Hemodynamic and tubular changes induced by contrast media

Association between Pan-Immune-Inflammation Value and Contrast-Induced Nephropathy with Coronary Angiography

Background: Contrast-induced nephropathy (CIN) is one of the most important complications after invasive cardiovascular procedures. Considering the pivotal role of inflammation in CIN development, the use of peripheral blood-based indexes may be an easily available biomarker to predict CIN risk. Therefore, in the present study, we evaluated the association between the pan-immune-inflammation value (PIV) and the risk of CIN. Patients and Methods: A total of 1343 patients undergoing coronary angiography (CAG) were included. The PIV was calculated with the following equation: (neutrophil count × platelet count × monocyte count)/lymphocyte count. Multivariable regression analyses were used to determine the association between clinical and laboratory parameters and CIN development. Results: The median age of the cohort was 58 (IQR 50-67), and 48.2% of the patients were female. CIN developed in 202 patients (15%) in follow-up. In multivariate analyses, older age (OR: 1.015, 95% CI: 1.002-1.028, p = 0.020) and higher PIV levels (OR: 1.016, 95% CI: 1.004-1.028, p = 0.008) were associated with a higher CIN risk, while the use of antiplatelet agents was associated with a lower risk of CIN (OR: 0.670, 95% CI: 0.475-0.945, p = 0.022). Conclusions: We demonstrated that the risk of CIN was significantly higher in patients with higher PIV and older patients in a large cohort of patients undergoing CAG for stable ischemic heart disease. If supported with prospective evidence, PIV levels could be used as a minimally invasive reflector of CIN.

Contrast-induced acute kidney injury: a review of definition, pathogenesis, risk factors, prevention and treatment

Contrast-induced acute kidney injury (CI-AKI) has become the third leading cause of hospital-acquired AKI, which seriously threatens the health of patients. To date, the precise pathogenesis of CI-AKI has remained not clear and may be related to the direct cytotoxicity, hypoxia and ischemia of medulla, and oxidative stress caused by iodine contrast medium, which have diverse physicochemical properties, including cytotoxicity, permeability and viscosity. The latest research shows that microRNAs (miRNAs) are also involved in apoptosis, pyroptosis, and autophagy which caused by iodine contrast medium (ICM), which may be implicated in the pathogenesis of CI-AKI. Unfortunately, effective therapy of CI-AKI is very limited at present. Therefore, effective prevention of CI-AKI is of great significance, and several preventive options, including hydration, antagonistic vasoconstriction, and antioxidant drugs, have been developed. Here, we review current knowledge about the features of iodine contrast medium, the definition, pathogenesis, molecular mechanism, risk factors, prevention and treatment of CI-AKI.

C-Reactive Protein to Albumin Ratio as a Predictor of Contrast-Induced Nephropathy After Carotid Angiography

This study evaluated the role of the C-reactive protein (CRP)/albumin ratio (CAR) in estimating the probability of occurring contrast-induced nephropathy (CIN) after carotid artery angiography (CAAG). Patients (n = 410) who had CAAG for carotid artery stenosis (CAS) were included in this study. A spike in serum creatinine was used to define CIN within 72 h of the procedure (>.5 mg/dL or >25% above baseline). CAR was calculated by dividing the CRP by the albumin level. Patients with CIN had higher numbers of white blood cells (P = .002), numbers of neutrophils (P = .007), neutrophil-lymphocyte ratios (P = .026), high-sensitivity CRP levels (P < .001), and CAR levels (P < .001) than those without CIN. They were also older (P < .001) and more likely to have diabetes mellitus (P = .006) and hypertension (P = .016). According to receiver operator characteristic curve (ROC) analysis, the CAR value has a 75% sensitivity and a 68% specificity for identifying CIN at a cutoff of 1.8. Also, NLR and CRP predicted CIN with 71% sensitivity and 67% specificity, 71% sensitivity and 66% specificity at the best cutoff values of 1.96 and 7.91, respectively. According the present study, in patients with CAS, the development of CIN after CAAG is independently correlated with CAR at admission.

The Effects of Coenzyme Q10 on Contrast-Induced Acute Kidney Injury in Type 2 Diabetes: A Randomized Clinical Trial

Contrast-induced acute kidney injury (CI-AKI) is a frequent challenge following the injection of contrast media and its subsequent oxidative stress. The aim of the present study was to evaluate the preventive effects of coenzyme Q10 (Q10), as a mitochondrial-targeted antioxidant in CI-AKI in diabetic patients, who account for a large proportion of angiographic cases. A total of 118 diabetic patients were randomly assigned to receive 120 mg of oral coenzyme Q10 (Q10 group) or placebo (Placebo group) for four days, starting 24 hours before contrast media injection. Blood urea nitrogen (BUN), serum and urinary creatinine, estimated glomerular filtration rate (eGFR), urinary malondialdehyde (UMDA), urinary total antioxidant capacity (UTAC), and urinary mitochondrial to nuclearDNA ratios (mtDNA/nDNA ratio) were evaluated before and after the treatment period. Urine sediments were also evaluated to report the urine microscopy score (UMS).The levels of BUN, serum and urine creatinine, and UMS were similar in the Q10 and placebo groups. EGFR was lower in the Q10 group before the treatment (p=0.013) but not after. The urinary mtDNA/nDNA ratio was 3.05±1.68 and 3.69±2.58 in placebo and Q10 groups, but UTAC was found to be lower in Q10 both before (p=0.006) and after the treatment (p<0.001). The incidence of CI-AKI was 14.40% and the mtDNA/nNDA ratio was similar between CI-AKI and non-CI-AKI patients. In conclusion, Q10 treatment shows no favorable effect on prevention of CI-AKI or a urinary mtDNA/nDNA ratio among diabetic patients.

The intellectual base and global trends in contrast-induced acute kidney injury: a bibliometric analysis

Contrast-induced acute kidney injury (CI-AKI) has become the third leading cause of hospital-acquired kidney injury. A comprehensive analysis of the current state of research in the field of CI-AKI will help to reveal trends and hot topics in the field. To date, there are no published bibliometric analyses related to CI-AKI studies. Here, we analyze the relevant literature since the emergence of the concept and provide valuable insights. The literature was collected from the Web of Science Core Collection. The data were analyzed visually using CiteSpace and VOSviewer software. We collected a total of 4775 papers, with the United States and Guangdong Acad Med Sci as the major publishing powers in terms of country/region and institution. J AM COLL CARDIOL was the journal with the most published and cocited articles. Cluster analysis showed that clinical trials are the current research hotspot. The areas of risk assessment, prevention strategies, risk factors, and vascular lesions have been popular in recent years. Research on the mechanism of injury in CI-AKI will be the focus of future research, which will be crucial to reduce the clinical incidence of CI-AKI. In summary, this study provides a comprehensive analysis of the development process in the field of CI-AKI and discusses future research directions based on the analysis of objective data from many studies on CI-AKI.

Neutrophil Extracellular Traps Aggravate Contrast-Induced Acute Kidney Injury by Damaging Glomeruli and Peritubular Capillaries

Background

Contrast-induced acute kidney injury (CI-AKI) is considered to be the third leading cause of hospital-acquired kidney injury. Current studies mostly suggest that contrast agents mainly harm renal tubular epithelial cells, but we hypothesized that the development of CI-AKI should be the result of the interaction of renal vascular and tubular injury.

Methods

First we constructed a CI-AKI mouse model and verified the success of the model by pathological injury and serum creatinine level. Immunohistochemistry, protein quantification and qRT-PCR were used to detect the location and level of expression of neutrophil extracellular traps (NETs) in the kidney. Then, we blocked the in vivo accumulation of NETs using GSK484 and DNase I and detected the expression of NETs and the damage of glomerular and peritubular capillaries.

Results

We first identified the presence of NETs in CI-AKI mice, and NETs were mainly accumulated in glomeruli and peritubular capillaries. The expression of NETs was positively correlated with the severity of CI-AKI kidney. After inhibition of NETs release or promotion of NETs degradation by drugs, renal vascular endothelial cell injury was reduced and renal pathological changes and creatinine levels were reversed in CI-AKI mice. In addition, inhibition of NETs reduced apoptosis and pyroptosis of renal cells and attenuated inflammation in vivo.

Conclusion

These findings suggest that NETs are involved in the development of CI-AKI by damaging glomerular and peritubular capillary endothelial cells. This study will provide a new strategy for clinical prevention and treatment of CI-AKI.

