Fenoldopam mesylate for the prevention of contrast-induced nephropathy: a randomized controlled trial

Evaluating the Differential Risk of Contrast-Induced Nephropathy Among Diabetic and Non-diabetic Patients Following Percutaneous Coronary Intervention

Background Contrast-induced nephropathy (CIN) significantly complicates percutaneous coronary intervention (PCI), with a higher prevalence in diabetic patients. This study compares the incidence of CIN in diabetic and non-diabetic patients undergoing PCI. Material and methods Conducted at Lady Reading Hospital, Peshawar, PAK, from January to December 2023, this observational study involved 450 adult patients with coronary artery disease (CAD) undergoing PCI. The cohort was categorized based on diabetes status, excluding patients with chronic kidney disease and those on renal replacement therapy. Baseline characteristics documented included age, gender, blood pressure, creatinine levels, and the presence of acute coronary syndrome (ACS). CIN was defined as a ≥25% increase in serum creatinine from baseline within 48-72 hours post-PCI. Data analysis was performed using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25.0, Armonk, NY), incorporating descriptive statistics, Chi-square tests, and independent t-tests, with a significance level of p<0.05. Results The median age of the study population was 55 years. The cohort comprised 52% male (n=234) and 48% female (n=216). Notably, 33% (n=149) had ACS. Diabetic patients exhibited a significantly higher incidence of CIN post-PCI compared to non-diabetics. The highest incidence of CIN (17%, n=77) occurred in the 70+ age group. The findings highlight the criticality of renal function monitoring and procedural adjustments for diabetic patients. Conclusion Diabetic patients demonstrate an increased risk of CIN following PCI. This necessitates the development of tailored prevention strategies for this high-risk subgroup.

Contrast removal from coronary sinus for prevention of contrast-induced nephropathy: a review

The occurrence of contrast-induced-nephropathy (CIN) is related to the amount of contrast administration. Any removal of contrast from systemic circulation before reaching the kidneys might be beneficial using a device that removes contrast from a coronary sinus (CS). This manuscript aims to review the available literature regarding contrast removal from CS during coronary angiography or intervention for the prevention of CIN.

Contrast-induced acute kidney injury and its contemporary prevention

The complexity and application range of interventional and diagnostic procedures using contrast media (CM) have recently increased. This allows more patients to undergo procedures that involve CM administration. However, the intrinsic CM toxicity leads to the risk of contrast-induced acute kidney injury (CI-AKI). At present, effective therapy of CI-AKI is rather limited. Effective prevention of CI-AKI therefore becomes crucially important. This review presents an in-depth discussion of CI-AKI incidence, pathogenesis, risk prediction, current preventive strategies, and novel treatment possibilities. The review also discusses the difference between CI-AKI incidence following intraarterial and intravenous CM administration. Factors contributing to the development of CI-AKI are considered in conjunction with the mechanism of acute kidney damage. The need for ultimate risk estimation and the prediction of CI-AKI is stressed. Possibilities of CI-AKI prevention is evaluated within the spectrum of existing preventive measures aimed at reducing kidney injury. In particular, the review discusses intravenous hydration regimes and pre-treatment with statins and N-acetylcysteine. The review further focuses on emerging alternative imaging technologies, alternative intravascular diagnostic and interventional procedures, and new methods for intravenous hydration guidance; it discusses the applicability of those techniques in complex procedures and their feasibility in current practise. We put emphasis on contemporary interventional cardiology imaging methods, with a brief discussion of CI-AKI in non-vascular and non-cardiologic imaging and interventional studies.

Safety and feasibility of intravascular ultrasound guided zero-contrast percutaneous coronary intervention-A prospective study

BACKGROUND

There are published reports of safety and feasibility of percutaneous coronary intervention (PCI) without contrast, using intravascular ultrasound (IVUS) and coronary physiology guidance in chronic kidney disease population. We prospectively evaluated the safety and feasibility of zero-contrast PCI technique.

METHODS

In this prospective study, we hypothesized that PCI is feasible without contrast, using IVUS guidance alone without mandatory coronary physiology to rule out slow-flow or no-flow at the end of PCI in a population at risk of contrast-induced acute kidney injury (CI-AKI). In this study, we included 31 vessels in 27 patients at risk of CI-AKI and assessed the primary outcome of technical success at the end of PCI. Major adverse cardio-cerebro vascular events (MACCE) and percent change in estimated glomerular filtration rate(eGFR) one month after PCI were the secondary outcomes of the study.

RESULTS

The primary outcome was met in 87.1%(n = 27) of the procedures. Technical failure was seen in 12.9%(n = 4) of the procedures. None of the patients developed MACCE at one-month follow-up. The median percent change in eGFR at one-month follow-up was -8.19%(-24.40%, +0.92%). There was no newer initiation of renal replacement therapy at one-month follow-up.

CONCLUSIONS

Zero-contrast PCI is safe and feasible in selective coronary anatomies with IVUS guidance. Coronary physiology is not mandatory to rule out slow-flow or no-flow at the end of procedure. Contrast may be needed to tide over the crisis during the possible complications, namely slow-flow, geographical miss and intraprocedural thrombus.

Impact of 719Trp>Arg Polymorphism of KIF 6 Gene on Contrast Induced Nephropathy in Patients Undergoing Coronary Angiography or Percutaneous Coronary Intervention

Background:

The identification of preventive strategies, such as statin therapy, is crucial for the management of contrast-induced nephropathy (CIN). Several studies showed the association between KIF6 polymorphism (replacement of Trp719 with Arg) and an increased cardiovascular risk, while others showed a correlation between ‘pleiotropic’ effects of statins and a reduction in cardiovascular events in the population with the risk allele due to the documented modulation of response to statin by KIF6 polymorphism. Aim of this study is to assess the impact of KIF6 polymorphism on the development of CIN.

Methods:

We analysed 1253 consecutive patients undergoing coronary angiography/PCI. Serum creatinine was collected at baseline, 24 and 48 hours after contrast exposure. We identified the different allelic patterns and assessed the incidence of CIN (absolute increase of 0.5mg/dL or relative >25% in creatinine at 24 and 48h).

