Contrast-induced nephropathy: pathogenesis and prevention

The Value of C-reactive Protein/Albumin Ratio in the Prediction of Contrast-Induced Nephropathy in Emergency Department Patients

BACKGROUND

Contrast-induced nephropathy (CIN) is the third most common cause of acute renal failure in hospitalized patients and is an important cause of prolonged hospital stay, morbidity, and mortality. We aimed to investigate the effectiveness and sufficiency of the prognostic capacity of the inflammatory biomarkers C-reactive Protein (CRP) and albumin ratio (CAR) in predicting the development of CIN in patients undergoing contrast-enhanced computed tomography (CT) imaging in the emergency department (ED).

METHODS

This study was performed on patients whose laboratory values ​​could be reached within 48 hours after contrast-enhanced CT imaging in the emergency department of our hospital. The patients were divided into two groups as those with and without CIN according to their increased creatinine levels. Its effectiveness in detecting the development of CIN in the early period was evaluated comparatively.

RESULTS

One hundred and twenty-five patients were included. CIN developed in 10.4% of the patients. The CAR was 0.19 (IQR: 0.17-0.33) in the group with CIN and 0.02 (IQR: 0.01-0.06) in the group without CIN; and the difference between the two groups was significant (p<0.001). In multivariate logistic regression analysis, it was found that the CAR increased as an independent risk factor for CIN (OR: 2.326; 95% CI: 1.39-3.893; p=0.001).

CONCLUSIONS

We think that early identification of patients who may develop CIN through the CAR in EDs and early initiation of treatment for CIN may affect the morbidity-mortality rate and reduce the duration of hospitalization and treatment costs.

Retrospective analysis of liver lobe torsion in pet rabbits: 40 cases (2016-2021)

BACKGROUND

Liver lobe torsion (LLT) in rabbits can be under-recognised and potentially fatal. The clinical features of cases presented to an exotic animal veterinary service in Australia were retrospectively reviewed.

METHOD

Medical records of confirmed rabbit LLT cases between 2016 and 2021 were reviewed for signalment, clinical signs and findings, diagnostic imaging results, management strategies and outcomes. Variables of interest were analysed for statistical association with outcome.

RESULTS

A total of 40 rabbits were included. The mean presenting age was 56.2 months (SD 30.5). Neutered males (23/40, 57.5%) were over-represented. Common clinical signs and findings included reduced appetite (40/40, 100%), lethargy (32/40, 80.0%), reduced faecal production (16/40, 40.0%), a doughy distended stomach (20/40, 50.0%), pale mucous membranes (19/40, 47.5%) and hypothermia (17/40, 42.5%). Anaemia and elevated plasma alanine aminotransferase and blood urea nitrogen were common clinicopathologic findings. Computed tomography (CT) was performed in 34 of 40 rabbits, confirming the presence and position of LLT (34/34, 100%), stenosis of the caudal vena cava or portal system (28/34, 82.4%) and increased free peritoneal fluid (29/34, 85.3%). Fifteen (15/40, 37.5%) rabbits were medically managed, and surgical intervention was performed in 23 of 40 (57.5%) rabbits. Overall, 30 of 40 (75.0%) rabbits survived. Surgical intervention did not confer a significant difference in outcome compared to medical management (odds ratio 0.77, 95% confidence interval 0.15-4.10, p = 0.761).

CONCLUSION

CT can be an invaluable diagnostic modality for rabbit LLT. Favourable outcomes can be achieved in selected cases with medical management alone.

Acute kidney injury and aging

Our aging population is growing and developing treatments for age-related diseases such as Alzheimer's and Parkinson's disease has taken on an increasing urgency and is accompanied by high public awareness. The already high and rising incidence of acute kidney injury (AKI) in the elderly, however, has received relatively little attention despite the potentially fatal outcomes associated with an episode of AKI in this age group. When discussing AKI and aging, one should consider two aspects: first, elderly patients have an increased susceptibility to an AKI episode, and second, they have decreased kidney repair after AKI given the high incidence of progression to chronic kidney disease (CKD). It is unclear if the same factors that drive the increased susceptibility to AKI could be playing a role in the decreased repair capacity or if they are totally different and unrelated. This review will examine current knowledge on the risk factors for the increased susceptibility to AKI in the elderly and will also explore potential aspects that might contribute to a decreased kidney repair response in this age group.

Systemic Immune-Inflammation Index May Predict the Development of Contrast-Induced Nephropathy in Patients With ST-Segment Elevation Myocardial Infarction

The aim of this study was to investigate the predictive capacity of a systemic immune-inflammation index (SII) in the detection of contrast-induced nephropathy (CIN) following ST-segment elevation myocardial infarction (STEMI). A total of 477 STEMI patients were enrolled in the study. The patients were divided into 2 groups according to CIN development. A cutoff point of 5.91 for logarithm-transformed SII was identified with 73.0% sensitivity and 57.5% specificity to predict CIN following STEMI. According to a pairwise analysis of receiver operating characteristic curve analysis, the predictive power of SII in detecting CIN following STEMI was similar to that of high-sensitivity C-reactive protein and better than the neutrophil/lymphocyte ratio or platelet/lymphocyte ratio. As a result, SII can be used as one of the independent predictors of CIN after STEMI.

Prevalence and Predictors of Contrast-Induced Nephropathy (CIN) in Patients with ST-Segment Elevation Myocardial Infarction (STEMI) Undergoing Percutaneous Coronary Intervention (PCI): A Meta-Analysis

Background

Contrast-induced nephropathy (CIN) becomes more and more frequent after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). There have been no reported meta-analyses to determine the role of these risk factors in predicting CIN in patients with STEMI undergoing PCI. So we made this meta-analysis to summarize the incidence of CIN in patients with STEMI undergoing PCI and to study associations between CIN and several risk factors that are mentioned in most prevention guidelines.

Hypothesis

The overall incidence of CIN in patients with STEMI undergoing PCI is not low. Many risk factors could influence the occurrence of CIN, such as hypertension, diabetes mellitus (DM), and lower estimated glomerular filtration rate.

Methods

Databases, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Chinese BioMedical (CBM), were searched for articles published before May 21, 2019, to identify all relevant studies on CIN. The pooled data were analyzed using either fixed-effects or random-effects models depending on heterogeneity (assessed via the I ² index).

