Changing trends in incidence and predictors of radiographic contrast nephropathy after percutaneous coronary intervention with use of fenoldopam

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.

Repeated Glutathione Sodium Salt Infusion May Counteract Contrast-Associated Acute Kidney Injury Occurrence in ST-Elevation Myocardial Infarction Patients Undergoing Primary PCI: A Randomized Subgroup Analysis of the GSH 2014 Trial

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is still a major concern for referring physicians, especially in the setting of ST-elevation myocardial infarction (STEMI) patients undergoing primary-PCI (pPCI). To evaluate whether glutathione sodium salt (GSS) infusion impacts favorably on CA-AKI, an unplanned exploratory data analysis of the GSH 2014 trial was performed.

METHODS

One hundred patients with STEMI were assigned at random to an experimental group (No. 50) or to a placebo group (No. 50). Treatment consisted of an intravenous infusion of GSS lasting over 10 min before p-PCI. The placebo group received the same quantity of normal saline solution. After the interventions, glutathione was administered in the same doses to both groups at 24, 48 and 72 h.

RESULTS

CA-AKI occurred in 5 out of 50 patients (10%) allocated to the experimental group (GSS infusion) and in 19 out of 50 patients (38%) allocated to the placebo group (p between groups < 0.001). No patients in either group required renal replacement therapy. After allowing for multiple confounders, GSS administration (OR 0.17, 95% CI 0.04-0.61) and door-to-balloon time (in hours) (OR 1.61, 95% CI 1.01-2.58) have been the only independent predictors of CA-AKI.

CONCLUSIONS

the results of this sub-study, which show a significant trend towards an improved nephroprotection in the experimental group, led to the hypothesis of a possible new prophylactic approach to counteract CA-AKI using repeated GSS infusion. Subsequent studies with specific clinical outcomes would be necessary to confirm these data.

Contrast-induced nephropathy and oxidative stress: mechanistic insights for better interventional approaches

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI) is an iatrogenic acute kidney injury observed after intravascular administration of contrast media for intravascular diagnostic procedures or therapeutic angiographic intervention. High risk patients including those with chronic kidney disease (CKD), diabetes mellitus with impaired renal function, congestive heart failure, intraarterial intervention, higher volume of contrast, volume depletion, old age, multiple myeloma, hypertension, and hyperuricemia had increased prevalence of CIN. Although CIN is reversible by itself, some patients suffer this condition without renal recovery leading to CKD or even end-stage renal disease which required long term renal replacement therapy. In addition, both CIN and CKD have been associated with increasing of mortality. Three pathophysiological mechanisms have been proposed including direct tubular toxicity, intrarenal vasoconstriction, and excessive production of reactive oxygen species (ROS), all of which lead to impaired renal function. Reports from basic and clinical studies showing potential preventive strategies for CIN pathophysiology including low- or iso-osmolar contrast media are summarized and discussed. In addition, reports on pharmacological interventions to reduce ROS and attenuate CIN are summarized, highlighting potential for use in clinical practice. Understanding this contributory mechanism could pave ways to improve therapeutic strategies in combating CIN.

Fenoldopam Mesylate: A Narrative Review of Its Use in Acute Kidney Injury

Background:

Fenoldopam mesylate is a selective agonist of DA-1 receptors. It is currently used for the in-hospital treatment of severe hypertension. DA-1 receptors have high density in renal pa-renchyma and for this reason, a possible reno-protective role of Fenoldopam mesylate was investigated.

Methods:

We examined all studies regarding the role of Fenoldopam mesylate in Acute Kidney Injury (AKI); particularly, those involving post-surgical patients, intensive care unit patients and contrast-induced nephropathy.

Results:

Fenoldopam mesylate was found to be effective in reducing the onset of postoperative AKI, when used before the development of the kidney damage. Positive results were also obtained in the management of intensive care unit patients with AKI, although the clinical studies investigated were few and conducted on small samples.

Conclusion:

Conflicting results were achieved in contrast-induced nephropathy.

Endovascular Abdominal Aortic Aneurysm Repair

Although endovascular surgery for aortic aneurysms can be traced to the 19th century, open surgery has dominated during the past 50 years. Indeed, open repair of aneurysms has been one of the most successful developments in vascular surgery. Despite improvements in mortality rates, open repair remains a major operation often undertaken in patients with significant comorbidities. Starting from basic research dating back several decades, the 1990s were noted for very active clinical development of endovascular abdominal aortic repair in an attempt to provide an alternative to open repair, especially for high-risk patients. Early successes with decreased intensive care unit and hospital stays were tempered by technical issues and the “endoleak,” the term given to an incomplete exclusion of the aneurysm from the circulation. This potential for rupture, despite treatment, was cause for concern. The need for long-term surveillance and secondary procedures, if not conversion to open repair, further compounded these issues. Despite these concerns, progress continued, and by the end of 2002, the Food and Drug Administration had approved three devices for marketing. Although surgeons are faced with increasingly complex issues related to endovascular repair, anesthesiologists have found their management of this procedure to be simpler in many ways. The smaller incisions and improved hemodynamic stability have led to a variety of anesthetics being tried, including monitored anesthesia care. Anesthesiologists continue to explore a number of opportunities to improve patient outcome in these procedures. These include selection of the most optimal anesthetic, the most appropriate perioperative renal protection, and the best preparation for and management of a conversion to an open procedure. Whatever the final role for endovascular surgery in the management of abdominal aortic aneurysms, it is an intellectually stimulating and scientifically promising technique for surgeons, anesthesiologists, and the patients they serve.