Results:

KIF6 Arg mutation was found in 669 patients (heterozygotes n = 525, homozygotes n = 144). The total prevalence of CIN was 12.5% and we did not find any association between KIF6 polymorphism and CIN development (11.3%, 13.7%, 13.2% p = 0.30). At subgroups analysis among statin ‘naïve’ patients we found a higher prevalence of CIN in homozygous patients as compared to wild-type (20.7% vs 11.3%, p = 0.05), while opposite results were observed among patients with statin therapy (8.6% vs 13.2%, p = 0.28).

Conclusion:

KIF6 homozygous Arg was associated with a significant increase in the risk of CIN only among statin naive patients. Future studies are needed to evaluate the beneficial effects of statin especially in this subset of patients.

Manual der Arbeitsgruppe Interventionelle Kardiologie (AGIK) der Deutschen Gesellschaft für Kardiologie – Herz- und Kreislaufforschung e. V. (DGK)

Dieses Manual zur diagnostischen Herzkatheteruntersuchung (Teil 1) ist eine Anwendungsempfehlung für interventionell tätige Ärzte, die den gegenwärtigen Kenntnisstand unter Berücksichtigung neuester Studienergebnisse wiedergibt. Hierzu wurde in den einzelnen Kapiteln speziell auf die Alltagstauglichkeit der Empfehlungen geachtet, sodass dieses Manual jedem interventionell tätigen Kardiologen als Entscheidungshilfe im Herzkatheterlabor dienen soll. Trotz der von vielen Experten eingebrachten praktischen Hinweise kann dieses Manual dennoch nicht die ärztliche Evaluation des individuellen Patienten ersetzen und damit eine Anpassung der Diagnostik bzw. Therapie ersetzen.

Trimetazidine reduces contrast-induced nephropathy in patients with renal insufficiency undergoing coronary angiography and angioplasty: A systematic review and meta-analysis (PRISMA)

OBJECTIVES

This systematic review and meta-analysis assesses the utility of trimetazidine (TMZ) to prevent contrast induced nephropathy (CIN) in patients with renal insufficiency undergoing coronary angiography and angioplasty.

MATERIALS AND METHODS

This meta-analysis was formulated and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of databases was conducted by 2 researchers independently for clinical trials, comparing hydration plus TMZ vs conventional hydration alone for prevention of CIN through January 2020. All patients had renal insufficiency (defined as GFR < 89 ml/minute/1.73 m2) and the outcome of interest was the incidence of contrast induced acute kidney injury. The odds ratio (OR) was estimated with 95% confidence interval (CI). Heterogeneity was reported with the I2 statistic, using a fixed-effects model, and >50% of I2 was considered to be statistically significant.

RESULTS

Eleven studies, 1611 patients, met the inclusion/exclusion criteria: 797 patients comprised the TMZ plus hydration group and the remaining 814 patients comprised the control (hydration only) group. Heterogeneity was low I2 = 0%, P = .84, and the heterogeneity of each study was also low. The incidence of CIN in the TMZ plus hydration group was 6.6% (53/797), while the incidence of CIN in the control (hydration only) group was 20% (165/814). Pooled analysis of all studies showed TMZ reduced incidence of CIN compared to saline hydration alone (OR risk 0.30, 95% CI 0.21, 0.42, P < .0001).

CONCLUSION

TMZ added to hydration reduces CIN in renal insufficiency patients undergoing coronary angiography.

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.

Acute Kidney Injury: From Diagnosis to Prevention and Treatment Strategies

Acute kidney injury (AKI) is characterized by an acute decrease in renal function that can be multifactorial in its origin and is associated with complex pathophysiological mechanisms. In the short term, AKI is associated with an increased length of hospital stay, health care costs, and in-hospital mortality, and its impact extends into the long term, with AKI being associated with increased risks of cardiovascular events, progression to chronic kidney disease (CKD), and long-term mortality. Given the impact of the prognosis of AKI, it is important to recognize at-risk patients and improve preventive, diagnostic, and therapy strategies. The authors provide a comprehensive review on available diagnostic, preventive, and treatment strategies for AKI.

Impact of pretreatment with carnitine and tadalafil on contrast-induced nephropathy in CKD patients

Objective: The present study assesses whether phosphodiesterase type 5 (PDE-5) inhibitor or carnitine exert nephroprotective effects against clinical contrast-induced nephropathy (CIN).

Materials and Methods: The present study consisted of three groups of CKD patients. The first group was control group, who were treated with N-acetyl-L-cysteine 1 day before and on the day of radiocontrast administration. The second one was carnitine group, where the patients were infused with carnitine over 10 min 2 h prior to the radiocontrast administration and 24 h post CT. The third one was PDE-5 inhibitor group, where patients were given tadalafil 2 h prior to the administration of the radiocontrast and in the subsequent day. Urine and blood samples were collected before and at the following time sequence: 2, 6, 12, 24, 48, and 120 h after the contrast administration, for creatinine and NGAL determination.

Results: Pretreated with N-acetyl-L-cysteine prior to administration of contrast media (CM) to CKD patients caused a significant increase in urinary but not of plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum creatinine (SCr). In contrast, pretreatment with carnitine prevented the increase in urinary NGAL and reduced SCr below basal levels. Similarly, tadalafil administration diminished the elevation of CM-induced urinary NGAL.

Conclusions: These results indicate that carnitine and PDE-5 inhibitors may comprise potential therapeutic maneuvers for CIN.

Carbon dioxide-angiography for patients with peripheral arterial disease at risk of contrast-induced nephropathy

Patients with peripheral arterial disease (PAD) and critical limb ischemia are at risk for limb amputation and require urgent management to restore blood flow. Patients with PAD often have several comorbidities, including chronic kidney disease, diabetes mellitus, and hypertension. Diagnostic and interventional angiography using iodinated contrast agents provides excellent image resolution but can be associated with contrast-induced nephropathy (CIN). The use of carbon dioxide (CO₂) as a contrast agent reduces the volume of iodine contrast required for angiography and reduces the incidence of CIN. However, CO₂ angiography has been underutilized due to concerns regarding safety and image quality. Modern CO₂ delivery systems with advanced digital subtraction angiography techniques and hybrid angiography have improved imaging accuracy and reduced the incidence of CIN. Awareness of the need for optimal imaging conditions, contraindications, and potential complications have improved the safety of CO₂ angiography. This review aims to highlight current technological advances in the delivery of CO₂ in vascular angiography for patients with PAD and critical limb ischemia, which result in limb preservation while preventing kidney damage.

