Prophylactic hydration to protect renal function from intravascular iodinated contrast material in patients at high risk of contrast-induced nephropathy (AMACING): a prospective, randomised, phase 3, controlled, open-label, non-inferiority trial

A contemporary simple risk score for prediction of contrast-associated acute kidney injury after percutaneous coronary intervention: derivation and validation from an observational registry

BACKGROUND

Contrast-associated acute kidney injury can occur after percutaneous coronary intervention (PCI). Prediction of the contrast-associated acute kidney injury risk is important for a tailored prevention and mitigation strategy. We sought to develop a simple risk score to estimate contrast-associated acute kidney injury risk based on a large contemporary PCI cohort.

METHODS

Consecutive patients undergoing PCI at a large tertiary care centre between Jan 1, 2012, and Dec 31, 2020, with available creatinine measurements both before and within 48 h after the procedure, were included; only patients on chronic dialysis were excluded. Patients treated between 2012 and 2017 comprised the derivation cohort and those treated between 2018 and 2020 formed the validation cohort. The primary endpoint was contrast-associated acute kidney injury, defined according to the Acute Kidney Injury Network. Independent predictors of contrast-associated acute kidney injury were derived from multivariate logistic regression analysis. Model 1 included only pre-procedural variables, whereas Model 2 also included procedural variables. A weighted integer score based on the effect estimate of each independent variable was used to calculate the final risk score for each patient. The impact of contrast-associated acute kidney injury on 1-year deaths was also evaluated.

FINDINGS

32 378 PCI procedures were performed and screened for inclusion in the present analysis. After the exclusion of patients without paired creatinine measurements, patients on chronic dialysis, and multiple procedures, 14 616 patients were included in the derivation cohort (mean age 66·2 years, 29·2% female) and 5606 were included in the validation cohort (mean age 67·0 years, 26·4% female). Contrast-associated acute kidney injury occurred in 860 (4·3%) patients. Independent predictors of contrast-associated acute kidney injury included in Model 1 were: clinical presentation, estimated glomerular filtration rate, left ventricular ejection fraction, diabetes, haemoglobin, basal glucose, congestive heart failure, and age. Additional independent predictors in Model 2 were: contrast volume, peri-procedural bleeding, no flow or slow flow post procedure, and complex PCI anatomy. The occurrence of contrast-associated acute kidney injury in the derivation cohort increased gradually from the lowest to the highest of the four risk score groups in both models (2·3% to 34·9% in Model 1, and 2·0% to 38·8% in Model 2). Inclusion of procedural variables in the model only slightly improved the discrimination of the risk score (C-statistic in the derivation cohort: 0·72 for Model 1 and 0·74 for model 2; in the validation cohort: 0·84 for Model 1 and 0·86 for Model 2). The risk of 1-year deaths significantly increased in patients with contrast-associated acute kidney injury (10·2% vs 2·5%; adjusted hazard ratio 1·76, 95% CI 1·31-2·36; p=0·0002), which was mainly due to excess 30-day deaths.

INTERPRETATION

A contemporary simple risk score based on readily available variables from patients undergoing PCI can accurately discriminate the risk of contrast-associated acute kidney injury, the occurrence of which is strongly associated with subsequent death.

FUNDING

None.

Length of Preprocedure Fasting Was Associated With Contrast Associated-Acute Kidney Injury in High-Risk Patients Undergoing Coronary Angiography

Hydration is recommended to prevent contrast associated-acute kidney injury (CA-AKI) but interactions between blood pressure, left ventricular end diastolic pressure (LVEDP) and hydration status on CA-AKI are incompletely understood. This analysis presents the results of a single-center prospective study of patients undergoing coronary angiography with a predicted risk of CA-AKI >14%. 146 patients were enrolled with a mean (±SD) age of 71 ± 11 years; 94 (64.4%) were men, 142 (97.3%) had hypertension, 96 (65.8%) had diabetes mellitus and the mean (SD) serum creatinine was 1.21 ± 0.36 mg/dl. CA-AKI occurred in 31 (21%) patients. There were no significant differences in demographics, comorbidities, renal function, LVEDP, systolic blood pressure, diastolic blood pressure, heart rate, mean arterial pressure or pulse pressure in patients who developed versus those who did not develop CA-AKI. There was no association between the amount of peri-procedure intravenous fluids and change in creatinine postprocedure. In multivariate analysis, hemoglobin, the time that the patient was fasting from solids (NPO time), and contrast volume were associated with the development of CA-AKI. There was a highly significant interaction (p = 0.0028) between the amount of intravenous fluids, NPO time and contrast volume and changes in postprocedure creatinine. In summary, hemoglobin, NPO time and contrast volume, but not hemodynamic variables, correlated with worsening renal function following coronary angiography in this population of high-risk patients. Results suggested that intravenous hydration is important in subgroups of patients depending on NPO time and contrast volume.

[Contrast media use in kidney disease - clinical practice recommendations]

Contrast media use in patients with renal disease regularly ensures discussions in everyday clinical practice. Both X-ray and MRI contrast media are predominantly eliminated by the kidneys and therefore closely linked to kidney function. Risk stratification prior to contrast media use in patients with pre-existing renal dysfunction should be based on eGFR-determination. Patients with an eGFR ≥ 30 ml/min require an individual risk assessment. In patients with advanced renal insufficiency ensuring euvolemia is crucial. Currently, there is no evidence for any other preventive approach. Therefore, no further specific procedures preventing contrast-associated kidney injury are recommended. Timing of contrast media injection and dialysis sessions in patients with end stage renal disease is necessary only after MRI contrast media use. Independently, acute kidney injury requires a patient individual decision.

The Predictive Value of Soluble Urokinase-Type Plasminogen Activator Receptor in Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention

Objective

Soluble urokinase-type plasminogen activator receptor (SuPAR) is a circulating protein and a novel identified promising biomarker for various renal diseases and kidney injury. However, it remains unknown on the predictive value of suPAR in contrast induced acute kidney injury (CI-AKI) in patients undergoing percutaneous coronary intervention (PCI).

Methods

A total of 399 patients undergoing PCI were enrolled in the research from June 2020 to June 2021 in Zhongda Hospital. Patients were divided into CI-AKI and non-CI-AKI groups according to the preoperative and postoperative serum creatinine levels. Plasma suPAR level was detected through enzyme-linked immunosorbent assay on admission. Demographic data, hematological parameters, coronary angiography data and medications were recorded and compared between CI-AKI and non-CI-AKI groups. Logistic regression analysis and receiver operator characteristic (ROC) curve analysis were performed for identifying the independent risk factors of CI-AKI and assessment of the predictive value of suPAR for CI-AKI.