Ox-LDL aggravates contrast-induced injury of renal tubular epithelial cells

Hypercholesterolemia can aggravate contrast-induced acute kidney injury, and the exacerbation of renal tubular epithelial cell (RTEC) injury is a major cause. However, the exact mechanisms remain obscure. Mitophagy, a type of autophagy, selectively eliminates damaged mitochondria and reduces mitochondrial oxidative stress, which is strongly implicated in cell homeostasis and acute kidney injury. Oxidized low-density lipoprotein (Ox-LDL) is accumulated in hypercholesterolemia and has a cytotoxic effect. This study aimed to determine whether and how ox-LDL exacerbates contrast-induced injury in RTECs and to further explore whether PINK1/Parkin-dependent mitophagy is involved in this process. Iohexol and ox-LDL were used alone or in combination to treat HK-2 cells. Rapamycin pretreatment was utilized to enhance mitophagy. Cell viability, apoptosis, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) were detected by cell counting kit-8, TUNEL staining, JC-1 kit and MitoSOX fluorescence, respectively. The expression of mitophagy-related proteins (including PINK1, Parkin, and so on) and cleaved caspase-3 was confirmed by western blot. Colocalization of MitoTracker-labeled mitochondria and LysoTracker-labeled lysosomes was observed by fluorescence microscopy to evaluate mitophagy. The results of our study showed that ox-LDL aggravated MMP decline, mtROS release and apoptosis in iohexol-treated HK-2 cells, accompanied by a further increased autophagy level. Enhancement of PINK1/Parkin-dependent mitophagy by rapamycin alleviated apoptosis and mitochondrial injury in HK-2 cells in response to iohexol under ox-LDL condition. Therefore, our findings indicate that ox-LDL aggravates contrast-induced injury of RTECs by increasing mitochondrial damage and mitochondrial oxidative stress, which may be associated with the relative insufficiency of PINK1/Parkin-dependent mitophagy.

Potential therapeutic effects of Chinese meteria medica in mitigating drug-induced acute kidney injury

Drug-induced acute kidney injury (DI-AKI) is one of the leading causes of kidney injury, is associated with high mortality and morbidity, and limits the clinical use of certain therapeutic or diagnostic agents, such as antineoplastic drugs, antibiotics, immunosuppressants, non-steroidal anti-inflammatory drugs, and contrast media. In recent years, numerous studies have shown that many Chinese meteria medica, metabolites derived from botanical drugs, and Chinese medicinal formulas confer protective effects against DI-AKI by targeting a variety of cellular or molecular mechanisms, such as oxidative stress, inflammatory, cell necrosis, apoptosis, and autophagy. This review summarizes the research status of common DI-AKI with Chinese meteria medica interventions, including cisplatin, gentamicin, contrast agents, methotrexate, and acetaminophen. At the same time, this review introduces the metabolites with application prospects represented by ginseng saponins, tetramethylpyrazine, panax notoginseng saponins, and curcumin. Overall, this review provides a reference for the development of promising nephroprotectants.

The triglyceride-glucose index and contrast-induced nephropathy in non-ST elevation myocardial infarction patients undergoing percutaneous coronary intervention

The triglyceride glucose (TyG) index is an indicator of insulin resistance and associated with increased risk of diabetes mellitus and cardiovascular events. Our study investigates the correlation between TyG index and contrast induced nephropathy (CIN) in non-diabetic patients with non-ST elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI). 350 non-diabetic NSTEMI patients (183, 52.3% male) undergoing PCI were retrospectively enrolled. The enrolled cohort was divided into 2 groups based on the calculated TyG index, namely values < 8.65 or higher. CIN was defined as an increase in serum creatinine > 25% or 0.5 mg/dL from baseline in the first 48 to 72 hours after PCI. A total of 56 (16%) cases of CIN were diagnosed. In contrast to patients with lower TyG indexes, patients with higher TyG indexes (≥8.65) had a higher frequency of CIN, 9.5%. versus 20.8% respectively (P .004). Patients with CIN also had higher TyG indexes (8.74 ± 0.12 vs 8.67 ± 0.11, P < .001). In addition, TyG index, age, and glomerular filtration rate were identified as independent risk factors for CIN in logistic regression model (OR: 2.5 CI: 1.3-4.6, P .006, OR: 1.0 CI: 1.0-1.1, P < .001, OR: 1.0 KI: 1.03-1.06, P .025). In the ROC analysis, the area under the curve predictive of CIN was 0.666 (P < .001, 95% [CI] 0.58-0.75) with a cutoff value of 8.69 (sensitivity 71,4%, specificity 55.1%) TyG index. Higher TyG indexes are associated with an increased risk of CIN in non-diabetic patients with NSTEMI.

Recent advances in molecular mechanisms of acute kidney injury in patients with diabetes mellitus

Several insults can lead to acute kidney injury (AKI) in native kidney and transplant patients, with diabetes critically contributing as pivotal risk factor. High glucose per se can disrupt several signaling pathways within the kidney that, if not restored, can favor the instauration of mechanisms of maladaptive repair, altering kidney homeostasis and proper function. Diabetic kidneys frequently show reduced oxygenation, vascular damage and enhanced inflammatory response, features that increase the kidney vulnerability to hypoxia. Importantly, epidemiologic data shows that previous episodes of AKI increase susceptibility to diabetic kidney disease (DKD), and that patients with DKD and history of AKI have a generally worse prognosis compared to DKD patients without AKI; it is therefore crucial to monitor diabetic patients for AKI. In the present review, we will describe the causes that contribute to increased susceptibility to AKI in diabetes, with focus on the molecular mechanisms that occur during hyperglycemia and how these mechanisms expose the different types of resident renal cells to be more vulnerable to maladaptive repair during AKI (contrast- and drug-induced AKI). Finally, we will review the list of the existing candidate biomarkers of diagnosis and prognosis of AKI in patients with diabetes.

Crosstalk among apoptosis, inflammation, and autophagy in relation to melatonin protective effect against contrast-induced nephropathy in rats

Contrast medium (CM) is a chemical substance that is used for imaging anatomical boundaries and to explore normal and abnormal physiological findings; the use of CM was associated with kidney injury and acute renal failure. Melatonin (M) possesses antioxidant, anti-inflammatory, and antiapoptotic effects in addition to autophagy modulation. This study aimed to investigate the protective effect of M against contrast-induced nephropathy (CIN) and its impact on the crosstalk between inflammasome, apoptosis, and autophagy in CIN. Male albino rats received M (10, 20, and 40 mg/kg/day, intraperitoneally) for 3 days. One hour after the last administration, rats were subjected to CIN induction (10 mg/kg indomethacin, double doses of l-NAME 10 mg/kg, i.v., and meglumine diatrizoate 60% 6 mL/kg, i.v.). CIN-induced kidney damage was evidenced through elevated kidney function biomarkers and induced renal histopathological changes. Pretreatment with M caused a significant decrease in nephrotoxicity biomarkers and histopathological alterations. Moreover, CIN-induced oxidative stress, NLRP3 inflammasome, and apoptosis were attenuated by M. Furthermore, M modulates autophagy in CIN rats. M inhibits CIN-induced NLRP3-inflammasome activation and apoptosis as well as enhances autophagy.

Prevention and Management of AKI in ACS Patients Undergoing Invasive Treatments

PURPOSE OF REVIEW

Management of patients presenting with acute coronary syndrome (ACS) includes invasive procedures that may increase the risk of acute kidney injury (AKI). AKI adversely affects the outcomes of such procedures and complicates the management of ACS. We have summarized several strategies for the prevention and management of AKI in this critical patient group including in the pre-procedural, intraprocedural, and post-procedural settings.

RECENT FINDINGS

Definitive prevention and management strategies for AKI in patients presenting with ACS requiring invasive management can be confounded by the variation in data outcomes. Pre-procedural hydration with normal saline when accounting for time to catheterization, radial artery access, contrast stewardship, and close monitoring of renal function after catheterization should be implemented.

A Novel Predictor of Contrast-Induced Nephropathy in Patients With Carotid Artery Disease; the Systemic Immune Inflammation Index

Contrast-induced nephropathy (CIN) is associated with increased mortality and morbidity. The present study investigated the role of systemic immune inflammation index (SII) in predicting the risk of developing CIN after carotid artery angiography (CAAG). This study included 262 patients who underwent CAAG for symptomatic carotid artery stenosis (CAS). Simultaneous carotid stenting was applied to 232 of these patients. CIN was defined as an increase in serum creatinine level ≥.5 mg/dL or ≥25% above baseline within 72 hours after the procedure. The SII score was calculated as platelet × neutrophil/lymphocyte counts. Patients who developed CIN, had higher glucose (P = .009), total cholesterol (P < .001), low density lipoprotein cholesterol (<.001), and high sensitivity C-reactive protein (P = .001) levels, as well as greater neutrophil counts (P < .001), platelet counts (P < .001), neutrophil-lymphocyte ratio (P < .001), and SII score (P < .001) than those who did not develop CIN. The Receiver Operating Characteristic analysis showed that at a cutoff of 519.9, the SII exhibited 80% sensitivity and 64% specificity for detecting CIN. SII levels on admission were independently associated with CIN development after CAAG in patients with CAS.

