Pathophysiology of contrast-induced nephropathy

Renal Benefits of CO2 as a Contrast Media for EVAR Procedures: New Perspectives on 1 Year Outcomes

BACKGROUND AND OBJECTIVES

Endovascular aneurism repair (EVAR) is a minimally invasive alternative to open surgery for the treatment of abdominal aortic aneurysm. Iodine contrast medium (ICM) is considered the gold standard, at the high price of related nephrotoxicity and allergic reactions. Carbon dioxide (CO2) has been suggested as an alternative non-nephrotoxic contrast media agent. We aimed to evaluate the safety and the renal impact of the administration of CO2, compared with ICM in EVAR procedures.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We retrospectively reviewed data of patients who underwent EVAR at the Vascular Surgery Department of the Sant'Orsola Hospital in Bologna. Estimated glomerular filtration rate (eGFR) was evaluated before intervention, immediately after and at 12 months.

RESULTS

In total, 22 patients received CO2 and low-dose ICM (CO2 Group) and 22 received standard ICM (Control Group), matched for clinical characteristics and renal function at the time of procedure. Pre and post-operative renal function values (eGFR) were compared between the two groups: in the immediate post-operative the group treated with CO2 and low-dose ICM globally showed a slight improvement in renal function (mean eGFR +5.10%±3.2), meanwhile the group treated with standard dose of ICM presented a significant worsening of renal function compared with pre-procedure values (mean eGFR -9.65%±4). Incidence of post-contrast acute kidney injury (PC-AKI) was 9% in the CO2 group vs 27% in the Control group. At 12 months, the renal impairment was significantly greater in the ICM group than in the CO2 group (mean eGFR decrease -19.2%±11.1 and -7.40%±3.5, respectively).

CONCLUSIONS

Administration of either CO2 alone or along with low-dose ICM showed to be safer than full-dose ICM alone, lowering the incidence of PC-AKI in patients undergoing EVAR. Unexpectedly, our study revealed also a significant worsening of renal function in patients treated with standard dose of ICM in 1-year follow-up, introducing the concept that acute renal damage caused by ICM could elicit a chronic injury process that affect long-term renal outcomes.

CLINICAL IMPACT

Evaluating the safety and the renal impact of the administration of CO2, compared to Iodinate Contrast Medium, in EVAR procedures represents a first step in order to further tayloring medical procedures on patients characteristics. Our findings can guide the clinicians and surgeons in the procedures choice, not considering only the immediate effect of ICM on renal function but also the potential long-term effects.

EValuating the Effect of periopeRaTIve empaGliflOzin on cardiac surgery associated acute kidney injury: rationale and design of the VERTIGO study

Background

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication in patients undergoing cardiac surgery with extracorporeal circulation (ECC) that increases postoperative complications and mortality. CSA-AKI develops due to a combination of patient- and surgery-related risk factors that enhance renal ischemia-reperfusion injury. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin reduce renal glucose reabsorption, improving tubulo-glomerular feedback, reducing inflammation and decreasing intraglomerular pressure. Preclinical studies have observed that SGLT2i may provide significant protection against renal ischemia-reperfusion injury due to their effects on inadequate mitochondrial function, reactive oxygen species activity or renal peritubular capillary congestion, all hallmarks of CSA-AKI. The VERTIGO (EValuating the Effect of periopeRaTIve empaGliflOzin) trial is a Phase 3, investigator-initiated, randomized, double-blind, placebo-controlled, multicenter study that aims to explore whether empagliflozin can reduce the incidence of adverse renal outcomes in cardiac surgery patients.

Methods

The VERTIGO study (EudraCT: 2021-004938-11) will enroll 608 patients that require elective cardiac surgery with ECC. Patients will be randomly assigned in a 1:1 ratio to receive either empagliflozin 10 mg orally daily or placebo. Study treatment will start 5 days before surgery and will continue during the first 7 days postoperatively. All participants will receive standard care according to local practice guidelines. The primary endpoint of the study will be the proportion of patients that develop major adverse kidney events during the first 90 days after surgery, defined as ≥25% renal function decline, renal replacement therapy initiation or death. Secondary, tertiary and safety endpoints will include rates of AKI during index hospitalization, postoperative complications and observed adverse events.

Conclusions

The VERTIGO trial will describe the efficacy and safety of empagliflozin in preventing CSA-AKI. Patient recruitment is expected to start in May 2024.

Is eGFR ≥60 mL/min/1.73 m2 in Patients Undergoing Coronary Angiography Really Safe for Contrast Nephropathy?

The aim of the present study was to define the risk factors associated with contrast-induced acute kidney injury (CI-AKI) in patients who underwent coronary artery angiography (CAG). In this retrospective cohort study, patients who underwent CAG between March 2014 and January 2022 were evaluated. A total of 2923 eligible patients were included in the study. Univariate and multivariate logistic regression analysis was used to identify the predictive factors. CI-AKI developed in 77 (2.6%) of 2923 patients. In multivariate analysis, diabetes mellitus (DM), chronic kidney disease (CKD), and estimated glomerular filtration rate (eGFR) were found to be independent factors associated with CI-AKI. In the subgroup analysis of patients with eGFR ≥60 mL/min/1.73 m2, eGFR remained a predictor of CI-AKI (Odds ratio (OR): .89, 95% CI: .84-.93; that is, a lower eGFR remains a risk factor for CI-AKI). In the receiving operating characteristic (ROC) analysis of patients with eGFR ≥60 mL/min/1.73 m2, the area under the curve of the eGFR was .826. Using the ROC curve based on Youden's index, the eGFR cut-off was found to be 70 mL/min/1.73 m2 for patients with eGFR ≥60 mL/min/1.73 m2. eGFR is also an important risk factor in patients with eGFR 60-70 mL/min/1.73 m2.

Development and Validation of Nomogram Based on the Systemic-Immune Inflammation Response Index for Predicting Contrast-Induced Nephropathy in ST-Elevation Myocardial Infarction Patients

Contrast-induced nephropathy (CIN) is a prominent complication of ST-elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI). The systemic immune inflammation response index (SIIRI) is a novel inflammatory marker developed by multiplying the monocyte count by the systemic immune inflammation index (SII) and is associated with coronary artery disease severity. We investigated the predictive ability of SIIRI for detecting CIN in STEMI patients (n = 2289) following pPCI and developed a nomogram based on SIIRI for risk stratifying. CIN was diagnosed based on an elevation in baseline creatinine levels >.5 mg/dL or 25% within 72 h after pPCI; 219 CIN (+) and 2070 CIN (-) patients were included. CIN (+) patients had higher SIIRI than CIN (-) patients and SIIRI was an independent predictor of CIN. A nomogram based on SIIRI had good calibration and discrimination abilities for predicting CIN development. SIIRI was superior to SII in discriminating CIN (+) patients. Adding SIIRI to the baseline model, which consists of age, hypertension, hemoglobin, estimated glomerular filtration rate, albumin, ejection fraction, lesion length, and pain-to-balloon time, had a higher discriminative ability and benefit in detecting CIN (+) patients than baseline model as assessed by decision curve analysis.

Emergency CT Scans: Unveiling the Risks of Contrast-Associated Acute Kidney Injury

OBJECTIVES

This study aimed to identify the incidence and risk factors for contrast-associated acute kidney injury nephropathy (CA-AKI) in patients undergoing contrast-enhanced computed tomography (CCT) in the emergency department.

MATERIALS AND METHODS

In this retrospective single-center study, patients aged 18 and older who visited the emergency department and underwent CCT between January and February 2022 were included. The Mehran score, calculated from patient data, was used to assess risk. CA-AKI development was determined by measuring serum creatinine (SCr) levels 48-72 h post-contrast administration.