Results

CI-AKI occurred in 65 (16.3%) patients undergoing PCI. The level of suPAR in CI-AKI group was significantly higher than that in the non-CI-AKI group. Multivariate logistic regression indicated diabetes, lower LVEF, lower hydration rate, lower baseline eGFR, higher plasma suPAR (OR = 2.875, 95% CI = 2.038–3.672, P < 0.001) and volume of contrast media were all independent risk factors for CI-AKI after adjustment of the confounding factors. ROC analysis illustrated that the optimal area under the curve was 0.765, indicating plasma suPAR was a splendid predictor for CI-AKI. The corresponding cut-off value was 3.305 ng/mL, and the sensitivity and specificity were 63.1% and 82.3%, respectively.

Conclusion

Increased suPAR level is independently associated with elevated risk of suffering CI-AKI, and suPAR is a strong predictor for CI-AKI in patients undergoing PCI. SuPAR might act as a novel biomarker for CI-AKI in clinical practice.

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

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

Oral hydration as a safe prophylactic measure to prevent post-contrast acute kidney injury in oncologic patients with chronic kidney disease (IIIb) referred for contrast-enhanced computed tomography: subanalysis of the oncological group of the NICIR study

BACKGROUND

T he objective of this study is to evaluate oral hydration compared to intravenous (i.v.) hydration in the prevention of post-contrast acute kidney injury (PC-AKI) in the oncologic subgroup of patients with stage IIIb chronic kidney disease (CKD) included in the NICIR study referred for elective contrast-enhanced computed tomography (CE-CT).

MATERIAL AND METHODS

We performed a retrospective subanalysis of the oncological subgroup (174/228 patients, 74%) from a continuous prospective database of patients included in the recently published non-inferiority NICIR study. Patients received prophylaxis against PC-AKI with either oral hydration (500 mL of water 2 h before and 2000 mL during the 24 h after CE-CT) or i.v. hydration (sodium bicarbonate (166 mmol/L) 3 mL/kg/h starting 1 h before and 1 mL/kg/h during the first hour after CE-CT). The primary outcome was to compare the proportion of PC-AKI in the first 48 to 72 h after CE-CT in the two hydration groups. Secondary outcomes were to compare persistent PC-AKI, the need for haemodialysis, and the occurrence of adverse events related to prophylaxis in each group.

RESULTS

Of 174 patients included in the subanalysis, 82 received oral hydration and 92 received i.v. hydration. There were no significant differences in clinical characteristics or risk factors between the two study arms. Overall the PC-AKI rate was 4.6% (8/174 patients), being 3.7% in the oral hydration arm (3/82 patients) and 5.4% (5/92 patients) in the i.v. hydration arm. The persistent PC-AKI rate was 1.2% (1/82 patients) in the oral hydration arm and 3.3% (3/92 patients) in the i.v. hydration arm. No patient required dialysis during the first month after CE-CT or had adverse effects related to the hydration regime.

CONCLUSION

In oncological patients with stage IIIb CKD referred for elective CE-CT, the rate of PC-AKI in those receiving oral hydration did not significantly differ from that of patients receiving i.v. hydration.

Evaluation of Radiographic Contrast-Induced Nephropathy by Functional Diffusion Weighted Imaging

Contrast-induced nephropathy (CIN) resembles an important complication of radiographic contrast medium (XCM) displayed by a rise in creatinine levels 48-72 h after XCM administration. The purpose of the current study was to evaluate microstructural renal changes due to CIN in high-risk patients by diffusion weighted (DWI) and diffusion tensor imaging (DTI). Fifteen patients (five CIN and ten non-CIN) scheduled for cardiological intervention were included in the study. All patients were investigated pre- and post-intervention on a clinical 3T scanner. After anatomical imaging, renal DWI was performed by a paracoronal echo-planar-imaging sequence. Renal clinical routine serum parameters and advanced urinary injury markers were determined to monitor renal function. We observed a drop in cortical and medullar apparent diffusion coefficient (ADC) and fractional anisotropy (FA) before and after XCM administration in the CIN group. In contrast, the non-CIN group differed only in medullary ADC. The decrease of ADC and FA was apparent even before serum parameters of the kidney changed. In conclusion, DWI/DTI may be a useful tool for monitoring high-risk CIN patients as part of multi-modality based clinical protocol. Further studies, including advanced analysis of the diffusion signal, may improve the identification of patients at risk for CIN.

Contrast associated nephropathy after intravenous administration: what is the magnitude of the problem?

Intravenous contrast media (CM) is often used in clinical practice to enhance CT scan imaging. For many years, contrast-induced nephropathy (CIN) was thought to be a common occurrence and to result in dire consequences. When treating patients with abnormal renal function, it is not unusual that clinicians postpone, cancel, or replace contrast-enhanced imaging with other, perhaps less informative tests. New studies however have challenged this paradigm and the true risk attributable to intravenous CM for the occurrence of CIN has become debatable. In this article, we review the latest relevant medical literature and aim to provide an evidence-based answer to questions surrounding the risk, outcomes, and potential mitigation strategies of CIN after intravenous CM administration.

Risk of Worsening Renal Function Following Repeated Exposures to Contrast Media During Percutaneous Coronary Interventions

Background

Multiple contrast media exposures are common, but their cumulative effect on renal function is unknown. We aimed to investigate the renal consequences of repeated exposures to contrast media with coronary interventions.

Methods and Results

We studied 2942 patients who underwent between 1 and 9 procedures. The primary end point was a persistent creatinine increase of ≥50% above baseline at ≥90 days after the last procedure. The effect of cumulative contrast media dose was assessed using Cox models, with cumulative exposure as a time‐dependent variable, and propensity score matching. The primary end point occurred in 190 patients (6.5%), with 6.1%, 6.8%, and 6.2% of patients with 1, 2 or 3, and ≥4 procedures, respectively (P=0.75). In the multivariable Cox model, baseline renal function, diabetes, anemia, acute coronary syndrome, and heart failure were independent predictors of the primary end point (all P≤0.01), whereas cumulative contrast dose was not (hazard ratio [HR], 1.29 [95% CI, 0.89–1.88] for the fourth contrast quartile [>509 mL] versus first contrast quartile [<233 mL]). Propensity score matching yielded 384 patient pairs with similar characteristics and either 1 or 2 to 9 contrast exposures (median cumulative dose, 160 and 480 mL, respectively). Despite large differences in the cumulative contrast exposure, there were similar rates of the primary end points (7.3% versus 6.3%, respectively; HR, 0.76 [95% CI, 0.44–1.32]).

