscular injection of 10 ml kg(-1) body weight (b.w.) of GLY. CAR was administered intraperitoneally. CM (8 ml kg(-1) b.w. iohexol, Omnipaque™; Opakim Medical Products, Istanbul, Turkey) was infused via the tail vein to the rats in Groups 3-5. l-carnitine administration significantly decreased serum creatinine and blood urea nitrogen levels. Superoxide dismutase and glutathione activity increased significantly in the treatment groups compared with the nephrotoxic groups. CAR400 significantly reduced malondialdehyde levels to healthy levels. In the treatment groups, tumour necrosis factor (TNF)-α, transforming growth factor 1β, interleukin 1β and caspase-3 gene expression decreased compared with the nephrotoxic groups. TNF-α and nuclear factor kappa-beta (NF-κB) protein expression increased after CM and CAR administration reduced both TNF-α and NF-κB expressions. Histopathologically, hyaline and haemorrhagic casts and necrosis in proximal tubules increased in the nephrotoxicity groups and decreased in the CAR groups. The results reveal that l-carnitine protects the oxidant/antioxidant balance and decreases proinflammatory cytokines and apoptosis in CM-induced nephrotoxicity in rats with underlying pathology. Depending on the underlying kidney pathologies, the incidence of CM-induced nephropathy (CIN) increases. Therefore, this is the best model to represent clinically observed CIN.

Feasibility study of the RenalGuard™ balanced hydration system: A novel strategy for the prevention of contrast-induced nephropathy in high risk patients

BackgroundContrast-induced nephropathy (CIN) is a frequent complication following angiographic procedures with significant impact on healthcare costs, and long-term outcomes. Multiple reno-protective strategies have been studied but few have shown benefit in prospective randomized studies beyond limiting the exposure to iodinated contrast and adequate intravenous. We studied the performance and safety of a novel system designed to achieve precise real-time high volume fluid balance using a closed loop hydration monitoring and infusion system. MethodsThis prospective, multi-center, FDA approved phase II feasibility study was designed to evaluate the safety and the performance of the RenalGuard matched hydration system. Between October 2006 and November 2007, twenty-three subjects at high risk for CIN (with an estimated glomerular filtration rate (eGFR)<50ml/min/1.73m2) undergoing diagnostic or therapeutic catheterization were treated with the system. The primary endpoint of the study was defined as the ability of the system to effectively dynamically match fluid administration to urine output. ResultsThe 23 subjects at high risk for CIN enrolled had a mean±SD eGFR of 39±9.3. Patients achieved an hourly urine flow rate of 620±400ml/h. The system had a mean effectiveness rate of 99.9% over the duration of therapy with an average saline volume infused of 3825ml closely matched, minute to minute, to urine output of 3579ml. There were no major device-related complications from the experimental therapy, though one patient developed hypokalemia requiring replacement. Two subjects (9.5%) developed CIN as defined by >0.5mg/dl or >25% rise in serum creatinine at 48–60h post contrast administration when compared with the baseline. ConclusionThe study confirmed that the RenalGuardTM system is safe and dynamically balances volume hydration with urine production. Further randomized studies are needed to confirm the efficacy of the system in reducing the incidence of CIN.

Effects of N-Acetylcysteine on Renal Hemodynamics in Contrast Media-Induced Nephropathy

Background: N-acetylcysteine (NAC) has been proposed to prevent radiocontrast nephropathy in high-risk patients. Methods: The effect of single-dose and prolonged administration of NAC before application of either the ionic, high-osmolar radiocontrast agent diatrizoate sodium (DTZ) or the nonionic, low-osmolar radiocontrast agent iohexol (IOH) in a rat model combining uninephrectomy, salt depletion, and administration of indomethacin was explored. Arterial blood pressure and total, cortical, and medullary blood flow were continuously recorded in anesthetized Sprague-Dawley rats. Results: NAC had no effect on renal hemodynamics in control rats. Both DTZ and IOH induced biphasic changes in renal blood flow and cortical renal blood flux and persistently reduced medullary blood flux. Neither single-dose nor prolonged administration of NAC prevented the hemodynamic changes following administration of DTZ or IOH, respectively. Acute prophylactic administration of NAC prevented increased urinary ET excretion after injection of IOH and, to a smaller degree, of DTZ. Both an ionic, high-osmolar (DTZ) and a nonionic, low-osmolar (IOH) radiocontrast agent induce marked changes in renal hemodynamics in salt-depleted rats treated with indomethacin. Conclusions: Renal perfusion is not affected by NAC application in a model of experimental contrast nephropathy in rats. Other effects of NAC might thus account for the presumed renoprotective properties.