RESULTS

The study included 532 patients, with a mean age of 57 ± 19 years; 53.2% were male. CA-AKI developed in 16% of cases, 5.82% required hemodialysis, and 7.9% died. The Mehran score was the only significant predictor of CA-AKI development. Patients with a Mehran score of 16 or higher had a 161-fold increased risk of developing CA-AKI compared to those with a score of 5 or lower. The model achieved a 91.3% correct classification rate. Logistic regression analysis showed that CA-AKI significantly increased mortality risk by 15.7 times.

CONCLUSION

The Mehran score, originally developed for predicting CA-AKI risk post-coronary intervention, is also effective for predicting CA-AKI risk after CCT. While CA-AKI is a significant factor affecting mortality, it is not the sole cause of death (Nagelkerke R2 value 0.310).

Predictive Value of the Naples Prognostic Score for Acute Kidney Injury in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

The purpose of this investigation was to investigate whether there was an association between the Naples prognostic score and the development of acute kidney injury (AKI) in ST-elevation myocardial infarction (STEMI) patients following primary percutaneous coronary intervention (pPCI). The study comprised 2901 consecutive STEMI patients who had pPCI. For each patient, the Naples prognostic score was determined. To evaluate the predictive performance of the Naples score (which included either continuous and categorical variables), we developed a Nested model and a nested model combined with the Naples score. The Naples prognostic score was the most significant predictor of AKI occurrence after admission creatinine, age, and contrast volume. The continuous Naples prognostic score model provided the best prediction performance and discriminative ability. The C-index of the Nested and full models with continuous Naples prognostic score were significantly higher than that of the Nested model. The decision curve analysis found that the overall model had a higher full range of probability of clinical net benefit than the baseline model, with a 10% AKI likelihood. The present study found that the Naples prognostic score may be useful to predict the risk of AKI in STEMI patients undergoing pPCI.

Navigating nephrotoxic waters: A comprehensive overview of contrast-induced acute kidney injury prevention

Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality. Its pathophysiology, although not well-established, revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney. Critically ill patients, as well as those with pre-existing renal disease and cardiovascular comorbidities, are more susceptible to CI-AKI. Despite the continuous research in the field of CI-AKI prevention, clinical practice is based mostly on periprocedural hydration. In this review, all the investigated methods of prevention are presented, with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

Vitamin E for the Prevention of Contrast-Induced Nephropathy: A Systematic Review and Meta-Analysis

Contrast-induced nephropathy (CIN) is a serious condition that may develop in patients undergoing diagnostic radiologic procedures. Several treatments have been assessed to prevent CIN development. This study aims to assess the efficacy and safety of vitamin E in the prevention of CIN compared to intravenous (IV) saline hydration. The literature search included MEDLINE/PubMed, Cochrane Central Register of Controlled Trials, the Web of Science, ProQuest, and Scopus for articles published until May 11, 2024, without language or time limits. The outcomes included the incidence of CIN, new-onset dialysis, and death (primary), as well as the change in serum creatinine and glomerular filtration rate (GFR) (secondary). Numerical and dichotomous outcomes were presented as standardized mean difference (SMD) and risk ratio (RR), respectively, with 95% confidence intervals (CI). Six clinical trials were included. Vitamin E was administered orally in varying doses, but one study used IV infusion. Vitamin E decreased the risk of developing CIN by 59% (n=5; pooled RR: 0.41; 95% CI: 0.25, 0.65; P<0.001) compared to IV hydration. None of the patients required renal replacement therapy. One patient on vitamin E died due to the occurrence of acute coronary syndrome. Vitamin E is a promising effective prophylaxis against CIN. However, the number of included studies and their sample sizes are small. The studies showed several limitations. There is a need for further high-quality clinical trials to ascertain the effectiveness of vitamin E compared to IV hydration and to compare vitamin E to other therapies, such as N-acetyl cysteine.

Acute Kidney Injury in Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention: The Role of Vascular Access Site

Background: in patients undergoing percutaneous coronary interventions (PCI), radial access should be favoured over femoral access as it reduces the risk of vascular complications and bleeding. Furthermore, a preventive role of radial access in the occurrence of acute kidney injury (AKI), mainly mediated by the reduction of bleeding and cholesterol crystal embolization into renal circulation, has been investigated in several studies, yielding conflicting results. Methods: we designed a retrospective study to appraise the effect of the use of a vascular access site on the occurrence of AKI in a cohort of 633 patients with acute myocardial infarction treated by PCI at our centre from 2018 to 2020. Results: after propensity score adjustment, radial access was associated with a reduced, albeit statistically not significant, incidence of AKI (14.7% vs. 21.0%; p = 0.06) and major bleeding (12.5% vs. 18.7%; p = 0.04) as compared to femoral access. At multivariate analysis, femoral access was an independent predictor of AKI, together with in-hospital occurrence of BARC 3-5 bleeding, Killip class >1 at presentation, female gender, baseline eGFR <60 mL/min, and baseline haemoglobin <12 g/dL. Conclusions: although limited by the observational design, our study supports the hypothesis that radial access may exert a protective role on the occurrence of AKI in patients with acute myocardial infarction undergoing PCI.

Transplant Outcomes After Exposure of Deceased Kidney Donors to Contrast Medium

BACKGROUND

The administration of contrast medium is associated with acute kidney injury; however, the effect of exposure of a deceased organ donor to contrast medium on kidney transplant outcomes has been poorly studied.

METHODS

A retrospective analysis of all deceased kidney donors between 2011 and 2021 and their corresponding recipients in the Netherlands was conducted. Multivariable analyses were performed to assess the associations between contrast medium exposure and delayed graft function (DGF)/graft survival. Linear mixed models were used to assess the differences in mean estimated glomerular filtration rate values in recipients 1 to 6 y after transplantation.

RESULTS

In total, 2177 donors and 3638 corresponding kidney graft recipients were included. Twenty-four percent of the donors (n = 520) were exposed to contrast medium, corresponding to 23% of recipients (n = 832). DGF was observed in 36% (n = 1321) and primary nonfunction in 3% (n = 122) of recipients. DGF rates for donation after brain death (DBD) and donation after circulatory death (DCD) donors showed no significant effect of contrast medium exposure ( P  = 0.15 and P  = 0.60 for DBD and DCD donors, respectively). In multivariable analyses, contrast medium administration was not significantly associated with a higher DGF risk (odds ratio 1.06; 95% confidence interval, 0.86-1.36; P  = 0.63) nor was a significant predictor for death-censored graft failure (hazard ratio 1.01; 95% confidence interval, 0.77-1.33; P  = 0.93). Linear mixed models showed no difference in mean estimated glomerular filtration rate values in recipients 1 to 6 y posttransplantation ( P  = 0.78).

CONCLUSIONS

This study indicates that contrast medium administration in DBD and DCD donors has no negative effect on early and long-term kidney graft function.

A new marker for the prediction of contrast induced-acute kidney injury following primary percutaneous coronary intervention: logarithm of haemoglobin-albumin product

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is a disorder that adversely affects the prognosis of STEMI. The study aimed to assess the predictive value of a new marker, logarithm of haemoglobin and albumin product (LHAP) on the risk of CI-AKI development after primary percutaneous coronary intervention (p-pcı).

METHOD

We retrospectively enrolled 3057 patients with ST-elevation acute myocardial infarction who were treated with p-PCI. The primary outcome was CI-AKI, defined as >25% or >0.5 mg/dl increase of baseline creatinine values during post-procedural 48 h.

