How to prevent contrast-induced nephropathy and manage risk patients: Practical recommendations

Selective Arterial Embolization of Pseudoaneurysms and Arteriovenous Fistulas after Partial Nephrectomy: Safety, Efficacy, and Mid-Term Outcomes

The primary objective was to evaluate the clinical success rate after endovascular embolization of iatrogenic vascular lesions caused during partial nephrectomy. The secondary objective was to evaluate the technical success and to assess potential effects on renal function. We retrospectively included consecutive patients from our center who underwent selective embolization to treat iatrogenic renal arterial lesions induced during partial nephrectomy between June 2010 and June 2020. The technical and clinical success rates and renal outcomes were collected. We identified 25 patients with 47 pseudoaneurysms and nine arteriovenous fistulas. Among them, eight were treated by coils only, eight by liquid embolization agents only, and nine by both. The technical success rate was 96% after the first attempt and 100% after the second attempt. The median follow-up was 27.1 ± 24.3 months. Clinical success, defined as no need for further hemostatic surgery during follow-up, was also obtained in 96% and 100% of patients with one and two attempts, respectively. Renal function estimated by the modification of diet in renal disease equation did not change significantly despite a mean 13.8% ± 15.1% decrease in kidney functional volume estimated by angiography. No complications were attributable to the endovascular treatment. No significant difference was found across embolization agents; however, the subgroup sizes were small. Endovascular embolization is safe and effective for treating iatrogenic arterial lesions after partial nephrectomy: success rates are high, complications are infrequent, and renal function is maintained. Recommendations by interventional radiology societies are needed to standardize this treatment.

A patient-informed approach to predict iodinated-contrast media enhancement in the liver

OBJECTIVE

To devise a patient-informed time series model that predicts liver contrast enhancement, by integrating clinical data and pharmacokinetics models, and to assess its feasibility to improve enhancement consistency in contrast-enhanced liver CT scans.

METHODS

The study included 1577 Chest/Abdomen/Pelvis CT scans, with 70-30% training/validation-testing split. A Gaussian function was used to approximate the early arterial, late arterial, and the portal venous phases of the contrast perfusion curve of each patient using their respective bolus tracking and diagnostic scan data. Machine learning models were built to predict the Gaussian parameters of each patient using the patient attributes (weight, height, age, sex, BMI). Pearson's coefficient, mean absolute error, and root mean squared error were used to assess the prediction accuracy.

RESULTS

The integration of the pharmacokinetics model with a two-layered neural network achieved the highest prediction accuracy on the test data (R2 = 0.61), significantly exceeding the performance of the pharmacokinetics model alone (R2 = 0.11). Applying the model demonstrated that adjusting the contrast administration directed by the model may reduce clinical enhancement inconsistency by up to 40 %.

CONCLUSIONS

A new model using a Gaussian function and supervised machine learning can be used to build liver parenchyma contrast enhancement prediction model. The model can have utility in clinical settings to optimize and improve consistency in contrast-enhanced liver imaging.

Optimizing the Outcomes of Percutaneous Coronary Intervention in Patients with Chronic Kidney Disease

Percutaneous coronary intervention (PCI) is one of the most common procedures performed in medicine. However, its net benefit among patients with chronic kidney disease (CKD) is less well established than in the general population. The prevalence of patients suffering from both CAD and CKD is high, and is likely to increase in the coming years. Planning the adequate management of this group of patients is crucial to improve their outcome after PCI. This starts with proper preparation before the procedure, the use of all available means to reduce contrast during the procedure, and the implementation of modern strategies such as radial access and drug-eluting stents. At the end of the procedure, personalized antithrombotic therapy for the patient’s specific characteristics is advisable to account for the elevated ischemic and bleeding risk of these patients.

Contrast-Associated Acute Kidney Injury

Contrast-associated acute kidney injury (CA-AKI) is an impairment of renal function, which occurs within days of intravascular administration of iodinated contrast media. Taking into account that minimally invasive cardiac interventions are becoming increasingly popular, compared to traditional surgery, given their impact on prognosis and costs, CA-AKI remains a subject of increasing interest for patients and physicians. This review summarizes the epidemiology and risk stratification, diagnostic criteria, pathophysiology and clinical implications of CA-AKI, providing evidence for the most studied preventive strategies.

Suspected contrast-induced nephropathy in three sequential patients undergoing computed tomography angiography and transarterial embolization for nonresectable neoplasia

CASE DESCRIPTION

During the same week, 3 sequential patients (a 10-year-old 8.7-kg spayed female poodle cross [dog 1], 13-year-old 2.6-kg spayed female domestic longhair cat, and 13-year-old 9.0-kg castrated male mixed-breed dog [dog 2]) underwent CT-angiography (day 0) and transarterial embolization (day 1) for nonresectable hepatocellular carcinoma (n = 2) or prostatic carcinoma (1).

CLINICAL FINDINGS

Contrast-induced nephropathy (CIN) was suspected in all animals on the basis of higher serum creatinine concentrations after contrast medium administration (exposure), compared with baseline concentrations before exposure, consistent with CIN definitions. The total dose of contrast medium was < 3 mL/kg for each exposure. For all 3 patients, creatinine concentration peaked at a median of 3 days (range, 2 to 3 days) after the first exposure (day 0), and the median absolute and relative increases in creatinine concentration after exposure (vs baseline concentrations before exposure) were 2.9 mg/dL (range, 2.2 to 3.7 mg/dL) and 410% (range, 260 to 720%), respectively.

TREATMENT AND OUTCOME

The patients received individually tailored supportive care for acute kidney injury. Serum creatinine concentrations began to improve at a median of 4 days (range, 3 to 4 days) and returned to within reference limits at a median of 7 days (range, 3 to 13 days) following initial exposure.

CLINICAL RELEVANCE

CIN should be considered as a potential complication following IV administration of contrast medium. Short-term outcome following CIN can be excellent with supportive care.