Iloprost Prevents Contrast-Induced Nephropathy in Patients With Renal Dysfunction Undergoing Coronary Angiography or Intervention

The prevention of contrast-induced nephropathy, which accounts for considerable morbidity and mortality, remains a vexing problem. Contrast-induced renal vasoconstriction is believed to play a pivotal role in the pathogenesis of contrast-induced nephropathy. The aim of this study was to examine the efficacy of the prostacyclin analog iloprost in preventing contrast-induced nephropathy in patients with renal dysfunction undergoing a coronary procedure. We conducted a randomized, double-blind, placebo-controlled trial of iloprost in 208 patients with a serum creatinine concentration >or=1.4 mg/dL who underwent coronary angiography and/or intervention. Iloprost 1 ng kg(-1) min(-1) or placebo was administered intravenously beginning 30 to 90 minutes before and ending 4 hours after the procedure. Contrast-induced nephropathy was defined by an absolute increase in serum creatinine >or=0.5 mg/dL or a relative increase >or=25% measured 2 to 5 days after the procedure. Contrast-induced nephropathy occurred in 23 of the 105 patients (22%) in the control group and in 8 of the 103 patients (8%) in the iloprost group (odds ratio, 0.29; 95% confidence interval, 0.12 to 0.69; P=0.005). In the control group, the estimated glomerular filtration rate declined from 49.7+/-15.5 to 46.6+/-16.6 mL min(-1) 1.73 m(-2) (P=0.01). In the iloprost group, the estimated glomerular filtration rate increased marginally from 47.5+/-14.5 to 48.6+/-16.1 mL min(-1) 1.73 m(-2) (P=0.26). The mean absolute estimated glomerular filtration rate decline in the control group was greater than its change in the iloprost group (difference, 4.2 mL min(-1) 1.73 m(-2); 95% confidence interval, 1.1 to 7.3; P=0.008). Prophylactic administration of iloprost may protect against contrast-induced nephropathy in high-risk patients undergoing a coronary procedure.

Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT – A pooled analysis of two randomized trials

The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients with glomerular filtration rate (GFR) <60 ml/min undergoing contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients with moderate-to-severe renal failure received a similar IV contrast dose (40 gI). Serum creatinine (SCr) was measured at screening, baseline and 48-72 +/- 6 h after the MDCT examination. Primary CIN outcome was an increase in SCr >or=0.5 mg/dl (>or=44.2 micromol/l) from baseline. The CIN rates were 2.3% in the total population, 0.6% when GFR >40 ml/min, 4.6% when GFR <40 ml/min and 7.8% in patients with GFR <30 ml/min. The incidence of CIN was significantly higher after iodixanol than after LOCM (seven patients, 4.7% following IOCM, no CIN cases following the LOCM; p = 0.007). Significant differences in favor of the LOCM were also observed in patients with GFR <40 ml/min and GFR <30 ml/min. Following the IV administration of nonionic contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM iopamidol and iomeprol, especially in high-risk patients. Differences in osmolality between these LOCM and iodixanol do not play a role in the genesis of CIN.

Cardiovascular Literature—Beyond Nephrology

Although the occurrence of radiocontrast-induced nephropathy is relatively rare overall, approximately 2%, it is appreciable in high-risk individuals, particularly patients with chronic kidney disease (CKD) (1,2) and diabetic nephropathy (3), especially when undergoing percutaneous interventions (4) with reported rates as high as 20%. In the past, it had been reported that the isosmolar dimeric nonionic radiocontrast agent iodixanol when compared with the low osmolar monomeric nonionic agent iohexol less frequently caused radiocontrast nephropathy in high-risk patients (5). A single-center trial, however, recently failed to show a difference in the incidence of radiocontrast-induced nephropathy when iodixanol was compared with the low osmolality but ionic ioxaglate in patients with CKD (6). This issue was reexamined in this multicenter, randomized, double-blind comparison of iodixanol and iopamidol in patients who had CKD (estimated GFR [eGFR] 20 to 59 ml/min per 1.73 m2) and underwent cardiac angiography or percutaneous coronary interventions. ### Findings. A total of 482 patients could be evaluated. The two groups were comparable with respect to all relevant parameters, particularly eGFR (49.3 ± 11.6 versus 50.2 ± 13.0 ml/min per 1.73 m2). The primary end point of an increase in serum creatinine >0.5 mg/dl was not significantly different between the two groups (6.7% iodixanol versus 4.4% iopamidol). The secondary end points of a >25% increase of serum creatinine occurred in 12.4% on iodixanol versus 9.8% on iopamidol (NS) and a decrease of eGFR in 10.0% on iodixanol versus in 5.9% on iopamidol. The secondary end points of postdose increase in serum creatinine and decrease of eGFR, respectively, were even in favor of iopamidol (serum creatinine 0.07 ± 0.22 mg/dl on iopamidol versus 0.12 ± 0.23 mg/dl on iodixanol; P < 0.03) particularly in the subgroup of patients with diabetes (0.07 ± 0.26 mg/dl versus 0.16 ± 0.27; P < 0.01). …

