Contrast-induced nephrotoxicity in patients undergoing cardiac catheterization

Timeout for Contrast: Using Physician Behavior Modification to Reduce Contrast in the Catheterization Laboratory

BACKGROUND

As the number of procedures using contrast media continues to rise, the ensuing complications place an ever increasing burden on the healthcare system. Contrast-induced nephropathy (CIN) is a common postprocedural complication after cardiac catheterization.

OBJECTIVES

The purpose of our study was to evaluate the impact of physician behavioral modification on reducing the amount of contrast used during the procedure.

METHODS

All patients who underwent procedures in the cardiac catheterization laboratory from January 2013 to August 2016 were identified in addition to the total contrast used during the procedure, the type of procedure performed, and the operator performing the procedure. A new addition was made to the preprocedure checklist in September-October 2013 in the form of maximum allowed contrast for the patient.

RESULTS

A total of 12,118 cases were identified. Across all procedures, the mean contrast used during the 8 months prior to the intervention was 118 ml per procedure. Mean contrast used per procedure for the first year after the revised timeout was 105 ml, for the second year was 106 ml, and for the third year was 99 ml.

CONCLUSION

A significant reduction in radiocontrast use across all operators and procedures after the introduction of a revised timeout procedure that was seen, which is a change that was sustained over a period of three years. With this straightforward intervention involving physician behavioral modification, patients were exposed to less of the nephrotoxic contrast and were consequently at a lower risk of developing dose-depended CIN and other associated complications.

Effect of Chronic Kidney Disease on Mortality in Patients Who Underwent Lower Extremity Peripheral Vascular Intervention

It is known that chronic kidney disease (CKD) is associated with increased postoperative morbidity and mortality in patients with peripheral artery disease who underwent lower extremity surgical revascularization; however, outcomes after peripheral vascular intervention (PVI) are less well established. This study sought to determine the impact of CKD on adverse outcomes in patients with peripheral artery disease who underwent PVI. Using data from the Veteran Affairs Clinical Assessment, Reporting, and Tracking System Program, we identified a cohort of 755 patients who underwent lower extremity PVI from June 2005 to August 2010 at 33 sites. The outcomes of interest were mortality, progression to dialysis, myocardial infarction, limb amputation, and stroke. Kaplan-Meier survival analysis and Cox proportional hazard frailty models assessed the association between CKD and adverse outcomes. Of the patients who underwent lower extremity PVI, 201 patients (27%) had CKD. The presence of CKD was associated with decreased survival (5-year survival probability of CKD compared with non-CKD: 49.9% [41.6% to 59.9%] vs 80.1% [76.2% to 84.1]), which persisted after risk adjustment (HR 1.57; 95% confidence interval 1.13 to 2.19). In addition, there was a significant association between CKD and progression to dialysis (HR 6.62; 95% confidence interval 2.25 to 19.43). In contrast, there was no association between CKD and re-hospitalization for myocardial infarction, limb amputation, or stroke. In conclusion, CKD is present in 1 of 4 patients who underwent PVI and is associated with increased risk of mortality and progression to dialysis.

Detection of left atrial dysfunction with speckle tracking echocardiography

BACKGROUND

The aim of this study was to evaluate the relationship between the SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score and left ventricular end-diastolic pressure (LVEDP) measured with an invasive method and with speckle-tracking echocardiography (STE).

METHODS

The study included 124 patients who underwent cardiac catheterization. LVEDP values and coronary images were obtained for all patients. SYNTAX scores were calculated and separated into three tertiles (SYNTAX = 0, SYNTAX < 22, and SYNTAX > 22). Standard echocardiography and STE were performed on all the patients. Peak LA strain (LAs strain) in ventricular end-systole and LA strain during LA contraction (LAa strain) values were obtained with STE.

RESULTS

In univariate analysis, a strong correlation was observed between the SYNTAX score and LAs strain and a moderate correlation with LAa strain. A moderate correlation was also found between both LAs strain and LAa strain and LVEDP. In multiple regression analysis, LAs strain and LVEDP were observed to be independent predictors of SYNTAX score.

CONCLUSION

LAs strain and LVEDP were observed to be independent predictors of SYNTAX scores. The relationship between LAs strain, LVEDP, and SYNTAX score could be useful in clinical practice.