Results

Twelve articles encompassing a total of 6342 patients were included. The overall pooled CIN incidence was 13.3% (95% CI: 10.4-17.1). The forest plots showed positive associations between CIN and the presence of hypertension, diabetes mellitus, history of prior myocardial infarction, age, damaged left anterior descending artery, Killip class ≥2, decreased left ventricular ejection fraction, lower estimated glomerular filtration rate, and left ventricular ejection fraction <40%; the odds ratios for these factors were 1.85 (95% CI: 1.57-2.18; p < 0.00001), 1.83 (95% CI: 1.47-2.29; p < 0.00001), 2.14 (95% CI: 1.46-3.14; p < 0.0001), 7.79 (95% CI: 5.24-10.34; p < 0.00001), 1.92 (95% CI: 1.15-3.22; p=0.01), 3.12 (95% CI: 2.21-4.40; p < 0.00001), -6.15 (95% CI: -9.52 to -2.79; p=0.0003), -15.06 (95% CI: -24.75 to -5.36; p=0.002), and 5.53 (95% CI: 1.10-27.95; p=0.04), respectively.

Conclusion

The overall incidence of CIN in patients with STEMI undergoing PCI was not low and was closely associated with hypertension, diabetes mellitus, history of prior myocardial infarction, age, damaged left anterior descending artery, Killip class ≥2, decreased left ventricular ejection fraction, lower estimated glomerular filtration rate, and left ventricular ejection fraction <40%.

PEG-Citrate dendrimer second generation: is this a good carrier for imaging agents In Vitro and In Vivo?

While cancer is the leading cause of human's deaths worldwide, finding an imaging agent which can detect cancer tumours is needed for cancer diagnosis. In the present study, PEG-citrate dendrimer-G2 was used as a nano-carrier of FITC dye and Iohexol to help passive targeting and uptake of both imaging agents in cancer cells/tumour in vitro and in vivo. Dendrimer was synthesisedand the product characterised using LC-MS, FT-IR, DLS, ELS, AFM, and 1HNMR. After FITC loading into dendrimer, MTT was performed to determine the cytotoxicity of formulation on HEK-293 and MCF-7 cells. In vitro imaging using dendrimer-FITC was done via fluorescent microscope thereafter. Moreover, CT imaging using Iohexol was employed to show the targeting nature and ability of the complex to use as imaging agent in vivo. Data yielded in this study corroborate the notion that the promised dendrimer was synthesised properly and had no toxicity along with FITC on normal cell. Furthermore, CT and fluorescent images showed the targeting nature and imaging ability of Iohexol/FITC loaded dendrimer in vitro and in vivo. Overall, results showed promising characteristics of the novel complexes using dendrimer-G2 both in vitro and in vivo.

Contrast Induced Acute Kidney Injury and Direct Cytotoxicity of Iodinated Radiocontrast Media on Renal Proximal Tubule Cells

The administration of intravenous iodinated radiocontrast media (RCM) to visualize internal structures during diagnostic procedures has increased exponentially since their first use in 1928. A serious side effect of RCM exposure is contrast-induced acute kidney injury (CI-AKI), which is defined as an abrupt and prolonged decline in renal function occurring 48-72 hours after injection. Multiple attempts have been made to decrease the toxicity of RCM by altering ionic strength and osmolarity, yet there is little evidence to substantiate that a specific RCM is superior in avoiding CI-AKI. RCM-associated kidney dysfunction is largely attributed to alterations in renal hemodynamics, specifically renal vasoconstriction; however, numerous studies indicate direct cytotoxicity as a source of epithelial damage. Exposure of in vitro renal proximal tubule cells to RCM has been shown to affect proximal tubule epithelium in the following manner: 1) changes to cellular morphology in the form of vacuolization; 2) increased production of reactive oxygen species, resulting in oxidative stress; 3) mitochondrial dysfunction, resulting in decreased efficiency of the electron transport chain and ATP production; 4) perturbation of the protein folding capacity of the endoplasmic reticulum (ER) (activating the unfolded protein response and inducing ER stress); and 5) decreased activity of cell survival kinases. The present review focuses on the direct cytotoxicity of RCM on proximal tubule cells in the absence of in vivo complications, such as alterations in renal hemodynamics or cytokine influence.

Effects of Serum Cytochrome c on Contrast-Induced Nephropathy in Patients with ST-Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background and Aims

Contrast-induced nephropathy (CIN) is a relatively infrequent complication after percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). However, little is known about the association between cytochrome c (cyt c) and increased risk of CIN. We conducted this study to explore the impact of serum cyt c on the occurrence of CIN.

Methods

We prospectively examined cyt c levels before undergoing PCI in 240 patients with STEMI. The logistic regression was performed to identify the independent risk factors for the occurrence of CIN. The receiver operating characteristic (ROC) analysis was employed to evaluate the predictive value of cyt c for the occurrence of CIN.

Results

29 patients (12.1%) had developed CIN after the PCI procedure. The cyt c levels at baseline were significantly higher in patients who developed CIN than those in non-CIN group (0.65±0.08 versus 0.58±0.1; P = 0.001). The multivariate logistic regression showed that cyt c was an independent risk factor for the occurrence of CIN (OR, 7.421; 95% CI, 6.471–20.741; P = 0.034) after adjusting for age, history of hypertension and diabetes mellitus, levels of creatinine, uric acid, and glucose. The ROC curve analysis showed that the area under the curve of cyt c was 0.697 (95% CI, 0.611–0.783; P = 0.001), and cyt c > 0.605 ng/mL predicted CIN with sensitivity of 79.3% and specificity of 56.9%.

Conclusion

Our results show that a higher cyt c level was significantly associated with the occurrence of CIN after PCI in STEMI patients. This study has been registered in the Chinese Clinical Trial Registry. The clinical trial registration number is ChiCTR1800019368.

Glomerular filtration decrease after diagnostic cardiac catheterisation in children with congenital cardiac malformation - the role of serum creatinine, cystatin C, neutrophil gelatinase and urine output monitoring

Introduction

Diagnosis of contrast induced-nephropathy (CIN) by a classic renal biomarker such as creatinine concentration can be delayed because of various factors that can influence this marker. Changes in new biomarkers such as neutrophil-gelatinase associated lipocalin (NGAL) and cystatin C are postulated to be more sensitive for recognizing patients prone to CIN-acute kidney injury (AKI).