Association of the Novel Inflammatory Marker Systemic Immune-Inflammation index and Contrast-Induced Nephropathy in Patients Undergoing Transcatheter Aortic Valve Replacement for Severe Aortic Stenosis

This study investigated whether the systemic immune-inflammation index (SII) is an independent predictor of contrast-induced nephropathy (CIN) in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis. TAVR patients (n = 130) were included in the study. The patients were divided into 2 groups: those who developed CIN [CIN (+)] and those who did not [CIN (−)]. The SII was calculated as the ratio of the product of the total neutrophil count and the total platelet count to the lymphocyte count. CIN developed in 20 (15.3%) patients after TAVR. White blood cell count (7.66 ± 1.75 vs 6.78 ± 1.71 103/mm3 P = .038), neutrophil count (5.1 (3.9–6.7) vs 4.2 (3.5-5.1) 103/mm3 P = .024), neutrophillymphocyte ratio (4.20 (2.39–7.00) vs 2.75 (2.06-3.88), P = .010) and SII index (1069 (616–1514) vs 598 (426-955), P = .003) were at higher levels in patients with CIN. In addition, the SII index was an independent predictor for the development of CIN. The SII index, which can be easily calculated from a complete blood count, is an independent predictor of CIN in patients undergoing TAVR for severe aortic stenosis.

The Pathophysiology and the Management of Radiocontrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is an impairment of renal function that occurs after the administration of an iodinated contrast medium (CM). Kidney dysfunction in CIN is considered transient and reversible in most cases. However, it is the third most common cause of hospital-acquired acute kidney injury and is associated with increased morbidity and mortality, especially in high-risk patients. Diagnostic and interventional procedures that require intravascular CM are being used with increasing frequency, especially among the elderly, who can be particularly susceptible to CIN due to multiple comorbidities. Therefore, identifying the exact mechanisms of CIN and its associated risk factors is crucial not only to provide optimal preventive management for at-risk patients, but also to increase the feasibility of diagnostic and interventional procedure that use CM. CM induces kidney injury by impairing renal hemodynamics and increasing the generation of reactive oxygen species, in addition to direct cytotoxicity. Periprocedural hydration is the most widely accepted preventive strategy to date. Here, we review the latest research results on the pathophysiology and management of CIN.

15-Hydroxyprostaglandin dehydrogenase inhibitor prevents contrast-induced acute kidney injury

The two primary mechanisms by which iodinated contrast media (CM) causes contrast-induced acute kidney injury (CIAKI) are the hemodynamic effect causing intrarenal vasoconstriction and the tubular toxic effect causing acute tubular necrosis. Inhibition of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), which degrades prostaglandin E2 (PGE2), promotes tissue repair and regeneration in many organs. PGE2 causes intrarenal arterial vasodilation. In this study, we investigated whether a 15-PGDH inhibitor can act as a candidate for blocking these two major mechanisms of CIAKI. We established a CIAKI mouse model by injecting a 10 gram of iodine per body weight (gI/kg) dose of iodixanol into each mouse tail vein. A 15-PGDH inhibitor (SW033291), PGE1, or PGE2 were administered to compare the renal functional parameters, histologic injury, vasoconstriction, and renal blood flow changes. In addition, human renal proximal tubular epithelial cells were cultured in a CM-treated medium. SW033291, PGE1, or PGE2 were added to compare any changes in cell viability and apoptosis rate. CIAKI mice that received SW033291 had lower serum levels of creatinine, neutrophil gelatinase-associated lipocalin, and kidney injury molecule 1 (p < 0.001); lower histologic injury score and TUNEL positive rates (p < 0.001); and higher medullary arteriolar area (p < 0.05) and renal blood flow (p < 0.001) than CM + vehicle group. In cell culture experiments, Adding SW033291 increased the viability rate (p < 0.05) and decreased the apoptosis rate of the tubular epithelial cells (p < 0.001). This 15-PGDH inhibitor blocks the two primary mechanisms of CIAKI, intrarenal vasoconstriction and tubular cell toxicity, and thus has the potential to be a novel prophylaxis for CIAKI. Abbreviations: 15-PGDH: 15-hydroxyprostaglandin dehydrogenase; AMP: adenosine monophosphate; CIAKI: contrast-induced acute kidney injury; CM: contrast media; EP: prostaglandin E2 receptor; hRPTECs: human-derived renal proximal tubule epithelial cells; KIM-1: kidney injury molecule-1; MTT: 3-(4,5-Dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide; NGAL: neutrophil gelatinase-associated lipocalin; PBS: phosphate-buffered saline; PGE1: prostaglandin E1; PGE2: prostaglandin E2; RBF: renal blood flow; TUNEL: terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling; α-SMA: α-Smooth muscle actin.

Trimetazidine an emerging paradigm in renal therapeutics: Preclinical and clinical insights

Trimetazidine (TMZ) is a well-known anti-ischemic agent used for the treatment of angina pectoris. In the past decades, the efficacy of this drug has been tested in a wide range of kidney injuries, including drug-induced nephrotoxicity (DIN), radio-contrast agent-induced nephropathy, and surgically induced renal ischemic injury. TMZhas renoprotective effects by attenuating oxidative stress, inflammatory cytokine release, maintaining oxygen and energy balance. Moreover, TMZ administration prevented kidney graft rejection in the porcine model by suppressing the infiltration of mononuclear cells, preserving mitochondrial functions, and maintaining Ca+ homeostasis. In DIN and diabetic kidney diseases,TMZ treatment prevents renal injury by inactivating immune cells, attenuating renal fibrosis, inflammation, apoptosis, and histological abnormalities. Interestingly, the clinical therapeutic efficacy of TMZ has also been documented in pre-existing kidney disease patients undergoing contrast exposure for diagnostic intervention. However, the mechanistic insights into the TMZ mediated renoprotective effects in other forms of renal injuries, including type-2 diabetes, drug-induced nephrotoxicity, and hypertension-induced chronic kidney diseases, remain uninvestigated and incomplete. Moreover, the clinical utility of TMZ as a renoprotective agent in radio-contrast-induced nephrotoxicity needs to be tested in a large patient population. Nevertheless, the available pieces of evidence suggest that TMZ is a promising and emerging renal therapy for the treatment and management of kidney diseases of variable etiologies. This review discusses the various pre-clinical and clinical findings and provides mechanistic insights into the TMZ mediated beneficial effects in various kidney diseases.

Calorie Restriction Protects against Contrast-Induced Nephropathy via SIRT1/GPX4 Activation

Calorie restriction (CR) extends lifespan and increases resistance to multiple forms of stress, including renal ischemia-reperfusion (I/R) injury. However, whether CR has protective effects on contrast-induced nephropathy (CIN) remains to be determined. In this study, we evaluated the therapeutic effects of CR on CIN and investigated the potential mechanisms. CIN was induced by the intravenous injection of iodinated contrast medium (CM) iopromide (1.8 g/kg) into Sprague Dawley rats with normal food intake or 40% reduced food intake, 4 weeks prior to iopromide administration. We found that CR was protective of CIN, assessed by renal structure and function. CM increased apoptosis, reactive oxygen species (ROS), and inflammation in the renal outer medulla, which were decreased by CR. The silent information regulator 1 (SIRT1) participated in the protective effect of CR on CIN, by upregulating glutathione peroxidase 4 (GPX4), a regulator of ferroptosis, because this protective effect was reversed by EX527, a specific SIRT1 antagonist. Our study showed that CR protected CIN via SIRT1/GPX4 activation. CR may be used to mitigate CIN.

