Prevention of contrast-induced nephropathy by limb ischemic preconditioning: underlying mechanisms and clinical effects

The relationship between perioperative serum albumin and contrast-induced acute kidney injury in patients after percutaneous coronary intervention

OBJECTIVE

Contrast-induced acute kidney injury (CI-AKI) is a common complication in patients undergoing percutaneous coronary intervention (PCI). Studies have shown that perioperative serum albumin levels may play a role in the occurrence of CI-AKI. In this study, we aimed to investigate the effect of perioperative serum albumin (delta albumin or &Alb) levels on the occurrence and long-term prognosis of CI-AKI patients after PCI.

METHODS

A total of 959 patients who underwent PCI between January 2017 and January 2019 were selected for this study. A receiver operating characteristic curve was used to determine the optimal cut-off value of the &Alb level for predicting CI-AKI after PCI. Patients were divided into two groups based on the optimal cut-off value: the high &Alb group (&Alb ≥ 4.55 g/L) and the control group (&Alb < 4.55 g/L). The incidences of CI-AKI and major adverse cardiac events (MACEs, including all-cause death, nonfatal myocardial infarction, and target vessel revascularization) were compared between the groups. Cox regression analysis was used to identify predictors of long-term prognosis after PCI.

RESULTS

Of the 959 patients, 147 (15.3%) developed CI-AKI after PCI. The CI-AKI group had a greater level of &Alb than did the non-CI-AKI group [(6.14 (3.90-9.10) versus 3.48 (4.31-6.57), P < 0.01)]. The incidence of CI-AKI in the high &Alb group was significantly greater than that in the low group (23.6% versus 8.3%, P < 0.01). After a 1-year follow-up, the incidence of MACEs was significantly greater in the high &Alb group than in the low group (18.6% versus 14.5%, P = 0.030). Cox regression analysis confirmed that CI-AKI was an independent predictor of MACEs at the 1-year follow-up (HR 1.43, 95% CI 1.04-1.96, P = 0.028). In addition, patients with low preoperative serum albumin levels had s significantly greater incidence of MACEs than did those with high preoperative serum albumin levels (23.2% versus 19.5%, P = 0.013).

CONCLUSION

In summary, high baseline &Alb levels are an independent risk factor for CI-AKI in patients after PCI. The occurrence of CI-AKI in the perioperative period is also an independent predictor of long-term prognosis after PCI. These findings highlight the importance of monitoring &Alb levels and taking steps to prevent CI-AKI in patients undergoing PCI.

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.

Berberine alleviates contrast-induced nephropathy by activating Akt/Foxo3a/Nrf2 signalling pathway

Contrast-induced nephropathy (CIN) is a condition that causes kidney damage in patients receiving angiography with iodine-based contrast agents. This study investigated the potential protective effects of berberine (BBR) against CIN and its underlying mechanisms. The researchers conducted both in vivo and in vitro experiments to explore BBR's renal protective effects. In the in vivo experiments, SD rats were used to create a CIN model, and different groups were established. The results showed that CIN model group exhibited impaired renal function, severe damage to renal tubular cells and increased apoptosis and ferroptosis. However, BBR treatment group demonstrated improved renal function, decreased apoptosis and ferroptosis. Similar results were observed in the in vitro experiments using HK-2 cells. BBR reduced ioversol-induced apoptosis and ferroptosis, and exerted its protective effects through Akt/Foxo3a/Nrf2 signalling pathway. BBR administration increased the expression of Foxo3a and Nrf2 while decreasing the levels of p-Akt and p-Foxo3a. In conclusion, this study revealed that BBR effectively inhibited ioversol-induced apoptosis and ferroptosis in vivo and in vitro. The protective effects of BBR were mediated through the modulation of Akt/Foxo3a/Nrf2 signalling pathway, leading to the alleviation of CIN. These findings suggest that BBR may have therapeutic potential for protecting against CIN in patients undergoing angiography with iodine-based contrast agents.