Aim

To investigate the role of NGAL and cystatin C as early biomarkers in the diagnosis of kidney injury after cardiac catheterisation.

Material and methods

The study group consisted of 50 patients with congenital heart malformation admitted for scheduled cardiac catheterisation. The biomarkers serum creatinine, serum NGAL and serum cystatin C were tested at 5 time-points sequentially from start to 48 h after the procedure.

Results

Significant changes were noted during the research in the serum creatinine concentration (p < 0.001) and serum NGAL concentration (p < 0.001). CIN-AKI, diagnosed by the modified Schwartz formula, occurred in 16 (32%) patients after 24 h and in 8 (16%) after 48 h. Subsequent analysis showed that serum creatinine significantly rose in the first 2 h of the study with simultaneous reduction in the eGFR. Maximum growth in serum NGAL occurred at 6 h after contrast administration and then returned to the baseline values at 24 h. Serum cystatin C level did not significantly change during the study.

Conclusions

We observed a transient decrease in eGFR and a rise of serum NGAL after 2 h but NGAL was most pronounced at 6 h after the procedure. The potential role of cystatin C as a biomarker of CIN-AKI was not proved.

Effect of ligustrazine on preventing contrast-induced nephropathy in patients with unstable angina

Objective

Our purpose was to assess the effect of ligustrazine in the prevention of contrast-induced nephropathy (CIN) in patients with unstable angina (UA).

Methods

148 patients with UA undergoing coronary angiography and/or percutaneous coronary intervention (PCI) were selected for observation; the patients were divided into a control group (group A, n=74) and a ligustrazine group (group B, n=74). Group A was given routine treatment, while group B was given routine treatment combined with ligustrazine. Serum creatinine (Scr), cystatin C and glomerular filtration rate (eGFR) concentrations were measured before and 1 day, 2 days and 3 days after treatment, and the incidence of contrast-induced nephropathy (CIN) and major cardiovascular events (MACE) were observed in both groups.

Results

The Scr, Cystatin C and eGRF levels in group B were better than in group A after 1 day (OR: 2.64, 95% CI: 2.47-4.98; OR: 2.66, 95% CI: 2.62-5.77; OR: 4.02, 95% CI: 3.02-5.53, respectively), 2 days (OR: 3.58, 95% CI: 2.41-4.92; OR: 2.92, 95% CI: 2.83-5.02; OR: 3.28, 95% CI: 3.24-5.14, respectively) and 3 days of treatment (OR: 3.26, 95% CI: 2.17-4.35; OR: 2.85, 95% CI: 2.26-4.02; OR: 3.19, 95% CI: 2.53-4.34, respectively). The incidence of CIN (9.26% vs 16.67%) and MACE (7.41% vs 18.51%) of group B were significantly lower than in group A (P<0.05).

Conclusions

Our study suggests that ligustrazine can reduce CIN and MACE in patients with UA when undergoing coronary angiography and/or PCI.

AS1411 Aptamer-Anionic Linear Globular Dendrimer G2-Iohexol Selective Nano-Theranostics

Molecular theranostics is of the utmost interest for diagnosis as well as treatment of different malignancies. In the present study, anionic linear globular dendrimer G2 is employed as a suitable carrier for delivery and AS1411 aptamer is exploited as the targeting agent to carry Iohexol specifically to the human breast cancer cells (MCF-7). Dendrimer G2 was prepared and conjugation of dendrimer and aptamer was carried out thereafter. Based on the data yielded by AFM, morphology of smooth and spherical non-targeted dendrimer changed to the rough aspherical shape when it conjugated. Then, conjugation was confirmed using DLS, ELS and SLS methods. Toxicity on nucleolin positive MCF-7 cells and nucleolin negative HEK-293 cells was assessed by XTT and apoptosis/necrosis assays. In vitro uptake was determined using DAPI-FITC staining and ICP-MS methods. In vivo studies including in vivo CT imaging, pathology and blood tests were done to confirm the imaging ability, bio-safety and targeted nature of the Nano-Theranostics in vivo. In a nutshell, the prepared construction showed promising effects upon decreasing the toxicity of Iohexol on normal cells and accumulation of it in the cancer tumors as well as reducing the number of cancer cells.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Impact of contrast exposure from computed tomography angiography on acute kidney injury after neonatal cardiopulmonary bypass surgery

OBJECTIVE

Acute kidney injury (AKI) is a frequent complication after cardiopulmonary bypass (CBP) for cardiac surgery in neonates. It is unclear if exposure to computed tomography angiography (CTA) in the preoperative period increases the risk of AKI. We hypothesized a short interval between CTA and CPB surgery would be associated with higher rates of AKI in infants.

DESIGN

In this single center retrospective review of patients between 2012 and 2015, neonates less than one month old were analyzed if they had CTA prior to cardiac surgery with CPB. Baseline, demographic, fluid balance, and laboratory data was analyzed. AKI was staged according to KDIGO criteria.

RESULTS

Fifty-six neonates were analyzed. AKI developed in 42 (75%) of patients; severe AKI (KDIGO stages 2 and 3) occurred in 18 (32%). Patient characteristics were similar at baseline and at time of CTA between those with and without severe AKI. Patients with severe AKI had longer CPB time, lower postoperative urine output, higher peak serum creatinine, and longer hospital length of stay. When considering intervals between CTA and CPB surgery ≤1 day (n = 19), ≤3 days (n = 28), and >3 days (n = 28); there was no difference in AKI incidence nor postoperative outcomes among these three interval cohorts.

CONCLUSION

Routine exposure to CTA and CPB surgery in close succession does not appear to increase the risk of AKI after neonatal cardiac surgery. Though other risks need to be weighed (eg, sedation, intubation, radiation exposure), this result may enable more liberal utilization of CTA for preoperative surgical planning of congenital heart operations in patients with unclear or complex anatomy.