Identification of novel therapeutic targets for contrast induced acute kidney injury (CI-AKI): alpha blockers as a therapeutic strategy for CI-AKI

Iodinated contrast is used for imaging and invasive procedures and it can cause contrast induced acute kidney injury (CI-AKI), which is the third leading hospital-acquired health problem. The purpose of the present study was to determine the effect of α-adrenergic receptor-1b (Adra1b) inhibition by using terazosin on change in kidney function, gene, and protein expression in C57BL/6J male mice, 6-8 weeks with chronic kidney disease (CKD). CKD was induced by surgical nephrectomy. Twenty eight days later, 100-µL of iodinated contrast (CI group) or saline (S group) was given via the carotid artery. Whole-transcriptome RNA-sequencing (RNA-Seq) analysis of the kidneys was performed at day 2. Mice received either 50-µL of saline ip or terazosin (2 mg/kg) in 50-µL of saline ip 1 hour before contrast administration which was continued every 12 hours until the animals were euthanized 2 and 7 days later. The kidneys were removed for gene expression, immunohistochemical analysis, and blood serum analyzed for kidney function. Differential gene expression analysis identified 21 upregulated and 436 downregulated genes (fold change >2; P < 0.05) that were common to all sample (n = 3 for both contrast and saline). We identified Adra1b using bioinformatic analysis. Mice treated with terazosin had a significant decrease in serum creatinine, urinary Kim-1 levels, HIF-1α, apoptosis, and downstream Adrab1 genes including Ece1, Edn1, pMAPK14 with increased cell proliferation. Contrast exposure upregulated Adra1b gene expression in HK-2 cells. Inhibition of Adra1b with terazosin abrogated Ece1, Edn1, and contrast-induced Fsp-1, Mmp-2, Mmp-9 expression, and caspase-3/7 activity in HK-2 cells.

The Application of Functional Magnetic Resonance Imaging in Type 2 Diabetes Rats With Contrast-Induced Acute Kidney Injury and the Associated Innate Immune Response

AIMS

Contrast-induced acute kidney injury (CI-AKI) is the third most common in-hospital acquired AKI, and its mechanism is not fully clear. Its morbidity increases among populations with chronic kidney disease (CKD), older age, diabetes mellitus (DM), and so on. Immediate and effective noninvasive diagnostic methods are lacking, so CI-AKI often prolongs hospital stays and increases extra medical costs. This study aims to explore the possibility of diagnosing CI-AKI with functional magnetic resonance imaging (fMRI) based on type 2 DM rats. Moreover, we attempt to reveal the immune response in CI-AKI and to clarify why DM is a predisposing factor for CI-AKI.

METHODS

A type 2 DM rat model was established by feeding a high-fat and high-sugar diet combined with streptozotocin (STZ) injection. Iodixanol-320 was the contrast medium (CM) administered to rats. Images were obtained with a SIEMENS Skyra 3.0-T magnetic resonance imager. Renal histopathology was evaluated using H&E staining and immunohistochemistry (IHC). The innate immune response was revealed through western blotting and flow cytometry.

RESULTS

Blood oxygenation level-dependent (BOLD) imaging and intravoxel incoherent motion (IVIM) imaging can be used to predict and diagnose CI-AKI effectively. The R 2 ∗ value (r > 0.6, P < 0.0001) and D value (| r| > 0.5, P < 0.0001) are strongly correlated with histopathological scores. The NOD-like receptor pyrin 3 (NLRP3) inflammasome participates in CI-AKI and exacerbates CI-AKI in DM rats. Moreover, the percentages of neutrophils and M1 macrophages increase dramatically in rat kidneys after CM injection (neutrophils range from 56.3 to 56.6% and M1 macrophages from 48 to 54.1% in normal rats, whereas neutrophils range from 85.5 to 92.4% and M1 macrophages from 82.1 to 89.8% in DM rats).

CONCLUSIONS/INTERPRETATION

BOLD and IVIM-D can be effective noninvasive tools in predicting CI-AKI. The innate immune response is activated during the progression of CI-AKI and DM will exacerbate this progression.

[Contrast-induced acute kidney injury]

The nephrotoxicity of iodinated contrast agent/media is defined by acute renal failure occurring within 48 to 72 hours after injection of iodized contrast product, in the absence of other etiology. The risk factors for contrast agent renal injury must systematically be sought before the exam. The presence of risk factors, including the existence of a renal failure defined by a creatinine clearance (eGFR) of less than 60 mL/min/1.73 m², requires to take prevention measures including hydration. If eGFR is less than 30 mL/min/1.73 m², the advice of a nephrologist is necessary.

Preventing contrast-induced nephropathy (CIN) with herbal medicines: A review

OBJECTIVES

Currently, the use of iodinated contrast media in diagnostic imaging has been increased in clinical medicine. Contrast-induced nephropathy (CIN) is an important adverse effect of contrast media injection. According to the significant role of oxidative stress in the pathophysiology of CIN, different herbal antioxidants have been used for the prevention of nephropathy in different studies. In this review, we discussed the preventive effects of herbal medicine and natural products against CIN.

METHODS

We searched the electronic databases or search engines including PubMed, Scopus, ISI, Google Scholar with search terms such as "Contrast-induced nephropathy" and "Herbal medicine," "Contrast acute kidney injury" AND "natural products" and similar headings such as plant and extract.

RESULTS

Known medicinal plants and active ingredients such as green tea, ginger, garlic, silymarin, curcumin, resveratrol, and thymoquinone have been examined for prophylactic effects or treatment of contrast media nephropathy.

CONCLUSION

Herbal medicines have promising effects in the laboratory-based studies for the prevention and/or treatment of CIN. However, more practical and completed clinical trials are needed to investigate the clinical benefits of natural products against CIN.

Renal protective effect of sodium ferulate on pulmonary hypertension patients undergoing computed tomography pulmonary angiography

This study aimed to explore the correlation of sodium ferulate and the renal protective effect on computed tomography pulmonary angiography in patients suffering from pulmonary hypertension. This prospective study enrolled 92 consecutive patients with pulmonary hypertension diagnosed by echocardiography, and all included patients underwent computed tomography pulmonary angiography after admission. The participants were randomized, divided into sodium ferulate group (n = 49) and control group (n = 43), of which patients in the sodium ferulate group received intravenous sodium ferulate 3.0 g per day from 12 h before computed tomography pulmonary angiography examination to 72 h after that, and patients in the control group were provided with routine treatment. Renal function was assessed by measuring serum creatinine, estimated glomerular filtration rate, Cystatin-C as well as 24 h, 48 h, and 72 h after computed tomography pulmonary angiography, followed by the calculation of the incidence of contrast-induced nephropathy for contrast-induced nephropathy and non-contrast-induced nephropathy grouping. Besides, renal resistive index was determined via Doppler ultrasound examination before, after 1 h and 24 h after computed tomography pulmonary angiography. There were no significant differences between the two groups in serum creatinine at baseline and 24 h after computed tomography pulmonary angiography (P > 0.05, respectively), but at 48 h and 72 h, it was lower in the sodium ferulate group (P < 0.05). There were no significant differences of estimated glomerular filtration rate between the two groups (P > 0.05). The level of Cystatin-C at 48 h and 72 h after computed tomography pulmonary angiography was lower than in the sodium ferulate group (P < 0.05). Contrast-induced nephropathy was identified in nine patients (9.78%). Sodium ferulate was associated with a decline in the incidence of contrast-induced nephropathy (4.08 vs. 16.28 %, P < 0.05). Compared to patients with contrast-induced nephropathy, lower renal resistive index were observed at 1 h and 24 h after computed tomography pulmonary angiography in patients without contrast-induced nephropathy (P < 0.05). Infusion of sodium ferulate before and after computed tomography pulmonary angiography was associated with a decline in incidence of contrast-induced nephropathy.

The Mechanism of Contrast-Induced Acute Kidney Injury and Its Association with Diabetes Mellitus

Contrast-induced acute kidney injury (CI-AKI) is the third most common hospital-acquired AKI after AKI induced by renal perfusion insufficiency and nephrotoxic drugs, taking great adverse effects on the prognosis and increasing hospital stay and medical cost. Diabetes nephropathy (DN) is a common chronic complication of DM (diabetes mellitus), and DN is an independent risk factor for chronic kidney disease (CKD) and CI-AKI. The incidence of CI-AKI significantly increases in patients with renal injury, especially in DM-related nephropathy. The etiology of CI-AKI is not fully clear, and research studies on how DM becomes a facilitated factor of CI-AKI are limited. This review describes the mechanism from three aspects. ① Pathophysiological changes of CI-AKI in kidney under high-glucose status (HGS). HGS can enhance the oxidative stress and increase ROS which next causes stronger vessel constriction and insufficient oxygen supply in kidney via vasoactive substances. HGS also aggravates some ion pump load and the latter increases oxygen consumption. CI-AKI and HGS are mutually causal, making the kidney function continue to decline. ② Immunological changes of DM promoting CI-AKI. Some innate immune cells and pattern recognition receptors (PRRs) in DM and/or DN may respond to some damage-associated molecular patterns (DAMPs) formed by CI-AKI. These effects overlap with some pathophysiological changes in hyperglycemia. ③ Signaling pathways related to both CI-AKI and DM. These pathways involved in CI-AKI are closely associated with apoptosis, inflammation, and ROS production, and some studies suggest that these pathways may be potential targets for alleviating CI-AKI. In conclusion, the pathogenesis of CI-AKI and the mechanism of DM as a predisposing factor for CI-AKI, especially signaling pathways, need further investigation to provide new clinical approaches to prevent and treat CI-AKI.