Comparison of Two Hemofiltration Protocols for Prevention of Contrast-induced Nephropathy in High-risk Patients

Comparison of Two Hemofiltration Protocols for Prevention of Contrast-induced Nephropathy in High-risk Patients

Effect of a Rapid Intra-Arterial Infusion of Dextrose 5% Prior to Coronary Angiography on Frequency of Contrast-Induced Nephropathy in High-Risk Patients

Effect of a Rapid Intra-Arterial Infusion of Dextrose 5% Prior to Coronary Angiography on Frequency of Contrast-Induced Nephropathy in High-Risk Patients

Iloprost for prevention of contrast-mediated nephropathy in high-risk patients undergoing a coronary procedure. Results of a randomized pilot study

The prevention of contrast-mediated nephropathy (CMN), which accounts for considerable morbidity and mortality, remains a vexing problem. Contrast induced renal vasoconstriction is believed to play a pivotal role in the CMN mechanism. The aim of this pilot study was to examine the safety and efficacy of two doses of the prostacyclin analogue iloprost in preventing CMN in high-risk patients undergoing a coronary procedure. Forty-five patients undergoing coronary angiography and/or intervention who had a serum creatinine concentration >or=1.4 mg/dL were randomized to receive iloprost at 1 or 2 ng/kg/min or placebo, beginning 30-90 minutes before and terminating 4 hours after the procedure. CMN was defined by an absolute increase of serum creatinine >or=0.5 mg/dL or a relative increase of >or=25% measured 2 to 5 days after the procedure. Study drug infusion was discontinued in 2 patients in the low-dose iloprost group due to flush/nausea and in 5 patients in the high-dose group due to severe hypotension. The mean creatinine concentration change in the placebo group (0.02 mg/dL) was unfavorable compared to that in the low-dose iloprost group (-0.11 mg/dL; p=0.08) and high-dose iloprost group (-0.23 mg/dL; p=0.048). The difference between the absolute changes in creatinine clearance was favorable compared to placebo for both the low (mean difference 6.1 mL/min, 95%CI -0.5 to 12.8 mL/min, p=0.07) and the high-dose iloprost group (11.8 mL/min, 95%CI 4.7 to 18.8 mL/min, p=0.002). Three cases of CMN were recorded; all in the placebo group (p=0.032). The results of this pilot study suggest that prophylactic administration of iloprost may effectively prevent CMN, but higher dosages are connected with substantial tolerability issues.

Effect of a Rapid Intra-Arterial Infusion of Dextrose 5% Prior to Coronary Angiography on Frequency of Contrast-Induced Nephropathy in High-Risk Patients

Contrast-induced nephropathy (CIN) is a common complication of coronary angiography that is associated with significant morbidity and mortality. Preexisting renal dysfunction is the most important risk factor for the development of CIN. A novel strategy of infusing 1 L of 5% dextrose immediately before catheterization is associated with a lower rate of CIN in those at high risk (creatinine clearance < or = 60 ml/min). CIN occurred in 47 patients (5.7%) in the control group and 2 patients (1.4%) in the group treated with 5% dextrose. The relative risk decrease was 73% (p = 0.03). This is an effective, quick, and inexpensive method of improving outcomes in patients who undergo percutaneous coronary interventions.

Comparison of Two Hemofiltration Protocols for Prevention of Contrast-induced Nephropathy in High-risk Patients