Conclusions

In patients with multiple exposures to contrast media, worsening of renal function over time is associated with known risk factors for the progression of kidney disease but not with cumulative contrast volume.

Facile Synthesis of Holmium-Based Nanoparticles as a CT and MRI Dual-Modal Imaging for Cancer Diagnosis

The rapid development of medical imaging has boosted the abilities of modern medicine. As single modality imaging limits complex cancer diagnostics, dual-modal imaging has come into the spotlight in clinical settings. The rare earth element Holmium (Ho) has intrinsic paramagnetism and great X-ray attenuation due to its high atomic number. These features endow Ho with good potential to be a nanoprobe in combined x-ray computed tomography (CT) and T₂-weighted magnetic resonance imaging (MRI). Herein, we present a facile strategy for preparing HoF₃ nanoparticles (HoF₃ NPs) with modification by PEG 4000. The functional PEG-HoF₃ NPs have good water solubility, low cytotoxicity, and biocompatibility as a dual-modal contrast agent. Currently, there is limited systematic and intensive investigation of Ho-based nanomaterials for dual-modal imaging. Our PEG-HoF₃ NPs provide a new direction to realize in vitro and vivo CT/MRI imaging, as well as validation of Ho-based nanomaterials will verify their potential for biomedical applications.

National Cardiovascular Data Registry-Acute Kidney Injury (NCDR) vs. Mehran risk models for prediction of contrast-induced nephropathy and need for dialysis after coronary angiography in a German patient cohort

BACKGROUND

Contrast-induced nephropathy (CIN) is a major adverse event in patients undergoing coronary angiography. The Mehran risk model is the gold-standard for CIN risk prediction. However, its performance in comparison to more contemporary National Cardiovascular Data Registry-Acute Kidney Injury (NCDR-AKI) risk models remains unknown. We aimed to compare both in this study.

METHODS AND RESULTS

Predictions of Mehran and NCDR-AKI risk models and clinical events of CIN and need for dialysis were assessed in a total of 2067 patients undergoing coronary angiography with or without percutaneous coronary intervention. Risk models were compared regarding discrimination (receiver operating characteristic analysis), net reclassification improvement (NRI) and calibration (graphical and statistical analysis). The NCDR risk model showed superior risk discrimination for predicting CIN (NCDR c-index 0.75, 95% CI 0.72-0.78; vs. Mehran c-index 0.69, 95% CI 0.66-0.72, p < 0.01), and continuous NRI (0.22; 95% CI 0.12-0.32; p < 0.01) compared to the Mehran model. The NCDR risk model tended to underestimate the risk of CIN, while the Mehran model was more evenly calibrated. For the prediction of need for dialysis, NCDR-AKI-D also discriminated risk better (c-index 0.85, 95% CI 0.79-0.91; vs. Mehran c-index 0.75, 95% CI 0.66-0.84; p_NCDRvsMehran < 0.01), but continuous NRI showed no benefit and calibration analysis revealed an underestimation of dialysis risk.

CONCLUSION

In German patients undergoing coronary angiography, the modern NCDR risk model for predicting contrast-induced nephropathy showed superior discrimination compared to the GRACE model while showing less accurate calibration. Results for the outcome 'need for dialysis' were equivocal.

Cost-effectiveness of point-of-care creatinine testing to assess kidney function prior to contrast-enhanced computed tomography imaging

BACKGROUND

Patients undergoing contrast-enhanced computed tomography (CECT) imaging in a non-emergency outpatient setting often lack a recent estimated Glomerular Filtration Rate measurement. This may lead to inefficiencies in the CECT pathway. The use of point-of-care (POC) creatinine tests to evaluate kidney function in these patients may provide a safe and cost-effective alternative to current practice, as these can provide results within the same CECT appointment.

METHODS

A decision tree model was developed to characterise the diagnostic pathway and patient management (e.g., intravenous hydration) and link these to adverse renal events associated with intravenous contrast media. Twelve diagnostic strategies including three POC devices (i-STAT, ABL800 Flex and StatSensor), risk factor screening and laboratory testing were compared with current practice. The diagnostic accuracy of POC devices was derived from a systematic review and meta-analysis; relevant literature sources and databases informed other parameters. The cost-effective strategy from a health care perspective was identified based on highest net health benefit (NHB) which were expressed in quality-adjusted life years (QALYs) at £20,000/QALY.

RESULTS

The cost-effective strategy, with a NHB of 9.98 QALYs and a probability of being cost-effective of 79.3%, was identified in our analysis to be a testing sequence involving screening all individuals for risk factors, POC testing (with i-STAT) on those screening positive, and performing a confirmatory laboratory test for individuals with a positive POC result. The incremental NHB of this strategy compared to current practice, confirmatory laboratory test, is 0.004 QALYs. Results were generally robust to scenario analysis.

CONCLUSIONS

A testing sequence combining a risk factor questionnaire, POC test and confirmatory laboratory testing appears to be cost-effective compared to current practice. The cost-effectiveness of POC testing appears to be driven by reduced delays within the CECT pathway. The contribution of intravenous contrast media to acute kidney injury, and the benefits and harms of intravenous hydration remain uncertain.

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

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

Incidence of contrast-induced nephropathy after a computed tomography scan

BACKGROUND AND AIMS

The term contrast-induced nephropathy is used to describe acute deterioration of renal function after the intravenous administration of iodinated contrast material. We aimed to estimate the incidence of contrast-induced nephropathy and to analyze the evolution of different biomarkers of renal function in patients who underwent computed tomography with intravenous contrast administration after premedication with oral hydration and N-acetylcysteine.

MATERIAL AND METHODS

This prospective observational study included 112 patients with chronic renal failure (glomerular filtration rate (GFR) 30ml-60ml/min/1.73m²) scheduled for computed tomography with intravenous iodinated contrast material. We recorded demographic variables, dose of contrast material, diabetes mellitus, hypertension, and serum hemoglobin. We measured serum creatinine and GFR after premedication and after the CT examination. We summarized variables as means, standard deviations, and percentages. We used the Wilcoxon and Mann-Whitney tests to compare pre- and post-CT values and Pearson's r to analyze correlations.