Acute kidney injury - A frequent and serious complication after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

OBJECTIVES

The aim of the study was to investigate the incidence, risk factors and long-term prognosis of acute kidney injury (AKI) in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (primary PCI).

METHOD

A large-scale, retrospective cohort study based on procedure-related variables, biochemical and mortality data collected between 2009 and 2014 at Rigshospitalet, Copenhagen, Denmark. AKI was defined as an increase in serum creatinine of 25% during the first 72 hours after the index procedure.

RESULTS

A total of 4239 patients were treated with primary PCI of whom 4002 had available creatinine measurements allowing for assessment of AKI and inclusion in this study. The mean creatinine value upon presentation for all patients was 84 μmol/l (standard deviation (SD) ±40) and 97 μmol/l (SD ±53) at peak. AKI occurred in a total of 765 (19.1%) patients. Independent risk factors for the occurrence of AKI were age, time from symptom onset to procedure, peak value of troponin-T, female sex and the contrast volume to eGFR ratio. In a multivariable adjusted analysis AKI was independently associated with a higher mortality rate at 5 years follow-up (hazard ratio 1.39 [95%-confidence interval 1.03-1.88]).

CONCLUSION

In STEMI patients treated with primary PCI one in five experiences acute kidney injury, which was associated with a substantial increase in both short- and long-term mortality.

Fenoldopam Mesylate: A Narrative Review of Its Use in Acute Kidney Injury

Background:

Fenoldopam mesylate is a selective agonist of DA-1 receptors. It is currently used for the in-hospital treatment of severe hypertension. DA-1 receptors have high density in renal pa-renchyma and for this reason, a possible reno-protective role of Fenoldopam mesylate was investigated.

Methods:

We examined all studies regarding the role of Fenoldopam mesylate in Acute Kidney Injury (AKI); particularly, those involving post-surgical patients, intensive care unit patients and contrast-induced nephropathy.

Results:

Fenoldopam mesylate was found to be effective in reducing the onset of postoperative AKI, when used before the development of the kidney damage. Positive results were also obtained in the management of intensive care unit patients with AKI, although the clinical studies investigated were few and conducted on small samples.

Conclusion:

Conflicting results were achieved in contrast-induced nephropathy.

The protective effect of klotho against contrast-associated acute kidney injury via the antioxidative effect

As oxidative stress is one major factor behind contrast-associated acute kidney injury (CA-AKI), we investigated the protective effect of klotho against CA-AKI via the antioxidative effect. In in vitro experiments, cells (NRK-52E) were divided into the following three groups: control, iopamidol, or iopamidol + recombinant klotho (rKL) groups. Moreover, cell viability was measured with the Cell Counting Kit-8 assay, and oxidative stress was examined with 2',7'-dichlorodihydrofluorescein diacetate fluorescence intensity. RT-PCR and Western blot analysis were performed to assess propidium iodide klotho expression, and Bax-to-Bcl-2 and apoptosis ratios were evaluated with annexin V/Hoechst 33342 staining. Furthermore, we knocked down the klotho gene using siRNA to verify the endogenous effect of klotho. In our in vivo experiments, oxidative stress was evaluated with the thiobarbituric acid-reactive substance assay, and apoptosis was evaluated with the Bax-to-Bcl-2 ratio and cleaved caspase-3 immunohistochemistry. Additionally, cell and tissue morphology were investigated with transmission electron microscopy. In both in vitro and in vivo experiments, mRNA and protein expression of klotho significantly decreased in CA-AKI mice compared with control mice, whereas oxidative stress and apoptosis markers were significantly increased in CA-AKI mice. However, rKL supplementation mitigated the elevated apoptotic markers and oxidative stress in the CA-AKI mouse model and improved cell viability. In contrast, oxidative stress and apoptotic markers were more aggravated when the klotho gene was knocked down. Moreover, we found more cytoplasmic vacuoles in the CA-AKI mouse model using transmission electron microscopy but fewer cytoplasmic vacuoles in rKL-supplemented cells. The present study shows that klotho in proximal tubular cells can protect against CA-AKI via an antioxidative effect.

Global epidemiology and outcomes of acute kidney injury

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to decreased kidney function. In addition to retention of waste products, impaired electrolyte homeostasis and altered drug concentrations, AKI induces a generalized inflammatory response that affects distant organs. Full recovery of kidney function is uncommon, which leaves these patients at risk of long-term morbidity and death. Estimates of AKI prevalence range from <1% to 66%. These variations can be explained by not only population differences but also inconsistent use of standardized AKI classification criteria. The aetiology and incidence of AKI also differ between high-income and low-to-middle-income countries. High-income countries show a lower incidence of AKI than do low-to-middle-income countries, where contaminated water and endemic diseases such as malaria contribute to a high burden of AKI. Outcomes of AKI are similar to or more severe than those of patients in high-income countries. In all resource settings, suboptimal early recognition and care of patients with AKI impede their recovery and lead to high mortality, which highlights unmet needs for improved detection and diagnosis of AKI and for efforts to improve care for these patients.

Ciliotherapy: Remote Control of Primary Cilia Movement and Function by Magnetic Nanoparticles

Patients with polycystic kidney disease (PKD) are characterized with uncontrolled hypertension. Hypertension in PKD is a ciliopathy, an abnormal function and/or structure of primary cilia. Primary cilia are cellular organelles with chemo and mechanosensory roles. In the present studies, we designed a cilia-targeted (CT) delivery system to deliver fenoldopam specifically to the primary cilia. We devised the iron oxide nanoparticle (NP)-based technology for ciliotherapy. Live imaging confirmed that the CT-Fe₂O₃-NPs specifically targeted primary cilia in cultured cells in vitro and vascular endothelia in vivo. Importantly, the CT-Fe₂O₃-NPs enabled the remote control of the movement and function of a cilium with an external magnetic field, making the nonmotile cilium exhibit passive movement. The ciliopathic hearts displayed hypertrophy with compromised functions in left ventricle pressure, stroke volume, ejection fraction, and overall cardiac output because of prolonged hypertension. The CT-Fe₂O₃-NPs significantly improved cardiac function in the ciliopathic hypertensive models, in which the hearts also exhibited arrhythmia, which was corrected with the CT-Fe₂O₃-NPs. Intraciliary and cytosolic Ca²⁺ were increased when cilia were induced with fluid flow or magnetic field, and this served as a cilia-dependent mechanism of the CT-Fe₂O₃-NPs. Fenoldopam-alone caused an immediate decrease in blood pressure, followed by reflex tachycardia. Pharmacological delivery profiles confirmed that the CT-Fe₂O₃-NPs were a superior delivery system for targeting cilia more specifically, efficiently, and effectively than fenoldopam-alone. The CT-Fe₂O₃-NPs altered the mechanical properties of nonmotile cilia, and these nano-biomaterials had enormous clinical potential for ciliotherapy. Our studies further indicated that ciliotherapy provides a possibility toward personalized medicine in ciliopathy patients.