A hypothesis on the conflicting results of angiotensin converting enzyme inhibitor in the prevention of contrast-induced nephropathy

Contrast-induced nephropathy (CIN) is regarded as acute tubular necrosis resulting from the cytotoxicity of contrast media and the medullary hypoxia linking to the interplay of vasoconstriction and vasodilatation. Saline infusion may prevent CIN by inhibiting renin release and thus production of angiotensin II (ANG II), a vasoconstrictor, from angiotensin I (ANG I). Yet the use of angiotensin converting enzyme inhibitor (ACEI) yields conflicting results in the prevention of CIN. We hypothesise that ACEI will be useful for CIN prevention when the saline infusion is insufficient, useless when the saline infusion is sufficient, and counterproductive when the saline infusion is excessive, respectively. When the production of ANG I and thus ANG II is insufficiently inhibited by insufficient saline infusion, ACEI may help prevent CIN by conferring extra inhibition on the production of ANG II from ANG I. The counterproductive effect may result from ACEI blocking the generation of angiotensin 1-7, a potent vasodilator, from angiotensin 1-9 whose precursor, ANG I, is excessively diminished by excessive saline infusion. Clinical data suggest that normal saline infusion at a rate of 1 ml/kg/h for 12 h, 1 ml/kg/h for 6 h, and 2 ml/kg/h for 6 h before and after contrast injection provide sufficient, insufficient, and excessive hydration in the prevention of CIN, respectively. The mainstream guideline is to stop ACEI and provide sufficient hydration for CIN prevention. Alternatively one may continue to have ACEI but the use of normal saline infusion must be limited to 1 ml/kg/h for 6 h before and after contrast injection.

Fenoldopam for the prevention of contrast-induced nephropathy (CIN)-do we need more trials? A meta-analysis

We conducted a pooled analysis of clinical trials comparing intravenous Fenoldopam (FP) with Saline/Placebo/N-acetyl cysteine (NAC) for the prevention of contrast-induced nephropathy (CIN). Five studies were eligible. Quantitative analyses were done with Review Manager (RevMan version 5.2.). A total of 85 out of 353 patients in Fenoldopam group while 73 among 366 in the control group were affected due to CIN. The risk ratio for the development of CIN in the Fenoldopam group was 1.19 compared to the control group. This was not statistically significant. Fenoldopam is no better than Placebo/Saline or NAC in preventing CIN, but more studies are required.

Prevention of contrast-induced nephropathy through a knowledge of its pathogenesis and risk factors

Contrast-induced nephropathy (CIN) is an iatrogenic acute renal failure (ARF) occurring after the intravascular injection of iodinated radiographic contrast media. During the past several years, in many patients undergoing computed tomography, iodinated contrast media have not been used for the fear of ARF, thereby compromising the diagnostic procedure. But recent studies have demonstrated that CIN is rarely occurring in patients with normal renal function and that preexisting chronic renal failure and/or diabetes mellitus represent(s) predisposing condition(s) for its occurrence. After the description of CIN and its epidemiology and pathophysiology, underlying the important role played by dehydration and salt depletion, precautions for prevention of CIN are listed, suggested, and discussed. Maximum priority has to be given to adequate hydration and volume expansion prior to radiographic procedures. Other important precautions include the need for monitoring renal function before, during, and after contrast media injection, discontinuation of potentially nephrotoxic drugs, use of either iodixanol or iopamidol at the lowest dosage possible, and administration of antioxidants. A long list of references is provided that will enable readers a deep evaluation of the topic.

Acute kidney injury by radiographic contrast media: pathogenesis and prevention

It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure (ARF). We may define contrast-induced Acute Kidney Injury (AKI) as ARF occurring within 24-72 hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species (ROS), reduction of nitric oxide (NO) production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.

Contrast-induced Nephropathy

Contrast-induced nephropathy (CIN) is a serious complication of angiographic procedures resulting from the administration of contrast media (CM). It is the third most common cause of hospital acquired acute renal injury and represents about 12% of the cases. 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 h. More sensitive markers of renal injury are desired, therefore, several biomarkers of tubular injury are under evaluation. Multiple risk factors may contribute to the development of CIN; these factors are divided into patient- and procedure-related factors. Treatment of CIN is mainly supportive, consisting mainly of careful fluid and electrolyte management, although dialysis may be required in some cases. The available treatment option makes prevention the corner stone of management. This article will review the recent evidence concerning CIN incidence, diagnosis, and prevention strategies as well as its treatment and prognostic implications.

Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention

Radiocontrast media (RCM) are medical drugs used to improve the visibility of internal organs and structures in X-ray based imaging techniques. They may have side effects ranging from itching to a life-threatening emergency, known as contrast-induced nephropathy (CIN). We define CIN as acute renal failure occurring within 24-72 hrs of exposure to RCM that cannot be attributed to other causes. It usually occurs in patients with preexisting renal impairment and diabetes. The mechanisms underlying CIN include reduction in medullary blood flow leading to hypoxia and direct tubule cell damage and the formation of reactive oxygen species. Identification of patients at high risk for CIN is important. We have reviewed the risk factors and procedures for prevention, providing a long list of references enabling readers a deep evaluation of them both. The first rule to follow in patients at risk of CIN undergoing radiographic procedure is monitoring renal function by measuring serum creatinine and calculating the eGFR before and once daily for 5 days after the procedure. It is advised to discontinue potentially nephrotoxic medications, to choose radiocontrast media at lowest dosage, and to encourage oral or intravenous hydration. In high-risk patients N-acetylcysteine may also be given.

Dopamine-1 Receptor Agonist: Renal Effects and Its Potential Role in the Management of Radiocontrast-Induced Nephropathy

Radiocontrast-induced nephropathy remains the third leading cause of hospital-acquired acute renal failure. Once established, this syndrome is associated with increased morbidity and mortality as well as increased health care costs. Recently, studies have been initiated to evaluate the potential of a selective dopamine-1 receptor agonist (fenoldopam) in ameliorating radiocontrast-induced renal failure. Selective dopamine-1 receptor agonists exhibit many desirable renal effects that support their use for the prophylaxis of radiocontrast-induced nephropathy, including decreases in renal vascular resistance and increases in renal blood flow, glomerular filtration, and sodium and water excretion. Several reports have documented a beneficial effect of fenoldopam administration in attenuating radiocontrast-induced nephropathy. In contrast, a recent multicenter, randomized study did not demonstrate a renoprotective effect of fenoldopam against radiocontrast-induced nephropathy. The presence of multiple confounders, however, precludes a definitive conclusion regarding the ability of fenoldopam to protect against radiocontrast-induced nephropathy. Additional studies are needed to properly evaluate the role of fenoldopam in radiocontrast-induced nephropathy prophylaxis.