Prevention of Contrast-induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury has varying definitions, but in general, increased serum creatinine level by ≥ 0.3 mg/dL (26.5 µmol/L) or 1.5x of baseline value or urine output <0.5 mL/kg/h within 1-7 days after contrast media (CM) administration can be considered as CIN. CIN is one of the most common complications and is associated with increased mortality in patients undergoing percutaneous coronary intervention (PCI). Thus, risk stratification for CIN should be made and preventive strategies should be employed in which the intensity of the approach must be tailored to patient's risk profile. In all patients, adequate hydration is required, nephrotoxic medications should be discontinued, and pre-procedural high-intensity statin is recommended. In patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, IV hydration should be started 12 hours pre-procedure up until 12-24 hours after the procedure. Remote ischemic preconditioning may be performed pre-procedurally. Radial first approach for vascular access is recommended. During the procedure, low or iso-osmolar CM should be used and its volume should be limited to eGFR x 3.7. In patients at high risk for CIN, additional contrast-sparing strategies may be applied, such as using a contrast reduction system, 5 Fr catheter with no sideholes, CM dilution, limiting test injection, confirming placement using guidewire, use of stent enhancing imaging technology, using metallic/software roadmap to guide PCI, use of IVUS or dextran-based OCT, and coronary aspiration. A more advanced hydration technique based on central venous pressure, left ventricular end-diastolic pressure, or using furosemide-matched hydration, might be considered.

The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is manifested by an abrupt decline in kidney function as a consequence of intravascular exposure to contrast media. With the increased applicability of medical imaging and interventional procedures that utilize contrast media for clinical diagnosis, CI-AKI is becoming the leading cause of renal dysfunction. The pathophysiological mechanism associated with CI-AKI involves renal medullary hypoxia, the direct toxicity of contrast agents, oxidative stress, apoptosis, inflammation, and epigenetic regulation. To date, there is no effective therapy for CI-AKI, except for the development of strategies that could reduce the toxicity profiles of contrast media. While most of these strategies have failed, evidence has shown that the proper use of personalized hydration, contrast medium, and high-dose statins may reduce the occurrence of CI-AKI. However, adequate risk predication and attempts to develop preventive strategies can be considered as the key determinants that can help eliminate CI-AKI. Additionally, a deeper understanding of the pathophysiological mechanism of CI-AKI is crucial to uncover molecular targets for the prevention of CI-AKI. This review has taken a step further to solidify the current known molecular mechanisms of CI-AKI and elaborate the biomarkers that are used to detect early-stage CI-AKI. On this foundation, this review will analyze the molecular targets relating to apoptosis, inflammation, oxidative stress, and epigenetics, and, thus, provide a strong rationale for therapeutic intervention in the prevention of CI-AKI.

Ioversol Induced Microglia Proinflammatory Activation and Oxidative Stress in Rats

Contrast-induced encephalopathy (CIE) following angiography, though not often and reversible, can in some cases lead to permanent neurological dysfunction. To identify how neuroinflammation is involved in CIE, we investigated microglia responses to a bolus injection of ioversol in the internal carotid artery (ICA) in rats. MicroCT scanning indicated that the injected ioversol was cleared from the rat's brain within 25 min. However, proinflammatory activated and significantly increased microglia were found in the rat occipital cortex at 1 day, and the number of blood vessel-associated microglia was still significantly higher at 3-day post-injection, compared with sham- and PBS-treated rats. Moreover, significantly upregulated malondialdehyde (MDA), downregulated superoxide dismutase (SOD) levels, and elevated proinflammatory cytokines were observed in the brain of rats treated with ioversol. Ioversol administration decreased cell viability of primarily cultured microglia and induced significant proinflammatory activation. Furthermore, ioversol remarkably upregulated astrocytic aquaporin (AQP) 4 expression in the rats brain, and transwell cultures showed significantly enhanced microglia migrating to ioversol-treated endothelial cells. Immediate injection of edaravone dexborneol, a novel antioxidative drug, after ioversol injection effectively rescued ioversol-induced neuroinflammation. Together, these findings suggest that ioversol induced neuroinflammation and oxidative stress in the brain via microglia activation in a direct and indirect manner, which might contribute to the pathogenesis of CIE.

Mechanism of Abelmoschus manihot L. in the Treatment of Contrast-Induced Nephropathy on the Basis of Network Pharmacology Analysis

Background

Contrast-induced nephropathy (CIN) is increasingly seen in patients receiving contrast medium. Abelmoschus manihot (L.) Medik. (Malvaceae) and its preparations are widely used and effective in the treatment of various chronic kidney diseases and CIN in China. It is supposed to be an important adjuvant therapy for CIN.