Impact of Non-cardiac Comorbidities in Adults with Congenital Heart Disease: Management of Multisystem Complications

The prevalence and impact of non-cardiac comorbidities in adult patients with congenital heart disease increase over time, and these complications are often specifically a consequence of the long-term altered cardiovascular physiology or sequelae of previous therapies. For the ACHD patient admitted to the intensive care unit (ICU) for either surgical or medical treatment, an assessment of the burden of multisystem disease, as well as an understanding of the underlying cardiovascular pathophysiology, is essential for optimal management of these complex patients. This chapter takes an organ-system-based approach to reviewing common comorbidities in the ACHD patient, focusing on conditions that are directly related to ACHD status and may significantly impact ICU care.

Methods for Reducing Contrast Use and Avoiding Acute Kidney Injury During Endovascular Procedures

Iodinated Contrast Media (CM) has a plethora of applications in routine non-invasive or percutaneous invasive imaging examinations and therapeutic interventions. Unfortunately, the use of CM is not without complications, with contrast-induced acute kidney injury (CI-AKI) being among the most severe. CI-AKI is a syndrome defined as a rapid development of renal impairment after a few days of CM endovascular injection, without the presence of any other underlying related pathologies. Although mostly transient and reversible, for a subgroup of patients with comorbidities related to renal failure, CI-AKI is directly leading to longer hospitalization, elevated rates of morbidity and mortality, as well as the increased cost of funding. Thus, a need for classification in accordance with clinical and peri-procedural criteria is emerged. This would be very useful for CI-AKI patients in order to predict the ones who would have the greatest advantage from the application of preventive strategies. This article provides a practical review of the recent evidence concerning CI-AKI incidence, diagnosis, and sheds light on prevention methods for reducing contrast use and avoiding AKI during endovascular procedures. In conclusion, despite the lack of a specific treatment protocol, cautious screening, assessment, identification of the high-risk patients, and thus the application of simple interventions -concerning modifiable risk factors- can significantly reduce CI-AKI risk.

Effectiveness of contrast-associated acute kidney injury prevention methods; a systematic review and network meta-analysis

BACKGROUND

Different methods to prevent contrast-associated acute kidney injury (CA-AKI) have been proposed in recent years. We performed a mixed treatment comparison to evaluate and rank suggested interventions.

METHODS

A comprehensive Systematic review and a Bayesian network meta-analysis of randomised controlled trials was completed. Results were tabulated and graphically represented using a network diagram; forest plots and league tables were shown to rank treatments by the surface under the cumulative ranking curve (SUCRA). A stacked bar chart rankogram was generated. We performed main analysis with 200 RCTs and three analyses according to contrast media and high or normal baseline renal profile that includes 173, 112 & 60 RCTs respectively.

RESULTS

We have included 200 trials with 42,273 patients and 44 interventions. The primary outcome was CI-AKI, defined as ≥25% relative increase or ≥ 0.5 mg/dl increase from baseline creatinine one to 5 days post contrast exposure. The top ranked interventions through different analyses were Allopurinol, Prostaglandin E1 (PGE1) & Oxygen (0.9647, 0.7809 & 0.7527 in the main analysis). Comparatively, reference treatment intravenous hydration was ranked lower but better than Placebo (0.3124 VS 0.2694 in the main analysis).

CONCLUSION

Multiple CA-AKI preventive interventions have been tested in RCTs. This network evaluates data for all the explored options. The results suggest that some options (particularly allopurinol, PGE1 & Oxygen) deserve further evaluation in a larger well-designed RCTs.

Goal-directed therapy in patients with early acute kidney injury: a multicenter randomized controlled trial

OBJECTIVES

Acute kidney injury is associated with many conditions, and no interventions to improve the outcomes of established acute kidney injury have been developed. We performed this study to determine whether goal-directed therapy conducted during the early stages of acute kidney injury could change the course of the disease.

METHODS

This was a multicenter prospective randomized controlled study. Patients with early acute kidney injury in the critical care unit were randomly allocated to a standard care (control) group or a goal-directed therapy group with 8h of intensive treatment to maximize oxygen delivery, and all patients were evaluated during a period of 72h. ClinicalTrials.gov: NCT02414906.

RESULTS

A total of 143 patients were eligible for the study, and 99 patients were randomized. Central venous oxygen saturation was significantly increased and the serum lactate level significantly was decreased from baseline levels in the goal-directed therapy group (p=0.001) compared to the control group (p=0.572). No significant differences in the change in serum creatinine level (p=0.96), persistence of acute kidney injury beyond 72h (p=0.064) or the need for renal replacement therapy (p=0.82) were observed between the two groups. In-hospital mortality was significantly lower in the goal-directed therapy group than in the control group (33% vs. 51%; RR: 0.61, 95% CI: 0.37-1.00, p=0.048, number needed to treat=5).

CONCLUSIONS

Goal-directed therapy for patients in the early stages of acute kidney injury did not change the disease course.

Contrast-Induced Nephropathy: Update on the Use of Crystalloids and Pharmacological Measures

Contrast-induced nephropathy (CIN) is a frequent and severe complication in subjects receiving iodinated contrast media for diagnostic or therapeutic purposes. Several preventive strategies were evaluated in the past. Recent clinical studies and meta-analyses delivered some new aspects on preventive measures used in the past and present. We will discuss all pharmacological and nonpharmacological procedures. Finally, we will suggest individualized recommendations for CIN prevention.

Effects of fenoldopam on kidney function parameters and its therapeutic efficacy in the management of acute kidney injury in dogs with heatstroke

Background

Acute kidney injury (AKI) is common in dogs, but evidence of efficacy of its treatment is lacking.

Objective

To evaluate the efficacy of fenoldopam in the management of AKI.