Association between contrast-induced nephrotoxicity and contrast enhanced computed tomography followed by endoscopic retrograde cholangiopancreatography

PURPOSE

To determine if endoscopic retrograde cholangiopancreatography (ERCP) performed within 72 h after contrast enhanced computed tomography (CECT) increases contrast-induced nephrotoxicity (CIN) risk in patients with abdominal complaints.

METHOD

This single-center retrospective cohort study included consecutive adult patients with abdominal complaints who underwent CECT between October 1, 2016, and June 30, 2019 at an emergency department (ED). CIN was diagnosed based on serum creatinine (SCr) level >0.5 mg/dL within 72 h after CECT or that increased >25 % compared to pre-CECT level. Logistic regression analysis was performed to determine independent risk factors for CIN, including age, sex, body mass index, comorbidities, medication, pre-CECT SCr level >1.5 mg/dL, and ERCP performed within 72 h after CECT. For persistent CIN, SCr level was obtained after 3 months at the earliest and compared to data obtained within 72 h after ERCP and CECT.

RESULTS

Of 1457 patients with CECT, 90 (6.2 %) underwent ERCP within 72 h after CECT and 93 (6.4 %) developed CIN. Multivariate analysis revealed that ERCP performed within 72 h after CECT (odds ratio, 3.31; 95 % confidence interval, 1.74, 6.29; p < 0.001) and pre-CECT SCr level >1.5 mg/dL (odds ratio, 9.86; 95 % confidence interval, 5.08, 19.2; p < 0.001) were independent risk factors for CIN. Of 93 patients with CIN, 10 (11 %) had persistent CIN. No specific factors were correlated with persistent CIN in the 3-month time frame.

CONCLUSION

ERCP performed within 72 h after CECT and pre-CECT SCr level >1.5 mg/dL are associated with CIN development.

Quercetin, a Promising Clinical Candidate for The Prevention of Contrast-Induced Nephropathy

Iodinated contrast media (CM) are the leading cause of acute renal failure of toxic origin. Between 21% and 50% of patients that receive them develop contrast-induced nephropathy (CIN). All prophylactic measures used so far have failed to provide effective prevention. Since oxidative stress is involved in the damage, a possible preventive strategy could be the administration of antioxidant substances, such as quercetin. This compound has shown renoprotective effects in experimental studies. The aim of this study was to evaluate whether quercetin may be helpful in preventing CIN in patients undergoing coronary catheterization. A clinical phase II study was conducted. Patients were distributed in two groups, namely, CM (patients who only received contrast media) and CM+Q (patients who were pretreated with quercetin orally for 3-5 days). Results showed less incidence of CIN in the CM+Q group, possibly due to glomerular protection, evidenced by a lower increase in serum creatinine and albuminuria; and a lower decrease in the glomerular filtration rate (GFR). Furthermore, in this group, the relative risk of developing CIN observed in patients that received a high dose of contrast media was inferior. In conclusion, this is the first study that demonstrates that quercetin is a promising safe candidate in preventing CIN.

CHA2DS2-VASC Score Predicts Risk of Contrast-Induced Nephropathy in Non-ST Elevation Myocardial Infarction Patients Undergoing Percutaneous Coronary Interventions

BACKROUND

The CHA2DS2-VASC score, used for embolic risk stratification in atrial fibrillation, has been reported recently to predict adverse clinical outcomes in patients with coronary artery disease. We investigated the correlation between the CHA2DS2-VASC score and contrast-induced nephropathy (CIN) in patients with non-ST elevation myocardial infarction (NSTEMI) who underwent percutaneous coronary intervention (PCI).

METHODS

We retrospectively enrolled 363 (191; 52.6% men) NSTEMI patients undergoing PCI. The CHA2 DS2-VASC score was calculated for each patient, and the study population was divided into 2 groups: CHA2DS2-VASC score <2 group (low score; n = 259, 71.3%) and CHA2DS2-VASC score ≥2 group (high score; n = 104, 28.6%). Patients were then reallocated to 2 groups according to the presence or absence of CIN. CIN was defined as a rise in serum creatinine >0.5 mg/dL or >25% increase in baseline within 72 h after PCI.

RESULTS

Overall, 56 cases (15.4%) of CIN were diagnosed. When patients with a CHA2DS2-VASC score of <2 were compared with those with a CHA2DS2-VASC score of ≥2, patients with a high score had a higher frequency of CIN (33) 31.7% versus (23) 8.9%; p < 0.001. Also patients with CIN had higher CHADS2 VASC score (3.94 ± 1.13 vs. 1.68 ± 0.46, p < 0.001). Additionally, in-hospital mortality, length of hospital stay, major bleeding, requirement of mechanical ventilation, and dialysis were observed significantly higher in patients with CHA2DS2-VASC score of ≥2 (p = 0.001, p = 0.002, p = 0.006, p = 0.001, p = 0.001, respectively). In receiver operating characteristic curve analysis, the area under the curve for predicting CIN was 0.702 (p < 0.001, 95% CI 0.617-0.787) and cutoff value was 2.5 (sensitivity 58.9%, specificity 76.9%) for the number of CHA2DS2-VASC score.

CONCLUSION

In NSTEMI patients undergoing PCI, CHADS2 VASC score is associated with an increased risk for CIN and in-hospital morbidity and mortality.

Clinical Advantages of Using Low Tube Voltage in Third-Generation 192-Slice Dual-Source Computed Tomographic Angiography Before Transcatheter Aortic Valve Implantation

Low-voltage computed tomographic angiography (CTA) is a highly effective technique to reduce contrast media volume. We sought to examine the suitability of low tube voltage CTA with a reduced contrast media volume protocol using third-generation 192-slice dual-source CT in patients undergoing transcatheter aortic valve implantation (TAVI). CTA was performed to aid TAVI planning for 40 consecutive patients with severe aortic stenosis. For the first 10 patients (120/100 kV group), we used a conventional tube voltage combined CTA protocol (an ECG-gated helical scan; 120 kV, non-gated helical scan; 100 kV). For the subsequent 30 patients (70-kV group), we adopted a low tube voltage CTA protocol. We evaluated vascular attenuation, image noise, contrast-to-noise ratio (CNR), and renal function. The mean contrast media (CM) volume was 77.7 ± 17.7 mL in the 120/100-kV group and 30.9 ± 6.3 mL in the 70-kV group (P < 0.001). In the images of the aortic valve complex, the mean attenuation was not significant difference for both groups. In the images of the aorto-femoral arteries, mean attenuation was > 250 Hounsfield Units and CNR was > 10 in all vascular segments for both groups. There was no significant difference in the change of renal function in the 70-kV group, but renal function in the 120/100-kV group decreased within 1-3 months after CTA. Low tube voltage CTA using third-generation dual-source CT is suitable to assess procedural planning for TAVI. This approach maintains image quality and reduces the required CM volume.

CHA2DS2-VASc score as a novel predictor for contrast-induced nephropathy after percutaneous coronary intervention in acute coronary syndrome

Background

CHA2DS2-VASc score, used for atrial fibrillation to assess the risk of embolic complications, have shown to predict adverse clinical outcomes in acute coronary syndrome (ACS), irrespective of atrial fibrillation. This study envisaged to assess the predictive role of CHA2DS2-VASc score for contrast-induced nephropathy (CIN) in patients with ACS undergoing percutaneous coronary intervention (PCI).

Methods

A total of 300 consecutive patients with ACS undergoing PCI were enrolled in this study. CHA2DS2-VASc score was calculated for each patient. These patients were divided into two groups as Group 1 (with CIN) and Group 2 (without CIN). CIN was defined as increase in serum creatinine level ≥0.5 mg/dL or ≥25% increase from baseline within 48 h after PCI. After receiver operating characteristic curve analysis, the study population was again classified into two groups: CHA2DS2-VASc score ≤3 group (Group A) and score ≥4 group (Group B).

Results

CIN was reported in 41 patients (13.6%). Patients with CIN had a higher frequency of hypertension, diabetes mellitus, and had a lower left ventricular ejection fraction and baseline estimated glomerular filtration rate. Receiver operating characteristic curve analysis showed good predictive value of CHA2DS2-VASc score for CIN (area under the curve 0.81, 95% CI 0.73–0.90). Patients with a CHA2DS2-VASc score of ≥4 had a higher frequency of CIN as compared with patients with score ≤3 (56.8% vs 4.8%; p = 0.0001) with multivariate analysis demonstrating CHA2DS2-VASc score of ≥4 to be an independent predictor of CIN.