The Utility of Systolic and Diastolic Echocardiographic Parameters for Predicting Coronary Artery Disease Burden as Defined by the SYNTAX Score

BACKGROUND

Early identification of high-grade ischemia based on echocardiographic diastolic abnormalities may be clinically useful in the acute coronary syndrome (ACS) setting. This could provide the clinician with an awareness of the burden of coronary artery disease (CAD) before angiography is performed to allow for early intervention of suspected ischemic lesions. The objective of the study was to assess whether 2D transthoracic echocardiography (TTE)-derived tissue Doppler imaging parameters can predict the severity of CAD in comparison with the cardiac catheterization-derived SYNTAX score.

METHODS

A retrospective study of 74 stable angina or patients with ACS was performed in 2012 at a single tertiary care center. In all study subjects, TTE and angiography were performed within 6 months of each other without revascularization in the interim.

RESULTS

The study population included a total of 74 patients (mean age 67 ± 12 years) with 77% presenting with an ACS. The median SYNTAX score was 24.0 (6.0-35.0). The E-wave velocity was higher, and deceleration time (DT) was lower in the high SYNTAX group in comparison with the low/intermediate SYNTAX group (P = 0.045 and P = 0.001, respectively). Septal mitral annular S' was lower in the high SYNTAX group (P = 0.02). After multivariate analysis, E/A ratio (OR 0.03, 95% 0.00-0.36, P = 0.0067), DT (OR 0.93, 95% CI 0.89-0.97, P = 0.0001) and septal annular S'-wave velocity (OR 0.34, 95% CI 0.16-0.71, P = 0.0038) remained strong predictors of a high SYNTAX score.

CONCLUSION

Early identification of systolic and diastolic dysfunction based on echocardiographic parameters may be of important clinical significance for predicting CAD burden prior to invasive angiography.

Non-invasive detection of ischemic left ventricular dysfunction using rest gated SPECT: expectation of simultaneous evaluation of both myocardial perfusion and wall motion abnormality

OBJECTIVE

Although the accurate detection of ischemic etiology is important in the management of patients with severe left ventricular (LV) dysfunction, it is difficult to determine using a non-invasive strategy. The present study investigates whether perfusion and regional functional abnormalities identified by quantitative electrocardiographic gated single-photon emission computed tomography (QGS) at rest can detect ischemic LV dysfunction in patients with severe LV dysfunction.

METHODS

Rest QGS with (99m)Tc-tetrofosmin was performed on 54 consecutive patients with LV ejection fraction of </=40%. Ischemic LV dysfunction (n = 32) was defined according to the established standard. Regional perfusion and wall motion were calculated using a 14-segment model (six mid-ventricular and eight apical segments) and compared with a normal control group.

RESULTS

The numbers of reduced [mean -1 standard deviation (SD) of normal individuals] and severely reduced (mean -2 SD) wall motion segments were similar between patients with ischemic and non-ischemic LV dysfunction (13.5 +/- 1.1 vs. 13.6 +/- 0.9 and 10.6 +/- 2.0 vs. 9.9 +/- 3.0 segments, respectively). The number of hypoperfused (mean -1 SD) segments was significantly greater in patients with ischemic LV dysfunction than in those with non-ischemic LV dysfunction (9.3 +/- 3.8 vs. 2.0 +/- 2.8 segments, P < 0.0001). The analysis of the receiver operating characteristics showed that a cut-off value of 4 hypoperfused segments among 14 segments provided the best separation between ischemic and non-ischemic LV dysfunction (sensitivity = 88% and specificity = 91%). Furthermore, patients with non-ischemic LV dysfunction had no severely hypoperfused (mean -2 SD) segments in any of the segments, whereas patients with ischemic LV dysfunction had 4.4 +/- 0.2 segments.

CONCLUSIONS

The QGS strategy at rest can accurately differentiate patients with ischemic LV dysfunction from those with severe LV dysfunction by simultaneous regional evaluation of wall motion and myocardial perfusion.

Efficacy of N-acetylcysteine and hydration versus placebo and hydration in decreasing contrast-induced renal dysfunction in patients undergoing coronary angiography with or without concomitant percutaneous coronary intervention

OBJECTIVE

Contrast-induced renal dysfunction is an iatrogenic complication that occurs more frequently in patients with preexisting renal dysfunction. A prospective, double-blind, randomized, placebo, controlled trial was completed to assess the efficacy of N-acetylcysteine in decreasing the incidence of contrast-induced renal dysfunction in patients with an acute coronary syndrome and renal insufficiency who underwent coronary angiography with or without percutaneous coronary intervention.