Animals

Forty dogs with naturally occurring heatstroke.

Methods

Dogs were prospectively enrolled and divided into treatment and the placebo groups (fenoldopam, constant rate infusion [CRI] of 0.1 µg/kg/min or saline, respectively). Urine production (UP) was measured using a closed system. Urinary clearances were performed at 4, 12, and 24 hours after presentation to estimate the effect of fenoldopam on UP, glomerular filtration rate (GFR) and sodium fractional excretion (NaFE).

Results

At presentation, severity of heatstroke, based on a previously developed scoring system, was similar between the study groups, but was significantly worse in nonsurvivors compared with survivors. Fenoldopam administration was not associated with hypotension. Overt AKI was diagnosed, based on the International Renal Interest Society guidelines in 22/40 (55%) of the dogs. Overall, 14/40 dogs (35%) died, with no significant (P = .507) mortality rate difference between the fenoldopam (6/20 dogs; 30%) and placebo (8/20; 40%) groups. The proportion of dogs with AKI did not differ between the fenoldopam and the placebo groups (9/20; 45% versus 13/20; 65%, respectively; P = .204). There were no differences in UP, GFR, and NaFE between the fenoldopam and the placebo groups.

Conclusion and Clinical Importance

Fenoldopam CRI at 0.1 µg/kg/min did not have a clinically relevant effect on kidney function parameters in dogs with severe heatstroke‐associated AKI.

Contrast-Induced Nephropathy in STEMI Patients With and Without Chronic Kidney Disease

INTRODUCTION

Contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) is associated with adverse outcomes; however, there are scarce data comparing clinical outcomes of post-PCI CIN in ST elevation myocardial infarction (STEMI) patients with and without chronic kidney disease (CKD). We sought to assess the incidence, clinical predictors, and short-term and long-term clinical outcomes of post-PCI CIN in STEMI patients with and without CKD.

METHODS

We performed a retrospective observational cohort study involving 554 patients who underwent PCI for STEMI from February 2010 to November 2013. CKD was defined as estimated glomerular filtration rate ≤60 mL/min and CIN as creatinine increase by ≥25% or ≥0.5 mg/dL from baseline within 72 hours after catheterization contrast exposure.

RESULTS

In the entire population, CIN developed in 89 (16%) patients. The incidence of CIN was 19.7% (27/137) in CKD patients and 11.1% (62/417) in non-CKD patients, P < 0.05. Univariate analysis predictors of CIN were older age (65 vs. 60 years), diabetes (35% vs. 21%), peripheral artery disease (11% vs. 5%), cardiogenic shock (24% vs. 13%), hemodynamic support placement (34% vs. 14%), and Mehran score (9.4 ± 7 vs. 5.4 ± 5.2) with all P < 0.05. The predictors of CIN were the same across the CKD and non-CKD cohort with the exception of diabetes. In multivariate analysis, the strongest predictor of CIN in CKD patients was diabetes (odds ratio, 5.8; CI, 1.8-18.6); however, diabetes was not a predictor in the non-CKD population. In the non-CKD population, each single unit increase in the Mehran score was associated with a 1.1 times greater likelihood of CIN (odds ratio, 1.1; CI, 1.01-1.2). Patients with CIN had higher rates of inpatient mortality (14.6% vs. 2.8%), longer length of hospitalization (8 ± 11 vs. 3.4 ± 4.4 days), need for inpatient dialysis (11.2% vs. 0%), higher 30-day mortality (14.6% vs. 3.0%), and higher incidence of long-term serum creatinine >0.5 mg/dL from baseline (16.9% vs. 2.4%) with all P < 0.05.

CONCLUSIONS

Overall, we found that CKD patients undergoing PCI for STEMI have a higher incidence of CIN than non-CKD patients. CIN confers worse short-term and long-term outcomes irrespective of baseline renal function.

Acute Kidney Injury and Progression of Diabetic Kidney Disease

Diabetic kidney disease, commonly termed diabetic nephropathy (DN), is the most common cause of end-stage kidney disease (ESKD) worldwide. The characteristic histopathology of DN includes glomerular basement membrane thickening, mesangial expansion, nodular glomerular sclerosis, and tubulointerstitial fibrosis. Diabetes is associated with a number of metabolic derangements, such as reactive oxygen species overproduction, hypoxic state, mitochondrial dysfunction, and inflammation. In the past few decades, our knowledge of DN has advanced considerably although much needs to be learned. The traditional paradigm of glomerulus-centered pathophysiology has expanded to the tubule-interstitium, the immune response and inflammation. Biomarkers of proximal tubule injury have been shown to correlate with DN progression, independent of traditional glomerular injury biomarkers such as albuminuria. In this review, we summarize mechanisms of increased susceptibility to acute kidney injury in diabetes mellitus and the roles played by many kidney cell types to facilitate maladaptive responses leading to chronic and end-stage kidney disease.

Prevention of contrast induced nephropathy by ischemic preconditioning in patients undergoing percutaneous coronary angiography

Background

Contrast-induced nephropathy (CIN) is the acute deterioration of renal function after parenteral administration of radio contrast media in the absence of other causes. The true incidence of CIN varies because of differences among the published studies in the definition of CIN, the proportion of high-risk patients, the types of contrast media, and the use of preventive measures. Remote ischemic preconditioning (IPC) may offer a non-pharmacological prevention strategy for lowering CIN in patients undergoing coronary procedures. The assumption that IPC produces protective effects on tissues or organs by multiple brief cycles of ischemia and reperfusion applied to another remote tissue or organ.

Aim

To investigate the effect of ischemic preconditioning in prevention of CIN in patients with renal impairment undergoing percutaneous coronary angiography.

Results

In this study, 100 patients undergoing elective PCI with a base line creatinine clearance <60 ml/min were studied. Patients were divided into two equal groups (ischemic preconditioning group and control group). The incidence of CIN was markedly lower in ischemic preconditioning group 14% VS 38% in control group. The incidence of CIN difference as was found to be (24%). Amount of dye used, decreased LVEF and presence of a significant LAD lesion were significant risk factors for occurrence of CIN.

Conclusions

The current study showed that remote ischemic preconditioning plays an important role in prevention of CIN in patients undergoing PCI with renal impairment GFR < 60 ml/min. The amount of contrast, decreased LVEF, and presence of LAD significant lesion were significant risk factors for developing of CIN and these subgroups benefited from application of ischemic preconditioning.