RESULTS

First, a baseline model was produced to determine the predictors of CI-AKI, then haemoglobin, albumin and LHAP were included in the base model and the performances of all models were compared. The predictive accuracy (Likelihood ratio χ2 and R2) and discrimination (ROC-AUC) of the model including LHAP were significantly higher than that of models including both albumin and Hgb. LHAP best cut-off value for the development of CI-AKI was 9.26 (sensitivity 68% and specificity 66%).

CONCLUSION

LHAP values were the most important predictor of CI-AKI, followed by creatinine value and Killip class. LHAP values are significantly associated with CI-AKI after p-PCI.

The Diagnosis and Non-pharmacological Management of Acute Kidney Injury in Patients with Cirrhosis

Acute kidney injury in patients with cirrhosis is quite common, and is seen in up to 50% of patients hospitalized for decompensated cirrhosis. Causes of acute kidney injury include prerenal, renal, or postrenal etiologies. The diagnosis and early institution of nonpharmacologic and pharmacologic management are key to the recovery of renal function. The objective of this review is to provide a practical approach to the use of diagnostic biomarkers and highlight the nonpharmacologic management and prevention of acute kidney injury.

Cardioprotective and Antianginal Efficacy of Nicorandil: A Comprehensive Review

ABSTRACT

Angina pectoris remains a significant burden despite advances in medical therapy and coronary revascularization. Many patients (up to 30%) with angina have normal coronary arteries, with coronary microvascular disease and/or coronary artery vasospasm being major drivers of the myocardial demand-supply mismatch. Even among patients revascularized for symptomatic epicardial coronary stenosis, recurrent angina remains highly prevalent. Medical therapy for angina currently centers around 2 disparate goals, viz secondary prevention of hard clinical outcomes and symptom control. Vasodilators, such as nitrates, have been first-line antianginal agents for decades, along with beta-blockers and calcium channel blockers. However, efficacy in symptoms control is heterogenous, depending on underlying mechanism(s) of angina in an individual patient, often necessitating multiple agents. Nicorandil (NCO) is an antianginal agent first discovered in the late 1970s with a uniquely dual mechanism of action. Like a typical nitrate, it mediates medium-large vessel vasodilation through nitric oxide. In addition, NCO has adenosine triphosphate (ATP)-dependent potassium channel agonist activity (K ATP ), mediating microvascular dilatation. Hence, it has proven effective in both coronary artery vasospasm and coronary microvascular disease, typically challenging patient populations. Moreover, emerging evidence suggests that cardiomyocyte protection against ischemia through ischemic preconditioning may be mediated through K ATP agonism. Finally, there is now fairly firm evidence in favor of NCO in terms of hard event reduction among patients with stable coronary artery disease, following myocardial infarction, and perhaps even among patients with congestive heart failure. This review aims to summarize the mechanism of action of NCO, its efficacy as an antianginal, and current evidence behind its impact on hard outcomes. Finally, we review other cardiac and emerging noncardiac indications for NCO use.

THE RISK OF ACUTE KIDNEY INJURY AFTER ELECTIVE VERSUS EMERGENCY CORONARY INTERVENTION

OBJECTIVE

The aim: A serious and common complication after percutaneous coronary intervention is acute kidney injury, which is associated with an increased risk of renal, cardiovascular and even mortality; therefore, early prognosis and identification of patients at higher risk are essential for early initiation of preventive measures. The aim of this study is to predict and compare the risk for the development of CI-AKI in patient with ACS who undergo emergency PCI or elective (i.e. after medical stabilization) PCI by utilizing the sensitivity of serum NGAL as an early and reliable predictor for CI-AK.

PATIENTS AND METHODS

Materials and methods: The study include 37 patients with acute coronary syndrome, baseline serum creatinine, complete blood count and pre and two hours post operative serum neutrophil gelatinase-associated lipocalin were measured and all patients underwent percutaneous coronary intervention according to the standard protocol used in Al Najaf Cardiac Center.

RESULTS

Results: This is a Two-Arm study that included a total of 37 patients with acute coronary syndrome aged 38-83 years. Eighteen of them had emergency percutaneous coronary intervention while the remaining 19 had elective percutaneous coronary intervention (after medical stabilization). Elevation of serum neutrophil gelatinase-associated lipocalin level two hours after percutaneous coronary intervention was found to be significantly higher among emergency percutaneous coronary intervention group compared to elective group.

CONCLUSION

Conclusions: Acute coronary syndrome patients are undergoing emergency percutaneous coronary intervention are at an increasing risk for the development of contrast induced acute kidney injury than those undergoing elective percutaneous coronary intervention.

A multiple-metabolites model to predict preliminary renal injury induced by iodixanol based on UHPLC/Q-Orbitrap-MS and 1H-NMR

BACKGROUND & AIMS

There are some problems, such as unclear pathological mechanism, delayed diagnosis, and inaccurate therapeutic target of Contrast-induced acute kidney injury (CI-AKI). It is significantly important to find biomarkers and therapeutic targets that can indicate renal injury in the early stage of CI-AKI. This study aims to establish a multiple-metabolites model to predict preliminary renal injury induced by iodixanol and explore its pathogenesis.

METHODS

Both UHPLC/Q-Orbitrap-MS and ¹H-NMR methods were applied for urine metabolomics studies on two independent cohorts who suffered from a preliminary renal injury caused by iodixanol, and the multivariate statistical analysis and random forest (RF) algorithm were used to process the related date.

RESULTS

In the discovery cohort (n = 169), 6 metabolic markers (leucine, indole, 5-hydroxy-L-tryptophan, N-acetylvaline, hydroxyhexanoycarnine, and kynurenic acid) were obtained by the cross-validation between the RF and liquid chromatography-mass spectrometry (LC-MS). Secondly, the 6 differential metabolites were confirmed by comparison of standard substance and structural identification of ¹H-NMR. Subsequently, the multiple-metabolites model composed of the 6 biomarkers was validated in a validation cohort (n = 165).

CONCLUSIONS

The concentrations of leucine, indole, N-acetylvaline, 5-hydroxy-L-tryptophan, hydroxyhexanoycarnitine and kynurenic acid in urine were proven to be positively correlated with the degree of renal injury induced by iodixanol. The multiple-metabolites model based on these 6 biomarkers has a good predictive ability to predict early renal injury caused by iodixanol, provides treatment direction for injury intervention and a reference for reducing the incidence of clinical CI-AKI further.

Prevention of Contrast-Induced Nephropathy After Cardiovascular Catheterization and Intervention With High-Dose Strong Statin Therapy in Japan - The PREVENT CINC-J Study

BACKGROUND

Previous studies have reported that high-dose strong statin therapy reduces the incidence of contrast-induced nephropathy (CIN) in statin naïve patients; however, the efficacy of high-dose strong statins for preventing CIN in real-world clinical practice remains unclear. The aim of this study was to evaluate the efficacy of strong statin therapy in addition to fluid hydration for preventing CIN after cardiovascular catheterization.

METHODS AND RESULTS

This prospective, multicenter, randomized controlled trial included 420 patients with chronic kidney disease who underwent cardiovascular catheterization. They were assigned to receive high-dose pitavastatin (4 mg/day × 4 days) on the day before and of the procedure and 2 days after the procedure (Statin group, n=213) or no pitavastatin (Control group, n=207). Isotonic saline hydration combined with a single bolus of sodium bicarbonate (20 mEq) was scheduled for administration to all patients. In the control group, statin therapy was continued at the same dose as that before randomization. CIN was defined as a ≥0.5 mg/dL increase in serum creatinine or ≥25% above baseline at 48 h after contrast exposure. Before randomization, 83% of study participants were receiving statin treatment. The statin group had a higher incidence of CIN than the control group (3.0% vs. 0%, P=0.01). The 12-month rate of major adverse cardiovascular events was similar between the 2 groups.