The Relationship Between Contrast Associated Nephropathy and Coronary Collateral Circulation in very Old Patients

Background: The aim of this study was to investigate whether there is a relationship between coronary collateral circulation (CCC) and contrast associated nephropathy (CAN) in very elderly patients. Methods: Patients aged 90 years or older with at least one major occlusion of the coronary artery proximal or mid-section were included in the study. CCC was graded according to the Rentrop classification. CAN was defined as an increase in blood creatinine value of 25% or more on the second day after coronary angiography. Results: Thirty-six patients who met the study criteria were included in the study. In the study group, CAN developed in 12 patients (CAN (+) group), 24 patients did not develop CAN (CAN (−) group). The creatinine levels before coronary angiography were 1.05 ± 0.12 in the CAN (−) group and 1.22 ± 0.14 in the CAN (+) group. Baseline creatinine values were significantly higher in the CAN (+) group (p = 0.001). The contrast agent used in the CAN (+) group was significantly higher (p = 0.001). In the CAN (+) group, nine patients (43%) had poor collateral circulation, whereas only three patients (20%) had well-developed collateral circulation. In a logistic regression analysis, the collateral class was not a risk factor for CAN, whereas contrast agent volume and basal creatinine were independent predictors of CAN. Conclusion: We found that CCC grade was not associated with the development of CAN in very old patients, but the amount of contrast agent and pre-procedure creatinine values were independent variables in the development of CAN.

Effect of Alprostadil on the Prevention of Contrast-Induced Nephropathy: A Meta-Analysis of 36 Randomized Controlled Trials

Contrast-induced nephropathy (CIN) is the third leading cause of acquired acute renal injury in hospitalized patients. Alprostadil plays a role in the maintenance and redistribution of intrarenal blood flow and the excretion of electrolytes and water. However, the effectiveness of alprostadil in preventing CIN remains controversial. Thirty-six articles with a total of 5495 patients were included in this study. Both groups (experimental group and control group) received standard hydration therapy. In the experimental group, patients received different doses of alprostadil. Serum creatinine (SCr), blood urea nitrogen (BUN), estimated glomerular filtration rate (eGFR), cystatin C, creatinine clearance rate (CCr), and β2-microglobulin (β2-MG) were measured at 24, 48, and 72 hours after contrast media injection. The incidence of CIN in the experimental group was significantly lower than that in the control group (6.56% vs 16.74%). The level of SCr, cystatin C, BUN, and β2-MG in the experimental group was lower than those in the control group; CCr and eGFR in the experimental group were higher than those in the control group. This study demonstrated that alprostadil may reduce the incidence of CIN in patients undergoing coronary angiogram and/or percutaneous coronary intervention.

Is the risk of contrast-induced nephropathy a real contraindication to perform intravenous contrast enhanced Computed Tomography for non-traumatic acute abdomen in Emergency Surgery Department?

BACKGROUND

Contrast enhanced Computed Tomography (CCT) is the most used imaging test to investigate acute abdominal clinical conditions, because of its high sensitivity and specificity. It is mandatory to make a correct and prompt diagnosis when life threatening abdominal diseases as mesenteric ischemia are suspected. Contrast medium administration was linked to acute renal failure, therefore radiologist often prefer to perform CCT without contrast in patients needing to undergo the exam with increased serum creatinine.  The aim of the review was to focus on the incidence of contrast induced nephropathy in patients presenting non-traumatic acute abdominal clinical conditions, who underwent CCT with intravenous contrast agent administration in emergency setting.

MATERIALS AND METHODS

The systematic review protocol was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocol (PRISMA-P). Quality of the evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

The strongest currently available evidence on the incidence of post-contrast acute kidney injury (AKI) following intravenous contrast agent administration consists in a meta-analysis of observational studies. Data extracted from meta-analyses demonstrate that, compared with non-contrast CT, CCT was not significantly associated with AKI. Moreover, the risk of AKI (RR=0.79; 95% confidence interval [CI]: 0.62, 1.02; P=.07), death (RR=0.95; 95% CI: 0.55, 1.67; P=.87), and dialysis (RR=0.88; 95% CI: 0.23, 3.43; P=.85) is similar, compared with the risk of AKI in the non-contrast medium group. Furthermore, intravenous low-osmolality iodinated contrast material is a nephrotoxic risk factor, but not in patients with a stable SCr level less than 1.5 mg/dL, therefore many factors other than contrast material could affect PC-AKI rates.

DISCUSSION AND CONCLUSIONS

The benefits of diagnostic information gained from contrast enhanced TC in assessing AA are fundamental in some clinical scenarios. The risk of contrast induced nephropathy (CIN) is negligible in patients with normal renal function but the incidence appears to rise to as high as 25% in patients with pre-existing renal impairment or in the presence of risk factors such as diabetes, advanced age, vascular disease and use of certain concurrent medications. The incidence of CIN/AKI after intravenous contrast administration is very low in general population. Radiologists and referring physicians should be familiar with the risk factors for renal disease, CIN and preventing measures.

Influence of symptomatic pseudoaneurysms on postoperative renal function after partial nephrectomy: results of a matched pair analysis

PURPOSE

A symptomatic pseudoaneurysm (SPA) is a rare but severe complication after partial nephrectomy (PN). Selective trans-arterial embolization (TAE) is the treatment of choice with high success rates. However, the influence of this intervention on postsurgical renal function has not been studied.

METHODS

Between 2005 and 2016 we performed 1047 PNs at our institution. Postsurgical SPA occurred in 40 patients (3.8%). Patients with and without SPA were matched in a 1:2 ratio concerning tumor complexity (RENAL) and pre-operative renal function (CKD stage). Any CKD upstage and a relevant CKD progression (CKD ≥ III) were defined as endpoints. Furthermore, the influence of the amount of contrast agent applied during TAE was assessed.