Baseline Chloride Levels are Associated with the Incidence of Contrast-Associated Acute Kidney Injury

Although hypo- and hyperchloremia have been associated with worsening renal outcomes, there has been no study that correlates hypo- and hyperchloremia and the incidence of contrast-associated acute kidney injury (CA-AKI). A total of 13,088 patients with less than 2.0 mg/dL of serum creatinine (Cr) who underwent contrast-enhanced abdominal CT (CECT) were included. Patients were divided into 3 groups based on Cl (the hypo-, normo- and hyperchloremia groups). Patients were also classified by baseline Cr (<1.2; the ‘Normal Cr group’ and 1.2–2.0 mg/dL; the ‘Slightly increased Cr group’). Multivariate logistic regression analysis was used to reveal the association between Cl and CA-AKI. Among patients, 2,525 (19.3%) and 241 (1.8%) patients were classified in the hypo- and hyperchloremia group. The incidence of CA-AKI was significantly lower in the normochloremia group (4.0%) compared to the hypo- (5.4%) and hyperchloremia groups (9.5%). On multivariate logistic regression, hypochloremia was significantly associated with the incidence of CA-AKI compared with normochloremia (1.382, P = 0.002). Moreover, hypochloremia was still significantly associated with the incidence of CA-AKI in ‘Normal Cr group’ compared with normochloremia (1.314, P = 0.015), while hyperchloremia did not show significant association with CA-AKI incidence. In conclusion, hypochloremia might be associated with the incidence of CA-AKI even in patients who have normal-range Cr levels.

Prospective evaluation of the development of contrast-induced nephropathy in patients with acute coronary syndrome undergoing rotational coronary angiography vs. conventional coronary angiography: CINERAMA study

INTRODUCTION AND OBJECTIVES

Rotational coronary angiography (RCA) requires less contrast to be administered and can prevent the onset of contrast-induced nephropathy (CIN) during invasive coronary procedures. The aim of the study is to evaluate the impact of RCA on CIN (increase in serum creatinine ≥0.5mg/dl or ≥25%) after an acute coronary syndrome.

METHODS

From April to September 2016, patients suffering acute coronary syndromes who underwent diagnostic coronary angiography, with the possibility of ad hoc coronary angioplasty, were prospectively enrolled. At the operator's discretion, patients underwent RCA or conventional coronary angiography (CCA). CIN (primary endpoint), as well as analytical, angiographic and clinical endpoints, were compared between groups.

RESULTS

Of the 235 patients enrolled, 116 patients received RCA and 119 patients received CCA. The RCA group was composed of older patients (64.0±11.8 years vs. 59.7±12.1 years; p=0.006), a higher proportion of women (44.8 vs. 17.6%; p<0.001), patients with a lower estimated glomerular filtration rate (76±25 vs. 86±27ml/min/1.73 m²; p=0.001), and patients who underwent fewer coronary angioplasties (p<0.001) compared with the CCA group. Furthermore, the RCA group, received less contrast (113±92 vs. 169±103ml; p<0.001), including in diagnostic procedures (54±24 vs. 85±56ml; p<0.001) and diagnostic-therapeutic procedures (174±64 vs. 205±98ml; p=0.049) compared with the CCA group. The RCA group presented less CIN (4.3 vs. 22.7%; p<0.001) compared to the CCA group, and this finding was maintained in the regression analysis (Adjusted relative risk: 0.868; 95% CI: 0.794-0.949; p=0.002). There were no differences in clinical endpoints between the groups.

CONCLUSIONS

RCA was associated with lower administration of contrast during invasive coronary procedures in acute coronary syndrome patients, resulting in lower incidence of CIN, in comparison with CCA.

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

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

AKIGUARD (Acute Kidney Injury GUARding Device) trial: in-hospital and one-year outcomes

AIMS

Contrast-induced acute kidney injury (CIAKI) in patients with chronic kidney disease undergoing coronary angiography or percutaneous coronary intervention is a common iatrogenic complication associated with increased morbidity and mortality. This study compares sodium bicarbonate/isotonic saline/N-acetylcysteine/vitamin C prophylaxis (BS-NAC) against high-volume forced diuresis with matched hydration in CIAKI prevention.

METHODS

One-hundred and thirty-three consecutive patients undergoing coronary angiography or percutaneous coronary intervention with estimated glomerular filtration rate less than 60 mL/min/1.73m were randomized to the study group receiving matched hydration (MHG) or to the control group receiving BS-NAC. MHG received in vein (i.v.) 250 mL isotonic saline bolus, followed by a 0.5 mg/kg furosemide i.v. bolus to forced diuresis. A dedicated device automatically matched the isotonic saline i.v. infusion rate to the urinary output for 1 h before, during and 4 h after the procedure.

RESULTS

MHG had the lowest incidence of CIAKI (7 vs. 25%, P = 0.01), major adverse cardiac and cerebrovascular events at 1 year (7 vs. 32%, P < 0.01) and readmissions to cardiology/nephrology departments (8 vs. 25%, P = 0.03; hospitalization days 1.0 ± 3.8 vs. 4.9 ± 12.5, P = 0.01). Three months after the procedure the decrease in the estimated glomerular filtration rate was 0.02% for MHG versus 15% for the control group.

CONCLUSION

Matched hydration was more effective than BS-NAC in CIAKI prevention. One-year follow-up showed that matched hydration was associated also with limited chronic kidney disease progression, major adverse cardiac and cerebrovascular events and hospitalizations.

Prevention of acute kidney injury in Intensive Care Units

Acute kidney injury (AKI) is a growing concern in Intensive Care Units. The advanced age of our patients, with the increase in associated morbidity and the complexity of the treatments provided favor the development of AKI. Since no effective treatment for AKI is available, all efforts are aimed at prevention and early detection of the disorder in order to establish secondary preventive measures to impede AKI progression. In critical patients, the most frequent causes are sepsis and situations that result in renal hypoperfusion; preventive measures are therefore directed at securing hydration and correct hemodynamics through fluid perfusion and the use of inotropic or vasoactive drugs, according to the underlying disease condition. Apart from these circumstances, a number of situations could lead to AKI, related to the administration of nephrotoxic drugs, intra-tubular deposits, the administration of iodinated contrast media, liver failure and major surgery (mainly heart surgery). In these cases, in addition to hydration, there are other specific preventive measures adapted to each condition.