Contrast-induced acute kidney injury: A review of practical points

Contrast-induced acute kidney injury (CI-AKI) is one of the most common causes of AKI in clinical practice. CI-AKI has been found to be strongly associated with morbidity and mortality of the patients. Furthermore, CI-AKI may not be always reversible and it may be associated with the development of chronic kidney disease. Pathophysiology of CI-AKI is not exactly understood and there is no consensus on the preventive strategies. CI-AKI is an active research area thus clinicians should be updated periodically about this topic. In this review, we aimed to discuss the indications of contrast-enhanced imaging, types of contrast media and their impact on nephrotoxicity, major pathophysiological mechanisms, risk factors and preventive strategies of CI-AKI and alternative non-contrast-enhanced imaging methods.

Association between Serum Ferritin and Contrast-Induced Nephropathy in Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background and Aims. CIN is a major and serious complication following PCI in patients with ACS. It is unclear whether a higher serum ferritin level is associated with an increased risk of CIN in high-risk patients. Thus, we conducted this study to assess the predictive value of SF for the risk of CIN after PCI. Methods. We prospectively examined SF levels in 548 patients with ACS before undergoing PCI. Multivariate logistic regression analysis was used to analyze the independent risk factors for CIN. The ROC analysis was performed to evaluate the predictive value of SF for CIN. Results. CIN occurred in 96 patients. Baseline SF was higher in patients who developed CIN compared to those who did not (257.05 ± 93.98 versus 211.67 ± 106.65; P < 0.001). Multivariate logistic regression analysis showed that SF was an independent predictor of CIN (OR, 1.008; 95% CI, 1.003–1.013; P = 0.002). The area under ROC curve for SF was 0.629, and SF > 180.9 μg/L predicted CIN with sensitivity of 80.2% and specificity of 41.4%. Conclusion. Our data show that a higher SF level was significantly associated with an increased risk of CIN after PCI.

Microalbuminuria in patients with preserved renal function as a risk factor for contrast-Induced acute kidney injury following invasive coronary angiography

OBJECTIVES

To investigate the association between pre-existing microalbuminuria among patients with preserved renal function and contrast- induced acute kidney injury (AKI) following coronary angiography.

MATERIAL AND METHODS

612 consecutive patients with preserved renal function (eGFR≥60ml/min and without macroalbuminuria) undergoing scheduled coronary angiography were stratified into microalbuminuria group (107 patients) and normal-albuminuria group (505 patients) according to the urine albumin to creatinine ratio (ACR) levels. Microalbuminuria was defined as ACR in the range of 30-300mg/g and normal-albuminuria was defined as ACR<30mg/g. Contrast-induced AKI was defined as a relative increase in serum creatinine (SCr) concentration of at least 25% or an absolute increase in SCr of 44.2μmol/L within 72h after the procedure.

RESULTS

The peak increases of SCr in microalbuminuria group were larger than those in normal-albuminuria group (10.6±12.4μmol/L vs. 4.8±8.9μmol/L，P<0.001). The incidence of AKI was higher in patients with microalbuminuria than those with normal-albuminuria (12.1% vs. 5.0%, P=0.005). Multivariate analysis revealed that there was an association between microalbuminuria and contrast-induced AKI risk after adjusting for confounders.

CONCLUSION

Pre-existing microalbuminuria is associated with greater risk for AKI in patients with a preserved renal function who undergo scheduled coronary angiography.

Contrast-induced nephropathy in CT: incidence, risk factors and strategies for prevention

In the past, a high percentage of hospital-acquired renal failure was attributed to contrast media. That position is now very controversial. Recently, doubts have been raised regarding the real relationship between acute kidney injury and intravenous contrast media administration. Similarly, statements about specific methods of preventing contrast-inducing nephropathy have been challenged. This review article addresses the controversies of incidence, causation, and prevention in an attempt to help the practicing radiologist adopt methods for their own department.

KEY POINTS

• The reported CIN incidence ranges from 2-12 % following contrast-enhanced CT. • Studies without a non-contrast CT control group may overestimate CIN incidence. • Development and application of a comprehensive CIN prevention strategy is recommended.

Serum NGAL, cystatin C and urinary NAG measurements for early diagnosis of contrast-induced nephropathy in children

AIM

The study investigated a number of biomarkers for the early diagnosis of contrast-induced nephropathy (CIN), which is an important cause of acute kidney injury (AKI).

MATERIAL AND METHODS

The study included 91 children scheduled for elective cardiac angiography and 50 healthy controls. Biomarkers including serum (s) and urinary (u) sodium, serum and u-creatinine, s-cystatin-C, serum neutrophil gelatinase-associated lipocalin (NGAL) and urinary N-acetyl beta glucosaminidase (u-NAG)/creatinine ratio were measured 4 times sequentially in the patients and once in the controls.

RESULTS

The patient group comprised 40 males (44%) and 51 females (56%) while the control group comprised 16 males (32%) and 34 females (68%). Age, gender, s-creatinine, estimated-glomerular filtration rate (eGFR), s-cystatin-C and fractional-excretion of sodium did not differ significantly between the groups. Serum sodium and s-NGAL were found to be lower in the patients than those of in the controls, while their u-NAG/creatinine ratio was found to be higher. Sequential data analysis revealed that s-NGAL and u-NAG/creatinine ratio increased in the first 6 h after radiocontrast media (RCM) administration and decreased at 12 and 24 h. Serum BUN and s-cystatin-C levels also showed a significant difference during the 24-h follow-up. eGFR, s-sodium and s-creatinine levels did not change in the following period. Serum cystatin-C levels revealed a significant negative correlation with eGFR. Administered RCM doses showed a positive correlation only with u-NAG/creatinine ratios.

CONCLUSION

In the first 24 h, s-cystatin-C, s-NGAL and especially u-NAG/creatinine ratio showed promise as biomarkers, but eGFR is not adequate for early diagnosis of CIN. Sequential measurement of biomarkers may contribute to more accurate diagnosis of AKI.

Impact of renal dysfunction on mid-term outcome after transcatheter aortic valve implantation: a systematic review and meta-analysis

Background

There is conflicting evidence regarding the impact of preexisting renal dysfunction (RD) on mid-term outcomes after transcatheter aortic valve implantation (TAVI) in patients with symptomatic aortic stenosis (AS).