RESULTS

All patients with SPA were treated successfully with TAE. No significant difference could be detected concerning clinical, functional and surgical aspects. Median follow-up time accounted for 12.5 (6.75-27.5) months. Kaplan-Meier analyses detected an increased rate of any CKD upstage (p = 0.066) and relevant CKD progression (p = 0.01) in patients with SPA. Multivariate analysis identified post-operative SPA to be an independent predictor for a relevant CKD progression (HR 4.15, p = 0.01). The amount of contrast agents used did not have an impact on the development of a relevant CKD progression (p = 0.72).

CONCLUSION

Patients treated with TAE after PN show an additional risk for an impairment of renal function over time. Hence, those patients should explicitly be informed about possible consequences and closely monitored by nephrologists.

Effect of trimetazidine on preventing contrast-induced nephropathy in diabetic patients with renal insufficiency

BACKGROUND

Our study sought to assess the effect of trimetazidine (TMZ) on preventing contrast-induced nephropathy (CIN) in diabetic patients with renal insufficiency.

MATERIALS AND METHODS

106 diabetic patients with renal insufficiency who were undergoing coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) were enrolled in this study. Standard hydration was administered to both groups (the TMZ group and the control group). In the TMZ group, patients were orally administered TMZ for 48 hours before and 24 hours after CAG and/or PCI. Serum creatinine (Scr), cystatin C and the glomerular filtration rate (eGFR) were measured before as well as 24 hours, 48 hours and 72 hours after contrast media injection. The incidence of CIN and major cardiovascular events (MACE) was also evaluated in both groups.

RESULTS

Scr, cystatin C and the eGRF in the TMZ group were better than those in the control group after 24 hours (OR: 0.78, 95% CI: 0.54-0.82; OR: 0.66, 95% CI: 0.62-0.73; OR: 1.2, 95% CI: 1.02-1.53, respectively), 48 hours (OR: 0.69, 95% CI: 0.52-0.73; OR: 0.76, 95% CI: 0.69-0.84; OR: 1.5, 95% CI: 1.25-1.68, respectively) and 72 hours (OR: 0.82, 95% CI: 0.77-0.91; OR: 0.85, 95% CI: 0.71-0.92; OR: 1.67, 95% CI: 1.33-1.72, respectively). The incidence of CIN (9.26% vs 16.67%) and MACE (7.41% vs 18.51%) in the TMZ group was significantly lower than that in the control group (P < 0.05).

CONCLUSIONS

Our study suggests that TMZ could reduce the incidence of CIN and MACE in diabetic patients with renal insufficiency who are undergoing CAG and/or PCI.

Association of post-procedural early (within 24h) increases in serum creatinine with all-cause mortality after coronary angiography

BACKGROUND

The majority of patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI) are discharged early, with only early (within 24h) serum creatinine (SCr) data available without evidence of clinical prognosis. We aimed to systemically evaluate the association between post-procedural early increase in SCr and all-cause mortality following CAG.

METHODS

We performed a retrospective sub-study analysis within a prospective observational study including 3091 consecutive patients with baseline and post-procedural early (within 24h) SCr data. The degree (mild, moderate, or large) of absolute and relative increases in SCr from baseline. The mean follow-up time was 2.49years.

RESULT

Moderate or large early increases in SCr were relatively rare (large increase: >1.0mg/dl [0.5%], >100% [0.4%]), whereas mild absolute and relative increases in SCr were more common (mild increase: 0.25 to 0.50mg/dl [4.5%], 25% to 50% [5.9%]). During the follow-up period, there were 136 post-procedural deaths (5.6%). After adjustment for confounders, mild absolute and relative increases in SCr were associated with increased mortality (hazard ratio [HR]: 1.9 and 1.8, respectively, both P<0.05). Moderate or large increases in SCr were associated with higher mortality, even higher than with pre-existing renal dysfunction (HR: 5.36 and 4.12 for moderate increase [0.5 to 1.0mg/dl] and estimated glomerular filtration rate<60ml/min).

CONCLUSION

Post-procedural mild, moderate, or large early increase in SCr, is associated with significantly increased long-term mortality. Although moderate or large increase in SCr following CAG was relatively rare, the prognosis is more serious, and is worse than that of pre-existing renal dysfunction.

CLINICAL TRIAL REGISTRATION

Predictive Value of Contrast Volume to Creatinine Clearance Ratio (PRECOMIN, ClinicalTrials.govNCT01400295).

An Individually Optimized Protocol of Contrast Medium Injection in Enhanced CT Scan for Liver Imaging

Objective

To investigate the effectiveness of a new individualized contrast medium injection protocol for enhanced liver CT scan.

Methods

324 patients who underwent plain and dual phase enhanced liver CT were randomly assigned to 2 groups: G1 (n = 224, individualized contrast medium injection protocol); G2 (n = 100, standard contrast medium injection with a dose of 1.5 ml/kg). CT values and ΔHU (CT values difference between plain and enhanced CT) of liver parenchyma and tumor-liver contrast (TLC) during hepatic arterial phase (HAP) and portal venous phase (PVP) and contrast medium dose were measured. The tumor conspicuity of hepatocellular carcinoma (HCC) between two groups was independently evaluated by two radiologists.

Results

The mean contrast medium dose of G1 was statistically lower than that of G2. There were no significantly statistical differences in CT values and ΔHU of liver parenchyma during HAP, TLC values during HAP, and PVP between two groups. The CT values and ΔHU of liver parenchyma during PVP of G2 were significantly higher than those of G1. Two independent radiologists were both in substantial conformity in grading tumor conspicuity.

Conclusion

Using the individually optimized injection protocol might reduce contrast medium dose without impacting on the imaging quality in enhanced liver CT.

Concurrent renal artery stent during endovascular infrarenal aortic aneurysm repair confers higher risk for 30-day acute renal failure

OBJECTIVE

Concurrent renal artery angioplasty and stenting (RAAS) during endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysm (AAA) has been practiced in an attempt to maintain renal perfusion. The aim of this study was to identify the current practice of RAAS during EVAR and its effect on perioperative renal outcome.