CONCLUSIONS

High-dose pitavastatin increases the incidence of CIN in this study population.

Serum Uric Acid to Albumin Ratio Can Predict Contrast-Induced Nephropathy in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Contrast-induced nephropathy (CIN) is one of the common complication of ST-elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (pPCI). Serum uric acid to albumin ratio (UAR) is a novel marker, which is associated with acute kidney injury in intensive care unit patients. We investigated the predictive value of UAR for the development of CIN in STEMI patients (n = 1379) after pPCI. The diagnosis of CIN was made based on an increase of basal creatinine levels >.5 mg/dL or 25% within 72 h after pPCI; 128 patients were in the CIN (+) group and 1251 patients were in the CIN (-) group. CIN (+) patients had higher serum uric acid (SUA), UAR, and lower albumin levels than CIN (-) patients. Age, diabetes, hypertension, hemoglobin, glucose at admission, basal creatinine, peak troponin I, total bilirubin, contrast volume/glomerular filtration rate, and UAR were independent predictors of CIN. A cutoff value of 1.62 for UAR detected CIN development with a sensitivity of 54% and specificity of 87.4%, and the discrimination ability of UAR was better than that of SUA or albumin. In conclusion, UAR was an independent predictor of the development of CIN.

Resveratrol and lycopene ameliorate contrast-induced nephropathy in a rabbit model

Oxidative stress appears to possess a central role in CIN pathophysiology. Resveratrol (Res) and lycopene (Lyc) are strong natural antioxidants evaluated in a limited number of CIN animal studies in vivo. The aim of the study was to evaluate the potential renoprotective effects of Res/Lyc in a CIN rabbit model. Twenty-four adult male New Zealand white rabbits were equally assigned into four groups: control (saline), CIN (intravenous iopromide; 7.5 g iodine/kg), Res + CIN (per os Res; 5 mg/kg), and Lyc + CIN (per os Lyc; 4 mg/kg). Serum Cr (sCr); symmetric/asymmetric dimethylarginine (SDMA/ADMA); oxidative stress biomarkers: malondialdehyde; total antioxidant capacity; catalase; glutathione) were evaluated in blood samples at three time points: right after (0 h); 24 h; 48 h after iopromide/saline administration. CD20⁺/CD3⁺ lymphocytes were determined (48 h). All animals were sacrificed at 48 h and both kidneys collected. Oxidative stress biomarkers were measured in renal tissue. sCr and SDMA/ADMA levels increased significantly in CIN compared to all groups. Oxidative stress secondary to CIN in blood/kidneys was suppressed by Res/Lyc. B and T lymphocytes decreased significantly in CIN compared to all groups. The present study provides emerging evidence that Res/Lyc ameliorate CIN by modulating oxidant/antioxidant balance in blood/renal tissue and by inhibiting vasoconstriction/blood cytotoxicity.

A Novel Prediction Model of Acute Kidney Injury Based on Combined Blood Variables in STEMI

BACKGROUND

Development of acute kidney injury (AKI) is associated with poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

This study sought to investigate whether a combination of pre-procedural blood tests could predict the incidence of AKI in patients with STEMI.

METHODS

A total of 908 consecutive Japanese patients with STEMI who underwent primary percutaneous coronary intervention within 48 hours of symptom onset were recruited and divided into derivation (n = 617) and validation (n = 291) cohorts. A risk score model was created based on a combination of parameters assessed on routine blood tests on admission.

RESULTS

In the derivation cohort, multivariate analysis showed that the following 4 variables were significantly associated with AKI: blood sugar ≥200 mg/dL (odds ratio [OR]: 2.07), high-sensitivity troponin I >1.6 ng/mL (upper limit of normal ×50) (OR: 2.43), albumin ≤3.5 mg/dL (OR: 2.85), and estimated glomerular filtration rate <45 mL/min/1.73 m² (OR: 2.64). Zero to 4 points were given according to the number of those factors. Incremental risk scores were significantly associated with a higher incidence of AKI in both cohorts (P < 0.001). Receiver-operating characteristic curve analysis of risk models showed adequate discrimination between patients with and without AKI (derivation cohort, area under the curve: 0.754; 95% confidence interval: 0.733-0.846; validation cohort, area under the curve: 0.754; 95% confidence interval: 0.644-0.839).

CONCLUSIONS

Our novel laboratory-based model might be useful for early prediction of the post-procedural risk of AKI in patients with STEMI.

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

CASE DESCRIPTION

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

CLINICAL FINDINGS

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

TREATMENT AND OUTCOME

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

CLINICAL RELEVANCE

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

Albuminuria Pre-Emptively Identifies Cardiac Patients at Risk of Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is a complication associated with the administration of contrast media (CM). The CIN diagnosis is based on creatinine, a biomarker late and insensitive. The objective proposed was to evaluate the ability of novel biomarkers to detect patients susceptible to suffering CIN before CM administration. The study was carried out with patients undergoing cardiac catheterization involving CM. Patients were divided into two groups: (1) CIN, patients who developed this pathology; (2) control, patients who did not suffer CIN. Prior to the administration of CM, urine samples were collected to measure proteinuria, N-acetyl-β-d-glucosaminidase, neutrophil gelatinase-associated lipocalin and kidney injury molecule-1, albumin, transferrin, t-gelsolin and GM2 ganglioside activator protein (GM2AP). The risk factors advanced age, low body mass index and low estimated glomerular filtration rate; and the urinary biomarkers albumin, transferrin and GM2AP showed significant predictive capacity. Of all of them, albuminuria demonstrated the highest diagnostic power. When a cutoff point was established for albuminuria at values still considered subclinical (10–30 µg/mg Cr_u), it was found that there was a high incidence of CIN (40–75%). Therefore, albuminuria could be applied as a new diagnostic tool to prevent and predict CIN with P4 medicine criteria, independently of risk factors and comorbidities.

Prognostic nutritional index and the risk of acute kidney injury in patients with acute coronary syndrome

OBJECTIVE

Recent studies have linked malnutrition with undesirable outcomes in cardiovascular diseases. However, the underlying mechanism is unknown. Contrast-induced acute kidney injury (CI-AKI) increased cardiovascular mortality after percutaneous coronary intervention (PCI). This study hypothesizes that prognostic nutritional index (PNI) plays a role in the development of CI-AKI in patients with acute coronary syndrome undergoing emergency PCI.

METHODS

This study enrolled 551 patients. PNI was determined as 10× serum albumin (g/dL)+0.005×total lymphocyte count (mm3). CI-AKI was characterized as the increase in serum creatinine ≥0.3 mg/dL level within 48 h after PCI. Patients were classified as either CI-AKI (+) or CI-AKI (-).

RESULTS

CI-AKI has occurred in 72 of 551 patients (13.1%). PNI was significantly lower in the CI-AKI (+) group than in the CI-AKI (-) group (44.4±6.6 versus 47.2±5.8, p<0.001, respectively). Multivariate logistic regression analysis showed that PNI [odds ratio, OR: 1.631, 95% confidence interval (CI): 1.168-2.308, p=0.02] and estimated glomerular filtration rate (OR: 3.26, 95%CI 1.733-6.143, p<0.001) were independent risk factors for CI-AKI.

CONCLUSIONS

PNI is an independent risk factor for CI-AKI. The development of CI-AKI may be the mechanism responsible for the relationship between poor nutritional status and adverse cardiac events.