Methods

PubMed and CNKI were searched for the main compounds of A. manihot L. The Swiss target prediction platform, OMIM, GeneCards, DisGeNET, and DrugBank databases were mined for information relevant to the prediction of targets that A. manihot L. in the treatment of CIN. Subsequently, STRING database was applied for the construction of the PPI protein interaction network, meanwhile, the core targets were screened. DAVID database was used to perform the GO function and Kegg signal pathway enrichment analysis. AutoDockTools and PYMOAL were used for molecular docking. Vitro experiments were used to verify the effect of TFA, the main active component of A. manihot L., in the intervention of iopromide-induced cells injury.

Results

A total of 17 chemical components and 133 potential targets in A. manihot L. were obtained. The top 15 proteins with higher degree value were selected from the PPI network model, AKT1, PIK3R1, EGFR, SRC,AR, APP, TNF, GAPDH, MMP9, and PTPN1, etc. may be core targets. The enrichment analysis indicated that A. manihot L. was involved in the regulation of PI3K/AKT signaling pathway, FoxO signaling pathway, VEGF signaling pathway, HIF-1, TNF signaling pathway, melanoma, hepatitis B, and other signaling pathways which were mainly associated with the regulation of transcription and apoptosis, protein phosphorylation, inflammatory response, aging, and cell proliferation. Molecular docking indicated that the key components and core targets had a good binding ability. The vitro experiments illustrated that TFA reduces iopromide induced renal tubular cell injury and apoptosis, which may be related to regulating the phosphorylation of AKT.

Conclusion

The study preliminarily revealed the multi-component, multi-target, and multi-pathway synergistic effects of A. manihot L. on CIN, which provide theoretical reference and basis for the study of the pharmacological mechanism of A. manihot L. in the treatment of CIN.

Efficacy of brain natriuretic peptide vs. nicorandil in preventing contrast-induced nephropathy: a network meta-analysis

This study aimed to conduct a network meta-analysis (NMA) to compare the efficacy of brain natriuretic peptide (BNP) vs nicorandil for preventing contrast-induced nephropathy (CIN). Databases of Pubmed, Cochrane, Embase, Web of Science were searched by keywords for eligible studies of randomized controlled trials investigating different agents (BNP, nicorandil, nitroglycerin, intravenous saline) for preventing CIN. The outcomes included a change in serum creatinine level at 48 h and the incidence of CIN after percutaneous coronary intervention (PCI) or coronary angiography (CAG). A total of 13 studies with 3,462 patients were included. Compared with intravenous saline alone, except for nitroglycerin (odds ratio [OR]: 1.02, 95% CI [0.36-2.88]), the other drugs significantly reduced the CIN incidence with OR of 0.35 (95% CI [0.24-0.51]) for BNP, 0.52 (0.29, 0.94) for usual-dose nicorandil, 0.28 (0.19, 0.43) for double-dose nicorandil. BNP and double-dose nicorandil significantly decreased the change of serum creatinine (SCr) levels with mean difference (MD) of -6.98, (-10.01, -3.95) for BNP, -8.78, (-11.63, -5.93) for double-dose nicorandil. No significant differences were observed in the change of SCr levels for nitroglycerin (-4.97, [-11.46, 1.52]) and usual-dose nicorandil (-2.32, [-5.52, 0.89]) compared with intravenous saline alone. For double-dose nicorandil, the CIN incidence and the change of SCr level in group of 4-5 days treatment course were more than group of less than or equal to 24 h treatment course (OR of 1.48, [0.63-3.46] and MD of 2.48, [-1.96, 6.91]). In conclusion, BNP and double-dose nicorandil can have effects on preventing the incidence of CIN and double-dose nicorandil performed better than BNP. In double-dose nicorandil groups, a course of less than or equal to 24 h before and after procedure performed with better efficacy than a course of 4-5 days.

Disease a month: Update and review of contrast-associated acute kidney injury

Contrast associated acute kidney injury (CA-AKI) is a controversial subject in the field of nephrology, cardiology, radiology and hospital medicine. Much has been written and published concerning the causes, risk factors, outcomes, and potential treatments to avoid the ultimate outcome of complete kidney failure requiring dialysis. Over the decades many proposed preventative strategies and treatments have failed to be produe a reliable outcome . Additionally, there is now asdf is now a growing discussion of the severity and sincerity of CA-AKI being a major entity to worry about for patients. We discuss the present state of CA-AKI and highlight potential risk factors and possible therapeutic interventions to minimize any impact a contrast procedure may have on a patient in order to maximize the medical care.