METHODS

Patients with infrarenal AAA were identified from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP, 2011-2014) database. Baseline characteristics of patients with concurrent RAAS during EVAR were compared with those of patients who underwent EVAR only. Bivariate and multivariable logistic regression analyses controlling for patients' demographics, comorbidities, and operative factors were used to evaluate the predictors of 30-day acute renal failure (ARF). Sensitivity analysis was done to evaluate the role of RAAS in patients with prior kidney disease.

RESULTS

Overall, 6183 patients underwent EVAR for infrarenal AAA during the study period. Of them, 281 patients had RAAS during EVAR (4.5%). The median age of the patients was 74 years; 81.7% of the cohort was male, but a higher proportion of female patients received EVAR + RAAS compared with patients who underwent EVAR only (26.3% vs 17.9%; P < .001). There was no difference between groups in terms of comorbidities, being on dialysis, or functional status, yet the EVAR + RAAS group had a higher proportion of patients with glomerular filtration rate <60 mL/min/1.73 m2 (45.2% vs 37.2%; P = .011). RAAS was associated with significantly higher odds for development of ARF (adjusted odds ratio [aOR], 4.27; 95% confidence interval [CI], 2.06-8.84; P < .001). Other highly predictive factors of 30-day ARF were glomerular filtration rate <60 (aOR, 2.92; 95% CI, 1.47-5.78; P = .002), emergency status (aOR, 2.97; 95% CI, 1.21-7.27; P = .017), and ruptured AAA as the indication for EVAR (aOR, 4.74; 95% CI, 1.80-12.50; P = .002). Patients with prior kidney disease who had EVAR + RAAS demonstrated a 12-fold higher odds for 30-day ARF (aOR, 12.37; 95% CI, 4.66-32.89; P < .001).

CONCLUSIONS

Concurrent RAAS was found to be a significant determinant of adverse renal outcomes after EVAR for infrarenal AAA. This effect was present even after controlling for patients' risk factors that might contribute to postoperative ARF.

Contrast-Induced Acute Kidney Injury: An Update

Contrast-induced acute kidney injury (CI-AKI) is defined as an abrupt deterioration in renal function associated with the administration of iodinated contrast media. This type of acute kidney injury is frequently encountered as a complication of percutaneous coronary intervention (PCI) and is associated with adverse short- and long-term outcomes including mainly mortality, cardiovascular morbidity and prolongation of hospitalization. The incidence of CI-AKI after PCI ranges from 2 to 20 % according to baseline kidney function. It may also range according to the clinical setting, being higher after emergency PCI. The primary manifestation is a small decline in kidney function, occurring 1 to 3 days after the procedure. Kidney function usually returns to preexisting levels within 7 days. Incidence of acute renal failure requiring dialysis following PCI is rare (<1 %). The present article aims to review up-to-date published data concerning diagnosis, definition, epidemiology and prognosis of this novel in-hospital epidemic.

Diagnostic accuracy of serum cystatin C for early recognition of contrast induced nephropathy in Western Indians undergoing cardiac catheterization

Aims

We aimed to compare the diagnostic efficacy of serum cystatin C (sCyC) for contrast induced nephropathy (CIN) in Western Indians undergoing cardiac catheterization. We also aimed to propose a clinically applicable cut-off of sCyC for early identification of CIN in this ethnic group.

Methods

In this prospective study, 253 patients undergoing coronary angiography and/or percutaneous coronary intervention were enrolled. The demographic and risk factor details, levels of sCr at baseline, 24 and 48 h after the procedure, whereas baseline and 24 h levels of sCyC were noted. Increase of 0.5 mg/dl or ≥25% from baseline sCr was used to define CIN. Optimum cut off of sCyC for CIN diagnosis was obtained using Receiver Operating Characteristic (ROC) curve analysis.

Results

After 48 h of contrast media (CM) exposure, the incidence of CIN was 12.25% (31 patients) according to sCr definition, where only 3.9% (10 patients) had sCr rise in 24 h. Overall significant (p < 0.0001) rise in mean levels of sCr (48 h) and sCyC (24 h) was observed in CIN patients. However, the mean sCr rise at 24 h was non-significant. The optimum cut off of sCyC for diagnosing CIN was found to be a rise of ≥10% from baseline (AUC – 0.901; sensitivity – 100%, specificity – 77.89%). According to sCyC, 94 (37.15%) patients had CIN.

Conclusion

We may conclude that a rise of ≥10% in sCyC at 24 h could be used as a reliable marker for identification of CIN in western Indians undergoing cardiac catheterization.

Risk factors for contrast-induced nephropathy and their association with mortality in patients with blunt splenic injuries

BACKGROUND

Although angioembolization increases the success rate of non-operative management in patients with blunt splenic injuries (BSI), the issue of contrast-induced nephropathy (CIN) due to serial administration of contrast medium remains unclear. We aimed to examine the risk factors of CIN and their clinical effect on mortality in patients with BSI.

METHOD

We retrospectively studied the complete data on 377 trauma patients with BSI who survived more than 48 h between July 2003 and June 2015. CIN was defined as the relative (≥25%) or absolute (≥0.5 mg/dL) increase in serum creatinine within 48 h after contrast administration. A multivariate logistic regression analysis was conducted to identify the independent predictors of CIN and mortality.

RESULTS

CIN was independently associated with body mass index (BMI) ≥ 30 kg/m² (odds ratio [OR]: 3.25, 95% confidence interval [CI]: 1.20-8.76), injury severity score (ISS) ≥ 25 (OR: 6.08, 95% CI: 2.76-13.53), and 24-h hemoglobin (Hb) < 10 g/dL (OR: 3.16, 95% CI: 1.46-6.81). CIN (OR: 19.04, 95% CI: 6.15-58.94) and diabetes (OR: 3.43, 95% CI: 1.04-11.26) were also identified as independent predictors for mortality.