RESULTS

Incidence acute kidney injury: 0.9%; 95%CI: 0.36-1.4. Mean difference between pre- and post-CT creatinine: 0.04; 95%CI: 0.002-0.09, p<0.004. Mean difference between pre- and post-CT GFR: -3.06; 95%CI: -4.66 to -1.47), p<0.001.

CONCLUSIONS

The incidence of contrast-induced nephropathy in patients with chronic renal failure and GFR 30ml-60ml/min/1.73m² is low. The biomarkers of renal function analyzed improve in patients who receive premedication and the minimum dose of contrast material.

Tailored Versus Standard Hydration to Prevent Acute Kidney Injury After Percutaneous Coronary Intervention: Network Meta-Analysis

Background

Contrast‐induced acute kidney injury (CI‐AKI) is a serious complication after percutaneous coronary intervention. The mainstay of CI‐AKI prevention is represented by intravenous hydration. Tailoring infusion rate to patient volume status has emerged as advantageous over fixed infusion‐rate hydration strategies.

Methods and Results

A systematic review and network meta‐analysis with a frequentist approach were conducted. A total of 8 randomized controlled trials comprising 2312 patients comparing fixed versus tailored hydration strategies to prevent CI‐AKI after percutaneous coronary intervention were included in the final analysis. Tailored hydration strategies included urine flow rate–guided, central venous pressure–guided, left ventricular end‐diastolic pressure–guided, and bioimpedance vector analysis–guided hydration. Primary endpoint was CI‐AKI incidence. Safety endpoint was incidence of pulmonary edema. Urine flow rate–guided and central venous pressure–guided hydration were associated with a lower incidence of CI‐AKI compared with fixed‐rate hydration (odds ratio [OR], 0.32 [95% CI, 0.19–0.54] and OR, 0.45 [95% CI, 0.21–0.97]). No significant difference in pulmonary edema incidence was observed between the different hydration strategies. P score analysis showed that urine flow rate–guided hydration is advantageous in terms of both CI‐AKI prevention and pulmonary edema incidence when compared with other approaches.

Conclusions

Currently available hydration strategies tailored on patients' volume status appear to offer an advantage over guideline‐supported fixed‐rate hydration for CI‐AKI prevention after percutaneous coronary intervention. Current evidence suggests that urine flow rate–guided hydration as the most convenient strategy in terms of effectiveness and safety.

Glycosylated hemoglobin levels and the risk for contrast-induced nephropathy in diabetic patients undergoing coronary arteriography/percutaneous coronary intervention

Backgrounds

Diabetes mellitus is an independent risk factor for Contrast-induced nephropathy (CIN) in patients undergoing Coronary arteriography (CAG)/percutaneous coronary intervention (PCI). Glycosylated hemoglobin (HbA1c) is the gold standard to measure blood glucose control, which has important clinical significance for evaluating blood glucose control in diabetic patients in the past 3 months. This study aimed to assess whether preoperative HbA1c levels in diabetic patients who received CAG/PCI impacted the occurrence of postoperative CIN.

Methods

We reviewed the incidence of preoperative HbA1c and postoperative CIN in 670 patients with CAG/PCI from January 1, 2020 to October 30, 2020 and divided the preoperative HbA1c levels into 5 groups. Blood samples were collected at admission, 48 h and 72 h after operation to measure the Scr value of patients. Categorical variables were compared using a chi-square test, and continuous variables were compared using an analysis of variance. Fisher’s exact test was used to compare the percentages when the expected frequency was less than 5. Univariable and multivariable logistic regression analysis was used to exclude the influence of confounding factors, and P for trend was used to analyze the trend between HbA1c levels and the increased risk of CIN.

Results

Patients with elevated HbA1c had higher BMI, FBG, and LDL-C, and they were more often on therapy with hypoglycemic agents, Insulin and PCI. They also had higher basal, 48 h and 72 h Scr. The incidence of CIN in the 5 groups of patients were: 9.8, 11.9, 15.2, 25.3, 48.1%. (p < 0.0001) The multivariate analysis confirmed that in the main high-risk subgroup, patients with elevated HbA1C levels (≥8.8%) had a higher risk of CIN disease. Trend test showed the change of OR (1.000,1.248,1.553,2.625,5.829).

Conclusions

Studies have shown that in diabetic patients undergoing CAG/PCI, elevated HbA1c is independently associated with the risk of CIN, and when HbA1c > 9.5%, the incidence of CIN trends increase. Therefore, we should attach great importance to patients with elevated HbA1c at admission and take more active measures to prevent CIN.

Association of Intravenous Radiocontrast With Kidney Function: A Regression Discontinuity Analysis

IMPORTANCE

Radiocontrast has long been thought of as nephrotoxic; however, a number of recent observational studies found no evidence of an association between intravenous contrast and kidney injury. Because these studies are at high risk of confounding and selection bias, alternative study designs are required to enable more robust evaluation of this association.

OBJECTIVE

To determine whether intravenous radiocontrast exposure is associated with clinically significant long-term kidney impairment, using a study design that permits stronger causal interpretation than existing observational research.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included all emergency department patients aged 18 years or older undergoing D-dimer testing between 2013 and 2018 in the Canadian province of Alberta. A fuzzy regression discontinuity design was used, exploiting the fact that individuals just either side of the eligibility cutoff for computed tomographic pulmonary angiogram (CTPA)-typically 500 ng/mL-have markedly different probabilities of contrast exposure, but should otherwise be similar with respect to potential confounders.

EXPOSURES

Intravenous contrast in the form of a CTPA.

MAIN OUTCOMES AND MEASURES

Estimated glomerular filtration rate (eGFR) up to 6 months following the index emergency department visit.

RESULTS

During the study period 156 028 individuals received a D-dimer test. The mean age was 53 years, 68 206 (44%) were men and 87 822 (56%) were women, and the mean baseline eGFR level was 86 mL/min/1.73 m2. Patients just above and below the CTPA eligibility cutoff were similar in terms of measured confounders. There was no evidence for an association of contrast with eGFR up to 6 months later, with a mean change in eGFR of -0.4 mL/min/1.73 m2 (95% CI, -4.9 to 4.0) associated with CTPA exposure. There was similarly no evidence for an association with need for kidney replacement therapy (risk difference [RD], 0.07%; 95% CI, -0.47% to 0.61%), mortality (RD, 0.3%; 95% CI, -2.9% to 3.2%), and acute kidney injury (RD, 4.3%; 95% CI, -2.7% to 12.9%), though the latter analysis was limited by missing data. Subgroup analyses were potentially consistent with harm among patients with diabetes (mean eGFR change -6.4 mL/min/1.73 m2; 95% CI, -15.4 to 0.2), but not among those with other reported risk factors for contrast-induced nephropathy; these analyses, however, were relatively underpowered.