Renal failure: emergency evaluation and management

Patients with altered renal function are frequently encountered in the emergency department (ED) and emergency physicians often play an important role in the evaluation and management of renal disease. Early recognition, diagnosis, prevention of further iatrogenic injury, and management of renal disease have important implications for long-term morbidity and mortality. This article reviews basic renal physiology, discusses the differential diagnosis and approach to therapy, as well as strategies to prevent further renal injury, for adult patients who present to the ED with renal injury or failure.

Impact of renin-angiotensin-aldosterone blockade by angiotensin-converting enzyme inhibitors or AT-1 blockers on frequency of contrast medium-induced nephropathy: a post-hoc analysis from the Dialysis-versus-Diuresis (DVD) trial

BACKGROUND

After exposure to contrast medium (CM), about 10% of patients will develop contrast medium-induced nephropathy (CIN), with severe consequences for their prognosis. Although numerous studies evaluated risk factors for CIN development, it is still a matter of debate whether treatment with angiotensin-converting enzyme inhibitors (ACE-I) or AT-1 blockers increases the frequency of CIN after exposure to CM or not.

METHODS

We performed a prospective, single-centre study (January 2001-July 2004) to compare different treatments for CIN prevention. Creatinine levels within 72 h after CM application and in-hospital outcomes were documented. The impact of RAAS blockade on the frequency of CIN was assessed retrospectively.

RESULTS

Four hundred twelve patients were included (83.5% men, 29.1% diabetes mellitus, 74.6% hypertension). Of these, 269 patients (65.3%) were taking ACE-I (n = 236) or AT-1 blockers (n = 33). There were no significant differences in mean age (P = 0.075), creatinine levels (P = 0.113), gender (P = 0.281), diabetes mellitus (P = 0.172) or left ventricular ejection fraction (P = 0.09) between patients treated or not treated with RAAS blockade. Univariate analyses concerning development of CIN depending on treatment with RAAS blockade within 72 h found CIN to be significantly higher in patients treated with RAAS blockade (11.9 vs 4.2%, P = 0.006). Multivariate analyses (logistic regression) identified RAAS blockade to be an independent predictor of CIN (odds ratio 3.082, 95% confidence interval 1.234-7.698, P = 0.016).

CONCLUSION

Patients treated with RAAS blockade before exposure to CM develop significantly more often CIN within 72 h. Even after adjustment for confounding comorbidities, treatment with ACE-I or AT-1 blockers turned out to be an independent risk predictor.

Does renin-angiotensin aldosterone system blockade exacerbate contrast-induced nephropathy in patients with chronic kidney disease? A prospective 50-month Mayo Clinic study

Contrast induced nephropathy, a leading cause of new-onset renal failure in U.S. hospitals, may be accelerated by concurrent RAAS blockade in CKD patients. Current literature is inconclusive. Between September 2002 and February 2005, we prospectively enrolled all CKD patients on RAAS blockade who developed contrast-induced nephropathy. RAAS blockade was discontinued, standard nephrology care applied, and eGFR by MDRD was monitored. Seven patients (M:F, 3:4; age, 72.3 years) were enrolled. Mean duration of RAAS blockade at enrollment was 25.8 months. Baseline vs. enrollment eGFR was 45.5 +/- 17 vs. 16.6 +/- 6.8 mL/min/1.73 m(2), p = 0.009. Three of the seven patients (43%) required dialysis, one temporarily. Two older patients (mean age, 81.5 vs. 68.6 years, p = 0.017) progressed to ESRD. eGFR in five non-ESRD patients increased from 18.5 +/- 7.1 to 41.0 +/- 27.1 mL/min/1.73 m(2) after 29.4 months. Baseline eGFR was lower in the two patients who developed ESRD (29.5 vs. 51.2 mL/min/1.73 m(2)). Two patients exhibited very steep serum creatinine trajectories, indicative of rapid loss of eGFR. New onset proteinuria was observed. We have demonstrated very bad renal outcomes with three of seven (43%) patients requiring dialysis, with two (29%) progressing to ESRD. In two patients, loss of eGFR was clearly accelerated. These findings support the view that concurrent RAAS blockade, particularly in older CKD patients, exacerbates contrast-induced nephropathy. Also, lower baseline eGFR predicted worse renal outcomes. We support the recommendation to withhold RAAS blockade, 48 hours before contrast exposure, to improve renal outcomes.

Radiologists’ knowledge and perceptions of the impact of contrast-induced nephropathy and its risk factors when performing computed tomography examinations: A survey of European radiologists

BACKGROUND

The past decade has seen a proliferation in the number of CT procedures. As increasing numbers of elderly patients with multiple comorbidities undergo contrast media (CM)-enhanced procedures, more patients are at risk for contrast-induced nephropathy (CIN).

OBJECTIVES

To understand whether radiologists are sufficiently aware of the incidence, impact and risk factors of CIN, and whether they are taking sufficient measures to prevent CIN among patients undergoing CT.

MATERIALS AND METHODS

A telephone or online survey was conducted in 2005 with 509 radiologists from 10 European countries. Participants had a minimum of 3 years' experience and performed at least 50 CT scans per week.

RESULTS

Most (88%) radiologists believed that CIN is an important issue. While 45% identify that a patient is experiencing CIN when the serum creatinine level increases >25% (0.5mg/dL) from baseline within 48h, the remainder used criteria that might lead to significant under-diagnosis. Most (72%) radiologists believed that CIN is associated with increased morbidity; 56% did not believe that it is associated with increased mortality. Most respondents agreed that pre-existing renal impairment (97%), dehydration (90%) and diabetes (89%) were risk factors for CIN; however, 26%, 30% and 46%, respectively, did not identify advanced age, CM dose or congestive cardiac failure as risk factors. Only 7% of radiologists thought they were always made aware of CIN associated with their cases and 28% never consulted a nephrologist to discuss patients at risk of CIN or who had developed CIN.

CONCLUSION

There is highly variable awareness of the definition, impact and risk factors for CIN among European radiologists. Data regarding the importance of CIN in CT are limited. Improved efforts are required to better educate radiologists and referring physicians and to institute appropriate protocols to identify at-risk patients and prevent CIN.