Methods and results

Forty-seven articles representing 32,131 patients with AS undergoing a TAVI procedure were included in this systematic review and meta-analysis. Pooled analyses were performed with both univariate and multivariate models, using a fixed or random effects method when appropriate. Compared with patients with normal renal function, mid-term mortality was significantly higher in patients with preexisting RD, as defined by the author (univariate hazard ratio [HR]: 1.69; 95% confidence interval [CI]: 1.50–1.90; multivariate HR: 1.47; 95% CI: 1.17–1.84), baseline estimated glomerular filtration rate (eGFR) (univariate HR: 1.65; 95% CI: 1.47–1.86; multivariate HR: 1.46; 95% CI: 1.24–1.71), and serum creatinine (univariate HR: 1.69; 95% CI: 1.48–1.92; multivariate HR: 1.65; 95% CI: 1.36–1.99). Advanced stage of chronic kidney disease (CKD stage 3–5) was strongly related to bleeding (univariate HR in CKD stage 3: 1.30, 95% CI: 1.13–1.49; in CKD stage 4: 1.30, 95% CI: 1.04–1.62), acute kidney injure (AKI) (univariate HR in CKD stage 3: 1.28, 95% CI: 1.03–1.59; in CKD stage 4: 2.27, 95% CI: 1.74–2.96), stroke (univariate HR in CKD stage 4: 3.37, 95% CI: 1.52–7.46), and mid-term mortality (univariate HR in CKD stage 3: 1.57, 95% CI: 1.26–1.95; in CKD stage 4: 2.77, 95% CI: 2.06–3.72; in CKD stage 5: 2.64, 95% CI: 1.91–3.65) compared with CKD stage 1+2. Patients with CKD stage 4 had a higher incidence of AKI (univariate HR: 1.70, 95% CI: 1.34–2.16) and all-cause death (univariate HR: 1.60, 95% CI: 1.28–1.99) compared with those with CKD stage 3. A per unit decrease in serum creatinine was also associated with a higher mortality at mid-term follow-up (univariate HR: 1.24, 95% CI: 1.18–1.30; multivariate HR: 1.19, 95% CI: 1.08–1.30).

Conclusions

Preexisting RD was associated with increased mid-term mortality after TAVI. Patients with CKD stage 4 had significantly higher incidences of peri-procedural complications and a poorer prognosis, a finding that should be factored into the clinical decision-making process regarding these patients.

Impact of sex on the risk to develop contrast-induced nephropathy after transcatheter aortic valve implantation

OBJECTIVE

Contrast-induced nephropathy (CIN) is the third most common cause of acute renal failure and is associated with increased morbidity and in-hospital mortality. Some recent studies identified female sex as a risk factor of CIN. The aim of this study was to determine the relative impact of female sex on the development and clinical outcome of CIN in patients with preexisting renal impairment after transapical transcatheter aortic valve implantation (TAVI).

METHODS

From February 2008 to February 2011, a total of 55 TAVI patients [82.4 (6.5) years] with preprocedural serum creatinine level of greater than 1.1 mg/dL were retrospectively investigated. The incidence of postprocedural CIN, lengths of intensive care unit and hospital stay, and short-term mortality among men and women were compared. Contrast-induced nephropathy was defined as a creatinine increase of greater than 0.5 mg/dL or greater than 25% from baseline within 3 days after contrast medium (CM) exposure.

RESULTS

The women had significantly lower body surface area [1.8 (0.18) vs 1.95 (0.17) m2; P = 0.002), lower hemoglobin levels [11.5 (1.3) vs 12.7 (1.6) g/dL, P < 0.001], and lower estimated glomerular filtration rate [34.2 (9.7) vs 49.4 (12.3) mL/min per 1.73 m2, P = 0.002]. The amount of CM given was significantly higher in the women relative to body surface area [67.3 (42.5) vs 48.3 (16.6) mL/m2, P = 0.043]. The women received a higher number of blood cell transfusion units [4.4 (3.4) vs 2.1 (2.7) U, P = 0.006]. The frequency of CIN within 72 hours after CM exposure was significantly higher in the women (62.1% vs 26.9%, P = 0.009). A total of 31% of the women (n = 9) versus 7.7% of the men (n = 2) needed hemodialysis (P = 0.031). Analysis of the postoperative morbidity in terms of length of intensive care unit and hospital stay revealed no significant difference between the two groups. Mortality results reached a significant difference at 60 days, with 31% (n = 9) mortality in the women compared with 7.7% (n = 2) in the men (P = 0.031).

CONCLUSIONS

Women with preexisting renal impairment are at higher risk than men for CIN, with resultant higher early mortality after transapical TAVI.

Benefit of statin pretreatment in prevention of contrast-induced nephropathy in different adult patient population: systematic review and meta-analysis

Objective

Previous studies have suggested that statin pretreatment prevents contrast-induced nephropathy (CIN). However, single randomised trials are limited in their number of patients. This meta-analysis aims to assess the role of statin use in CIN prevention, as well as to determine patient subgroups that will benefit from statin pre-treatment.

Methodology

We searched PubMed, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomised controlled trials (RCT) comparing statin pretreatment versus placebo for preventing CIN. Our main outcome was the risk of CIN within 1–5 days after contrast administration.

Results

Data analysed from nine randomised studies with a total of 5143 patients, where 2559 received statins and 2584 received placebo, showed that statin pretreatment was associated with significant reduction in risk of CIN (MH-RR=0.47, 95% CI 0.34 to 0.64, Z=4.49, p<0.00001). This beneficial effect of statin was also seen in patients with baseline renal impairment (MH-RR=0.46, 95% CI 0.29 to 0.72, p=0.0008) and also those who were cotreated with NAC (MH-RR=0.46, 95% CI 0.25 to 0.83, p=0.01).

Conclusions

Statin pretreatment leads to significant reduction in CIN, and should be strongly considered in all patients who are planned for diagnostic and interventional procedures involving contrast-media administration.

The prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography compared to contrast-enhanced computed tomography of the brain

Background: Even though magnetic resonance imaging (MRI) is the gold standard investigation for intracranial pathology, it is not widely available in developing countries and computed tomography (CT) of the brain remains the first-line investigation for patients with suspected intracranial pathology. It is generally accepted that certain intracranial pathology can be missed on non-contrast-enhanced CT (NECT) of the brain if a contrast-enhanced CT (CECT) is not done. We have to consider on the one hand the risk of delayed or missed diagnosis and on the other hand the cost, increased radiation exposure and contrast-induced reactions. Advances in CT technology have also improved the resolution of CT scan images, making it easier to identify pathology on an NECT of the brain. To date, no study comparing NECT to CECT of the brain, utilising 64-slice CT technology, has been published.Objectives: To determine the prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography (NECT) scans of the brain reported as normal, on a 64-slice CT scanner.Method: A descriptive retrospective study was undertaken of CT brain scans done during a 12-month period at a tertiary provincial hospital in the Northern Tshwane district of Gauteng, South Africa. The CT brain scans were evaluated by three reviewers (general radiologists). The NECT and contrast-enhanced computed tomography (CECT) scans of the brain were reviewed independently on separate occasions. Reviewers were blinded to patient history, each other’s interpretation, and to their own interpretation of the NECT when evaluating the CECT and vice versa. Discrepancies in interpretation were resolved during a consensus meeting between all three reviewers. The reviewers also re-evaluated the NECT scans of the cases with undiagnosed abnormal findings during this session. A decision was made pertaining to the visibility of the abnormal findings on the NECT scan.Results: In this study, 3.28% of cases had abnormal findings undiagnosed by three reviewers on the NECT scans. Re-evaluation by the panel reduced this to 1.42%, indicating a reading error of 1.85%.Conclusion: There is a small prevalence of missed abnormal findings on the NECT scan when using only NECT. Omitting unnecessary CECT will reduce the radiation exposure to the patient and reduce the risk of adverse events from the use of intravenous iodinated contrast. Alternatively, doing only a CECT scan would reduce the risk of missing abnormal findings and would also decrease the patient’s exposure to radiation.

Derivation and validation of a risk score for contrast-induced nephropathy after cardiac catheterization in Chinese patients

BACKGROUND

To derive and validate a risk score for prediction of contrast-induced nephropathy (CIN) in the Chinese patients undergoing cardiac catheterization.

METHODS

The hospital medical records of 3945 patients undergoing coronary angiography or percutaneous coronary intervention were reviewed. Patients were randomly assigned into two cohorts: one was for derivation of risk score (n = 2764) and another for validation (n = 1181). The CIN was defined as an increase of serum creatinine level ≥44.2 μmol/L or ≥25 % and beyond its upper limit of normal value within 72 h following the procedure. On the basis of the odds ratio obtained from multivariate logistic regression, risk score of CIN was built up. The discrimination of the risk score was assessed using the area under the receiver operating characteristic curve and the calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

The incidences of CIN in the derivation and validation cohorts were 4.6 and 4.2 %, respectively. Independent predictors included age >60 years, hypertension, acute myocardial infarction, heart failure, use of intra-aortic balloon pump, decreased glomerular filtration rate and contrast volume >100 mL. The incidence of CIN was increased with increment of risk score. Both the derivation and validation cohorts showed adequate discrimination (an area under the ROC curve, 0.76 and 0.71, respectively) and good calibration (Hosmer-Lemeshow statistic test, P = 0.50 and P = 0.54, respectively).

CONCLUSION

A simple risk score for prediction of CIN development after cardiac catheterization in Chinese patients was built up by this study. Use of this risk score may help clinicians to perform early preventative strategies to minimize the risk of CIN.

Contrast-induced nephropathy in aged critically ill patients

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

Intravascular radiocontrast iodixanol increases permeability of proximal tubule epithelium: a possible mechanism of contrast-induced nephropathy

PURPOSE

To investigate the effect of Iodixanol on kidney proximal tubular cell line human kidney 2 (HK-2).

METHODS

The HK-2 cells were treated with Iodixanol. A Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was used to evaluate apoptosis. Cell viability was measured by proliferation assay kit. Cell permeability changes were assessed by transwell assay and intercellular gaps measurement. Expression of claudin-2 was assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and Western blot.

RESULTS

Iodixanol reduced tubule cell viability (P < .01) but did not cause apoptosis. The intercellular gap formation (P < .01) and transwell (P < .05) assays revealed that cell permeability significantly increased after Iodixanol treatment of monolayer cells. Western blot and qRT-PCR showed significant upregulation of claudin-2 protein (P < .05) and messenger RNA expression (P < .01).

CONCLUSIONS

Our in vitro data do not support the hypothesis that direct kidney cell death from Iodixanol is a major mechanism of contrast-induced nephropathy (CIN). However, increased permeability of proximal tubule epithelium caused by Iodixanol may play an important role in CIN.

Use of alpha-lipoic acid in prevention of contrast-induced nephropathy in diabetic patients

In this prospective study, we aimed to determine the protective antioxidant role of alpha-lipoic acid (ALA) on development of contrast-induced nephropathy (CIN) in diabetic patients undergoing coronary angiography. Seventy-eight diabetic patients undergoing coronary angiography were included. Thirty-nine patients were randomized to control group and 39 patients to ALA group. Both groups were hydrated on the day of angiography, and the ALA group had also received three doses of "Thioctacid 600 mg HR, MEDA Manufacturing GmbH" in pill form. Serum creatinine clearance, cystatin C, and urinary neutrophil gelatinase-associated lipocalin (NGAL) were studied before and after angiography. We defined CIN as either ≥25% or ≥0.5 mg/dL increase in serum creatinine at 48th hour after angiography. Baseline clinical characteristics were similar in both groups. Mehran risk score and creatinine clearance were comparable in control and therapy groups (5.59 ± 1.96 vs. 5.49 ± 1.73, p = 0.54 and 89 ± 21 vs. 96 ± 24, p = 0.13, respectively). The volumes of contrast media (median values of 80 mL vs. 75 mL) and hydration with saline (2862 ± 447 mL vs. 2637 ± 592 mL) were also similar (p > 0.05). The incidence of CIN was the same (8%) in both the groups. Alterations in serum creatinine, cystatin C, and urinary NGAL levels before and after the procedure were comparable between the ALA and control groups (group p-values were >0.05 in two-way repeated measures analysis of variance). We presented for the first time that ALA therapy added to hydration does not decrease the risk of CIN development in diabetic patients undergoing coronary angiography.

Aged rats are susceptible to nephrotoxicity induced by iodinated contrast media

OBJECTIVE

The objective of this study is to evaluate the effect and mechanism of aging on iodinated-contrast-media-induced nephropathy in male rats.