CONCLUSION

In this study, we found that BMI ≥ 30 kg/m², ISS ≥ 25, and 24-h Hb < 10 g/dL were independent risk factors for the occurrence of CIN in patients with BSI. However, angioembolization was not identified to be an independent risk factor for CIN. In addition, CIN and diabetes mellitus were identified as independent risk factors for mortality in patients with BSI.

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

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

A systematic review and meta-analysis indicates underreporting of renal dysfunction following endovascular aneurysm repair

Deterioration in renal function has been described after endovascular repair of abdominal aortic aneurysms (EVRs). The etiology is multifactorial and represents an important therapeutic target. A need exists to quantitatively summarize incidence and severity of renal dysfunction after EVR to allow better-informed attempts to preserve renal function and improve life expectancy. Here a systematic search was performed using Medline and Embase for renal function after EVR applying PRISMA statements. Univariate and multivariate random-effects meta-analyses were performed to estimate pooled postoperative changes in serum creatinine and creatinine clearance at four time points after EVR. Clinically relevant deterioration in renal function was also estimated at 1 year or more after EVR. Pooled probability of clinically relevant deterioration in renal function at 1 year or more was 18% (95% confidence interval of 14-23%, I2 of 82.5%). Serum creatinine increased after EVR by 0.05 mg/dl at 30 days/1 month, 0.09 mg/dl at 1 month to 1 year, and 0.11 mg/dl at 1 year or more (all significant). Creatinine clearance decreased after EVR by 5.65 ml/min at 1 month-1 year and by 6.58 ml/min at 1 year or more (both significant). Thus, renal dysfunction after EVR is common and merits attention.

Acute kidney injury after primary angioplasty: effect of different hydration treatments

AIMS

We evaluated the effect of different dose hydration protocols, with normal saline or bicarbonate, on the incidence of contrast-induced acute kidney injury (CI-AKI) in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PPCI).

METHODS

We considered 592 STEMI patients treated with PPCI in 5 Italian centers. Patients were randomized to receive standard or high-dose infusions of normal saline or sodium bicarbonate started immediately before contrast medium administration and continued for the following 12 h.

RESULTS

The cumulative incidence of CI-AKI was 18.1% without any difference among treatment groups. Shock, age, ejection fraction 35% or less, and basal serum creatinine were significantly associated with an increased risk of CI-AKI. Follow-up at 12 months was complete in 573 patients. Overall, 25 out of 573 patients died (4.3%). We observed higher short-term mortality rates in patients receiving high-volume hydration. Otherwise, only age, shock and CI-AKI were significantly associated with 1-year mortality.

CONCLUSION

In patients with STEMI undergoing PPCI, high-volume hydration with normal saline or sodium bicarbonate administrated at the time of contrast media administration was not associated with any significant advantage in terms of CI-AKI prevention.

Novel biomarkers for contrast-induced acute kidney injury

Biomarkers of acute kidney injury (AKI) may be classified in 2 groups: (1) those representing changes in renal function (e.g., serum creatinine or cystatin C and urine flow rate) and (2) those reflecting kidney damage (e.g., kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18, etc.). According to these 2 fundamental criteria, 4 subgroups have been proposed: (1) no marker change; (2) damage alone; (3) functional change alone; and (4) combined damage and functional change. Therefore, a new category of patients with “subclinical AKI” (that is, an increase in damage markers alone without simultaneous loss of kidney function) has been identified. This condition has been associated with higher risk of adverse outcomes (including renal replacement therapy and mortality) at followup. The ability to measure these physiological variables may lead to identification of patients at risk for AKI and early diagnosis of AKI and may lead to variables, which may inform therapeutic decisions.

Contrast-induced acute kidney injury: definition, epidemiology, and outcome

Contrast-induced acute kidney injury (CI-AKI) is commonly defined as a decline in kidney function occurring in a narrow time window after administration of iodinated contrast material. The incidence of AKI after contrast material administration greatly depends on the specific definition and cutoff values used. Although self-limiting in most cases, postcontrast AKI carries a risk of more permanent renal insufficiency, dialysis, and death. The risk of AKI from contrast material, in particular when administered intravenously for contrast-enhanced CT, has been exaggerated by older, noncontrolled studies due to background fluctuations in renal function. More recent evidence from controlled studies suggests that the risk is likely nonexistent in patients with normal renal function, but there may be a risk in patients with renal insufficiency. However, even in this patient population, the risk of CI-AKI is probably much smaller than traditionally assumed. Since volume expansion is the only preventive strategy with a convincing evidence base, liberal hydration should be encouraged to further minimize the risk. The benefits of the diagnostic information gained from contrast-enhanced examinations will still need to be balanced with the potential risk of CI-AKI for the individual patient and clinical scenario.

Incidence and Main Determinants of Contrast-Induced Nephropathy following Coronary Angiography or Subsequent Balloon Angioplasty

BACKGROUND/AIMS

Patient assessment by imaging studies using contrast media is currently replacing open procedures, especially in high-risk patients. However, the use of such contrast media might result in acute events and injuries after the procedure. In the present study, we first determined the incidence of contrast-induced nephropathy (CIN) in a sample of Iranian patients who candidated for coronary angiography and/or angioplasty, and then assessed major risk factors predicting the appearance of CIN following these procedures.

METHODS

Two hundred and fifty consecutive, eligible patients scheduled for coronary angiography and/or angioplasty at the Afshar Hospital in Yazd between January 2009 and August 2010 were considered for enrollment. Renal function was measured at baseline and 48 h after the intervention, and CIN was defined by an increase in creatinine of >0.5 mg/dl or 25% of the initial value. The predictive role of potential risk factors was determined in a multivariate model adjusted for comorbidities, preexisting renal impairment, and angiographic data.

RESULTS

CIN following coronary angiography or angioplasty appeared in 12.8% of the cases. A myocardial infarction before the procedure (OR = 2.121, p = 0.036) and a prior history of hypertension (OR = 2.789, p = 0.025) predicted the appearance of acute renal failure following angiography or subsequent angioplasty. A low estimated glomerular filtration rate at baseline slightly predicted CIN after these interventions.