The role of dialysis in contrast-induced nephropathy: doubts and certainties

Over past years, there has been a progressive increase in percutaneous endovascular procedures in patients with chronic renal disease, owing to the high incidence of vascular disease, particularly coronary artery disease, in this population. The use of contrast media may further worsen renal function in such patients, in some cases even accelerating the progression towards end-stage renal failure, and may increase patient morbidity and mortality. In this review, we discuss the role of dialysis in preventing contrast-induced nephropathy as well as present indications to its use in patients already on dialysis treatment undergoing diagnostic or therapeutic procedures with contrast medium injection.

Beneficial Impact of Fenoldopam in Critically Ill Patients With or at Risk for Acute Renal Failure: A Meta-Analysis of Randomized Clinical Trials

BACKGROUND

Acute kidney injury is common in critically ill patients. Fenoldopam mesylate is a potent dopamine A-1 receptor agonist that increases blood flow to the renal cortex and outer medulla. Because there is uncertainty about the benefits of fenoldopam in such a setting, we performed a systematic review of randomized controlled trials of intensive care unit patients or those undergoing major surgery.

METHODS

BioMedCentral, CENTRAL, PubMed, and conference proceedings were searched (updated October 2005). Investigators and external experts were contacted. Two unblinded reviewers selected randomized controlled trials that used fenoldopam in the prevention or treatment of acute kidney injury in postoperative or intensive care patients. Studies involving the prevention of contrast nephropathy or containing duplicate data were excluded from analysis. Two reviewers independently abstracted patient data, treatment characteristics, and outcomes.

RESULTS

A total of 1,290 patients from 16 randomized studies were included in the analysis. Pooled estimates showed that fenoldopam consistently and significantly reduced the risk for acute kidney injury (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.32 to 0.59; P < 0.001), need for renal replacement therapy (OR, 0.54; 95% CI, 0.34 to 0.84; P = 0.007), and in-hospital death (OR, 0.64; 95% CI, 0.45 to 0.91; P = 0.01). These benefits were associated with shorter intensive care unit stay (weighted mean difference, -0.61 days; 95% CI, -0.99 to -0.23; P = 0.002). Sensitivity analyses, tests for small-study bias, and heterogeneity assessment further confirmed the main analysis.

CONCLUSION

This analysis suggests that fenoldopam reduces the need for renal replacement and mortality in patients with acute kidney injury. A large, multicenter, appropriately powered trial will need to be performed to confirm these results.

Strategies to reduce the risk of contrast-induced nephropathy

In view of the clinical importance of contrast-induced nephropathy (CIN), numerous potential risk-reduction strategies have been evaluated. Adequate intravenous volume expansion with isotonic crystalloid (1.0-1.5 mL/kg per hr) for 3-12 hours before the procedure and continued for 6-24 hours afterward can lessen the probability of CIN in patients at risk. There are insufficient data on oral fluids (as opposed to intravenous volume expansion) as a CIN-prevention strategy. No adjunctive medical or mechanical treatment has been proved to be efficacious in reducing risk for CIN. Prophylactic hemodialysis and hemofiltration have not been validated as effective strategies. The CIN Consensus Working Panel considered that, of the pharmacologic agents that have been evaluated, theophylline, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), ascorbic acid, and prostaglandin E(1) deserve further evaluation. N-acetylcysteine is not consistently effective in reducing the risk for CIN. Fenoldopam, dopamine, calcium channel blockers, atrial natriuretic peptide, and l-arginine have not been shown to be effective. Use of furosemide, mannitol, or an endothelin receptor antagonist is potentially detrimental. Nephrotoxic drugs should be withdrawn before contrast administration in patients at risk for CIN.

Risk prediction of contrast-induced nephropathy

In order to make appropriate decisions about clinical management, it is important for physicians to be able to stratify patients according to their risk for contrast-induced nephropathy (CIN). The most important risk marker for nephropathy after exposure to iodinated contrast media is preexisting renal impairment. The risk of CIN is elevated and becomes clinically important in patients with chronic kidney disease characterized by an estimated glomerular filtration rate <60 mL/min per 1.73 m(2). In patients with renal impairment, diabetes mellitus amplifies the risk of CIN and complicates postprocedure management. Other markers associated with an increased risk of CIN include cardiovascular disease, periprocedural hemodynamic instability, use of nephrotoxic drugs, and anemia. The effect of risk factors is additive, and the presence of multiple risk factors in the same patient can create a very high risk for CIN and acute renal failure requiring dialysis. Risk models incorporating baseline and periprocedural characteristics have been developed using data from large databases of percutaneous coronary intervention patients. These schemes are potentially valuable, but at present the most practical approach to risk prediction is based on a simple model incorporating renal function and diabetes mellitus.

Epidemiology and prognostic implications of contrast-induced nephropathy

Contrast-induced nephropathy (CIN), usually defined as an increase in serum creatinine of 0.5 mg/dL (44.2 mumol/L), or a 25% increase from the baseline value 48 hours after the procedure, is a common and potentially serious complication of the use of iodinated contrast media in patients at risk of acute renal injury. It is an important cause of hospital-acquired renal failure, responsible for approximately 11% of cases. CIN may be difficult to distinguish from cholesterol embolization, another cause of postprocedure renal impairment. The reported incidence of CIN varies depending on the patient population studied. The impact of postprocedural renal impairment on clinical outcomes has been evaluated most extensively in patients undergoing percutaneous coronary intervention. CIN is associated with increased mortality both in hospital and at 1 year. A higher incidence of in-hospital and late cardiovascular events, as well as longer hospital stays, has been reported in patients developing CIN. In a small proportion of patients, CIN is severe enough to require dialysis, and these patients have a particularly poor prognosis. Many of the risk markers for CIN are also predictive of a worse prognosis.

Angiotensin-converting enzyme inhibitors as a risk factor for contrast-induced nephropathy

BACKGROUND/AIMS

The aim of the present study was to assess the influence of chronic angiotensin-converting enzyme (ACE) inhibitor administration on the development of contrast-induced nephropathy (CIN) in patients undergoing coronary angiography.