Purpose Contrast-induced nephropathy is a complication of contrast medium administration during diagnostic and interventional procedures, with important prognostic relevance. Patients with chronic kidney disease have a higher risk for contrast-induced nephropathy and poorer outcome. In patients with chronic kidney disease, hemofiltration reduces contrast-induced nephropathy incidence and improves long-term survival. We assessed the mechanisms involved in the prophylactic effect of hemofiltration and of the most effective hemofiltration protocol to prevent contrast-induced nephropathy in patients with chronic kidney disease. Subjects and methods We randomized 92 patients with chronic kidney disease (creatinine clearance ≤30 mL/min) to three different prophylactic treatments: intravenous hydration with isotonic saline (1 mL · kg · h for 12 hours before and after contrast exposure, control group; n = 30); intravenous hydration for 12 hours before contrast exposure, followed by hemofiltration for 18 to 24 hours after contrast exposure (post-hemofiltration group; n = 31), and hemofiltration performed for 6 hours before and for 18 to 24 hours after contrast exposure (pre/post-hemofiltration group; n = 31). The incidence of contrast-induced nephropathy (>25% increase in creatinine) and the in-hospital clinical course were compared in the three groups. Results Twelve patients (40%) in the control group, 8 patients (26%) in the post-hemofiltration group, and 1 patient (3%) in the pre/post-hemofiltration group experienced contrast-induced nephropathy ( P = .0013); hemodialysis was required in 9 (30%), three (10%), and zero (0%) patients, respectively ( P = .002). In-hospital mortality was 20%, 10%, and 0%, respectively ( P = .03). Conclusions Hemofiltration is an effective strategy for contrast-induced nephropathy prevention in patients with chronic kidney disease who are undergoing cardiovascular procedures. Pre-hemofiltration is required to obtain the full clinical benefit, suggesting that, among different mechanisms possibly involved, high-volume controlled hydration before contrast media exposure plays a major role.

Recent advances in the prevention of radiocontrast-induced nephropathy

Radiocontrast nephropathy is a serious clinical problem associated with increased morbidity and mortality, particularly in patients with chronic renal failure. The optimal strategy to prevent radiocontrast nephropathy has not been established. This article reviews recent clinical researches concerning new developments in the prevention of radiocontrast nephropathy and analyzes unresolved issues. Among all prophylactic measures that have been proposed, periprocedural hydration with isotonic saline has demonstrated effectiveness in the prevention of radiocontrast nephropathy. Thus, it remains the most frequently applied measure in clinical practice. Recently, additional benefit has been shown to derive from the infusion of isotonic alkalizing (sodium bicarbonate), instead of isotonic (sodium chloride) solutions. The use of nonionic low-osmolar and, more recently, nonionic iso-osmolar contrast agents has been demonstrated to significantly reduce the risk of radiocontrast nephropathy in patients with renal impairment, in comparison with hyperosmolar contrast media. Recently, periprocedural hemofiltration has emerged as a safe and very effective strategy to prevent radiocontrast nephropathy and to reduce its associated poor outcome in patients with severe chronic renal failure. In the past few years, several trials with acetylcysteine have shown conflicting results. Nevertheless, most of them indicated that acetylcysteine, particularly when associated with adequate hydration, might be useful in preventing radiocontrast nephropathy in patients with renal impairment. A possible dose-dependent protective effect has been suggested by more recent trials that included patients undergoing coronary interventional procedures requiring large contrast volume. Adequate prophylaxis is needed to reduce the high morbidity and mortality associated with radiocontrast nephropathy in high-risk patients. By reviewing the available evidence from clinical trials, this article provides an overview of current strategies and unresolved issues concerning the prevention of radiocontrast nephropathy.

Ascorbic Acid Prevents Contrast-Mediated Nephropathy in Patients With Renal Dysfunction Undergoing Coronary Angiography or Intervention

Contrast agents can cause a reduction in renal function that may be due to the generation of reactive oxygen species. Conflicting evidence suggests that administration of the antioxidant acetylcysteine prevents this renal impairment. The action of other antioxidant agents has not been investigated. We conducted a randomized, double-blind, placebo-controlled trial of ascorbic acid in 231 patients with a serum creatinine concentration > or =1.2 mg/dL who underwent coronary angiography and/or intervention. Ascorbic acid, 3 g at least 2 hours before the procedure and 2 g in the night and the morning after the procedure, or placebo was administered orally. Contrast-mediated nephropathy was defined by an absolute increase of serum creatinine > or =0.5 mg/dL or a relative increase of > or =25% measured 2 to 5 days after the procedure. Contrast-mediated nephropathy occurred in 11 of the 118 patients (9%) in the ascorbic acid group and in 23 of the 113 patients (20%) in the placebo group (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.17 to 0.85; P=0.02). The mean serum creatinine concentration increased significantly in the placebo group (from 1.36+/-0.50 to 1.50+/-0.54 mg/dL, P<0.001) and nonsignificantly in the ascorbic acid group (from 1.46+/-0.52 to 1.52+/-0.64 mg/dL, P=0.07). The mean increase in serum creatinine concentration was greater in the placebo group than in the ascorbic acid group (difference of 0.09 mg/dL; 95% CI, 0.00 to 0.17; P=0.049). Prophylactic oral administration of ascorbic acid may protect against contrast-mediated nephropathy in high-risk patients undergoing a coronary procedure.