Neutrophil gelatinase-associated lipocalin (NGAL) fails as an early predictor of contrast induced nephropathy in chronic kidney disease (ANTI-CI-AKI study)

The aim of the study was to evaluate the diagnostic accuracy of urinary neutrophil gelatinase- associated lipocalin (uNGAL) in patients with chronic kidney disease (CKD) as an early biomarker for contrast induced acute kidney injury (CI-AKI) and to investigate whether patients with an uNGAL increase might benefit from an additional intravenous volume expansion with regard to CI-AKI-incidence. We performed a prospective randomized controlled trial in 617 CKD-patients undergoing intra-arterial angiography. Urinary NGAL was measured the day before and 4-6hrs after angiography. In the event of a significant rise of uNGAL patients were randomized either into Group A, who received intravenous saline post procedure or Group B, who did not receive post-procedural i.v. fluids. Ten patients (1.62%) exhibited a significant rise of uNGAL after angiography and were randomized of whom one developed a CI-AKI. In the entire cohort the incidence of CI-AKI was 9.4% (58 patients) resulting in a specificity of 98.4% (95% CI: 97.0-99.3%) and a sensitivity of 1.72% (95% CI: 0.044-9.2%) of uNGAL for the diagnosis of CI-AKI. In this study uNGAL failed to predict CI-AKI and was an inadequate triage tool to guide an early intervention strategy to prevent CI-AKI.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01292317.

Design of Clinical Trials in Acute Kidney Injury: Lessons from the Past and Future Directions

Acute kidney injury (AKI) is a common condition with multiple etiologies and variable clinical findings and pathologic manifestations. AKI is associated with serious adverse clinical outcomes, including the development of de novo chronic kidney disease, accelerated progression of pre-existing chronic kidney disease, end-stage kidney disease, and increased mortality. Past research has advanced our understanding of the pathophysiology, epidemiology, and outcomes of AKI significantly, however, little progress has been made in the development of evidence-based interventions for its prevention and treatment. In this review, we discuss key considerations in the design of clinical trials in AKI and highlight significant methodologic limitations that precluded many past studies from determining the effectiveness of preventive and therapeutic strategies for this common and serious condition.

Efficacy and Safety of Coronary Sinus Aspiration During Coronary Angiography to Attenuate the Risk of Contrast-Induced Acute Kidney Injury in Predisposed Patients

Background—

The incidence of contrast-induced acute kidney injury is strongly related to the amount of the given contrast. Our objectives were to evaluate the efficacy and safety of coronary sinus aspiration (CSA) procedure to reduce the volume of the given contrast and attenuate the risk of contrast-induced acute kidney injury.

Methods and Results—

The study included 43 patients with type 2 diabetes mellitus and renal impairment (creatinine 1.5–3 mg/dL) who were candidates for coronary angiography. Eighteen patients were subjected to CSA procedure during coronary angiography (CSA group), and 25 patients served as a control group. Periprocedural standard care was given. In CSA group, the coronary sinus was cannulated via subclavian or femoral venous approaches, and aspiration was done directly from a transseptal sheath (8 patients) or through a balloon occlusion catheter placed through the sheath (10 patients) simultaneously during each coronary injection. Estimated volume of aspirated contrast was calculated based on the percentage reduction in hematocrit value of the aspirate in relation to the patient’s baseline hematocrit. Fraction of aspirated contrast was calculated by dividing estimated volume of aspirated contrast over the volume of injected contrast×100. Both study groups were matched in clinical and laboratory data, as well as volume of injected contrast. In CSA group, mean fraction of aspirated contrast was 39.35±10.47%. One patient in the CSA group, compared with 9 patients in the control group, developed contrast-induced acute kidney injury ( P =0.028).

Conclusions—

CSA during coronary angiography could effectively remove more than one third of the given contrast and may reduce the incidence of contrast-induced acute kidney injury in selected patients.

Acute kidney injury in the perioperative period and in intensive care units (excluding renal replacement therapies)

Acute kidney injury (AKI) is a syndrome that has progressed a great deal over the last 20 years. The decrease in urine output and the increase in classical renal biomarkers, such as blood urea nitrogen and serum creatinine, have largely been used as surrogate markers for decreased glomerular filtration rate (GFR), which defines AKI. However, using such markers of GFR as criteria for diagnosing AKI has several limits including the difficult diagnosis of non-organic AKI, also called "functional renal insufficiency" or "pre-renal insufficiency". This situation is characterized by an oliguria and an increase in creatininemia as a consequence of a reduction in renal blood flow related to systemic haemodynamic abnormalities. In this situation, "renal insufficiency" seems rather inappropriate as kidney function is not impaired. On the contrary, the kidney delivers an appropriate response aiming to recover optimal systemic physiological haemodynamic conditions. Considering the kidney as insufficient is erroneous because this suggests that it does not work correctly, whereas the opposite is occurring, because the kidney is healthy even in a threatening situation. With current definitions of AKI, normalization of volaemia is needed before defining AKI in order to avoid this pitfall.

The High Risk of Contrast-induced Nephropathy in Patients with Suspected Pulmonary Embolism Despite Three Different Prophylaxis: A Randomized Controlled Trial

OBJECTIVE

The objective was to compare the protective effects of N-acetylcysteine (NAC) plus normal saline (NS), sodium bicarbonate (NaHCO₃ ) plus NS, and NS alone in the prevention of contrast-induced nephropathy (CIN) after computed tomography pulmonary angiography (CTPA) in emergency patients.

METHODS

This study was planned as a randomized, controlled clinical research. Patients undergoing contrast-enhanced CTPA on suspicion of pulmonary embolism (PE) in the emergency department and with at least one risk factor for development of CIN were included in one of three different prophylaxis groups. The groups received 3 mL/kg intravenous (IV) NAC+NS or NaHCO₃ +NS solution or NS alone 1 hour before CTPA and 1 mL/kg IV per hour for a minimum of 6 hours after CTPA. CIN was evaluated as the primary outcome and moderate or severe renal insufficiency and in-hospital mortality as secondary outcomes.