Conclusion

In patients with ACS undergoing PCI, CHA2DS2-VASc score can be used as a novel, simple, and a sensitive diagnostic tool for the prediction of CIN.

Contrast-induced nephropathy in an animal model: Evaluation of novel biomarkers in blood and tissue samples

Identification of novel biomarkers of contrast-induced nephropathy (CIN) that may more accurately detect renal function changes; reflect kidney damage; assist monitoring; and elucidate pathophysiology attract considerable scientific attention nowadays. To evaluate novel biomarkers of nephrotoxicity in blood/tissue samples of a CIN model, 10 New Zealand white rabbits were divided into group 1 (n = 5; iopromide) and group 2 (n = 5; control). Blood was drawn at 0 h (immediately), 24 h and 48 h after contrast medium (CM) administration. Animals were euthanized at 48 h and kidneys were removed. Serum creatinine (sCr)/symmetric-asymmetric dimethylarginine (SDMA-ADMA) levels were measured. CM genotoxic/cytotoxic effect was investigated 48 h post-CM exposure using micronucleus assay in lymphocytes. Cytological examination was conducted using touch preparation technique (TPT). All animals in group 1 developed CIN: mean sCr levels increased by 68.2% within 48 h. Significant SDMA-ADMA level elevation was observed at 0 h and 24 h with insignificant drop at 48 h in group 1, remaining normal in group 2 at all time-points. Significant increase in bi-nucleated cells with micronuclei and micronuclei frequency was detected in group 1. Cytokinesis block proliferation index was reduced insignificantly in group 1. TPT revealed degenerative lesions/inflammation, cell degeneration, abnormal uterine tubular casts and rubella in kidneys of all animals in group 1. Group 2 presented normal cells.

Bilateral Sustained Nephrograms After Parenteral Administration of Iodinated Contrast Material: A Potential Biomarker for Acute Kidney Injury, Dialysis, and Mortality

OBJECTIVE

To determine whether persistent bilateral global nephrograms are associated with acute kidney injury (AKI), dialysis, and mortality.

PATIENTS AND METHODS

All patients who underwent (1) contrast-enhanced computed tomography (CT) or cardiac catheterization with iohexol between January 1, 2000, and December 31, 2014, and (2) noncontrast abdominal CT in the subsequent 24±6 hours were identified. Patients without preprocedure and postprocedure creatinine measurements or who received additional contrast material were excluded. Nephrograms were identified by radiologist review and CT attenuation measurements. Univariate and multivariate analyses were performed to determine nephrogram risk factors. Acute kidney injury (defined as a creatinine level of ≥0.5 mg/dL or Kidney Disease: Improving Global Outcomes stages 1-3), dialysis, and mortality proportions were compared between patients with and without bilateral global nephrograms using the Fisher's exact test.

RESULTS

A total of 123 patients met all inclusion criteria. The proportion of patients with a nephrogram was 37.4% (n=46), with a higher proportion following interventional (67% [18 of 30]) vs diagnostic (27.3% [9 of 33]) catheterization or contrast-enhanced computed tomography (31.7% [19 of 60]). Age (P=.002), chronic kidney disease (P=.05), and acute hypotension or shock (P=.02) were significant risk factors for nephrogram development. Patients with nephrogram had significantly higher rates of AKI (37.0% [17 of 46] vs 5.2% [4 of 77]; odds ratio [OR], 10.7 [95% CI, 3.31-34.5]; P<.001), dialysis (17.4% [8 of 46] vs 1.3% [1 of 77]; OR, 16.0 [95% CI, 1.93-133]; P=.001), and mortality (15.2% [7 of 46] vs 1.3% [1 of 77]; OR, 13.6 [1.62-115]; P=.003) than patients without nephrogram.

CONCLUSION

The presence of persistent bilateral global nephrograms suggests an increased risk of AKI, dialysis, and mortality when compared with patients whose kidneys fully eliminated the contrast material.

Coenzyme Q10 combined with trimetazidine in the prevention of contrast-induced nephropathy in patients with coronary heart disease complicated with renal dysfunction undergoing elective cardiac catheterization: a randomized control study and in vivo study

Background

Contrast-induced nephropathy (CIN) is one of the common hospital-acquired acute renal failures. The purpose of this study was to investigate whether Coenzyme Q10 (CoQ10) and trimetazidine (TMZ) can prevent the occurrence of CIN after elective cardiac catheterization in patients with coronary artery disease complicated with renal dysfunction.

Methods

Consecutive coronary artery disease patients with renal insufficiency scheduled for coronary angiography were enrolled in randomized, paralleled, double-blind, controlled trial. The development of CIN was occurrence at the 48 or 72 h after the procedure. The changes of serum creatinine (SCr), eGFR, and Cys-C within 72 h after the procedure were measured and compared. In vivo contrast medium (CM)-induced acute kidney injury (AKI) animal model was established, and CoQ10 plus TMZ was orally administrated to evaluate its renal protective effect.

Results

150 patients with renal insufficiency were enrolled finally. CIN occurred in 21 (14.00%) of the 150 patients. 72 h after the procedure, the incidence of CIN was significantly lower in CoQ10 plus TMZ group compared with control group (6.67 vs. 21.3%, p = 0.01). No cardiac death occurred in this study. No side effects were observed after administration of CoQ10 and TMZ. In vivo test demonstrated that CoQ10 and TMZ could significantly reduce the concentration of blood urea nitrogen (BUN) and SCR induced by CM i.v. injection, as well as tubular pathological injuries. Meanwhile, CoQ10 and TMZ could significantly reduce the oxidation stress in kidneys from CM-AKI animals.

Conclusion

CoQ10 plus TMZ could decrease the incidence of CIN in patients with renal insufficiency undergoing elective cardiac catheterization, and their effect may be due to its strong anti-oxidation effect.

Hypotonic contrast media is more toxic than isotonic contrast media on endothelial cells in vivo and in vitro

The aim of the current study was to investigate the cytotoxic effects of hypotonic (iopamidol) and isotonic (iodixanol) contract media (CMs) in vitro and in vivo. A total of 60 Wistar rats were included and were randomly divided into three groups (20 rats per group). Iodixanol (4 g iodine/kg), iopamidol (4 g iodine/kg) or equal volume of normal saline was injected via tail vein. HUVEC and H5V cell viability was determined by Cell Counting Kit‑8 agents. Western blotting was performed to detect ATP‑binding cassette subfamily G member 1 (ABCG1) expression. For histological analysis, hematoxylin and eosin staining was performed. Plasma endothelin, von Willebrand factor, tissue type plasminogen activator, plasminogen activator inhibitor, D‑Dimer, fibrinogen, anti‑thrombin III, plasminogen and nitric oxide synthase (NOS) were measured by using ELISA. Both iopamidol and iodixanol treatments deceased cell viability and increased apoptosis of HUVEC and H5V cells, along with downregulated NOS and ABCG1. The injection of iopamidol or iodixanol into rats changed the endothelium‑related plasma levels of biomarkers, including endothelin, von Willebrand factor, tissue type plasminogen activator, plasminogen activator inhibitor, D‑Dimer, fibrinogen and anti‑thrombin III. However, endothelia isolated from rat abdominal aorta in the iodixanol group retained their normal structure, whereas endothelial structure in the iopamidol group was injured and disrupted. The findings in the present study suggested that both hypotonic and isotonic CMs may lead to endothelial dysfunction and thrombin and fibrinolytic system disorder. However, hypotonic CMs may be more toxic than isotonic CMs. Therefore, additional cautions should be taken when selecting hypotonic CMs and their dosages during cardioangiography.

Contrast-induced nephropathy: Basic concepts, pathophysiological implications and prevention strategies

Contrast-induced nephropathy (CIN) is reversible acute renal failure observed following administration of iodinated contrast media (CM) during angiographic or other medical procedures such as urography. There are various mechanisms through which CM develop their nephrotoxic effects, including oxidative stress and apoptosis. CIN is a real-life, albeit not very rare, entity. Exact pathophysiology remains obscure and no standard diagnostic criteria apply. The Acute Kidney Injury Network criteria was recently employed but its incidence/clinical significance warrants further clarification based on recent methodological advancements, because most published studies to date were contaminated by bias. The current study is a comprehensive review conducted to provide an overview of the basic concepts of CIN and summarize recent knowledge on its pathophysiology and the evidence supporting potential prevention strategies. CIN is expected to increase morbidity, hospital stay and mortality, while all patients scheduled to receive CM should undergo risk assessment for CIN and high-risk patients may be considered candidates for prevention strategies. The value of using compounds with antioxidant properties other than sodium bicarbonate, remains controversial, warranting further clinical investigation.