The Definition of "Acute Kidney Injury" Following Percutaneous Coronary Intervention and Cardiovascular Outcomes

Acute kidney injury (AKI) is a complication of percutaneous coronary intervention (PCI), known to increase rates of adverse medical events. We aimed to identify the optimal definition of AKI in predicting adverse cardiovascular outcomes and mortality post PCI. From a large registry of patients undergoing PCI between 2006-2018 (n = 25,690) at our medical center, consecutive patients were assessed for the presence of AKI according to four different definitions: a relative elevation of ≥25% or ≥50%; or an absolute elevation of ≥0.3 mg/dL or ≥0.5 mg/dL in serum creatinine at 48 hours post PCI. We assessed the calculated rates of AKI according to the different definitions. The discriminant capacity for 30-day and 1-year mortality and MACE (MACE: all-cause death, myocardial infarction, target-vessel revascularization and coronary artery bypass graft surgery) of each definition was calculated using ROC curves and AUCs. Data of 15,153 patients was available for the final analysis. Rates of AKI were 12.1%, 3.2%, 8.1% and 3.9% according to the four definitions, respectively. The discriminant capacity of adverse outcomes was highest among those defined as AKI according to the third definition - an absolute elevation of ≥0.3 mg/dL in serum creatinine with an AUC of 0.82 (95% CI 0.80-0.84) for 30-day mortality (P value = 0.036) and an AUC of 0.78 (CI 0.76-0.79) for 30-day MACE. In conclusion, an absolute elevation of ≥ 0.3 mg/dL in serum creatinine 48 hours post PCI predicts overall mortality and MACE most accurately.

Significance of serum FGF-23 for risk assessment of contrast-associated acute kidney injury and clinical outcomes in patients undergoing coronary angiography

Background

Fibroblast growth factor (FGF)-23 levels rise as kidney function declines. Whether elevated FGF-23 levels are associated with an increased risk for contrast-associated acute kidney injury (CA-AKI) and major adverse cardiovascular events (MACE) in patients undergoing coronary angiography remain uncertain.

Methods

In total, 492 patients receiving coronary angiography were enrolled. Their serum FGF-23 levels were measured before administration of contrast media. The occurrence of CA-AKI was defined as a rise in serum creatinine of 0.5 mg/dL or a 25% increase from the baseline value within 48 h after the procedure. All patients were followed up for at least 1 year or until the occurrence of MACE including death, nonfatal myocardial infarction (MI), and ischemic stroke.

Results

Overall, CA-AKI occurred in 41 (8.3%) patients. During a median follow-up of 2.6 years, there were 24 deaths, 3 nonfatal MIs, and 7 ischemic strokes. Compared with those in the lowest FGF-23 tertile, individuals in the highest FGF-23 tertile had a significantly higher incidence of CA-AKI (P < 0.001) and lower incidence of MACE-free survival (P = 0.001). In multivariate regression analysis, higher FGF-23 level was found to be independently associated with a graded risk for CA-AKI (OR per doubling, 1.90; 95% CI 1.48–2.44) and MACE (HR per doubling, 1.25; 95% CI 1.02–1.52).

Conclusions

Elevated FGF-23 levels were associated with an increased risk for CA-AKI and future MACE among patients undergoing coronary angiography. FGF-23 may play a role in early diagnosis of CA-AKI and predicting clinical outcomes after coronary angiography.

Involvement of necroptosis in contrast-induced nephropathy in a rat CKD model

BACKGROUND

The risk of contrast-induced nephropathy (CIN) is high in patients with chronic kidney disease (CKD). However, the mechanism of CIN in CKD is not fully understood. Here, we prepared a clinically relevant model of CIN and examined the role of necroptosis, which potentially cross-talks with autophagy, in CIN.

METHODS

In Sprague-Dawley rats, CKD was induced by subtotal nephrectomy (SNx, 5/6 nephrectomy) 4 weeks before induction of CIN. CIN was induced by administration of a contrast medium (CM), iohexol, following administration of indomethacin and N-omega-Nitro-L-arginine methyl ester. Renal function and tissue injuries were assessed 48 h after CM injection.

RESULTS

Serum creatinine (s-Cre) and BUN were increased from 0.28 ± 0.01 to 0.52 ± 0.02 mg/dl and from 15.1 ± 0.7 to 29.2 ± 1.2 mg/dl, respectively, after SNx alone. CM further increased s-Cre and BUN to 0.69 ± 0.03 and 37.2 ± 2.1, respectively. In the renal tissue after CM injection, protein levels of receptor-interacting serine/threonine-protein kinase (RIP) 1, RIP3, cleaved caspase 3, and caspase 8 were increased by 64 ~ 212%, while there was reduction in LC3-II and accumulation of p62. Necrostatin-1, an RIP1 inhibitor, administered before and 24 h after CM injection significantly suppressed elevation of s-Cre, BUN and urinary albumin levels, kidney injury molecule-1 expression and infiltration of CD68-positive macrophages in renal tissues after CM injection.

CONCLUSION

The results suggest that necroptosis of proximal tubular cells contributes to CIN in CKD and that suppression of protective autophagy by pro-necroptotic signaling may also be involved.

Comparison of Different Hydration Strategies in Patients with Very Low-Risk Profiles of Contrast-Induced Nephropathy

Background

Hydration remains the mainstay of contrast-induced nephropathy (CIN) prevention, and new biomarkers of cystatin C (Cys C) and neutrophil gelatinase-associated lipocalin (NGAL) have been suggested. This study aimed to explore whether hydration is essential in patients with very low-risk profiles of CIN who are undergoing coronary angiography.

Material/Methods

A total of 150 patients were enrolled and randomly distributed to 3 groups: the Preventive Group (n=50, saline hydration was given 6 h before the procedure until 12 h after the procedure), the Remedial Group (n=50, saline hydration was given after procedure for 12 h), and the No Hydration (NH) group (n=50, saline was only given during the procedure). Serum creatinine (Cr), Cys C, and urinary NGAL were tested 3 times at different times.

Results

Six patients were excluded because of Mehran risk score >2. There was no CIN among 144 individuals. At 24 h and at 72 h after the procedure, we found no significant differences in the levels of Cr and Cys C (0.72±0.11 mg/L for the Preventive Group, 0.67±0.14 mg/L for the Remedial Group, and 0.70±0.1 6 mg/L for the NH Group) among the 3 groups. Urinary NGAL also did not differ significantly among the 3 groups at 6 h or at 48 h (6.31±6.60 ng/ml for the Preventive Group, 5.00±5.86 ng/ml for the Remedial Group, and 6.97±6.37 ng/ml for the NH Group) after the procedure. Subgroup analysis in patients who underwent percutaneous coronary intervention (PCI) showed that there was no significant difference in serum Cr, Cys C, or urinary NGAL at different time points among the 3 groups.

Conclusions

Saline hydration during the perioperative period might be unnecessary in patients with very low-risk profiles of CIN.

Impact of radial access on contrast-induced acute kidney injury in patients with coronary artery bypass grafts

PURPOSE

We investigated the impact of radial access on contrast-induced acute kidney injury (CI-AKI) in patients with coronary artery bypass graft (CABG) undergoing cardiac catheterization.

METHODS

This retrospective monocenter study included 527 CABG patients undergoing cardiac catheterization via radial (58.1%, N = 306) or femoral access (41.9%, N = 221). Primary outcome measure was CI-AKI defined in accordance with the KDIGO criteria. Independent predictors for CI-AKI were assessed. 1-year mortality was assessed depending on the occurrence of CI-AKI.