METHODS

Twenty-four healthy male rats were initially divided into 12-month-old and 24-month-old age groups (adult and older age groups, respectively; n = 12/group); subsequently, each age group was randomly divided into saline control (NS) and contrast media (CM) groups (n = 6/group). CM (76% diatrizoate, 10 mL/kg b.w.) was given through the caudal vein. Urinary creatinine (Ucr) and serum creatinine (Scr) were detected by an automatic biochemical analyzer. The activities of renal malondialdehyde (MDA), superoxide dismutase (SOD), angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and reduced form of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) were determined by spectrophotometric assays with commercially available kits according to the manufacturers' protocols. Renal histological changes were observed by hematoxylin and eosin staining and scored semiquantitatively.

RESULTS

In diatrizoate-injected aged rats, Scr, the activities of ACE, Ang II, MDA, and NADPH oxidase in renal tissues were significantly increased (p < 0.01). The histologic scores were higher in the aged animals with CM treatment than those of control or adult rats (p < 0.01). There was an increasing trend but no significant statistical difference in renal ACE, Ang II, MDA, and NADPH oxidase or histologic scores in adult CM-injected rats compared with control animals (p > 0.05).

CONCLUSIONS

Older age is an aggravating factor of iodinated-contrast-media-induced nephropathy in male rats. Oxidative stress and the renin-angiotensin system (RAS) may play an important role in nephrotoxicity induced by iodinated contrast media, especially in aged male rats.

Efficacy of ascorbic acid, N-acetylcysteine, or combination of both on top of saline hydration versus saline hydration alone on prevention of contrast-Induced nephropathy: a prospective randomized study

BACKGROUND

Antioxidant drugs such as N-acetylcysteine (NAC) and ascorbic acid have been evaluated in interventional studies to prevent contrast-induced nephropathy (CIN), however, there are limited data on comparing either or both, with background of standard intravenous saline hydration versus the standard intravenous saline hydration alone in preventing CIN.

METHODS

We conducted a single-center randomized trial among patients undergoing coronary angiography or percutaneous coronary intervention who had serum creatinine ≥ 1.3 mg/dL or were on diabetes mellitus medication. Eligible patients were randomly assigned to one of the following 4 groups: (1) NAC, (2) ascorbic acid, (3) combination of both drugs, and (4) control group. Additionally, all the groups received the standard intravenous saline hydration. Creatinine was measured 4-5 days after procedure.

RESULTS

A total of 243 patients were randomized; 62 to NAC, 57 to ascorbic acid, 58 to both drugs, and 66 to placebo. The development of 0.5 mg/dL absolute increase of serum creatinine, 25% relative decrease of creatinine clearance, or either (CIN) were measured in the ascorbic acid group (3.6% for all), NAC group (6.8%, 3.4%, 8.5%, respectively), combined group (5.5%, 5.5%, 9.1%, respectively), and control group (6.2%, 6.2%, 7.7%, respectively). None of these differences were significant (P = 0.896 for serum creatinine, P = 0.863 for creatinine clearance, and P = 0.684 for CIN).

CONCLUSIONS

In a cohort of patients at risk of developing CIN, we could not detect any significant benefit of the use of ascorbic acid, NAC, or a combination of both drugs over the standard hydration regimen in preventing CIN.

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.

Incidence and predictors of acute kidney injury after transcatheter aortic valve replacement

BACKGROUND

Patients undergoing transcatheter aortic valve replacement (TAVR) are at increased risk for acute kidney injury (AKI). The Valve Academic Research Consortium (VARC) recently published criteria for AKI after TAVR. We aimed to identify predictors, assess the prognostic impact of AKI after TAVR, and compare various criteria for AKI.

METHODS

Patients with aortic stenosis undergoing TAVR were retrospectively analyzed for periprocedural AKI (<72 hours) according to the VARC definition (increase in serum creatinine ≥0.3 mg/dL or ≥1.5× baseline) or according to the modified Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) criteria (decrease of >25% in estimated glomerular filtration rate at 48 hours).

RESULTS

Acute kidney injury, according to the VARC definition, occurred in 24 (14.6%) of 165 patients after TAVR. Acute kidney injury, according to RIFLE criteria, occurred in 19 patients (11.5%). Men (63% vs 38%, P = .03) and patients receiving blood transfusion (63% vs 39%, P = .04) were more likely to develop AKI. In multivariable analysis, only blood transfusion emerged as a predictor for AKI (odds ratio 3.74, 95% CI 1.36-10.3). Patients who developed AKI had higher in-hospital (21% vs 4%, P = .007) and 30-day mortality (29% vs 7%, P = .004) as compared with patients without AKI.

CONCLUSION

Acute kidney injury is a frequent complication of TAVR. Even a small increase (0.3 mg/dL) in baseline creatinine post-TAVR is associated with worse outcome. The poor prognosis of these patients should encourage improvement in patient selection and careful management for prevention of this complication.

Glycated albumin in diabetic patients with chronic kidney disease

Chronic hyperglycemia results in a non-enzymatic glycation of proteins, and produces Amadori products, such as glycated albumin (GA), glycosylated hemoglobin (HbA1c), and fructosamine. In current clinical practice, long-term glycemic control is assessed by quarterly measurements of HbA1c. Since the degree of hemoglobin glycosylation depends not only on the level of glycemic control, but also on the lifespan of red blood cells, patients with hemoglobin disorders or anemia of any cause may have erroneous HbA1c levels, and consequently receive insufficient treatment. Patients with chronic kidney disease (CKD) often suffer from various types of anemia, and consequently, they are frequently treated with iron and/or erythropoietin therapy or frequent blood transfusion. Thus, serum GA is a potentially useful glycemic index in diabetic patients with CKD, since it is not influenced by anemia and associated treatments. GA may also reflect the status of blood glucose more rapidly (2-3 weeks) than HbA1c (2-3 months), and is beneficial in those with wide variations in blood glucose or at higher risk for hypoglycemia. If clinical investigations support its utility, it may be applicable as a screening tool for all patients with diabetes during routine health examinations. Serum GA levels are also associated with AGE-related fluorescence and the number of glycation sites, and it may influence the structural and functional changes inalbumin. Since end-stage renal disease is an extreme microvascular complication of diabetic nephropathy, CKD patients with diabetes should be carefully managed to prevent disease progression. In this review, the clinical aspects of GA were discussed, including a comparison of GA with other glycated proteins, the utility and limitations of GA as a glycemic index, its influence on the therapeutic effects of hypoglycemic agents, its correlations with vascular complications, and its potential role in pathogenesis, specifically in diabetic patients with CKD.