METHODS

A total of 230 patients with renal insufficiency and age > or =65 years were divided into two groups according to prior use of ACE inhibitors (ACE inhibitor group, n = 109; control group, n = 121). CIN was defined as an increase of > or =25% in creatinine over the baseline value within 48 h of angiography.

RESULTS

CIN occurred in 17 patients (15.6%) in the ACE inhibitor group and 7 patients (5.8%) in the control group (p = 0.015). Serum creatinine level increased from 1.34 +/- 0.20 to 1.53 +/- 0.27 mg/dl in the ACE inhibitor group and from 1.33 +/- 0.18 to 1.45 +/- 0.19 mg/dl in the control group (p < 0.001). Chronic ACE inhibitor administration was a risk indicator of CIN [odds ratio 3.37; 95% confidence interval 1.14-9.94; p = 0.028]. Multi-vessel coronary involvement (p = 0.001), hypoalbuminemia (p = 0.005), diabetes mellitus (p = 0.006), GFR < or =40 ml/min (p = 0.010), and congestive heart failure (p = 0.024) were other risk indicators of CIN.

CONCLUSION

Chronic ACE inhibitor administration is a risk for developing CIN in elderly patients with renal insufficiency.

Contrast-induced nephropathy: Pharmacological prophylaxis

Contrast media-associated acute renal failure represents the third most common cause of in-hospital renal function deterioration after decreased renal perfusion and post-operative renal insufficiency. Although generally benign, this complication is associated with a mortality rate ranging from 3.8 to 64%, depending on the increase of creatinine concentration. Multiple drugs have been tested in an attempt to prevent this complication. Central to the pathophysiology of contrast-induced nephrotoxicity (CIN) is an alteration in renal hemodynamics. In an effort to reverse these hemodynamic changes, vasodilators and diuretics have been tested as prophylactic drugs. However, their effectiveness has not been confirmed. Recently, considerable interest has resulted from the initial positive data on the effectiveness of prophylactic administration of antioxidant compounds, such as acetylcysteine and ascorbic acid. In this review, we focus on the effectiveness of pharmacologic therapies for preventing CIN.

A comparison between fenoldopam and low-dose dopamine in early renal dysfunction of critically ill patients*

OBJECTIVE

Fenoldopam mesylate is a selective dopamine-1 agonist, with no effect on dopamine-2 and alpha1 receptors, producing a selective renal vasodilation. This may favor the kidney oxygen supply/demand ratio and prevent acute renal failure. The aim of the study was to investigate if fenoldopam can provide greater benefit than low-dose dopamine in early renal dysfunction of critically ill patients.

DESIGN

Prospective, multiple-center, randomized, controlled trial.

SETTING

University and city hospital intensive care units.

PATIENTS

One hundred adult critically ill patients with early renal dysfunction (intensive care unit stay<1 wk, hemodynamic stability, and urine output<or=0.5 mL/kg over a 6-hr period and/or serum creatinine concentration>or=1.5 mg/dL and<or= 3.5 mg/dL).

INTERVENTIONS

Patients were randomized to receive 2 microg/kg/min dopamine (group D) or 0.1 microg/kg/min fenoldopam mesylate (group F). Drugs were administered as continuous infusion over a 4-day period.

MEASUREMENTS AND MAIN RESULTS

Systemic hemodynamic and renal function variables were recorded daily. The two groups were well matched at enrollment for illness severity and hemodynamic and renal dysfunction. No differences in heart rate or systolic, diastolic, or mean arterial pressure were observed between groups. Fenoldopam produced a more significant reduction in creatinine values compared with dopamine after 2, 3, and 4 days of infusion (change from baseline at time 2, -0.32 vs. -0.03 mg/dL, p=.047; at time 3, -0.45 vs. -0.09 mg/dL, p=.047; and at time 4, -.041 vs. -0.09 mg/dL, p=.02, in groups F and D, respectively). The maximum decrease in creatinine compared with baseline was significantly greater in group F than group D (-0.53+/-0.47 vs. -0.34+/-0.38 mg/dL, p=.027). Moreover, 66% of patients in group F had a creatinine decrease>10% of the baseline value at the end of infusion, compared with only 46% in dopamine group (chi-square=4.06, p=.04). Total urinary output during drug infusion was not significantly different between groups. After 1 day, urinary output was lower in group F compared with group D (p<.05).

CONCLUSIONS

In critically ill patients, a continuous infusion of fenoldopam at 0.1 microg/kg/min does not cause any clinically significant hemodynamic impairment and improves renal function compared with renal dose dopamine. In the setting of acute early renal dysfunction, before severe renal failure has occurred, the attempt to reverse renal hypoperfusion with fenoldopam is more effective than with low-dose dopamine.

The safety of gadolinium in patients with stage 3 and 4 renal failure

BACKGROUND

Although there is a well-documented risk of acute renal failure (ARF) with the iodinated contrast agents, intravenous gadolinium-based contrast agents are considered non-nephrotoxic and have been widely used for magnetic resonance imaging (MRI). However, debate continues regarding the safety issue of gadolinium, especially in patients with kidney failure. Therefore, we aimed to evaluate the safety of gadolinium in patients with stage 3 and 4 renal failure as well as risk factors for nephrotoxicity.

METHOD

We retrospectively analysed 473 patients with chronic renal failure who underwent angiographic MRI procedures in our centre from February 1999 to March 2005 in whom gadolinium was used as the sole contrast agent at a dose of 0.2 ml/kg. Among them, 91 patients with stage 3 or 4 renal failure according to K/DOQI definition, who had available data in their files, were enrolled in the study. The ARF was defined as an increase of at least 0.5 mg/dl in serum creatinine level over baseline after using gadolinium.

RESULTS

Eleven of 91 (52 males, 39 females; median age 59 years; median estimated glomerular filtration rate (eGFR) 33 ml/min/1.73 m2) patients developed ARF (12.1%). The median eGFR was lower in patients with ARF than in those who did not develop ARF. The risk factors for ARF were baseline eGFR, older age, diabetic nephropathy and low baseline haemoglobin and albumin levels. Baseline eGFR and diabetic nephropathy were determined as the independent risk factors in regression analysis.