CONCLUSIONS AND RELEVANCE

Using a cohort study design and analysis that permits stronger causal interpretation than existing observational research, we found no evidence for a harmful effect on kidney function of intravenous contrast administered for CTPA in an emergency setting.

Post-Contrast Acute Kidney Injury in Patients with Various Stages of Chronic Kidney Disease-Is Fear Justified?

Post-contrast acute kidney injury (PC-AKI) is one of the side effects of iodinated contrast media, including those used in computed tomography. Its incidence seems exaggerated, and thus we decided to try estimate that number and investigate its significance in our clinical practice. We analyzed all computed tomographies performed in our clinic in 2019, including data about the patient and the procedure. In each case, we recorded the parameters of kidney function (serum creatinine concentration and eGFR) in four time intervals: before the test, immediately after the test, 14–28 days after the test, and over 28 days after the test. Patients who did not have a follow-up after computed tomography were excluded. After reviewing 706 CT scans performed in 2019, we included 284 patients undergoing contrast-enhanced CT and 67 non-enhanced CT in the final analysis. On this basis, we created two comparable groups in terms of age, gender, the severity of chronic kidney disease, and the number of comorbidities. We found that AKI was more common in the non-enhanced CT population (25.4% vs. 17.9%). In terms of our experience, it seems that PC-AKI is not a great risk for patients, even those with chronic kidney disease. Consequently, the fear of using contrast agents is not justified.

Low dose contrast media in step-and-shoot coronary angiography with third-generation dual-source computed tomography: feasibility of using 30 mL of contrast media in patients with body surface area <1.7 m2

Background

Reducing contrast media volume in coronary computed tomography angiography minimizes the risk of adverse events but may compromise diagnostic image quality. We aimed to evaluate coronary computed tomography angiography's diagnostic image quality while using 30 mL of contrast media in patients with a body surface area <1.7 m².

Methods

This prospective study included patients who underwent coronary computed tomography angiography from May 2018 to June 2019. The patients were divided into a low-dose group, who received 30 mL of contrast media, and a routine-dose group, who received contrast media based on body weight. Patient characteristics, coronary computed tomography angiography results, and quantitative and qualitative image results were assessed and compared.

Results

In total, 103 patients with a body surface area <1.7 m² were 53 in the low-dose group and 50 in the routine-dose group. Sex, age, body surface area, body weight, and heart rate were similar between the groups (P>0.05). A contrast media volume of 30±0 mL was used for the low-dose group, and 41.62±4.59 mL was used for the routine-dose group. The low-dose group's computed tomography values were significantly different from those of the routine-dose group (P<0.05). The radiologists demonstrated agreement regarding diagnostic image quality and accuracy (kappa =0.91 and 0.85, respectively).

Conclusions

Using 30 mL of contrast media for coronary computed tomography angiography in patients with a body surface area <1.7 m² provided a suitable diagnostic image quality for coronary artery disease diagnosis. Although radiation doses were similar between the groups, the decreased contrast media volume was likely beneficial for the patients.

Melatonin Alleviates Contrast-Induced Acute Kidney Injury by Activation of Sirt3

Oxidative stress and apoptosis play a vital role in the pathogenesis of contrast-induced acute kidney injury (CI-AKI). The purpose of our study was to investigate the protective effects and mechanisms of melatonin against CI-AKI in a CI-AKI mouse model and NRK-52E cells. We established the CI-AKI model in mice, and the animals were pretreated with melatonin (20 mg/kg). Our results demonstrated that melatonin treatment exerted a renoprotective effect by decreasing the level of serum creatinine (SCr) and blood urea nitrogen (BUN), lessening the histological changes of renal tubular injuries, and reducing the expression of neutrophil gelatinase-associated lipid (NGAL), a marker of kidney injury. We also found that pretreatment with melatonin remarkably increased the expression of Sirt3 and decreased the ac-SOD2 K68 level. Consequently, melatonin treatment significantly decreased the oxidative stress by reducing the Nox4, ROS, and malondialdehyde (MDA) content and by increasing the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity levels. The antiapoptotic effect of melatonin on CI-AKI was revealed by decreasing the ratio of Bax/Bcl2 and the cleaved caspase3 level and by reducing the number of apoptosis-positive tubular cells. In addition, melatonin treatment remarkably reduced the inflammatory cytokines of interleukin-1β (IL-1β), tumor necrosis factor α (TNFα), and transforming growth factor β (TGFβ) in vivo and in vitro. Sirt3 deletion and specific Sirt3 siRNA abolished the above renoprotective effects of melatonin in mice with iohexol-induced acute kidney injury and in NRK-52E cells. Thus, our results demonstrated that melatonin exhibited the renoprotective effects of antioxidative stress, antiapoptosis, and anti-inflammation by the activation of Sirt3 in the CI-AKI model in vivo and in vitro. Melatonin may be a potential drug to ameliorate CI-AKI in clinical practice.

A prospective study on the incidence of contrast-associated acute kidney injury after recanalization of chronic total coronary occlusions with contemporary interventional techniques

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO). This study should evaluate the incidence of CA-AKI in an era of advanced strategies of recanalization techniques and identify modifiable determinants.

METHODS

We analysed 1924 consecutive CTO procedures in 1815 patients between 2012 and 2019. All patients were carefully monitored at least up to 48 h after a CTO procedure for changes in renal function.

RESULTS

The incidence of CA-AKI was 5.6%, but there was no relation to the technical approach such as frequency of the retrograde technique, intravascular ultrasound or radial access. Procedures with CA-AKI had longer fluoroscopy times (37.6 vs 46.1 min; p = 0.005). The major determinants of CA-AKI were age, presence of diabetes and reduced ejection fraction, as well as chronic kidney disease stage ≥2, serum haemoglobin, and fluoroscopy time. Contrast volume or contrast volume/GFR ratio were not independent determinants of CA-AKI. Periprocedural perforations were more frequent in CA-AKI patients (11.3 vs 2.3%; p < 0.001), and in-hospital mortality was higher (2.8 vs 0.4%; p < 0.001).