Predictive Value of CHA2DS2-VASC Score for Contrast-Induced Nephropathy After Percutaneous Coronary Intervention for Acute Coronary Syndrome

The CHA2DS2-VASC score, used for embolic risk stratification in atrial fibrillation (AF), has been reported recently to predict adverse clinical outcomes in patients with acute coronary syndrome (ACS), regardless of having AF. We investigated the correlation between the CHA2DS2-VASC score and contrast-induced nephropathy (CIN) in patients with ACS who underwent urgent percutaneous coronary intervention (PCI). A total of 1,408 patients were enrolled in the study. The CHA2DS2-VASC score was calculated for each patient. Based on the receiver operating characteristic analysis, the study population was divided into 2 groups: CHA2DS2-VASC score ≤3 group (n = 944) and CHA2DS2-VASC score ≥4 group (n = 464). Patients were then reallocated to 2 groups according to the presence or absence of CIN. CIN was defined as a rise in serum creatinine >0.5 mg/dl or >25% increase in baseline within 72 hours after PCI. Overall, 159 cases (11.3%) of CIN were diagnosed. Receiver operating characteristic curve analysis revealed good diagnostic value of CHA2DS2-VASC score in predicting CIN (area under the curve 0.769, 95% confidence interval 0.733 to 0.805; p <0.001). When patients with a CHA2DS2-VASC score of ≥4 were compared with those with a CHA2DS2-VASC score of ≤3, patients with high score had a higher frequency of CIN (23.9% vs 5.1%; p <0.001), and multivariate analysis identified the CHA2DS2-VASC score of ≥4 as an independent predictor of CIN. In conclusion, CHA2DS2-VASC score can be used as a new, simple, and reliable tool to predict CIN in patients with ACS who underwent urgent PCI.

Efficacy of Short-Term Statin Treatment for the Prevention of Contrast-Induced Acute Kidney Injury in Patients Undergoing Coronary Angiography/Percutaneous Coronary Intervention: A Meta-Analysis of 21 Randomized Controlled Trials

BACKGROUND

The results of previous studies have been contradictory in terms of the efficacy of statin treatment in preventing contrast-induced acute kidney injury (CI-AKI) and clinical adverse events (AEs).

OBJECTIVE

This meta-analysis was undertaken to assess the role of short-term statin treatment in the prevention of CI-AKI and clinical AEs.

METHODS

We searched the Cochrane Library, EMBASE, and PubMed databases for randomized controlled trials (RCTs) with the development of CI-AKI as a primary outcome. Secondary outcomes were the post-procedural serum creatinine (SCr) level, estimated glomerular filtration rate (eGFR), and development of AEs. We also performed prespecified subgroup analyses.

RESULTS

A total of 21 RCTs involving 7746 patients were included. Short-term statin treatment significantly reduced the risk of CI-AKI [risk ratio (RR) 0.57; 95 % confident interval (CI) 0.47-0.69; p < 0.00001) and was associated with a lower post-procedural SCr level and a higher eGFR. High-dose statins resulted in a lower incidence of CI-AKI than the lower-dose statins. In addition, the benefit was seen across various subgroups for patients at risk of CI-AKI, statin-naïve patients, and East Asians, regardless of statin type, definition of CI-AKI, use of N-acetylcysteine (NAC) and hydration, and osmolality of contrast. However, there was no significant difference between the two groups in terms of the incidence of AEs.

CONCLUSIONS

The meta-analysis suggests that short-term statin treatment can effectively prevent CI-AKI, and the benefit is also observed in high-risk patients, statin-naïve patients, and an East Asian population. However, the effect of simvastatin for the prevention of CI-AKI, of statins for the prevention of AEs, and whether high-dose statins have a better effect than lower-dose statins are all still uncertain.

Impact of Iodinated Contrast on Renal Function and Hemodynamics in Rats with Chronic Hyperglycemia and Chronic Kidney Disease

Iodinated contrast (IC) is clinically used in diagnostic and interventional procedures, but its use can result in contrast-induced acute kidney injury (CI-AKI). Chronic kidney disease (CKD) and chronic hyperglycemia (CH) are important predisposing factors to CI-AKI. The aim of this study was to investigate the impact of iodinated contrast on the renal function and hemodynamics in rats with chronic hyperglycemia and chronic kidney disease. A total of 30 rats were divided into six groups; Sham: control of chronic renal disease; Citrate: control of chronic hyperglycemia (CH); Nx5/6: rats with 5/6 nephrectomy; Chronic Hyperglycemia: rats receiving Streptozotocin 65 mg/kg; Nx5/6 + IC: rats Nx5/6 received 6 mL/kg of IC; CH + IC: Chronic hyperglycemia rats receiving 6 mL/kg of IC. Renal function (inulin clearance; urinary neutrophil gelatinase-associated lipocalin, NGAL) and hemodynamics (arterial blood pressure; renal blood flow; renal vascular resistance) were evaluated. Iodinated contrast significantly increased urinary NGAL and reduced inulin clearance, while the hemodynamics parameters showed changes in arterial blood pressure, renal blood flow, and renal vascular resistance in both CKD and CH groups. The results suggest that the iodinated contrast in risk factors models has important impact on renal function and hemodynamics. NGAL was confirmed to play a role of highlight in diagnosis of CI-AKI.

Preventive effect of oral nicorandil on contrast-induced nephropathy in patients with renal insufficiency undergoing elective cardiac catheterization

This study aims to investigate the preventive effect of oral nicorandil on contrast-induced nephropathy (CIN) in patients with renal insufficiency undergoing elective cardiac catheterization. A total of 240 patients with an estimated glomerular filtration rate (eGFR) of 60 mL/min or less, who were undergoing elective cardiac catheterization, were randomly assigned to nicorandil group (n = 120, 10 mg nicorandil, three times daily from 2 days before to 3 days after procedure) or control group (n = 120, matching placebo as the same method). The primary endpoint was the incidence of CIN defined as 25 % increase in serum creatinine (SCr) from baseline or 44 μmol/L (0.5 mg/dL) increase in absolute value within 72 h after exposure to contrast medium. The secondary endpoints were: (1) the changes of SCr, Cystatin-C (Cys-C) and eGFR within 72 h; (2) major adverse events (MACE) occurring within 30 days. Baseline characteristics of the patients in the two groups were similar. The incidence of CIN was significantly lower in nicorandil group compared with control group (6.67 vs. 17.5 %, P = 0.017). Compared with the control group, nicorandil group tended to have a lower SCr and Cys-C levels as well as a higher eGFR at 48 h after the procedure (all P < 0.05). There was no difference about the incidence of MACE within 30 days between nicorandil group and control group (4.16 vs. 5.83 %, P = 0.767). Multivariate logistic analysis showed that nicorandil was an independent protective factor against CIN (OR = 0.260, 95 % CI = 0.1-0.676, P = 0.006). Therefore, we concluded that oral nicorandil was associated with a decline in the incidence of CIN in patients with renal insufficiency undergoing elective cardiac catheterization.

Targeting HO-1 by Epigallocatechin-3-Gallate Reduces Contrast-Induced Renal Injury via Anti-Oxidative Stress and Anti-Inflammation Pathways

Both oxidative stress and inflammation are involved in the pathogenesis of contrast-induced nephropathy (CIN). Epigallocatechin-3-gallate (EGCG), a purified catechin from green tea, has antioxidant and anti-inflammatory effects. However, it is unknown whether or not EGCG is effective in treating CIN. Our present study found that intravenous administration of EGCG, either before or just after the establishment of CIN, had a protective effect, determined by normalization of serum creatinine and blood urea nitrogen levels, improvement in renal histopathological scoring and alleviation of apoptosis, accompanied by decreased oxidative stress and inflammation. Because EGCG is a potent inducer of the antioxidant heme oxygenase-1 (HO-1), we studied HO-1 signaling in CIN. HO-1 levels were increased in CIN; treatment with EGCG further increased HO-1 levels, accompanied by an increase in Nrf2, a regulator of antioxidant proteins. Interestingly, blockade of HO-1 with protoporphyrin IX zinc(II) (ZnPP) prevented the protective effect of EGCG on CIN. ZnPP also blocked the ability of EGCG to increase the activity of an antioxidant (superoxide dismutase), and decrease markers of oxidative stress (myeloperoxidase and malondialdehyde) and inflammation (myeloperoxidase and IL-1β), indicating that HO-1 is the upstream molecule that regulates the EGCG-mediated protection. To determine further the role of HO-1 on the EGCG-mediated inhibition of inflammation, we studied the effect of EGCG on the NLRP3 inflammasome, an upstream signaling of IL-1β. EGCG down-regulated NLRP3 expression, which was blocked by ZnPP, indicating that HO-1 links EGCG with NLRP3. Therefore, EGCG, via up-regulation of HO-1, protects against CIN by amelioration of oxidative stress and inflammation.