CONCLUSIONS

An ARF can occur after gadolinium-based contrast agents in patients with moderate to severe chronic renal failure. Risk factors for ARF after gadolinium toxicity include diabetic nephropathy and low GFR.

Renal failure secondary to acute tubular necrosis: epidemiology, diagnosis, and management

Acute tubular necrosis (ATN) is a form of acute renal failure (ARF) that is common in hospitalized patients. In critical care units, it accounts for about 76% of cases of ARF. Despite the introduction of hemodialysis > 30 years ago, the mortality rates from ATN in hospitalized and ICU patients are about 37.1% and 78.6%, respectively. The purpose of this review is to discuss briefly the cause, diagnosis, and epidemiology of ARF, and to review in depth the clinical trials performed to date that have examined the influence of growth factors, hormones, antioxidants, diuretics, and dialysis. In particular, the role of the dialysis modality, dialyzer characteristics, and dosing strategies are discussed.

Nephropathy induced by contrast media: pathogenesis, risk factors and preventive strategies

With the increasing use of contrast media in diagnostic and interventional procedures, nephropathy induced by contrast media has become the third leading cause of hospital-acquired acute renal failure. It is also associated with a significant risk of morbidity and death. The current understanding of the pathogenesis indicates that contrast-medium nephropathy is caused by a combination of renal ischemia and direct toxic effects on renal tubular cells. Patients with pre-existing renal insufficiency, diabetes mellitus and congestive heart failure are at highest risk. Risk factors also include the type and amount of contrast medium administered. Therapeutic prevention strategies are being extensively investigated, but there is still no definitive answer. In this article, we review the current evidence on the causes, pathogenesis and clinical course of contrast-medium nephropathy as well as therapeutic approaches to its prevention evaluated in clinical trials.

Percutaneous Coronary Intervention–Related Bleeding Risk Factors in Current Practice

BACKGROUND:

Bleeding is a common and costly complication of percutaneous coronary intervention (PCI). Little is known about the risk factors for bleeding complications.

Objective:

To report our PCI-related observations from a single institution and use the information to establish risk factors for short-term bleeding complications, with special focus on examining the importance of renal function.

METHODS:

A retrospective record review was conducted of the admission of 300 patients grouped according to antithrombotic regimen: unfractionated heparin alone (n = 187), bivalirudin (n = 26), and glycoprotein IIb/IIIa antagonist plus heparin (n = 103). Bleeding and ischemic outcomes were tracked. A model was constructed to predict independent bleeding risk factors.

RESULTS:

Treatment groups differed significantly regarding any bleeding (p = 0.001), minor bleeding (p < 0.001), and length of stay (p = 0.01). Multivariate predictors of any bleeding included antithrombotic regimen, creatinine clearance (Clcr) <30 mL/min, and hypertension. Any bleeding was associated with prolonged length of stay. Major bleeding was predicted by Clcr <30 mL/min and was associated with prolonged length of stay and death. Minor bleeding was predicted only by choice of antithrombotic regimen.

CONCLUSIONS:

The major influences on bleeding risk appeared to be Clcr <30 mL/min and choice of antithrombotic regimen. It is important to note that other markers of renal function, including serum creatinine value and serum creatinine at a cutoff level of 1.5 mg/dL, did not predict bleeding events.

Renoprotective Action of Fenoldopam in High-Risk Patients Undergoing Cardiac Surgery

Background— Acute renal failure is a serious complication of cardiac surgery causing high morbidity and mortality. The aim of this study was to evaluate the usefulness of fenoldopam, a specific agonist of the dopamine-1 receptor, in patients at high risk of perioperative renal dysfunction.

Methods and Results— A prospective single-center, randomized, double-blind trial was performed after local ethical committee approval and after written consent was obtained from 80 patients undergoing cardiac surgery. Patients received either fenoldopam at 0.05 μg/kg per minute or dopamine at 2.5 μg/kg per minute after the induction of anesthesia for a 24-hour period. All these patients were at high risk of perioperative renal dysfunction as indicated by Continuous Improvement in Cardiac Surgery Program score >10. Primary end point was defined as 25% creatinine increase from baseline levels after cardiac surgery. The 2 groups (fenoldopam versus dopamine) were homogeneous cohorts, and no difference in outcome was observed. Acute renal failure was similar: 17 of 40 (42.5%) in the fenoldopam group and 16 of 40 (40%) in the dopamine group ( P =0.9). Peak postoperative serum creatinine level, intensive care unit and hospital stay, and mortality were also similar in the 2 groups.

Conclusions— Despite an increasing number of reports of renal protective properties from fenoldopam, we observed no difference in the clinical outcome compared with dopamine in a high-risk population undergoing cardiac surgery.

Renal protection strategies in the perioperative period

The development of acute renal failure (ARF) in the perioperative period continues to be a vexing condition associated with high morbidity and mortality rates which have been unchanged for several decades. In this article I briefly review recent research categorizing pathogenesis of ARF and mechanisms of recovery. Once ARF is established, its maintenance phase is dependent on several mechanisms that interact with cellular integrity. The main focus of the article is on assessing clinical and experimental interventions to prevent ARF. Unfortunately, existing pharmacological and other interventions show a rather limited efficacy in preventing ARF.

Nephrotoxic effects of X-ray contrast media

The annual sale of x-ray contrast media (CM) now represents 60 million doses, and contrast nephropathy (CN) has been the third-leading cause of hospital-acquired acute renal failure. In this review article, physicochemical, pharmacokinetic, and pharmacodynamic properties of CM are surveyed. The definition of CN is presented, as well as the mechanisms involved in the pathogenesis. Low osmolar monomeric CM (LOCM) are less nephrotoxic than the older ionic high osmolar CM (HOCM), but in risk patients the incidence of CN is still high after intravascular administration of LOCM. Non-ionic dimeric CM are iso-osmolar to plasma (IOCM), and they have reduced the nephrotoxicity even more than LOCM. The most important risk factors for CN are diabetes mellitus and impaired renal function. Selection of patients, hydration, and type of CM are essential for prevention and prophylaxis of CN. We do not recommend routine prophylaxis with N-acetylcysteine (NAC) during CM investigations, but its use in high-risk patients should be considered.