CONCLUSIONS

CA-AKI was associated with the risk of in-hospital adverse events. Established patient-related risk factors for CA-AKI (age, diabetes, preexisting chronic kidney disease, low ejection fraction) were confirmed in this study. In addition, the length of the procedure, coronary perforations and low preprocedural serum haemoglobin were risk factors that might be preventable in patients at high risk for CA-AKI.

Risk factors of contrast-induced nephropathy after percutaneous coronary intervention: a retrospective analysis

Objective

Contrast-induced nephropathy (CIN) is a serious complication in patients with acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI). This study aimed to analyze the potential risk factors for CIN in patients undergoing PCI.

Methods

Patients with ACS who underwent PCI treatment from January 2017 to January 2020 were selected. The patients’ characteristics and medical information were collected and compared.

Results

A total of 1331 patients undergoing PCI were included. The incidence of CIN was 15.33%. Logistic regression analyses showed that a left ventricular ejection fraction ≤45% (odds ratio [OR] 4.18, 95% confidence interval [CI] 1.10–7.36), serum creatinine levels ≤60 μmol/L (OR 3.03, 95% CI 1.21–5.57), age ≥65 years (OR 2.75, 95% CI 1.32–4.60), log N-terminal pro-B-type natriuretic peptide levels ≥2.5 pg/mL (OR 2.31, 95% CI 1.18–5.13), uric acid levels ≥350 μmol/L (OR 2.29, 95% CI 1.04–5.30), emergency percutaneous intervention (OR 1.35, 95% CI 0.34–3.12), and triglyceride levels ≤1.30 mmol/L (OR 1.10, 95% CI 0.01–2.27) were independent risk factors for CIN in patients who underwent PCI.

Conclusions

Early prevention is required to reduce the occurrence of CIN in patients who undergo PCI and have risk factors for CIN.

Zero contrast optical coherence tomography-guided percutaneous coronary intervention in patients with non-ST segment elevation myocardial infarction and chronic kidney disease

OBJECTIVES

To investigate a strategy for ultra-low volume contrast percutaneous coronary intervention (PCI) with the aims of preserving renal function and observing the 90-day clinical endpoint in patients with non-ST-elevated myocardial infarction (non-STEMI) and chronic kidney disease (CKD).

BACKGROUND

The feasibility, safety, and clinical utility of PCI with ultra-low radio-contrast medium in patients with non-STEMI and CKD are unknown.

METHODS

A total of 29 patients with non-STEMI and CKD (estimated glomerular filtration rate [eGFR] of ≤60 ml/min/1.73 m² ) were included. Ultra-low volume contrast PCI was performed after minimal contrast coronary angiography using zero contrast optical coherence tomography (OCT) guidance. Pre- and post-PCI angiographic measurements were performed using quantitative flow ratio (QFR) for pre-perfusion assessment and verifying improvement.

RESULTS

The median creatinine level was 2.1 (inter-quartile range 1.8-3.3), and mean eGFR was 48 ± 8 ml/min/1.73 m² pre-PCI. During the PCI procedure, OCT revealed 15 (52%) cases of abnormalities post-dilation. There was no significant change in the creatinine level and eGFR in the short- or long-term, and no major adverse events were observed.

CONCLUSION

In non-STEMI patients with high-risk CKD who require revascularization, QFR and no contrast OCT-guided ultra-low contrast PCI may be performed safely without major adverse events.

Cumulative iodinated contrast exposure for computed tomography during acute kidney injury and major adverse kidney events

OBJECTIVES

To determine if contrast-enhanced CT imaging performed in patients during their episode of AKI contributes to major adverse kidney events (MAKE).

METHODS

A propensity score-matched analysis of 1127 patients with AKI defined by KDIGO criteria was done. Their mean age was 63 ± 16 years with 56% males. A total of 419 cases exposed to CT contrast peri-AKI were matched with 798 non-exposed controls for 14 covariates including comorbidities, acute illnesses, and initial AKI severity; outcomes including MAKE and renal recovery in hospital were compared using bivariate analysis and logistic regression. MAKE was a composite of mortality, renal replacement therapy, and doubling of serum creatinine on discharge over baseline; renal recovery was classified as early versus late based on a 7-day timeline from AKI onset to nadir creatinine or cessation of renal replacement therapy in survivors.

RESULTS

Sixty-two patients received cumulatively > 100 mL of CT contrast, 143 patients had > 50-100 mL, and 214 patients had 50 mL or less; MAKE occurred in 34%, 17%, and 21%, respectively, as compared with 20% in non-exposed controls (p = 0.008 for patients with > 100 mL contrast versus none). More contrast-exposed patients experienced late renal recovery (27% versus 20%) and longer hospital days (median 10 versus 8) than non-exposed patients (all p < 0.01). On multivariate analysis, cumulative CT contrast > 100 mL was independently associated with MAKE (odds ratio 2.39 versus non-contrast, adjusted for all confounders, p = 0.005); cumulative CT contrast under 100 mL was not associated with MAKE.

CONCLUSIONS

High cumulative volume of CT contrast administered to patients with AKI is associated with worse short-term renal outcomes and delayed renal recovery.

KEY POINTS

• Cumulative intravenous iodinated contrast for CT imaging of more than 100 mL, during an episode of acute kidney injury, was independently associated with worse renal outcomes and less renal recovery. • These adverse outcomes including renal replacement therapy were not more frequent in similar patients who received cumulatively 100 mL or less of CT contrast, compared with non-exposed patients. • More patients with CT contrast exposure during acute kidney injury experienced delayed renal recovery.

αKlotho protein has therapeutic activity in contrast-induced acute kidney injury by limiting NLRP3 inflammasome-mediated pyroptosis and promoting autophagy

Contrast-induced acute kidney injury (CI-AKI) is a main cause of hospital-acquired renal failure. Nevertheless, limited measures have been shown to be effective for the treatment of CI-AKI. Here, we demonstrated that αKlotho, which is highly expressed in kidney, has therapeutic activity in CI-AKI. Our data showed that αKlotho expression levels were decreased both in the kidney and serum of CI-AKI mice. Administration of αKlotho protein protected the kidney and HK-2 cells against contrast-induced injury. Mechanistically, αKlotho reduced contrast-induced renal tubular cells pyroptosis by limiting NLRP3 inflammasome activation. Meanwhile, αKlotho up-regulated autophagy via inhibiting the AKT/mTOR pathway and decreased mitochondrial ROS level. Inhibition of autophagy blunted the suppression effect of αKlotho on NLRP3 inflammasome activation and cell pyroptosis in contrast-treated HK-2 cells. Taken together, our data suggest that αKlotho protein protects against CI-AKI through inhibiting NLRP3 inflammasome-mediated pyroptosis, which is likely by promoting autophagy. αKlotho may be a promising therapeutic strategy for CI-AKI.