METHODS

With similar intravenous hydration protocols, 20 patients received N-acetylcysteine (treatment group) and 20 patients received placebo (control group) in a twice per day dosing regimen with one dose before and three doses after contrast media exposure.

RESULTS

The two groups were similar at baseline on demographic and clinical characteristics, and preexisting renal insufficiency. Contrast-induced renal dysfunction, defined as an increase in serum creatinine greater than 44 micromol/L (.5 mg/dL) and/or 25% above baseline within 48 hours, occurred in 7.5% of the cohort, with 2.5% in the treatment group, and 5% in the control group, for an absolute difference of 2.5%. There was no difference in serum creatinine or creatinine clearance at 24 hours or at 48 hours between the treatment and control groups.

CONCLUSION

These results suggest that this cohort gained no added protection to renal function with the use of N-acetylcysteine.

Trimetazidine in the prevention of contrast-induced nephropathy after coronary procedures

OBJECTIVE

To evaluate the efficacy of trimetazidine (TMZ) in the prevention of contrast-induced nephropathy (CIN) in patients with high serum creatinine levels undergoing coronary angiography/angioplasty.

METHODS

TMZ (20 mg thrice daily) was administered orally for 72 h starting 48 h before the procedure. All patients were given intravenous saline (0.9%) at a rate of 1 ml/kg of body weight per hour for 24 h starting 12 h beforehand. Serum creatinine levels were measured before the procedure, 48 h and 7 days after the procedure. Increase in serum creatinine level exceeding 0.5 mg/day or one quarter of the basal value is considered as CIN. Venous blood samples for serum total antioxidant capacity (TAC) measurement were drawn before and after coronary angiography.

RESULTS

Basal serum creatinine levels and TAC were similar in TMZ and control groups. Serum creatinine levels in the control group increased significantly 2 days after the procedure, and returned to the baseline values on the seventh day. However, it did not change significantly on the second day, and even significantly decreased on the seventh day in the TMZ group. CIN developed in 2.5% (1/40) of patients in the TMZ group and in 16.6% (7/42) of patients in the control group (p<0.05). TAC values were not different between treatment groups.

CONCLUSION

TMZ along with isotonic saline infusion is more effective than isotonic saline alone in reducing the risk of CIN in patients with pre-existing renal dysfunction.

Effect of radiocontrasts on selected membrane transport systems

BACKGROUND

This study was aimed at examining the effects of radiocontrast agents on selected membrane transport functions.

METHODS

The effect of diatrizoate sodium (DS), diatrizoate meglumine (DM), and diatrizoate compound (DC) on Na+/K+ pump activity and number, L-arginine, and choline transports were evaluated in erythrocytes of normal individuals and patients undergoing cardiac catheterization.

RESULTS

Norrmal individuals' erythrocytes potassium influxes were 1.50+/-0.35, 1.32+/-0.37, 1.28+/-0.30, and 1.01+/-0.25 mmol/L cell/h in control, DS, DM, and DC groups, respectively (P=0.004; DC vs. control). Patients exposure to Hypaque M-76 significantly diminished Na+/K+ pump activity (1.40+/-0.36 before, vs. 1.27+/-0.40 mmol/L cell/h after; P=0.039). The number of Na+/K+ pumps was reduced (156+/-36 vs. 143+/-34 pumps/erythrocyte; P=0.015) in presence of DS. L-arginine and choline transports changed only at high radiocontrast concentrations.

CONCLUSION

Selective changes in erythrocytes membrane transport function take place on exposure to radiocontrasts.

Exploring oligodendrocyte guidance: 'to boldly go where no cell has gone before'

Oligodendrocytes, the myelinating cells of the central nervous system (CNS), originate early in the formation of the brain in specific foci, and migrate throughout the parenchyma. The instructional cues guiding the migration of these progenitor cells must be encoded into their developing environment. Soluble factors as well as membrane-bound cues most likely synergize to create a complex thoroughfare needed to sculpt and organize the brain into a functional organ with white and gray matter. Classically, the focus of many guidance related studies in the CNS has been limited to neuron physiology. However, It is becoming increasingly clear that their lifelong partners, oligodendrocytes, express both ligands and receptors able to both present and respond to these classical cues. In this short review, some recent findings in the Semaphorin and Eph fields will be presented with respect to oligodendrocyte expression and function.