CONCLUSION

Transient acute renal dysfunction occurred in 12.8% of the patients within 48 h after angiography or subsequent angioplasty and could be predicted by a myocardial infarction before the procedure or by a prior history of systolic hypertension.

Contrast-induced acute kidney injury following PCI

BACKGROUND

Coronary revascularization using percutaneous coronary intervention (PCI) is one of the major treatments for patients with stable coronary artery disease, with approximately 1.5 million patients undergoing PCI in the United States and Europe every year. An important neglected complication of PCI is contrast-induced acute kidney injury (CI-AKI).

DESIGN

In this article, we review the definition, pathogenesis and management of CI-AKI and highlight potential therapeutic options for preventing CI-AKI in post-PCI patients.

RESULTS

CI-AKI is an important but underdiagnosed complication of PCI that is associated with increased in-hospital morbidity and mortality. Patients with pre-existing renal impairment and diabetes are particularly susceptible to this complication post-PCI. Optimization of the patients' circulating volume remains the mainstay for preventing CI-AKI, although the best strategy for achieving this is still controversial.

CONCLUSION

Following PCI, CI-AKI is an overlooked complication which is associated with significant morbidity and mortality. In this article, we review the pathophysiology of CI-AKI in patients undergoing PCI and discuss the potential therapeutic options for preventing it.

Contrast-induced acute kidney injury following coronary angiography: a cohort study of hospitalized patients with or without chronic kidney disease

BACKGROUND

Contrast-induced acute kidney injury (CIAKI) has been linked to unfavorable consequences. In routine clinical practice, small increases in serum creatinine (SCr) following coronary angiography tend to be underestimated, especially in patients without chronic kidney disease (CKD).

METHODS

We conducted a retrospective observational cohort study to analyze in-hospital and long-term outcomes of CIAKI following coronary angiography in patients with or without CKD (eGFR ≥ 60 mL/min/1.73 m(2)) from January 2008 through December 2009. CIAKI was defined as SCr either ≥ 25% or ≥ 0.5 mg/dL from baseline within 72 h after contrast exposure. Multivariable logistic regression for in-hospital mortality and Cox proportional hazards calculations for long-term mortality and requirement for dialysis were performed.

RESULTS

A total of 1160 patients were included in the study. CIAKI occurred in 19% of CKD patients and in 18% of non-CKD patients. In CKD and non-CKD patients, CIAKI was more frequent in patients requiring mechanical ventilation or inotropes or in those given furosemide, and it was associated with adverse in-hospital (prolonged hospitalization, acute dialysis and mortality) and long-term (increased creatinine, initiation of dialysis and mortality) outcomes. In multivariable analysis, CKD patients had greater in-hospital mortality if they developed CIAKI (adjusted OR 8, 95% CI 1.9-34.5, P = 0.005), and non-CKD patients had greater long-term mortality if they developed CIAKI (adjusted HR 2.2, 95% CI 1.2-4.1, P = 0.016).

CONCLUSIONS

CIAKI following coronary angiography was associated with adverse in-hospital and long-term outcomes in both CKD and non-CKD patients.

Contrast-induced nephropathy

Radiological procedures utilizing intravascular iodinated contrast media are being widely applied for both diagnostic and therapeutic purposes and represent one of the main causes of contrast-induced nephropathy (CIN) and hospital-acquired renal failure. Although the risk of CIN is low (0.6-2.3 %) in the general population, it may be very high (up to 50 %) in selected subsets, especially in patients with major risk factors such as advanced chronic kidney disease and diabetes mellitus, and in those undergoing emergency percutaneous coronary interventions (PCI). Due to the lack of any effective treatment, prevention of this iatrogenic disease, which is associated with significant in-hospital and long-term morbidity and mortality and increased costs, is the key strategy. However, prevention of CIN continues to elude clinicians and is a main concern during PCI, as patients undergoing these procedures often have multiple comorbidities. The purpose of this study is to examine the pathophysiology, risk factors and clinical course of CIN, as well as the most recent studies dealing with its prevention and potential therapeutic interventions, especially during PCI.

How to reduce nephropathy following contrast-enhanced CT: a lesson in policy implementation

In excess of 50 contrast-enhanced computed tomography (CT) examinations are typically undertaken in our tertiary hospital NHS Trust each weekday, approximately 13,000 each year. In the Department of Radiology alone, we inject more than 1300 l of iodinated contrast medium per annum. There is a real need to devise a policy to anticipate contrast medium-induced nephropathy (CIN) and minimize its effects, without disrupting the high-intensity CT service. Having written a comprehensive yet pragmatic policy to reduce the incidence of this iatrogenic condition, it seemed sensible to share it with the wider radiology community and share the experience and lessons learnt in engaging all the stakeholders, ushering in the change with as little fuss as possible. The ramifications on primary and secondary care had to be anticipated, resource implications managed, and staff trained. This review is therefore presented in four sections: framing the problem, assessing its size and nature; a succeeding section on the available guidelines and their uptake; the policy itself to reduce CIN in CT is presented in the third section; and crucially, a description of the policy introduction process in the last section.

Predictors of creatinine rise post-endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular abdominal aortic aneurysm repair involves manipulation of the aorta around the renal arteries. Fenestrated grafts involve the direct cannulation, stenting and injecting of contrast into the renal arteries. These procedures may be associated with an acute post-operative creatinine rise.

METHODS

We retrospectively examined data from all endovascular aortic repairs at our institution from 2005 to 2009, where contrast dosage had been recorded. Renal impairment was defined as a 25% increase in creatinine during the 5-day postoperative period. Univariable analysis was undertaken for a number of likely predictors, including: age, contrast dosage, preoperative creatinine, graft type (fenestrated or standard), diabetes mellitus, hypertension, hypercholesterolaemia, ischaemic heart disease, aspirin therapy, statins therapy, non-steroidal anti-inflammatory drug use, preoperative N-acetyl-cysteine and intravenous pre-hydration. Multivariable analysis was then applied to variables with a univariable P-value of < 0.05.