RESULTS

A total of 257 patients were enrolled in the study. The total level of CIN development was 23.7% (61/257), the level of moderate and severe renal failure was 12.5% (32/257), and the in-hospital mortality rate was 12.8% (33/257). Rates of CIN development in the drug groups were 23.5% in the NAC group (20/85), 21.2% (18/85) in the NaHCO₃ group, and 26.4% in the NS group (23/87). Rates of development of moderate or severe renal insufficiency were 9.4% in the NAC group (8/85), 10.6% in the NaHCO₃ group (9/85), and 17.2% in the NS group (15/87). In-hospital mortality rates were 12.9% in the NAC group (11/85), 11.8% in the NaHCO₃ group (10/85), and 13.8% in the NS group (12/87). No difference was determined between the drug groups in terms of CIN, moderate or severe renal injury, or hospital mortality.

CONCLUSIONS

Our results indicate that there is a high risk of CIN in patients with suspected PE despite three different types of prophylaxis being administered, and no statistically significant differences were observed among prophylactic NAC, NaHCO₃ , and NS in prevention of CIN following contrast-enhanced CTPA.

From Pre-Existing Renal Failure to Perioperative Renal Protection: The Anesthesiologist's Dilemmas

CONTEXT

Pre-existing renal dysfunction presents specific features that anesthesiologists must deal with. Anesthesia and renal function are connected and can interfere with each other. Induced hypotension anesthesia and the toxic effects of anesthetic drugs can further deteriorate renal function.

EVIDENCE ACQUISITION

Decreased renal function can prolong anesthetic drug effects by decreased elimination of these drugs. Anesthesia can deteriorate renal function and decreased renal function can interfere with drug elimination leading to their prolonged effect. The anesthesiologist must understand all the physiological aspects of the patient, renal protection, and the relationships between anesthetic drugs and renal function. This review article aims to summarize these aspects.

RESULTS

Perioperative renal failure and renal protection is a crucial moment in clinical practice of every anesthesiologist.

CONCLUSIONS

Good knowledges for renal function remain a hallmark of daily practice of the anesthesiologist, considering renal function as an important determinant factor in anesthesia practice.

Radiocontrast-Induced Acute Renal Failure

The intravascular administration of iodinated radiocontrast media can lead to acute renal dysfunction. Even small changes in renal function have been associated with increased morbidity and mortality, making the prevention of radiocontrast nephropathy of paramount importance. This review summarizes the principal risk factors for radiocontrast nephropathy and evidence-based preventive strategies that should be used to limit its occurrence. Risk factors for radiocontrast nephropathy include preexistent kidney disease, diabetes mellitus, dose of radiocontrast used, advanced congestive heart failure, and intravascular volume depletion. Proven preventive measures include volume expansion with intravenous saline or sodium bicarbonate and the use of low-osmolar or iso-osmolar radiocontrast media. Studies evaluating N-acetylcysteine have been conflicting, with meta-analyses suggesting a small beneficial effect. Studies of other pharmacologic agents have not demonstrated clinical benefit.

Renal protection in cardiovascular surgery

Acute kidney injury (AKI) is one of the most relevant complications after major surgery and is a predictor of mortality. In Western countries, patients at risk of developing AKI are mainly those undergoing cardiovascular surgical procedures. In this category of patients, AKI depends on a multifactorial etiology, including low ejection fraction, use of contrast media, hemodynamic instability, cardiopulmonary bypass, and bleeding. Despite a growing body of literature, the treatment of renal failure remains mainly supportive (e.g. hemodynamic stability, fluid management, and avoidance of further damage); therefore, the management of patients at risk of AKI should aim at prevention of renal damage. Thus, the present narrative review analyzes the pathophysiology underlying AKI (specifically in high-risk patients), the preoperative risk factors that predispose to renal damage, early biomarkers related to AKI, and the strategies employed for perioperative renal protection. The most recent scientific evidence has been considered, and whenever conflicting data were encountered possible suggestions are provided.

Evaluation of different sodium bicarbonate regimens for the prevention of contrast medium-induced nephropathy

INTRODUCTION

The rapid decline in renal function caused by radiographic contrast agents usually is transient, but it can result in chronic kidney disease. The pathophysiology of contrast-induced nephropathy (CIN) is poorly understood, but it may include acute hypoxia-induced oxidative stress and free radicals generated within the acid environment of the renal medulla. Thus, the alkalization of urine by sodium bicarbonate has been regarded as resulting in the reduction of CIN. The aim of this study was to determine whether a long-duration sodium bicarbonate regimen is more effective than a short-duration regimen in reducing CIN.

METHODS

One hundred patients were assigned randomly to treatment with sodium bicarbonate solution using either the short regimen (intravenous bolus 3 mL/kg/h of 166 mEq/L sodium bicarbonate for 1 hour immediately before radiocontrast) or the long regimen (initial intravenous bolus of 3 mL/kg/h of 166 mEq/L sodium bicarbonate for 6 hr). Patients with renal dysfunction (estimated glomerular filtration rate [eGFR], 60 mL/min/1.73 m(2) or less) who underwent elective or emergent coronary angiography (CAG) with/without percutaneous coronary intervention (PCI) at Nephrology Department (Theodor Bilharz Research Institute) were enrolled in the study. Data were analyzed by SPSS version 12, using Kruskal Wallis, ANOVA, Chi square test and Spearman rank correlation coefficient.

RESULTS

There was a significant increase in serum creatinine and a decrease in eGFR 48 hr post-intervention in group 1 (short regimen) with no statically difference regarding those parameters group 2 (long regimen). Serum potassium clearly was decreased significantly post procedure in both groups.

CONCLUSIONS

The results of our study indicated that the long regimen of bicarbonate supplementation was a more effective strategy to prevent CIN than the short regimen.

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.

Preventing Contrast-induced Renal Failure: A Guide

Contrast-induced acute kidney injury (CI-AKI) is characterised by a rapid deterioration of renal function within a few days of parenteral administration of contrast media (CM) in the absence of alternative causes. CI-AKI is the most common form of iatrogenic kidney dysfunction with an estimated prevalence of 12 % in patients undergoing percutaneous coronary intervention. Although usually self-resolving, in patients with pre-existing chronic kidney disease (CKD) or concomitant risk factors for renal damage, CI-AKI is associated with increased short-and long-term morbidity and mortality. Therefore, risk stratification based on clinical and peri-procedural characteristics is crucial in selecting patients at risk of CI-AKI who would benefit the most from implementation of preventive measures.