RESULTS

In total, 99 CABG patients (18.8%) developed CI-AKI within 48 h after cardiac catheterization. Compared to patients without CI-AKI, amount of contrast media used (203.1 ± 102.6 ml vs. 204.2 ± 98.2 ml; P = 0.892) as well as procedural times (87.9 ± 44.8 vs. 79.8 ± 37.0; P = 0.190) were similarly. Regarding vascular access, there was no significant difference in the incidence of CI-AKI between radial and femoral approach (19.0% vs. 18.6%; p = 0.907). However, poor left ventricular ejection fraction (odds ratio [OR] = 1.72, P = 0.026), chronic kidney disease (OR = 2.30, P = 0.001) and acute coronary syndrome (OR = 1.64, P = 0.043) were independent predictors for CI-AKI. The occurrence of CI-AKI was significantly associated with an increased 1-year mortality (hazard ratio [HR] = 2.52, P = 0.003).

CONCLUSIONS

With 18.8%, CI-AKI is a frequent complication in CABG patients undergoing cardiac catheterization. Radial access did not decrease the risk when compared to the femoral approach.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman’s method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4 ${}^{\prime }$ ,6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

Zinc Preconditioning Provides Cytoprotection following Iodinated Contrast Media Exposure in In Vitro Models

Methods

Normal human proximal renal kidney cells (HK-2) were preconditioned with either increasing doses of ZnCl₂ or control. Following this preconditioning, cells were exposed to increasing concentrations of Iohexol 300 mg I₂/ml for four hours. Key outcome measures included cell survival (MTT colorimetric assay) and ROS generation (H₂DCFDA fluorescence assay).

Results

Contrast media induced a dose-dependent reduction in survival of HK-2 cells. Compared to control, contrast media at 150, 225, and 300 mg I₂/ml resulted in 69.5% (SD 8.8%), 37.3% (SD 4.8%), and 4.8% (SD 6.6%) cell survival, respectively (p < 0.001). Preconditioning with 37.5 μM and 50 μM ZnCl₂ increased cell survival by 173% (SD 27.8%) (p < 0.001) and 219% (SD 32.2%) (p < 0.001), respectively, compared to control preconditioning. Zinc preconditioning resulted in a reduction of ROS generation. Zinc pre-conditioning with 37.5 μM μM ZnCl₂ reduced ROS generation by 46% (p < 0.001) compared to control pre-conditioning.

Conclusions

Zinc preconditioning reduces oxidative stress following exposure to radiographic contrast media which in turn results in increased survival of renal cells. Translation of this in vitro finding in animal models will lay the foundation for future use of zinc preconditioning against contrast induced nephropathy.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman's method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4',6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

Efficacy of short-term moderate or high-dose statin therapy for the prevention of contrast-induced nephropathy in high-risk patients with chronic kidney disease: systematic review and meta-analysis

Although previous studies have indicated that statin therapy can effectively prevent the development of CIN, this observation remains controversial, especially in high-risk patients. A meta-analysis was performed to evaluate the efficacy of statin pretreatment for preventing the development of CIN in patients with chronic kidney disease (CKD) and to determine its effectiveness in various subgroups. We searched the online databases PubMed, EMBASE, and the Cochrane Library. RCTs that involved the comparison of the short-term moderate or high-dose statin pretreatment with placebo for CIN prevention in CKD patients undergoing angiography were included. The primary outcome was CIN prevalence. Seven RCTs comprising 4256 participants were investigated in this analysis. The risk of developing CIN in patients pretreated with statins was significantly lower than that in patients pretreated with placebo (RR=0.57, 95%CI=0.43-0.76, p=0.000). The SCr values of the statin group, when analyzed 48h after angiography were lower than those of the placebo group ((SMD=-0.15, 95% CI=-0.27 to -0.04, p=0.011). In the subgroup analysis, statin pretreatment could decrease the risk of CIN in CKD patients with DM (RR=0.54, 95% CI=0.39-0.76, p=0.000), but not in CKD patients without DM (RR=0.84, 95% CI=0.44-1.60, p=0.606). The efficacy of atorvastatin for preventing CIN was consistent with that observed with the use of rosuvastatin. The risk ratios (RR) were 0.51 (95% CI=0.32-0.81, p=0.004) and 0.60 (95% CI=0.41-0.88, p=0.009), respectively. Our study demonstrated that statin pretreatment could prevent the development of CIN in CKD patients. However, subgroup analysis demonstrated that statin pretreatment, despite being effective in preventing CIN in patients with CKD and DM, was not helpful for CKD patients without DM. Rosuvastatin and atorvastatin exhibited similar preventive effects with respect to CIN.

Prognostic Value of Estimated Glomerular Filtration Rate 3-6 Months after Percutaneous Coronary Intervention

BACKGROUND

The prognostic significance of follow-up (f/u) renal function for patients undergoing percutaneous coronary intervention (PCI) remains unknown. This study sought to investigate the prognostic implications of f/u renal function in patients undergoing PCI.

METHODS

A drug-eluting stent registry was used. We divided patients into 4 groups according to the change in the estimated glomerular filtration rate (eGFR) before PCI and 3-6 months after PCI. Patients with normal pre-PCI eGFR and f/u eGFR were assigned to group 1. Those with normal pre-PCI eGFR and abnormal f/u eGFR were assigned to group 2. Patients with abnormal pre-PCI eGFR and normal f/u eGFR were assigned to group 3. Patients with abnormal pre-PCI eGFR and f/u eGFR were allocated into group 4.

RESULTS

A total of 4,899 PCI patients were enrolled. The death rate in group 1, 2, 3, and 4 at 3 years was 2, 11, 4, and 9%, respectively. This showed significant differences between groups, except between groups 2 and 4. The prognosis of a group with aggravation from normal renal function was worse than that of a group with recovery from abnormal renal function. A prediction model that combines clinical risk factors and f/u eGFR has more power for predicting clinical outcomes than a combination of clinical risk factors and pre-PCI eGFR.

CONCLUSION

Post-PCI eGFR was more accurate for predicting patient outcomes than pre-PCI eGFR.

Preventive Effect of Pretreatment with Pitavastatin on Contrast-Induced Nephropathy in Patients with Renal Dysfunction Undergoing Coronary Procedure: PRINCIPLE-II Randomized Clinical Trial

This study aimed to evaluate the efficacy of pitavastatin pretreatment on contrast-induced nephropathy (CIN) in patients with chronic kidney disease (CKD) after a coronary procedure. This was a prospective, randomized, double-blinded, placebo-controlled, multicenter clinical trial. All consecutive 70 patients with CKD (eGFR < 60 mL/min/1.73 m²) were enrolled and randomized into two groups. Group I consisted of patients who were treated with statins (pitavastatin 4 mg/day) for seven days before and three days after the procedure (n = 37, 52.9%), and group II consisted of patients who were treated with a placebo (n = 33, 47.1%). The primary endpoint was the incidence of CIN, and the secondary endpoints were the change in serum creatinine (∆sCr) level and estimated glomerular filtration rate (∆eGFR) after the procedure. The mean age of the patients (males, 74%) was 70.4 ± 9.0 years. After the coronary procedure, the incidence of CIN was lower in group I than in group II, but the difference was not significant (5.4% vs. 9.1%, p = 0.661). The maximal ∆sCr was lower and the maximal ∆eGFR was higher in group I than in group II, but the difference was not significant (-0.11 ± 0.53 mg/dL and -0.04 ± 0.33 mg/dL, p = 0.678; 4.3 ± 11.2 mL/min/1.73 m² and -2.9 ± 20.4 mL/min/1.73 m², p = 0.161, respectively). This study showed the possibility of a clinical benefit of pretreatment with a high dose of pitavastatin for the prevention of CIN in patients with CKD after coronary procedure (ClinicalTrials.gov Identifier: NCT01871792).