RESULTS

We identified 106 consecutive cases, with complete data for 102. Twenty per cent of patients developed renal impairment (22/102). Contrast dose (P = 0.043) and fenestrated grafts (P = 0.006) were identified as significant risk factors for post-operative creatinine increase (P = 0.043). Multivariable analysis demonstrated that fenestrated grafts were a risk factor independent of contrast dosage (P < 0.05).

CONCLUSIONS

Patients who received a fenestration graft (P < 0.01) and increased contrast dose (P < 0.05) were at a significant increased risk of a 25% post-operative creatinine rise. The risk of fenestration grafts persisted when multivariable regression was performed to control for contrast dosage (P < 0.05). Other variables investigated were not found to be significant in this study.

Urinary liver-type fatty acid-binding protein level as a predictive biomarker of contrast-induced acute kidney injury

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is a well-known complication of contrast medium exposure in patients with chronic kidney disease. However, there are no biological markers to accurately predict the onset of CI-AKI. Liver-type fatty acid-binding protein (L-FABP), an intracellular carrier protein for free fatty acids, is markedly upregulated and abundantly expressed in the proximal tubules after renal ischaemia. We prospectively investigated whether urinary L-FABP is a suitable marker for the prediction of CI-AKI.

METHODS

We performed a prospective study of 220 consecutive patients with chronic kidney disease who underwent elective catheterization [serum creatinine (Cr) ≥ 1.2 mg/dL (106 M)]. Serum Cr and L-FABP levels were measured immediately before and 1 and 2 days after the procedure. CI-AKI was defined as an increase in serum Cr level of ≥ 0.3 mg/dL within 48 h after the procedure.

RESULTS

We observed the development of CI-AKI in 19 patients (8.6%). Urinary L-FABP levels were significantly higher in patients with CI-AKI than those without CI-AKI before contrast medium exposure. Receiver operating characteristic analysis showed that baseline urinary L-FABP level exhibited 82% sensitivity and 69% specificity, at a cut-off value of 24.5 μg/g Cr. Using multivariate analysis, we found that independent predictors of CI-AKI development were L-FABP level of ≥ 24.5 μg/g Cr [odds ratio (OR): 9.10; 95% confidence interval (CI), 3.20-28.9], and left ventricular ejection fraction ≤ 40% (OR, 3.42; 95% CI, 1.07-10.8).

CONCLUSIONS

Urinary L-FABP level is useful for predicting the onset of CI-AKI before contrast medium exposure.

Is contrast exposure safe among the highest risk trauma patients?

BACKGROUND

Despite improvements in the diagnosis and management of acute kidney injury (AKI), posttraumatic renal dysfunction continues to be associated with increased morbidity and mortality. Intravenous (IV) contrast is known to induce AKI in high-risk groups including the elderly and critically ill. We sought to determine whether IV contrast exposure among high-risk trauma patients resulted in renal dysfunction as defined by the Acute Kidney Injury Network criteria.

METHODS

We performed a 3-year retrospective analysis of all patients admitted to our Level I trauma center surgical intensive care unit for >48 hours. Patients with preexisting chronic renal dysfunction were excluded. We performed univariate and bivariate analyses to identify risk factors for AKI. Multivariable logistic regression analysis identified independent predictors for AKI. Subgroup analysis was undertaken among high-risk groups to include elderly patients (aged ≥65 years) with admission hypotension (systolic blood pressure <90 mm Hg) and an Injury Severity Score (ISS) ≥25.

RESULTS

Of the 6,317 patients, 571 (9.0%) patients met the inclusion criteria; 170 (29.8%) patients developed AKI. Age ≥65 years (odds ratio [OR] 2.26, 95% confidence interval [CI] = 1.06-4.80, p <0.034) and ISS ≥25 (OR 1.86, 95% CI = 1.12-3.07, p <0.015) were determined to be independent predictors of AKI. IV contrast was not identified to be a predictor of AKI. Upon subgroup analysis, IV contrast exposure was not a predictor of AKI among the elderly, hypotensive, or severely injured patients (ISS ≥25).

CONCLUSION

A complete trauma workup including studies requiring IV contrast exposure should be considered safe even among high-risk trauma patients.

Use and efficacy of saline hydration and N-acetyl cysteine to prevent contrast-induced nephropathy in low-risk populations undergoing coronary artery angiography

Contrast-induced nephropathy (CIN) is most commonly defined as acute renal failure occurring within 48-72 h of exposure to an intravascular radiographic contrast medium that is not attributable to other causes. In the international literature, a 25% increase in serum creatinine levels or an increase in absolute values of 0.5 mg/dl from baseline has been suggested to define CIN. The reported incidence of CIN varies widely, ranging from 2 to 50%. This variability results from differences in the presence or absence of risk factors. With a retrospective analysis we evaluated the use of saline hydration plus N-acetyl cysteine (NAC) to prevent CIN in a low-risk population of patients undergoing coronary artery angiography compared with an historic low risk group not treated. From January 2009 to December 2009, 152 consecutive patients who underwent coronary artery angiography with a low osmolarity contrast agent were enrolled in our study, and compared with an historic control group consisting of 172 low-risk patients. Nephrotoxic drugs such as diuretics, ACE-I and ARBs were stopped at least 24 h before the procedure. Inclusion criteria to define low-risk population were the absence of: diabetes, age >65 years, or baseline creatinine >1.4 mg/dl. We have treated group A (152 patients, 47.3%) with a saline hydration (1 ml/kg/h) plus N-acetyl cysteine 600 mg 12 h before and 12 h after the procedure; group B (group control of 170 patients, 52.7%) were not treated. The overall incidence of CIN was 7.1% (23 patients). In particular, the incidence of CIN was 2.6% (4 patients) in the group A and 11.2% (19 patients) in the group B (p = 0.002). In the multivariate analysis, including risk factor such as age, hypertension, hypercholesterolemia, current smoking habit baseline creatinine level, contrast index and hydration, the last variable was the only one inversely correlated independently with the incidence of CIN (p = 0.001). In conclusion, intravenous hydration with saline and NAC is an effective and low cost tool in preventing CIN in patients undergoing coronary artery angiography, and, according to the current guidelines, should be used in all high-risk patients for CIN. Our results show that even in patients at low risk, hydration with saline 0.9% plus NAC is useful and significantly reduces the incidence of CIN.