Induction of oxidative stress in kidney

Oxidative stress has a critical role in the pathophysiology of several kidney diseases, and many complications of these diseases are mediated by oxidative stress, oxidative stress-related mediators, and inflammation. Several systemic diseases such as hypertension, diabetes mellitus, and hypercholesterolemia; infection; antibiotics, chemotherapeutics, and radiocontrast agents; and environmental toxins, occupational chemicals, radiation, smoking, as well as alcohol consumption induce oxidative stress in kidney. We searched the literature using PubMed, MEDLINE, and Google scholar with “oxidative stress, reactive oxygen species, oxygen free radicals, kidney, renal injury, nephropathy, nephrotoxicity, and induction”. The literature search included only articles written in English language. Letters or case reports were excluded. Scientific relevance, for clinical studies target populations, and study design, for basic science studies full coverage of main topics, are eligibility criteria for articles used in this paper.

Efficacy of patient questionnaire in predicting renal dysfunction in outpatients older than 60 years of age prior to contrast-enhanced computed tomography

INTRODUCTION

Contrast-induced nephropathy (CIN), a common iatrogenic cause of acute renal failure, is preventable. Identification of impaired renal function prior to intravenous contrast is important. Questionnaire screening has been useful to negate the need for cumbersome and costly renal function testing on all patients prior to contrast-enhanced CT (CECT). The Royal Australian and New Zealand College of Radiologists guidelines include age older than 60 as a risk marker requiring renal function testing. The aim of this retrospective study is to assess the efficacy of the pre-CT questionnaire in identifying patients with pre-existing renal impairment even in this older than 60 age group.

METHODS

All outpatients were given questionnaires containing 11 CIN risk markers prior to CECT. Radiographers documented age, gender, serum creatinine and/or estimated glomerulofiltration rate (eGFR mL/min/1.72 m(2) ) within 3 months of CT. Questionnaires of all patients older than 60 years were collated. The data was tabulated and analyzed. Incomplete questionnaires were excluded.

RESULTS

134/171 (78.4%) patients had eGFR ≥ 60 and 37/171 (21.6%) had eGFR < 60, with 31/171 (18.1%) having eGFR between 30 and 60 and 3/171 (1.8%) having eGFR < 30. 47/171 (27.5%) circled 'no' to all risk markers. Percentage for sensitivity is 81.1% (95% confidence interval (CI) 64.8-92%), for specificity 29.9% (95% CI 22.3-38.4%), for positive predictive value 24.2% (95% CI 17-32.7%) and for negative predictive value 85.1% (95%CI 71.7-93.8%). Kidney disease, anaemia, myeloma and vasculitis seem to be statistically significant risk factors (P < 0.05). All three true-positive patients with eGFR < 30 indicated known kidney disease. Seven false-negative patients had eGFR 30-60, with 4/7 (57.1%) having CIN risk markers in their medical records.

CONCLUSION

Questionnaire screening for CIN risk has a high negative predictive value (85.1%) even in patients older than 60 years.

Impact of elevated serum glycated albumin levels on contrast-induced acute kidney injury in diabetic patients with moderate to severe renal insufficiency undergoing coronary angiography

BACKGROUND

Glycated albumin (GA) has been shown to be a better indicator than glycosylated hemoglobin A1c (HbA1c) in terms of severity of renal impairment in patients with type 2 diabetes mellitus (T2DM). This study aimed to determine whether elevated serum GA levels are associated with an increased risk for contrast-induced acute kidney injury (CI-AKI) and worse clinical outcome in patients with T2DM and at least moderate renal insufficiency (RI) undergoing coronary angiography.

METHODS

Serum levels of fasting blood glucose (FBG), HbA1c and GA were measured in 1030 patients with T2DM and moderate to severe RI (eGFR 15-59 mL/min/1.73 m(2)). CI-AKI was defined as ≥ 25% increase in serum creatinine within 72 h after the procedure. Receiver-operating characteristic curve was constructed to assess the predictive value of GA, HbA1c and FBG for CI-AKI. Multivariable logistic regression model was developed to identify risk factors for CI-AKI, and Kaplan-Meier curve analysis was used to compare the rates of dialysis and major adverse cardiac events (MACE) during one-year follow-up.

RESULTS

The overall rate of CI-AKI was 11.1%. GA was significantly higher in patients with CI-AKI than in those without, and correlated positively with changes of renal function after the procedure. After adjusting for age, sex, left ventricular ejection fraction, multi-vessel disease, type and volume of contrast media, FBG, and HbA1c, GA remained an independent risk factor for CI-AKI. GA ≥ 21% was associated with increased rates of dialysis and MACE during one-year follow-up in patients with or without CI-AKI.

CONCLUSIONS

Increased GA level serves as a valuable risk factor for CI-AKI and indicates poor one-year clinical outcome in patients with T2DM and moderate to severe RI.

Impact of Contrast-Induced Nephropathy and Cardiovascular Events by Serum Cystatin C in Renal Insufficiency Patients Undergoing Cardiac Catheterization

We assessed the usefulness of serum cystatin C for predicting contrast-induced nephropathy (CIN) in patients (n = 100) undergoing coronary catheterization. After a 12-month follow-up, the incidence of CIN was 8.3% (n = 5) in patients with mild renal insufficiency (estimated glomerular filtration rate [eGFR] 60-89 mL/min per 1.73 m2), 34.4% (n = 10) in those with moderate renal insufficiency (eGFR 30-59 mL/min per 1.73 m2), and 100% (n = 3) in those with severe renal insufficiency (eGFR 15-29 mL/min per 1.73 m2). The sensitivity was 81.8% and specificity was 90.9% at the cutoff level of serum cystatin C >1.18 mg/L. Serum cystatin C levels were significantly ( P < .001) higher in the patients with moderate renal insufficiency in the CIN group than those in the non-CIN group. Multivariate logistic regression analysis demonstrated that baseline serum cystatin C independently predicted short-term mortality (odds ratio [OR], 0.311; 95% confidence interval [CI] 0.058-0.538; P = .026). Baseline serum cystatin C significantly predicted the occurrence of CIN in the patients with moderate renal insufficiency.