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.

Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography

BACKGROUND

Contrast-induced nephropathy (CIN) after coronary angiography is associated with increased morbidity and mortality rates. Preliminary studies with N-acetylcysteine (NAC) have found conflicting results in the prevention of CIN in patients undergoing coronary angiography. This study was designed to evaluate the efficacy and safety of NAC in the prevention of CIN in patients undergoing coronary angiography.

METHODS

This study was prospective, randomized, double-blind, and placebo-controlled. Patients referred for elective coronary angiography with a baseline creatinine clearance level <50 mL/min and serum creatinine >1.2 mg/dL were randomly assigned to 1500 mg NAC or placebo, starting the evening before angiography and given every 12 hours for 4 doses. The primary study end point was the development of CIN, which was defined as an increase of >0.5 mg/dL or an increase of > or =25% in serum creatinine over baseline within 48 hours of angiography. Secondary end points included changes in serum creatinine and blood urea nitrogen, requirement of dialysis, side effects of study medication, hospital length of stay, and hospital charges.

RESULTS

CIN occurred in 8.2% (4/49) of patients taking NAC and 6.4% (3/47) of patients taking placebo. Changes in BUN and serum creatinine from baseline were not significantly different in the two treatment groups. Baseline BUN and volume of contrast were the only independent predictors of CIN. More patients with diabetes had development of CIN (5/43; 12%) compared with nondiabetic patients (2/52; 4%), but the difference was not significant (P =.15). The incidence of CIN in diabetic patients was not different in the two treatment groups. No patient with development of CIN required dialysis. Side effects (mostly gastrointestinal) occurred in 16% of patients taking NAC and in none of the patients taking placebo. Length of stay and hospital charges were not different between the treatment groups.

CONCLUSIONS

In patients with reduced renal function undergoing elective coronary angiography, NAC does not reduce the risk of CIN.

SCAI statement on ad hoc versus the separate performance of diagnostic cardiac catheterization and coronary intervention

Coronary intervention may be combined with diagnostic cardiac catheterization or performed separately. In the early years of angioplasty, performing these procedures separately was standard practice. Gradually, ad hoc intervention (performing diagnostic angiography and coronary intervention within the same session) has become more common, largely because of its convenience for patients and efficiency for physicians. However, the safety and potential cost savings of this approach remain uncertain. Criteria for the appropriate use of ad hoc intervention have not been established. Ad hoc intervention is reasonable for many, but not appropriate for all patients and should not be considered standard therapy. This document updates an earlier review of this topic and provides suggestions for the use of ad hoc intervention as a routine strategy.

Patient care before and after percutaneous coronary artery interventions

Care of the patient before and after percutaneous coronary interventions has changed largely because of the increased use of stents. Important patient management issues include the evaluation of chest pain after the procedure, recognition of acute vessel closure during the periprocedural period, management of the vascular access site, and prevention of contrast-induced renal dysfunction. Risk factor modification and drug therapies are important interventions for the secondary prevention of coronary events. Functional testing has a meaningful role in the evaluation of some patients after coronary intervention. It is important for the specialist in internal medicine to have a firm working knowledge of the various aspects of patient care before and after these procedures because their role in the management of these patients is increasing.

Contrast nephropathy : an evidence-based approach to prevention

Contrast-induced nephropathy occurs in 2-10% of patients exposed to intravascular radiographic contrast agents and results in significant morbidity and mortality. Although the exact mechanism of this disorder has not been fully elucidated, contrast nephropathy is probably due to a combination of decreased renal medullary blood flow, resulting in medullary ischemia, and direct toxicity to renal tubules. Contrast nephropathy is most commonly defined as either a >25% increase or a >0.5 mg/dL rise in serum creatinine level within 48 hours of contrast medium exposure. Baseline characteristics associated with an increased risk for development of contrast nephropathy include the presence of baseline renal dysfunction, diabetes mellitus, congestive heart failure, volume depletion, and concomitant administration of nephrotoxic drugs. Many strategies have been investigated in an effort to prevent the occurrence of renal dysfunction following contrast media exposure. Intravenous hydration has been shown to significantly decrease the incidence of nephropathy in high-risk patients. However, trials of several prophylactic pharmacologic interventions have been mostly disappointing, including the administration of calcium channel antagonists, diuretics, dopamine, endothelin receptor antagonists and fenoldopam. The use of N-acetylcysteine has been shown in some trials to decrease the incidence of contrast nephropathy in patients with a baseline renal dysfunction, and should currently be strongly considered in this high-risk patient subgroup in addition to hydration. Our purpose is to review the contemporary literature regarding contrast-induced renal dysfunction and present an evidence-based approach for prevention of this complication.