CHADS2 score predicts risk of contrast-induced nephropathy in stable coronary artery disease patients undergoing percutaneous coronary interventions

BACKGROUND/PURPOSE

To investigate the correlation between the CHADS2 score and risk of contrast-induced nephropathy (CIN), we conducted a retrospective study in patients who underwent elective percutaneous coronary intervention (PCI) and compared its accuracy with previous scoring systems.

METHODS

A total of 539 patients who underwent elective PCI were enrolled. Based on their underlying diseases, such as hypertension, diabetes, and kidney disease, CHADS2 score, R2CHADS2 score, and Mehran's risk score were calculated for each patient. Incidence of CIN was defined as a rise in serum creatinine >0.5 mg/dL or >25% increase in baseline within 48 hours after PCI. All study participants were followed up until October 2014, or until the occurrence of major adverse cardiovascular events (MACEs).

RESULTS

Overall, 55 cases (10.2%) of CIN and 90 cases (16.7%) of MACEs were identified after participants were followed up for 1.57 ± 1.46 years. The study cohort was divided into three groups according to CHADS2 scores: score 0, score 1-2, and score 3-6. In multivariate analysis, an increase of 1 point in the CHADS2 score was independently associated with a 37% increase in the risk of CIN (odds ratio, 1.37; 95% confidence interval, 1.00-1.87; p = 0.048) and a 49% increase in MACEs (hazard ratio, 1.49; 95% confidence interval, 1.18-1.88, p = 0.001). In pairwise comparison, the discriminatory performance of CHADS2 score was not inferior to either R2CHADS2 score (p = 0.226) or Mehran's risk score (p = 0.075).

CONCLUSION

CHADS2 score could be a simple and useful predictor for CIN in patients undergoing elective PCI.

Increased risk of contrast-induced acute kidney injury in patients with pulmonary thromboembolism

INTRODUCTION

Computed tomography pulmonary angiography (CTPA) is currently an effective, reliable and widely employed diagnostic test for pulmonary thromboembolism (PT). PT harbors intrinsic clinical and biochemical abnormalities which may be associated with an increased risk of contrast-induced acute kidney injury (CIAKI).

OBJECTIVES

To assess the incidence and risk factors of CIAKI among patients with PT diagnosed with CTPA.

METHODS

One hundred and twenty-two consecutive patients who had been diagnosed with PT using CTPA between February 2006 and December 2010 were evaluated retrospectively. In addition to the classical risk factors of CIAKI, arterial blood gases, CTPA and transthoracic echocardiography findings of the patients were also recorded.

RESULTS

The incidence of CIAKI was 13.1%. There were statistically important differences with respect to age, the presence of congestive heart failure (CHF), the use of angiotensin converting enzyme inhibitor-angiotensin II receptor blocker drugs (ACEI-ARB), the arterial blood pH (ABpH) and the length of hospitalization between the two groups of patients who developed (n:16) and did not develop (n:106) CIAKI. In the logistic regression analysis, age and ABpH were preserved in the final equation.

CONCLUSION

The incidence of CIAKI among PT patients is significantly higher than the expected average. Older age, the presence of CHF, the use of ACEI-ARB, and additionally, low ABpH are important risk factors of CIAKI in patients with PT. Hypoxemia and low bicarbonate levels intrinsic to PT may contribute to the increased risk of CIAKI in this patient population and their correction may carry a prophylactic potential.

Renalase protects against contrast-induced nephropathy in Sprague-Dawley rats

Background

Contrast-induced nephropathy (CIN) is the third leading cause of hospital-acquired acute renal failure. Oxidative stress, apoptosis and inflammation play crucial roles in CIN. Renalase is a newly discovered monoamine oxidase from the kidney. We hypothesize that renalase could protect against CIN through anti-oxidation, anti-inflammation and anti-apoptosis pathways.

Methods

We tested our hypothesis in vivo with a rat model of Ioversol-induced CIN and in vitro. Sprague-Dawley rats were divided into 4 groups (n = 6 per group): control group, Ioversol group (rats subjected to Ioversol-induced CIN), Ioversol plus vehicle group (CIN rats pretreated with vehicle) and Ioversol plus renalase group (CIN rats pretreated with 2 mg/kg recombinant renalase). HK2 cells were treated with Ioversol or H₂O₂.

Results

The results showed that pretreatment with renalase attenuated the deterioration of renal function, tubular necrosis, oxidative stress, apoptosis and inflammation (P<0.05). Furthermore, renalase protected HK2 cells against the cytotoxicity of Ioversol and suppressed Caspase-3 activity, oxidative stress and apoptosis induced by H₂O₂.

Conclusion

Recombinant renalase protected CIN in rats through anti-oxidation, anti-apoptosis and anti-inflammation mechanisms.

Reversal of radiocontrast medium toxicity in human renal proximal tubular cells by white grape juice extract

Radiocontrast media (RCM)-induced nephrotoxicity (CIN) is a major clinical problem accounting for 12% of all hospital-acquired cases of acute kidney injury. The pathophysiology of CIN is not well understood, but direct toxic effects on renal cells have been postulated as contributing to CIN. We have investigated the effect of a white grape (Vitis vinifera) juice extract (WGJe) on human renal proximal tubular (HK-2) cells treated with the radiocontrast medium (RCM) sodium diatrizoate. WGJe caused an increase in phosphorylation of the prosurvival kinases Akt and ERK1/2 in HK-2 cells. Treatment of HK-2 cells with 75 mgI/ml sodium diatrizoate for 2.5h and then further incubation (for 27.5h) after removal of the RCM caused a drastic decrease in cell viability. However, pre-treatment with WGJe, prior to incubation with diatrizoate, dramatically improved cell viability. Analysis of key signaling molecules by Western blotting showed that diatrizoate caused a drastic decrease in phosphorylation of Akt (Ser473), FOXO1 (Thr24) and FOXO3a (Thr32) during the initial 2.5h incubation period, and WGJe pre-treatment caused a reversal of these effects. Further analysis by Western blotting of samples from HK-2 cells cultured for longer periods of time (for up to 27.5h after an initial 2.5h exposure to diatrizoate with or without WGJe pre-treatment) showed that WGJe pre-treatment caused a negative effect on phosphorylation of p38, NF-κB (Ser276) and pERK1/2 whilst having a positive effect on the phosphorylation of Akt, FOXO1/FOXO3a and maintained levels of Pim-1 kinase. WGJe may alleviate RCM toxicity through modulation of signaling molecules that are known to be involved in cell death and cell survival and its possible beneficial effects should be further investigated.

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

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

Magnolin protects against contrast-induced nephropathy in rats via antioxidation and antiapoptosis

Background. Magnolin is the major active ingredient of the herb Magnolia fargesii which has anti-inflammatory and antioxidative effects. Oxidative stress and apoptosis are involved in the pathogenesis of contrast-induced nephropathy (CIN). We hypothesize that Magnolin could protect against CIN through antioxidative and antiapoptotic properties. Methods. To test whether Magnolin could attenuate CIN, oxidative stress and apoptosis, in vivo and in vitro, we utilized a rat model of ioversol-induced CIN and a cell model of oxidative stress in which HK2 cells were treated with H₂O₂. Rats were assigned to 4 groups (n = 6 per group): control group, ioversol group (ioversol-induced CIN), vehicle group (CIN rats pretreated with vehicle), and Magnolin group (CIN rats pretreated with 1 mg/kg Magnolin). Results. The results showed that magnolin ameliorated the renal tubular necrosis, apoptosis, and the deterioration of renal function (P < 0.05). Furthermore, Magnolin reduced the renal oxidative stress, suppressed caspase-3 activity, and increased Bcl-2 expression in vivo and in vitro. Conclusion. Magnolin might protect CIN in rats through antioxidation and antiapoptosis.

The Choice of the Iodinated Radiographic Contrast Media to Prevent Contrast-Induced Nephropathy

In patients with preexisting renal impairment, particularly those who are diabetic, the iodinated radiographic contrast media may cause contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI), that is, an acute renal failure (ARF), usually nonoliguric and asymptomatic, occurring 24 to 72 hours after their intravascular injection in the absence of an alternative aetiology. Radiographic contrast media have different osmolalities and viscosities. They have also a different nephrotoxicity. In order to prevent CIN, the least nephrotoxic contrast media should be chosen, at the lowest dosage possible. Other prevention measures should include discontinuation of potentially nephrotoxic drugs, adequate hydration with i.v. infusion of either normal saline or bicarbonate solution, and eventually use of antioxidants, such as N-acetylcysteine, and statins.