Iodinated contrast medium: Is there a re(n)al problem? A clinical vignette-based review

As we were taught, for decades, that iodinated contrast-induced acute kidney injury should be dreaded, considerable efforts were made to find out effective measures in mitigating the renal risk of iodinated contrast media. Imaging procedures were frequently either downgraded (unenhanced imaging) or deferred as clinicians felt that the renal risk pertaining to contrast administration outweighed the benefits of an enhanced imaging. However, could we have missed the point? Among the abundant literature about iodinated contrast-associated acute kidney injury, recent meaningful advances may help sort out facts from false beliefs. Hence, there is increasing evidence that the nephrotoxicity directly attributable to modern iodinated CM has been exaggerated. Failure to demonstrate a clear benefit from most of the tested prophylactic measures might be an indirect consequence. However, the toxic potential of iodinated contrast media is well established experimentally and should not be overlooked completely when making clinical decisions. We herein review these advances in disease and pathophysiologic understanding and the associated clinical crossroads through a typical case vignette in the critical care setting.

Avoiding the emergence of contrast-induced acute kidney injury in acute coronary syndrome: routine hydration treatment

BACKGROUND

Patients with acute coronary syndrome (ACS) have about a three-fold risk for developing contrast-induced acute kidney injury(CI-AKI). Investigating studies on routine hydration therapy have frequently included patients with stable coronary artery disease and high risk of CI-AKI [estimated glomerular filtration rate (eGFR) < 60 ml/min]. However, data on routine hydration treatment in non-ST segment elevation myocardial infarction (NSTEMI) patients with eGFR ≥60 ml/min are insufficient. We aimed to investigate the association between routine hydration therapy and CI-AKI development in NSTEMI patients at low risk for nephropathy.

METHODS AND RESULTS

We randomly assigned a total of 401 NSTEMI patients to two groups: the routine hydration group (198 patients) and the nonhydration group (control group) (203 patients). Intravenous hydration with isotonic saline (1 ml/kg/h, 0.9% sodium chloride) was given for 3-12 h before and 24 h after contrast exposure to the hydration group. CI-AKI was defined as the increase in serum creatinine values 0.5 mg/dl or 25% between 48 and 72 h after the invasive procedures. In our study, the incidence of CI-AKI development in the routine hydration group (7.1%) was significantly lower than in the nonhydration group (14.1%) (P: 0.02). This study revealed that older age, amount of contrast media, and routine hydration were independent risk factors for developing CI-AKI (P < 0.01, P: 0.04, P < 0.01, respectively).

CONCLUSION

We found that preprocedural and postprocedural intravenous hydration therapy reduces the development of CI-AKI in patients with NSTEMI at low risk for CI-AKI. We suggest administering routine hydration therapy in all ACS patients regardless of eGFR values.

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.

Remote Ischemic Preconditioning and Contrast-Induced Acute Kidney Injury in Patients Undergoing Elective Percutaneous Coronary Intervention: A Randomized Clinical Trial

Background

Contrast-induced acute kidney injury (CI-AKI) is a common cause of hospital-acquired AKI and a serious complication of percutaneous coronary intervention.

Objective

The aim of the present study was to assess whether remote ischemic preconditioning (RIPC) reduces the incidence of CI-AKI.

Methods

We conducted a prospective, randomized, sham-controlled clinical study. The study included 101 patients admitted to the Intensive Cardiac Therapy Clinic of Medical University of Lodz for elective percutaneous coronary intervention. The participants were randomly assigned in a 1:1 ratio to either a control group (n = 51) or an RIPC group (n = 50). In the latter, RIPC was achieved before percutaneous coronary intervention by 4 cycles of 5-minute inflation of a cuff on the left upper arm to 200 mm Hg followed by 5-minute deflation. In the control group, a deflated cuff was placed on the left arm for 40 minutes. Serum creatinine concentration was measured to check for the presence of CI-AKI within 48 to 72 hours of percutaneous coronary intervention. Serum neutrophil gelatinase-associated lipocalin level was also measured within 3 hours.

Results

CI-AKI occurred in 2 patients from the RIPC group (4%) and 3 patients from the control group (5.9%), but the difference was not significant (P = 0.98). The patients who developed CI-AKI also demonstrated increased serum neutrophil gelatinase-associated lipocalin concentrations (the area under the receiver operator characteristic curve = 0.97; 95% CI, 0.938–1.00; P < 0.00) and the optimal cutoff point value was 118.9 ng/mL.

Conclusions

The use of RIPC before elective percutaneous coronary intervention was not found to prevent CI-AKI. ClinicalTrials.gov identifier: NCT03761368. (Curr Ther Res Clin Exp. 2020; 81:XXX–XXX)

Current comments on contrast media administration in patients with renal insufficiency

Contrast media administration has been associated with complications such as nephropathy, cardiovascular morbidity, and neurovascular events, particularly in patients with renal insufficiency. This association has been questioned in recent studies. This review was performed to summarize the most current evidence on contrast induced nephropathy (CIN), contributing factors, and considerations in patients with renal insufficiency. The risk of CIN was over-estimated by the previous studies, due to a lack of control groups or presence of non-randomized control groups, which led to a selection bias. However, the thresholds associated with an increased risk of CIN are controversial and require risk-benefit analysis on an individual basis. Regarding the administration of contrast media (CM) in the emergency setting, the majority of studies suggested that CM exposure does not meaningfully increase the risk of acute kidney injury in critically ill patients (including trauma patients). Several strategies have been suggested to reduce the risk of CIN, including volume expansion to increase renal blood flow, sodium bicarbonate or N-acetylcysteine administration, and use of low-osmolal contrast media in end-stage renal disease.

Contrast Administration to the Deceased Kidney Donor Has No Impact on Post-Transplant Outcomes

BACKGROUND

Contrast-induced acute kidney injury may occur in patients undergoing imaging studies. This study reviews all deceased kidney donors at a single center during a 15-y period to determine if donor contrast exposure results in contrast-induced acute kidney injury in the donor or is associated with worse outcomes in the transplant recipient.

METHODS

Donor and recipient renal functions were recorded, including donor serum creatinine and recipient delayed graft function, creatinine clearance at 1 y, and early and late graft survival. Donor contrast exposure was recorded as the number of preprocurement contrasted studies.

RESULTS

Donor and recipient records were available for 1394 transplants (88%). There were 51% of donors who received any contrasted study (38%, one study; 12%, two studies, and 1%, three studies). Donor contrast exposure was not associated with significant differences in preprocurement serum creatinine levels. Post-transplant, donor contrast exposure was associated with risk of neither delayed graft function (4% for all) nor early kidney graft loss. Creatinine clearance at 1 y was equivalent. Five-year Cox regression demonstrated higher graft survival for contrast-exposed grafts (P = 0.03).

CONCLUSIONS

There is no negative effect of donor contrast administration on early and late kidney graft function. These findings included donor kidneys exposed to as many as three contrasted studies.

DDAH-2 alleviates contrast medium iopromide-induced acute kidney injury through nitric oxide synthase

BACKGROUND

Contrast medium-induced acute kidney injury (CI-AKI) is one of the most common causes of hospital-acquired acute renal failure. However, the pathogenesis of CI-AKI remains unclear. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide synthase (NOS) inhibitor that is largely metabolised by dimethylarginine dimethylaminohydroxylase (DDAH) in humans. Two isoforms of DDAH exist, namely, DDAH-1 and DDAH-2. In the present study, we examined whether the DDAH-2/ADMA/NOS pathway is involved in the pathogenesis of CI-AKI.