Use of fenoldopam to prevent radiocontrast nephropathy in high-risk patients

We evaluated the ability of fenoldopam, a newly available renal vasodilator, to prevent radiocontrast nephropathy in high-risk patients undergoing interventional diagnostic and therapeutic angiographic procedures. We reviewed the results from 46 consecutive procedures in patients with serum creatinine > or = 1.5 mg/dL if diabetic and > or = 1.7 mg/dL if nondiabetic. We compared our results to a previously published cohort of similarly at-risk patients. The incidence of radiocontrast nephropathy, defined as an increase in serum creatinine of > or = 25% at 48 hr following the procedure, was 13% in the group treated with fenoldopam, compared to an expected 38%. The percentage change in serum creatinine at 48 hr was +16% vs. +118%, respectively, in the two groups. In this preliminary experience, the use of fenoldopam in high-risk patients appears to minimize the likelihood of radioncontrast nephropathy. Cathet Cardiovasc Intervent 2001;53:341-345.

Prevention of contrast media-induced renal dysfunction with prostaglandin E1: a randomized, double-blind, placebo-controlled study

Preexisting renal impairment is an all-encompassing risk factor for radiocontrast-associated nephrotoxicity. Renal impairment appears to be associated with the inadequate production of renal prostaglandins at the critical time of radiocontrast administration and for a variable time period afterward. We prospectively studied 130 patients with chronic renal insufficiency (serum creatinine > or =1.5 mg/dL) who were undergoing radiocontrast administration. Using a double-blind, randomized, prospective technique, patients were assigned to either placebo or one of three prostaglandin E1 (PGE1) treatment groups (10, 20, or 40 ng/kg/min). Infusion was started 60 +/- 30 minutes before the administration of radiocontrast and was continued for a total of 6 hours. In the placebo group, radiocontrast administration resulted in a mean increase (+/- SD) in serum creatinine of 0.72 +/- 1.15 mg/dL at 48 hours. This increase was less in each of the PGE1 treatment groups after 48 hours, with a significant difference between placebo and the 20 ng/kg/min PGE1 group (P = 0.01). Using baseline adjusted means, analysis of covariance with baseline serum creatinine as the covariable demonstrated significant differences between the placebo and 20 ng/kg/min PGE1 group (P = 0.03) and between the placebo and 10 ng/kg/min PGE1 group P = 0.047). In a subgroup analysis of the diabetic patients, the increase in serum creatinine was less pronounced in the three PGE1 groups versus the placebo group, and the 20 ng/kg/min PGE1 group had the most favorable outcome. The parenteral administration of PGE1 immediately before radiocontrast exposure and continued for a period of 5 to 5.5 hours significantly reduced the elevation of serum creatinine poststudy. The most effective of the three PGE1 dosing regimens was 20 ng/kg/min.

Prostaglandin E1: a new agent for the prevention of renal dysfunction in high risk patients caused by radiocontrast media? PGE1 Study Group

BACKGROUND

Acute renal failure following the administration of radiocontrast media (RCM) is a complication found especially in patients with impaired renal function. Within the limits of a pilot study, the objective was to (a) show the effectiveness and compatibility of prostaglandin E(1) (PGE(1)=Alprostadil) in preventing acute renal failure in patients with elevated levels of serum creatinine and (b) to identify the most appropriate PGE(1)-dose.

METHODS

130 patients with renal impairment (serum creatinine >/=1.5 mg/dl) were included in the study prior to intravascular RCM injection. The patients received one of three different doses of PGE(1) (10, 20, or 40 ng/kg bodyweight/min) or placebo (physiologic sodium chloride solution) intravenously over a time period of 6 h (beginning 1 h prior to RCM application). Serum creatinine was measured 12, 24, and 48 h post RCM-application and creatinine clearance was determined with two 12 h collection periods, as well as one 24 h collection within 48 h post RCM administration. Adverse events during PGE(1) administration were recorded.