Preventing contrast nephropathy: what is the best strategy? A review of the literature

Patients receiving radiocontrast for diagnostic and interventional procedures are at risk for developing contrast nephropathy (CN). In fact, radiocontrast nephropathy is currently the third leading cause of hospital-acquired renal failure. Understanding that CN has been associated with increased length of hospitalization and mortality, determining the best prevention strategy is of utmost importance. Patients at the greatest risk for developing acute renal failure are patients with diabetes and underlying renal insufficiency. Several therapies have been investigated for the prevention of CN; unfortunately, very few have shown a consistent benefit. Therapies that have been studied include saline hydration, N-acetylcysteine (NAC), theophylline, calcium channel blockers, diuretics, dopamine, endothelin receptor antagonists, atrial natriuretic peptide, angiotensin-converting enzyme inhibitors, and prostaglandin E-1. Using adequate hydration, using low-osmolar dyes, and minimizing the dose of contrast have all been shown to be effective in reducing CN and are considered the standard of care. While trials with many pharmacologic agents have produced conflicting results, intervention with NAC has also been promising. This article reviews the pathophysiology, risk factors, and therapies that are currently available for the prevention of CN.

Prophylaxis of Iodinated Contrast Media-Induced Nephropathy

Iodinated contrast media are a frequent cause of acute renal failure, especially in patients whose renal function is already impaired. In addition to hydration, which remains the most commonly acknowledged means of protection, numerous pharmacological approaches for the prophylaxis of contrast nephropathy have been tested so far. They include diuretics, calcium channel blockers, adenosine receptor antagonists, N-acetylcysteine, low-dose dopamine and the dopamine D1 receptor agonist fenoldopam, endothelin receptor antagonists, and even captopril. The present review of the literature critically discusses the drugs used to prevent contrast nephropathy from a pharmacological point of view.

Vasoactive drugs and the kidney

Protection of renal function and prevention of acute renal failure (ARF) are important goals of resuscitation in critically ill patients. Beyond fluid resuscitation and avoidance of nephrotoxins, little is known about how such prevention can be achieved. Vasoactive drugs are often administered to improve either cardiac output or mean arterial pressure in the hope that renal blood flow will also be improved and, thereby, renal protection achieved. Some of these drugs (especially low-dose dopamine) have even been proposed to have a specific beneficial effect on renal blood flow. However, when all studies dealing with vasoactive drugs and their effects on the kidney are reviewed, it is clear that none have been demonstrated to achieve clinically important benefits in terms of renal protection. It is also clear that, with the exception of low-dose dopamine, there have been no randomized controlled trials of sufficient statistical power to detect differences in clinically meaningful outcomes. In the absence of such data, all that is available is based on limited physiological gains (changes in renal blood flow or urine output) with one or another drug in one or another subpopulation of patients. Furthermore, given our lack of understanding of the pathogenesis of ARF, it is unclear whether haemodynamic manipulation is an appropriate avenue to achieve renal protection. There is a great need for large randomized controlled trials to test the clinical, instead of physiological, effects of vasoactive drugs in critical illness.

Contrast nephropathy after coronary angiography

Contrast nephropathy after coronary angiography is associated with considerable morbidity and mortality. We discuss the incidence, definition, and pathologic mechanisms of contrast nephropathy; provide an overview of risk factors; highlight proven preventive interventions; clarify which interventions have shown no benefit; and discuss future possibilities. The prevention of contrast nephropathy is crucial for the care of patients undergoing coronary angiography and should be possible with an understanding of risk factors and proven management strategies.

Fenoldopam andN-acetylcysteine for the Prevention of Radiographic Contrast Material-Induced Nephropathy: A Review

Radiographic contrast material-induced nephropathy (RCIN) is the third most common cause of hospital-acquired renal insufficiency and has been associated with an increase in patient mortality. Many strategies to prevent RCIN have been explored unsuccessfully. The standard of care remains hydration with 0.45% sodium chloride before and after administration of contrast material. Recently, N-acetylcysteine and fenoldopam have been studied to determine their efficacy in preventing RCIN. Of seven prospective studies using various dosing regimens of N-acetylcysteine, four revealed beneficial results. Although some discrepancies exist, the data strongly suggest that N-acetylcysteine has a role in patients at risk for the development of RCIN. The data for fenoldopam are more limited, with only one retrospective study showing benefit. Additional prospective data are required to determine if fenoldopam has a role in the prevention of RCIN.

Fenoldopam mesylate for the prevention of contrast-induced nephropathy: a randomized controlled trial

CONTEXT

The development of contrast-induced nephropathy in patients undergoing invasive cardiac procedures is associated with a marked increase in cardiovascular morbidity and mortality. Fenoldopam mesylate, a specific agonist of the dopamine-1 receptor, preserves renal blood flow after iodinated contrast administration and has shown promise in ameliorating contrast nephropathy in previous observational and small randomized trials.

OBJECTIVE

To examine the efficacy of fenoldopam mesylate in preventing contrast nephropathy after invasive cardiovascular procedures.

DESIGN

Prospective, placebo-controlled, double-blind, multicenter randomized trial with serial serum creatinine levels measured at a central biochemistry laboratory (at baseline and 1, 24, 48, and 72 to 96 hours after study drug administration) and 30-day clinical follow-up.

PATIENTS AND SETTING

Between March 2001 and July 2002, 315 patients with creatinine clearance less than 60 mL/min (1.00 mL/s) at 28 centers in the United States were randomized to receive fenoldopam mesylate (n = 157) or placebo (n = 158).

INTERVENTIONS

Patients were hydrated and randomized to receive intravenous fenoldopam (0.05 microg/kg/min titrated to 0.10 microg/kg/min) vs matching placebo, starting 1 hour prior to angiography and continuing for 12 hours.

MAIN OUTCOME MEASURE

Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine level within 96 hours postprocedure.