Comparison of contrast-induced nephrotoxicity of iodixanol and iopromide in patients with renal insufficiency undergoing coronary angiography

This prospective, randomized, double-blind study was performed to compare the incidence of contrast-induced nephropathy (CIN) after the administration of the iso-osmolar contrast medium iodixanol to the low-osmolar contrast medium iopromide during coronary angiography in patients with impaired renal function. Patients with creatinine clearance (CrCl) <60 ml/min who underwent coronary angiography and/or percutaneous coronary intervention were randomized to receive either iodixanol (n = 215) or iopromide (n = 205). The primary study end point was the incidence of CIN, which was defined as an absolute increase in serum creatinine (SCr) ≥0.5 mg/dl (44.2 mol/L) or a relative increase ≥25% compared to baseline SCr. The secondary end points were the proportion of patients with increases in SCr ≥0.5 mg/dl, the proportion with SCr increases ≥1.0 mg/dl (88.4 mol/L), and the peak increase in SCr. Age, the presence of diabetes mellitus, mean baseline SCr, CrCl, the use of N-acetylcysteine, contrast volume, and the predicted risk score for CIN were similar in the 2 groups. CIN developed in 39 patients (9.3%); there was no significant difference between the iodixanol and iopromide groups (10.7% and 7.8%, respectively; absolute difference 2.9%, 95% confidence interval -3.1% to 8.9%, p = 0.394). The proportions of patients with SCr increases ≥0.5 mg/dl (6.5% vs 6.3%) and ≥1.0 mg/dl (2.8% vs 2.9%) were similar in the 2 groups. There was a tendency for more patients with relative increases ≥25% (10.2% vs 6.8%) and greater peak increases in SCr (0.037 ± 0.375 vs 0.029 ± 0.351 mg/dl) to be in the iodixanol group, but these differences were not statistically significant. In conclusion, the incidences of CIN after coronary angiography did not significantly differ between the iodixanol and iopromide groups in patients with impaired renal function.

Contrast-induced nephropathy in patients undergoing elective and urgent procedures

Contrast-induced nephropathy (CIN) is an acute and severe complication after contrast media administration. The most important step in preventing CIN is identifying high-risk patients. In this review, we evaluate and summarize the evidence regarding the CIN prophylaxis, including the withdrawal of the potentially nephrotoxic drugs, hydration by isotonic solution or NaHCO(3), pharmaceutical treatment with N-acetylcysteine (N-AC), adenosine antagonists, ascorbic acid, renal procedures including hemofiltration or dialysis, and to the optimal use of the contrast. We suggest it is possible to reduce the burden of CIN by carefully incorporating these recommendations. After review of published literature in this field, we conclude that the cornerstone of the CIN prevention should be combination of hydration (normal saline or NaHCO(3)) and the use of N-AC.

Contrast-induced nephropathy: current practices among cardiologists

OBJECTIVE

Contrast-induced nephropathy (CIN) is a serious complication of diagnostic and therapeutic coronary angiography. There are an increasing number of guidelines in the literature to help lessen this complication. Practice patterns in the cardiology community remain relatively unknown. This survey is an effort to better understand such practices.

METHODS

Questions were written based on the American College of Cardiology (ACC), the American Heart Association (AHA), and the Society of Cardiovascular Angiography and Intervention (SCAI) guidelines to identify cardiologist background and experience. The survey was emailed to 5000 randomly chosen cardiologists in December 2009.

RESULTS

A total of 291 responses were received. Among these, 97% reported checking renal function in all patients prior to angiography, 45% checked both estimated glomerular filtration rate (eGFR) and serum creatinine (SCr), 31% checked SCr alone, 19% checked eGFR alone, and 2% checked albumin-to-creatinine (A-C) ratio. Among responding cardiologists, 70% considered eGFR level less than 60 mL/min/1.73 m(2) a high risk for CIN whereas 25% considered a level less than 30 mL/min/1.73 m(2) a high risk. Thirty percent used only isosmolar media in high-risk patients, 33% used only low osmolar media, and 37% used either one.

CONCLUSIONS

There is significant diversity in the measures taken by cardiologists to prevent CIN. More studies and clearer guidelines are needed to unify the practices.

Preprocedural evaluation and endovascular treatment of iliofemoral artery disease without contrast media for patients with pre-existing renal insufficiency

BACKGROUND

Generally, both the preprocedural evaluation and endovascular therapy (EVT) for lower limb arteries require contrast media that is harmful for patients with chronic renal insufficiency. In the present study these procedures were performed without using nephrotoxic contrast media in patients with preexisting renal insufficiency and iliofemoral artery disease.

METHODS AND RESULTS

The 36 consecutive patients with chronic renal insufficiency underwent preprocedural evaluation with duplex examination, magnetic resonance angiography (MRA) without contrast media, and plain computed tomography (CT). A total of 51 lesions were treated using intravascular ultrasound (IVUS) without contrast media. The overall technical success was 100% without any complications. Pre- and postprocedural ankle-brachial indices changed from 0.59 ± 0.23 to 0.92 ± 0.14. The mean serum creatinine concentration before and after treatment, and 3 months after treatment did not change (2.1 ± 1.4, 2.0 ± 1.4, and 2.1 ± 1.6 mg/dl, respectively). The overall 3-month survival rate and limb salvage rate was 100%.

CONCLUSIONS

EVT comprising duplex, MRA, and CT for preprocedural evaluation and IVUS-guided procedure is feasible and may avoid intra-arterial contrast injection in selected patients deemed at high risk for renal failure from nephrotoxic contrast material.