Computed Tomography Angiography of the Aorta-Optimization of Automatic Tube Voltage Selection Settings to Reduce Radiation Dose or Contrast Medium in a Prospective Randomized Trial

OBJECTIVES

The aim of this study was to compare the image quality of low-kV protocols with optimized automatic tube voltage selection (ATVS) settings to reduce either radiation dose or contrast medium (CM) with that of a reference protocol for computed tomography angiography (CTA) of the thoracoabdominal aorta.

MATERIALS AND METHODS

In this institutional review board-approved, single-center, prospective randomized controlled trial, 126 patients receiving CTA of the aorta were allocated to one of three computed tomography protocols: (A) reference protocol at 120 kVp and standard weight-adapted CM dose; (B) protocol at 90 kVp, reduced radiation and standard CM dose; and (C) protocol at 90 kVp, standard radiation and reduced CM dose. All three protocols were performed on a third-generation dual-source computed tomography scanner using the semimode of the ATVS system. The image-task-dependent optimization settings of the ATVS (slider level) were adjusted to level 11 (high-contrast task) for protocols A and B and level 3 (low-contrast task) for protocol C. Radiation dose parameters were assessed. The contrast-to-noise ratios (CNRs) of protocols B and C were tested for noninferiority compared with A. Subjective image quality was assessed using a 5-point Likert scale.

RESULTS

Size-specific dose estimate was 34.3% lower for protocol B compared with A (P < 0.0001). Contrast medium was 20.2% lower for protocol C compared with A (P < 0.0001). Mean CNR in B and C was noninferior to protocol A (CNR of 30.2 ± 7, 33.4 ± 6.7, and 30.5 ± 8.9 for protocols A, B, and C, respectively). There was no significant difference in overall subjective image quality among protocols (4.09 ± 0.21, 4.03 ± 0.19, and 4.08 ± 0.17 for protocols A, B, and C, respectively; P = 0.4).

CONCLUSIONS

The slider settings of an ATVS system can be adjusted to optimize either radiation dose or CM at noninferior image quality in low-kV CTA of the aorta. This optimization could be used to extend future ATVS algorithms to take clinical risk factors like kidney function of individual patients into account.

Left Ventricular End-Diastolic Pressure Versus Urine Flow Rate-Guided Hydration in Preventing Contrast-Associated Acute Kidney Injury

OBJECTIVES

This study compared left ventricular end-diastolic pressure (LVEDP)-guided and urine flow rate (UFR)-guided hydration.

BACKGROUND

Tailored hydration regimens improve the prevention of contrast-associated acute kidney injury (CA-AKI).

METHODS

Between July 15, 2015, and June 6, 2019, patients at high risk for CA-AKI scheduled for coronary and peripheral procedures were randomized to 2 groups: 1) normal saline infusion rate adjusted according to the LVEDP (LVEDP-guided group); and 2) hydration controlled by the RenalGuard System in order to reach UFR ≥300 ml/h (UFR-guided group). The primary endpoint was the composite of CA-AKI (i.e., serum creatinine increase ≥25% or ≥0.5 mg/dl at 48 h) and acute pulmonary edema (PE). Major adverse events (all-cause death, renal failure requiring dialysis, PE, and sustained kidney injury) at 1 month were assessed.

RESULTS

The primary endpoint occurred in 20 of 351 (5.7%) patients in the UFR-guided group and in 36 of 351 (10.3%) patients in the LVEDP-guided group (relative risk [RR]: 0.560; 95% confidence interval [CI]: 0.390 to 0.790; p = 0.036). CA-AKI and PE rates in the UFR-guided group and LVEDP-guided group were 5.7% and 10.0% (RR: 0.570; 95% CI: 0.300 to 0.960; p = 0.048), and, respectively, 0.3% and 2.0% (RR: 0.070; 95% CI: 0.020 to 1.160; p = 0.069). Three patients in the UFR-guided group experienced complications related to the Foley catheter. Hypokalemia rate was 6.2% in the UFR-guided group and 2.3% in the LVEDP-guided group (p = 0.013). The 1-month major adverse events rate was 7.1% in the UFR-guided group and 12.0% in the LVEDP-guided group (p = 0.030).

CONCLUSIONS

The study demonstrates that UFR-guided hydration is superior to LVEDP-guided hydration to prevent the composite of CA-AKI and PE.

Acute Kidney Injury After CT in Emergency Patients with Chronic Kidney Disease: A Propensity Score-matched Analysis

INTRODUCTION

Acute kidney injury (AKI) after intravenous contrast administration for computed tomography (CT) occurs infrequently, but certain patients may be susceptible. This study evaluated AKI incidence among emergency department (ED) patients with pre-existing chronic kidney disease (CKD) undergoing CT exams.

METHODS

This retrospective cohort study in an integrated healthcare system included ED patients previously diagnosed with CKD stages 3-5 (estimated glomerular filtration rate <60 milliliters per minute per 1.73 meters squared over at least three months), undergoing CT exams with or without intravenous contrast, from January 1, 2013-December 31, 2017. We excluded patients with CT prior to (30 days) or following (14 days) index CT and missing serum creatinine (sCr) measurements. We applied propensity score matching, and then multivariable regression adjustment for post-CT ED disposition and ED diagnosis, to calculate adjusted risk of AKI. Secondary patient-centered outcomes included 30-day mortality, end-stage renal disease (ESRD) diagnosis, and dialysis initiation.

RESULTS

Among 103,573 eligible ED patients undergoing CT, propensity score matching yielded 5,589 pairs. Adjusted risk ratio (ARR) for AKI was higher overall for contrast-enhanced CT (1.60; 95% confidence interval [CI], 1.43-1.79). However, secondary outcomes were infrequent: 19/5,589 non-contrast vs 40/5,589 contrast patients with new dialysis initiation at 30 days (adjusted risk 0.3% vs 0.7%; adjusted risk reduction 0.4%; 95% CI, 0.1%-0.7%).

CONCLUSION

In ED patients with chronic kidney disease undergoing CT, intravenous contrast was associated with higher overall adjusted risk of AKI, but patient-centered secondary outcomes were rare. The clinical significance of transient kidney injury after CT is unclear, although patients with advanced chronic kidney disease appear to have elevated risk.