RESULTS

Mean (SD) patient age was 70 (11) years, and 49% had diabetes mellitus. Mean (SD) baseline creatinine clearance was 29.0 (10.0) mL/min (0.48 [0.16] mL/s) (range, 7.5-56.8 mL/min [0.12-0.94 mL/s]), and 157 (108) mL of contrast was administered during the procedures. The primary end point of contrast-induced nephropathy occurred in 33.6% of patients assigned to receive fenoldopam vs 30.1% assigned to receive placebo (relative risk, 1.11; 95% confidence interval, 0.79-1.57; P =.61). There were no significant differences in the 30-day rates of death (2.0% vs 3.8%, P =.50), dialysis (2.6% vs 1.9%, P =.72), or rehospitalization (17.6% vs 19.9%, P =.66) in fenoldopam vs placebo randomized patients, respectively.

CONCLUSION

The selective dopamine-1 agonist fenoldopam mesylate does not prevent further renal function deterioration after contrast administration in patients with chronic renal insufficiency.

Contrast media and the kidney: European Society of Urogenital Radiology (ESUR) guidelines

The Contrast Media Safety Committee of the European Society of Urogenital Radiology (ESUR) has looked at the effects of contrast media on the kidney including prevention of contrast medium induced nephropathy. This has resulted in four reports dealing with 1) contrast medium induced nephrotoxicity, 2) haemodialysis and contrast media, 3) use of gadolinium contrast media instead of iodinated contrast media and 4) contrast media injection in diabetic patients receiving metformin. The review presents an overview of these four reports and offers the current understanding of the interaction between contrast agents and the kidney.

Contrast agent--associated nephrotoxicity

Radiocontrast media can lead to a reversible form of acute renal failure that begins soon after the contrast dye administration and generally is benign. Contrast media accounts for 10% of all causes of hospital-acquired acute renal failure and represents the third leading cause of in-hospital renal function deterioration after decreased renal perfusion and postoperative renal insufficiency. The in-hospital mortality rate in patients developing renal insufficiency is related directly to the magnitude increase of serum creatinine concentration. The mortality rate ranges from 3.8% with an increase in serum creatinine level of 0.5 to 0.9 mg/dL to 64% with an increase of greater than 3.0 mg/dL. The mechanism by which contrast-induced renal failure occurs is not well understood. Contrast agent-associated nephrotoxicity appears to be a result of direct contrast-induced renal tubular epithelial cell toxicity and renal medullary ischemia. Furthermore, a key mechanism seems to be alteration in renal dynamics, probably caused by imbalances between vasodilator and vasoconstrictor factors, including the activities of nitric oxide, prostaglandins, endothelin, and reactive oxygen species. The optimal strategy to prevent contrast-associated nephrotoxicity remains uncertain. At present, recommendations are as follows: (1) periprocedural hydration, (2) use of a low-osmolality contrast, and (3) limiting the amount of contrast agent. Recently, considerable interest has resulted from the preliminary positive data on the effectiveness of prophylactic administration of acetylcysteine and fenoldopam. The former may prevent the direct oxidative tissue damage, whereas the latter is a selective intrarenal vasodilator.

Radiocontrast-induced nephropathy and percutaneous coronary intervention: a review of preventive measures

Injectable and absorbable contrast media for the use in radiology, all of which contains iodine as an essential component, has been, and continues to be, one of the main sources of agents which cause hospital-acquired renal failure. Although numerous methods have been explored to prevent renal contrast damage, radiocontrast-induced nephropathy continues to be a concern in patients with existing renal insufficiency, who undergo contrast-enhanced radiographic examinations. Patients who develop contrast-induced nephropathy (CIN) have a worse prognosis and an increased risk of complications and mortality. Prevention of CIN during radiocontrast procedures continues to elude clinicians and is a chief concern during percutaneous coronary intervention, as these patients often have multiple comorbidities. A wide variety of animal and clinical investigations, and substances have been tried in order to prevent this complication, including: dialysis, contrast volume and type; adenosine antagonists; acetylcysteine; fenoldopam; and various others. The purpose of this review is to appraise all the past and current strategies employed to prevent CIN, especially during percutaneous coronary intervention.

Oral acetylcysteine does not protect renal function from moderate to high doses of intravenous radiographic contrast

The use of radiographic contrast during cardiac catheterization can cause acute renal failure with an increase in morbidity and mortality. Prophylactic acetylcysteine plus intravenous hydration have been shown to prevent contrast-induced nephropathy (CIN) in patients with chronic renal failure undergoing computed tomography scan, who receive low doses of intravenous contrast. Whether the use of prophylactic acetylcysteine can decrease the incidence of CIN when larger doses of contrast are used remains to be determined. We sought to evaluate whether the prophylactic administration of acetylcysteine plus intravenous hydration is superior to intravenous hydration alone in prevention of CIN in patients with chronic renal failure undergoing cardiac catheterization and receiving moderate to high doses of intravenous contrast (> 1 cc/kg). Seventy-three consecutive patients with renal insufficiency who received intravenous hydration and 600 mg of acetylcysteine twice a day 24 hr before and the day of the cardiac catheterization were compared with 106 consecutive patients who received hydration alone. Baseline and 48-hr serum creatinine concentrations were compared between the two groups before and after cardiac catheterization. Multivariate and univariate analysis were performed to assess the effects of acetylcysteine and other clinical variables in the change of serum creatinine after the procedure. Both groups had comparable clinical characteristics and received similar volumes of intravenous hydration. The volume of contrast used was similar for the two groups (2.2 +/- 1.7 vs. 2.3 +/- 1.5 cc/kg; P = 0.67). A mean change in serum creatinine of 0.17 +/- 0.54 mg/dl for the acetylcysteine group vs. 0.19 +/- 0.40 mg/dl for the control group (P = 0.77) was observed at 48 hr. The incidence CIN was 13% in the acetylcysteine vs. 12% in the control group (P = 0.84). Acetylcysteine, whether analyzed with multivariate or univariate analysis, failed to demonstrate a significant effect in the change of serum creatinine after cardiac catheterization. In patients with chronic renal insufficiency, acetylcysteine in a dose of 600 mg twice a day before and after cardiac catheterization, along with intravenous fluids, is as effective as fluids alone in the prevention of CIN when moderate to high doses of contrast are used.