RESULTS

In the placebo group, the mean elevation of serum creatinine was markedly higher (0.72 mg/dl) 48 h after RCM administration compared with the three PGE(1) groups (0.3 mg/dl in the 10 ng/kg/min group, 0. 12 mg in the 20 ng/kg/min group, and 0.29 mg/dl in the 40 ng/kg/min group). No clinically relevant changes were seen regarding the creatinine clearance in the four groups examined.

CONCLUSIONS

Results from this pilot-study suggest that intravenous PGE(1) may be used efficaciously and safely to prevent RCM-induced renal dysfunction in patients with pre-existing impaired renal function.

Cyanotic nephropathy and use of non-ionic contrast agents during cardiac catherization in patients with cyanotic congenital heart disease

BACKGROUND

Chronic cyanosis with its associated rheologic changes is a known risk factor for glomerular nephropathy. Therefore, contrast-induced nephrotoxicity should be an important consideration for angiographers comparable to diabetics. On the other hand, progressions in diagnostic and interventional techniques have led to expanded indications and a more widespread use of x-ray contrast agents. The aim of this study was to investigate the risk of contrast-induced nephropathy in the small group of patients with cyanotic heart disease prior to surgical repair.

METHODS

We investigated 23 cyanotic patients with an oxygen saturation of 82 (50-92)%, age 25 (5-63) years, and 13 control subjects with atrial septal defect, age 37 (20-66) years. Blood viscosity was measured before and after cardiac catherization. Renal damage was evaluated by selective analysis of urinary proteins and enzymes.

RESULTS

Before cardiac catheterization, 48% of the cyanotic patients had a moderate glomerulopathy. Cardiac catherization was performed with 3.0 (1.2-6.8) mls/kg non ionic contrast medium. Only one of the 23 patients (4.3%) with normal urinary analysis before cardiac catheterization showed renal damage, which involved tubular and glomerular function. Elevated blood viscosity in cyanotic patients was slightly reduced by the contrast. None of the acyanotic controls had contrast-induced nephropathy.

CONCLUSIONS

The use of non-ionic contrast medium does not worsen cyanotic glomerulopathy. This finding may be due to the reduction of blood viscosity by the application of the contrast medium. The finding of contrast-induced nephropathy in one patient underlines the importance of monitoring renal function after cardiac catheterization.

The renal effect of low-dose dopamine in high-risk patients undergoing coronary angiography

OBJECTIVES

The purpose of the study was to examine the potential renal protective effect of low-dose dopamine in high-risk patients undergoing coronary angiography.

BACKGROUND

Contrast nephropathy is prevalent in patients with chronic renal failure (CRF) and/or diabetes mellitus (DM). Decreased renal blood flow due to vasoconstriction was suggested as a contributory mechanism. Low-dose dopamine has a dilatory effect on the renal vasculature.

METHODS

Sixty-six patients with mild or moderate CRF and/or DM undergoing coronary angiography were prospectively double-blindedly randomized, to either 120 ml/day of 0.9% saline plus dopamine 2 microg/kg/min (Dopamine group) or saline alone (Control group) for 48 h.

RESULTS

Thirty-three Dopamine-treated (30 diabetics and 6 with CRF) and 33 Control (28 diabetics and 5 with CRF) patients were compared. Plasma creatinine (Cr) level increased in the Control group from 100.6+/-5.2 before to 112.3+/-8.0 micromol/liter within five days after angiography (p = 0.003), and in the Dopamine group from 100.3+/-5.4 before to 117.5+/-8.8 micromol/liter after angiography (p = 0.0001), respectively. There was no significant difference in the change of Cr level (deltaCr) between the two groups. However, in a subgroup of patients with peripheral vascular disease (PVD), deltaCr was -2.4+/-2.3 in the Control group and 30.0+/-12.0 micromol/liter in the Dopamine group (p = 0.01). No significant difference occurred in deltaCr between Control and Dopamine in subgroups of patients with preangiographic CRF or DM.