Remote Ischemic Preconditioning for Prevention of Contrast-Induced Acute Kidney Injury in Patients of CKD Stage III and IV Undergoing Elective Coronary Angiography: A Randomized Controlled Trial

Introduction:

Contrast-induced acute kidney injury (CI-AKI) is a serious complication of coronary angiography (CA). The aim of this randomized, parallel group, single blind, sham-controlled trial was to assess the safety and efficacy of the remote ischemic preconditioning on the prevention of CI-AKI.

Methods:

Patients of 18–80 years of age with CKD 3 and 4, who were admitted for elective coronary angiography in a tertiary care hospital in eastern India were randomized in a 1:1 ratio to standard care with ischemic preconditioning (n = 45; intermittent arm ischemia through 4 cycles of 5-min inflation and 5-min deflation of a blood pressure cuff) or with standard care and sham ischemic preconditioning (n = 42). Overall, both study groups were at moderate risk of developing CI-AKI according to the Mehran risk score. The primary endpoint was the incidence of CI-AKI, defined as an increase in serum creatinine ≥25% or ≥0.5 mg/dL above baseline at 48 h after contrast medium exposure.

Results:

CI-AKI occurred in 8 patients (19.04%) in the control group and 2 (4.4%) in the remote ischemic preconditioning group (odds ratio, 0.198, 95% confidence interval, 0.087 to 0.452; P = 0.04). No major adverse events were related to remote ischemic preconditioning.

Conclusions:

This study indicates that remote ischemic preconditioning is a simple and well-tolerated procedure, which reduces the incidence of CI-AKI in CKD 3 and 4 patients undergoing coronary angiography.

Advances in the pathogenesis and prevention of contrast-induced nephropathy

With the increasing application of medical imaging contrast materials, contrast-induced nephropathy has become one of the leading causes of iatrogenic renal insufficiency. The underlying mechanism is associated with renal medullary hypoxia, direct toxicity of contrast agents, oxidative stress, apoptosis, immune/inflammation and epigenetic regulation in contrast-induced nephropathy. Up to date, there is no effective therapy for contrast-induced nephropathy, and thus risk predication and effective preventive strategies are keys to reduce the occurrence of contrast-induced nephropathy. It was found that the proper use of contrast medium, personalized hydration, and high-dose statins may reduce the occurrence of contrast-induced nephropathy, while antioxidants have not shown significant therapeutic benefits. Additionally, the role of remote ischemia preconditioning and vasodilators in the prevention of contrast-induced nephropathy needs further study. This review aims to discuss the incidence, pathogenesis, risk prediction, and preventive strategies for contrast-induced nephropathy.

Limb ischemic preconditioning ameliorates renal microcirculation through activation of PI3K/Akt/eNOS signaling pathway after acute kidney injury

Purpose

Contrast-induced acute kidney injury (CI-AKI) resulting from administration of iodinated contrast media (CM) is the third leading cause of hospital-acquired acute kidney injury and is associated with substantial morbidity and mortality. Deteriorated renal microcirculation plays an important role in CI-AKI. Limb ischemic preconditioning (LIPC), where brief and non-injurious ischemia/reperfusion is applied to a limb prior to the administration of the contrast agent, is emerging as a promising strategy for CI-AKI prevention. However, it is not known whether the renal protection of LIPC against CI-AKI is mediated by regulation of renal microcirculation and the molecular mechanisms remain largely unknown.

Methods

In this study, we examined the renal cortical and medullary blood flow in a stable CI-AKI model using 5/6-nephrectomized (NE) rat. The LIPC and sham procedures were performed prior to the injection of CM. Furthermore, we analyzed renal medulla hypoxia using in vivo labeling of hypoxyprobe. Pharmacological inhibitions and western blotting were used to determine the underlying molecular mechanisms.

Results

In this study, we found LIPC significantly ameliorated CM-induced reduction of medullary blood flow and attenuated CM-induced hypoxia. PI3K inhibitor (wortmannin) treatment blocked the regulation of medullary blood flow and the attenuation of hypoxia of LIPC. Phosphorylation of Akt/eNOS was significantly decreased via wortmannin treatment compared with LIPC. Nitric oxide synthase-inhibitor [Nω-nitro-l-arginine methyl ester (L-NAME)] treatment abolished the above effects and decreased phosphorylation of eNOS, but not Akt.