METHODS AND RESULTS

Exposure to the contrast medium iopromide led to increase in creatinine and blood urea nitrogen (BUN) levels, accumulation of ADMA, increase in reactive oxygen species (ROS) generation, and an inflammatory response in mice kidney tissue. The injection of adenovirus-harbouring DDAH-2 lowered renal ADMA levels and had a reno-protective effect against contrast-medium injury by decreasing cell apoptosis, ROS, and fibrosis. By contrast, contrast medium-induced renal injury was exacerbated in heterozygous DDAH-2 knockout mice. In the in vitro study, overexpression of DDAH-2 increased the levels of nitrite and intracellular cGMP, while the DDAH-2 knockdown induced the opposite effect. These findings were also observed in the in vivo sample.

CONCLUSIONS

Our findings provide the first evidence that the DDAH-2/ADMA/NOS pathway is involved in the pathogenesis of CI-AKI and that the protective effect of DDAH-2 probably arises from the modulation of NOS activity, oxidative stress, and the inflammatory process.

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.

Risk of acute kidney injury after contrast-enhanced computed tomography in emergency department

Background:

Despite its risks associated with renal injury, intravenous contrast media increases diagnostic efficacy and hence the chance of early diagnosis and treatment, which leaves clinicians in a dilemma regarding its use in emergency settings.

Objective:

The aim of this study was to determine the risk and predictors of contrast-induced acute kidney injury following intravenous contrast media administration for computed tomography in the emergency department.

Methods:

All patients aged 18 years and older who had a basal creatinine measurement within the last 8 h before contrast-enhanced computed tomography and a second creatinine measurement within 48–72 h after computed tomography scan between 1 January 2015 and 31 December 2017 were included in the study. Characteristics of patients with and without contrast-induced acute kidney injury development were compared. Multivariate regression analysis was used to assess the predictors for contrast-induced acute kidney injury.

Results:

A total of 631 patients were included in the final statistical analysis. After contrast media administration, contrast-induced acute kidney injury developed in 4.9% ( n = 31) of the patients. When the characteristics of patients are compared according to the development of contrast-induced acute kidney injury, significant differences were detected for age, initial creatinine, initial estimated glomerular filtration rate, and all acute illness severity indicators (hypotension, anemia, hypoalbuminemia, and need for intensive care unit admission). A multivariate logistic regression analysis was performed. The need for intensive care unit admission (odds ratio: 6.413 (95% confidence interval: 1.709–24.074)) and hypotension (odds ratio: 5.575 (95% confidence interval: 1.624–19.133)) were the main factors for contrast-induced acute kidney injury development.

Conclusion:

Our study results revealed that hypotension, need for intensive care, and advanced age were associated with acute kidney injury in patients receiving contrast media. Therefore, we believe that to perform contrast-enhanced computed tomography in emergency department should not be decided only by checking for renal function tests and that these predictors should be taken into consideration.

The conundrum of contrast-induced acute kidney injury

More than sixty years have elapsed since contrast induced nephropathy (CIN) was first described in the medical literature. This term has since been extensively explored, with a variety of studies conducted to investigate its incidence and various mechanisms examined to explain its pathophysiology. However, the topic of CIN remains one of controversy with a widely variable and often questionable incidence derived from various studies. The past two decades have seen a surge in reports questioning the existing of CIN altogether and if more harm is actually being caused to patients out of fear of this potential complication. We have attempted to review relevant studies regarding CIN and highlight the key points of its surmised understanding. The review has a higher focus on more recent literature and updates, in order to determine if an accurate estimate can be made on the incidence of CIN. While there was certainly no lack of material available, practically all the studies reviewed were limited by one or more significant drawbacks that limited the reliability of their conclusions regarding CIN. Based on the information reviewed, the strengths and the flaws encountered in other studies can be used to design a randomized control trial that may help in concluding the longstanding debate on this topic. However due to time, financial, and perhaps even ethical constraints such a trial will be difficult to arrange, and so a definitive answer on CI-AKI, and whether it really exist, may continue to elude clinicians.

A Randomized Trial of Recombinant Human C1-Esterase-Inhibitor in the Prevention of Contrast-Induced Kidney Injury

OBJECTIVES

This study sought to determine the efficacy profile and safety of recombinant human C1 esterase inhibitor (rhC1INH) in the prevention of contrast-associated acute kidney injury after elective coronary angiography.

BACKGROUND

Contrast-associated acute kidney injury is caused by tubular cytotoxicity and ischemia/reperfusion injury. rhC1INH is effective in reducing renal ischemia/reperfusion injury in experimental models.

METHODS

In this placebo-controlled, double-blind, single-center trial 77 patients with chronic kidney disease were randomized to receive 50 IU/kg rhC1INH before and 4 h after elective coronary angiography or placebo. The primary outcome was the peak change of urinary neutrophil gelatinase-associated lipocalin within 48 h, a surrogate marker of kidney injury.

RESULTS

Median peak change of urinary neutrophil gelatinase-associated lipocalin was lower in the rhC1INH group (4.7 ng/ml vs. 22.5 ng/ml; p = 0.038) in the per-protocol population but not in the modified intention-to-treat analysis, and in patients with percutaneous coronary interventions (median, 1.8 ng/ml vs. 26.2 ng/ml; p = 0.039 corresponding to a median proportion peak change of 11% vs. 205%; p = 0.002). The incidence of a cystatin C increase ≥10% within 24 h was lower in the rhC1INH group (16% vs. 33%; p = 0.045), whereas the frequency of contrast-associated acute kidney injury was comparable. Adverse events during a 3-month follow-up were similarly distributed.

CONCLUSIONS

Administration of rhC1INH before coronary angiography may attenuate renal injury as reflected by urinary neutrophil gelatinase-associated lipocalin and cystatin C. The safety profile of rhC1INH was favorable in a patient population with multiple comorbidities. (Recombinant Human C1 Esterase Inhibitor in the Prevention of Contrast-induced Nephropathy in High-risk Subjects [PROTECT]; NCT02869347).

Incidence and Risk Factors of Acute Kidney Injury after Kasai Operation for Biliary Atresia: A Retrospective Study

Background: Biliary atresia is a progressive, inflammatory, and destructive pathology of the bile ducts. Patients who undergo surgery for correction of biliary atresia (Kasai operation) are at risk of acute kidney injury (AKI) because of their young age at the time of surgery, long operation time, and liver fibrosis or failure as complication of biliary atresia. Conversely, AKI is associated with poor outcomes after surgery. This study therefore aimed to evaluate the incidence, risk factors, and outcomes of AKI after Kasai operation. Methods: All consecutive patients who underwent Kasai operation between March 2006 and December 2015 in a single tertiary-care university hospital were enrolled. AKI was defined based on the Acute Kidney Injury Network criteria. Multivariate logistic regression models were used to assess risk factors for AKI. Results: One hundred sixty-six patients received Kasai operation during study period. Of these, AKI occurred in 37 of 166 patients (22.3%). In multivariate logistic regression analysis, age older than 30 days, higher preoperative estimated glomerular filtration rate, and preoperative contrast use within 7 days were associated with the development of AKI. Perioperative packed red blood cells transfusion was related to reduced occurrence of AKI. AKI was associated with longer ICU stay (OR = 1.015, p = 0.016). More patients with AKI were also found to receive additional surgery except liver transplantation within 1 year compared to those without AKI (10.8 % vs. 2.3 %, p = 0.045). Conclusions: Increased age is strongly associated with the development of AKI after Kasai operation. These findings indicate a rational basis for early corrective surgery for biliary atresia, early screening for AKI, and intervention to improve the results of Kasai operation.