CONCLUSIONS

Contrast material caused a small but significant increase in Cr blood level in high-risk patients. There is no advantage of dopamine over adequate hydration in patients with mild to moderate renal failure or DM undergoing coronary angiography. Dopamine should be avoided in patients with PVD exposed to contrast medium.

Acute renal failure after coronary intervention: incidence, risk factors, and relationship to mortality

PURPOSE

This study set out to define the incidence, predictors, and mortality related to acute renal failure (ARF) and acute renal failure requiring dialysis (ARFD) after coronary intervention.

PATIENTS AND METHODS

Derivation-validation set methods were used in 1,826 consecutive patients undergoing coronary intervention with evaluation of baseline creatinine clearance (CrCl), diabetic status, contrast exposure, postprocedure creatinine, ARF, ARFD, in-hospital mortality, and long-term survival (derivation set). Multiple logistic regression was used to derive the prior probability of ARFD in a second set of 1,869 consecutive patients (validation set).

RESULTS

The incidence of ARF and ARFD was 144.6/1,000 and 7.7/1,000 cases respectively. The cutoff dose of contrast below which there was no ARFD was 100 mL. No patient with a CrCl > 47 mL/min developed ARFD. These thresholds were confirmed in the validation set. Multivariate analysis found CrCl [odds ratio (OR) = 0.83, 95% confidence interval (CI) 0.77 to 0.89, P <0.00001], diabetes (OR = 5.47, 95% CI 1.40 to 21.32, P = 0.01), and contrast dose (OR = 1.008, 95% CI 1.002 to 1.013, P = 0.01) to be independent predictors of ARFD. Patients in the validation set who underwent dialysis had a predicted prior probability of ARFD of between 0.07 and 0.73. The in-hospital mortality for those who developed ARFD was 35.7% and the 2-year survival was 18.8%.

CONCLUSION

The occurrence of ARFD after coronary intervention is rare (<1%) but is associated with high in-hospital mortality and poor long-term survival. Individual patient risk can be estimated from calculated CrCl, diabetic status, and expected contrast dose prior to a proposed coronary intervention.

Iodinated contrast material in uroradiology. Choice of agent and management of complications

Many conditions seen by urologists require imaging examinations with iodinated radiographic contrast material as a key part of the primary evaluation of the patient. A basic understanding of contrast media, risks of administration, choice of agents, and premedication regimens for high-risk patients, is beneficial in helping patients prepare for their examinations. Urologists may be the primary physicians administering contrast material or may be working with radiologists in the care of patients receiving contrast agents. Because contrast reactions may occur unexpectedly, even during examinations in which the agents are not given intravenously, urologists should be able to recognize and treat the various types of adverse reactions.

Use of dopamine in prevention of contrast induced acute renal failure--a randomised study

We report the use of dopamine in renal doses (5 micrograms/kg/min) to prevent contrast induced nephropathy (CIN). Forty patients with diabetes mellitus who were undergoing coronary angiography were randomly divided into two groups. Gr I (20 patients) was infused with dopamine starting 30 min before cardiac catheterization and continued for 6 h thereafter. Gr II (20 patients) did not receive dopamine. Baseline blood chemistry was performed before catheterization and then repeated 24 h after the procedure. The mean age and sex distribution were similar in both the groups. Urograffin (76%; 120-150 ml) was used in all the cases. The mean serum creatinine and blood urea nitrogen (BUN) levels in Gr I patients before catheterization were 1.5 +/- 0.32 mg % and 16.3 +/- 8.05 mg %, respectively. The corresponding values for Gr II were 1.52 +/- 0.68 mg % and 19.6 +/- 13.4 mg %, respectively. After angiography, Gr I patients did not show significant changes in renal parameters (serum creatinine, 1.37 +/- 0.25 mg % and BUN, 14.7 +/- 5.5 mg %) while Gr II patients showed a significant rise (serum creatinine, 1.96 +/- 1.2 mg % and BUN, 23.25 +/- 12.7 mg %; P = 0.01 and P = 0.05, respectively). Ten patients in Gr II (50%) developed a 25% rise in serum creatinine levels within 24 h of injection of the contrast. None of the patients developed renal failure severe enough to warrant dialysis. Hence alterations of renal function are common after cardiac catheterization. Dopamine in renal doses appears to be an effective means to prevent deterioration in renal function induced by contrast.