Conclusions

Collectively, the results demonstrate that LIPC ameliorates CM-induced renal vasocontraction and is mediated by activation of PI3K/Akt/eNOS signaling pathway.

Remote ischemic preconditioning reduces the incidence of contrast-induced nephropathy in patients undergoing coronary angiography/intervention: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Contrast-induced nephropathy (CIN) is associated with increased mortality and morbidity in patients undergoing coronary angiography (CAG) and percutaneous coronary intervention (PCI). We aimed to assess the latest evidence on the effect of remote ischemic preconditioning (RIPC) on the incidence of CIN in patients undergoing CAG/PCI.

METHODS

We performed a comprehensive search on topics assessing RIPC and CIN in CAG/PCI patients from inception up until July 2019 through several electronic databases.

RESULTS

There were a total of 1,925 subjects from 14 randomized controlled trials. Remote ischemic preconditioning was associated with reduced CIN incidence in patients undergoing CAG/PCI (OR 0.41 [0.30, 0.55], p < .001; I² : 22%). The nephroprotective effect was also demonstrated in those at moderate-high risk for CIN subgroup (OR 0.41 [0.29, 0.58], p < .001; I² : 26%) and PCI-only subgroup (OR 0.41 [0.29, 0.58], p < .001; I² : 0%). Time from RIPC to CAG/PCI has similar effectiveness among ≤45, ≤60, and ≤120 min. Mortality, rehospitalization, hemodialysis, and major adverse events were lower in the RIPC group (OR 0.50 [0.33, 0.76], p = .001; I² : 0%). Grading of recommendations assessment, development and evaluation (GRADE) assessment showed that RIPC has high evidence certainty for reducing CIN in patients undergoing PCI/CAG, moderate-high risk subgroup, and PCI-only subgroup with absolute reduction of 97 per 1,000, 129 per 1,000, and 121 per 1,000, respectively. Harbord test showed no evidence for the presence of small-study effects (p = .157).

CONCLUSIONS

Remote ischemic preconditioning is an effective procedure to reduce the risk of CIN and should be considered in patients with moderate-high risk at developing CIN.

tert-Butylhydroquinone Treatment Alleviates Contrast-Induced Nephropathy in Rats by Activating the Nrf2/Sirt3/SOD2 Signaling Pathway

Oxidative stress plays a critical role in the pathophysiology of contrast-induced nephropathy (CIN). Since the specific treatment of CIN remains an unmet medical need, it is imperative to find an effective strategy against the clinical management of CIN. The transcription factor Nrf2 is known to regulate antioxidative stress response. The aim of the present study was to assess the effects of tert-butylhydroquinone (t-BHQ), an activator of Nrf2, in the prevention of CIN and elucidate the underlying mechanism of its action in vitro and in vivo. We established a rat model of CIN and treated the animals with t-BHQ (25 mg/kg). The effects of t-BHQ treatment on CIN rats were elucidated by assessing renal function, HE staining, immunohistochemistry, and western blotting. We also studied the activity of oxidative stress-related markers, such as intracellular ROS level, MDA level, SOD2 activity, and GSH/GSSG ratio. We validated our results by siRNA-mediated silencing of Nrf2 in HK-2 cells exposed to the radiocontrast agent. Treatment with t-BHQ significantly ameliorated the renal function and the histopathological lesions in CIN rats. Further, pretreatment with t-BHQ significantly increased the SOD2 activity and GSH/GSSG ratio and decreased the levels of ROS and MDA in animals subjected to ioversol exposure. In addition, t-BHQ treatment increased the expression of Nrf2, Sirt3, and SOD2 and concomitantly decreased the expression of acetylated-SOD2. When Nrf2-silenced HK-2 cells were exposed to radiocontrast agent, they suffered severe cell oxidative stress, exhibited lower expression of Sirt3 and SOD2, and expressed higher levels of acetylated-SOD2; however, t-BHQ treatment did not affect the protein expression of these indicators in si-Nrf2 HK-2 cells. Our findings suggested that Nrf2 plays an important role in the regulation of the Sirt3/SOD2 antioxidative pathway, and t-BHQ may be a potential agent to ameliorate radiocontrast-induced nephropathy via activating the Nrf2/Sirt3/SOD2 signaling pathway in vitro and in vivo.