A Novel Risk Assessment Model Using Urinary System Contrast Blush Grading to Predict Contrast-Induced Acute Kidney Injury in Low-Risk Profile Patients

Contrast-induced acute kidney injury (CI-AKI) can occur after coronary interventions despite protective measures. We evaluated the effect of urinary system contrast blush grading for predicting post-procedure CI-AKI in 486 patients with chronic coronary artery disease. Patient characteristics and blood samples were collected. Urinary system contrast blush grade was recorded during the coronary angiography and interventions. Post-procedure third to fourth day blood samples were collected for diagnosis of CI-AKI. The median age of the patients was 61 years (53-70, interquartile range), and 194 (39.9%) participants were female. Contrast-induced acute kidney injury occurred in 78 (16%) patients. By comparing full and reduced models with the likelihood ratio test, it was observed that in the reduced model, factors such as age, diabetes mellitus, body weight-adapted contrast media (CM), hemoglobin, and urinary system blush were associated with CI-AKI presence. The probability of CI-AKI presence increased slightly from grade 0 to 1 blush, but it increased sharply grade from 1 to 2 blush. According to our results, an increase in body weight-adapted CM and urinary blush grading were the main predictors of CI-AKI. These findings suggest that when body weight-adapted CM ratio exceeds 3.5 mL/kg and urinary contrast blush reaches grade 2, the patients should be followed up more carefully for the development of CI-AKI.

Impact of small and dense low-density lipoprotein (sd-LDL)on contrast-induced acute kidney injury in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVE

To investigate the impact of serum small and dense low-density lipoprotein (sd-LDL) on contrast-induced acute kidney injury (CI-AKI) after emergency percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHOD

From November 2019 to August 2020, 352 patients with STEMI who underwent primary PCI were recruited consecutively. Patients were divided into CI-AKI group (n = 71) and non-CI-AKI group (n = 281). CI-AKI was defined as an increase in serum creatinine (≥ 25% or ≥ 0.5 mg/dL) from baseline occurring 72 h after PCI. All subjects were tested for sd-LDL.

RESULTS

In the 352 eligible patients with STEMI receiving emergency PCI, 71 patients (20.2%) developed CI-AKI. The levels of sd-LDL in CI-AKI group was higher than those in the non-CI-AKI group, and the difference was statistically significant (P < 0.05). The area under the curve (AUC) of the sd-LDL was 0.741 [95% confidence interval (CI) 0.538-0.636] in the STEMI patients receiving emergency PCI. CI-AKI model included the following five predictors: sd-LDL, NLR, Diabetes, Pre-PCI eGFR, and Log NT-proBNP. The AUC of forecast probability was 0.835 [95% confidence interval (CI) 0.786-0.883].The Hosmer-Lemeshow test has a P value of 0.519, which confirms the model's goodness of fit.

CONCLUSION

Increased sd-LDL is independently associated with risk of CI-AKI in STEMI patients treated by primary PCI.

Obesity as a Risk Factor for Radiographic Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is common. Risk factors include preexisting renal impairment, diabetes, elderly age, and dehydration. In a single-centre prospective study, we investigated which factors are implicated for CIN in patients with peripheral arterial disease due for angiography. Serum creatinine was measured before, 1, 2, and 7 days post-angiography. We also considered the chronic kidney disease stage of the patients at admission and 48 hours post-contrast. All patients received 500 mL normal saline pre- and post-angiography and a low-osmolality contrast medium. 6 of 94 patients developed CIN: 1 required dialysis and 1 died partly due to renal failure. Only 2 factors were associated with CIN: body mass index (BMI; P = .019) and kidney function (P = .001); 4 of 6 patients with CIN were obese (BMI ≥30) and only 2 were nonobese (P = .0092). Diabetes, contrast volume, and age were not significant risk factors. Our results confirm renal impairment raises the risk of CIN. To our knowledge, we report for the first time that obesity may be a risk factor for CIN. Pending confirmatory studies and given the rising prevalence of obesity, this finding could help identify at-risk patients and hence reduce the burden of CIN.

Intravenous contrast use and acute kidney injury: a retrospective study of 1,238 inpatients undergoing computed tomography

OBJECTIVE

To determine the incidence of nephropathy induced by intravenous contrast in hospitalized patients undergoing computed tomography (CT).

MATERIALS AND METHODS

This was a retrospective cohort study involving 1,238 patients who underwent CT with or without intravenous administration of a contrast agent (iopromide). The primary outcome measure was acute kidney injury (AKI), as defined by the traditional criteria-an absolute or relative increase in serum creatinine (SCr) ≥ 0.5 mg/dL or ≥ 25% over baseline, respectively, at 2-3 days after contrast administration-and the newer, Kidney Disease: Improving Global Outcomes (KDIGO) criteria-an absolute or relative increase in SCr ≥ 0.3 mg/dL or ≥ 50% over baseline, respectively, at 2-7 days after contrast administration.

RESULTS

The overall incidence of AKI was 11.52% when the KDIGO criteria were applied. Univariate logistic regression demonstrated a significant association between an absolute post-CT increase in SCr ≥ 0.5 mg/dL and AKI, although that association did not retain significance in the multivariate analysis. Multivariate logistic regression initially found an association between an absolute post-CT increase in SCr ≥ 0.3 mg/dL and advanced age, although that association was not maintained after correction. We found no association between AKI and the risk factors evaluated.

CONCLUSION

We identified no criteria for contrast-induced nephropathy after CT; nor did we find AKI to be associated with the classical risk factors.

Novel biomarkers for post-contrast acute kidney injury identified from long non-coding RNA expression profiles

Background: Post-contrast acute kidney injury (PC-AKI) is a severe complication of cardiac catheterization. Emerging evidence indicated that long non-coding RNAs (lncRNAs) could serve as biomarkers for various diseases. However, the lncRNA expression profile and potential biomarkers in PC-AKI remain unclear. This study aimed to investigate novel lncRNA biomarkers for the early detection of PC-AKI. Methods: lncRNA profile in the kidney tissues of PC-AKI rats was evaluated through RNA sequencing. Potential lncRNA biomarkers were identified through human-rat homology analysis, kidney and blood filtering in rats and verified in 112 clinical samples. The expression patterns of the candidate lncRNAs were detected in HK-2 cells and rat models to evaluate their potential for early detection. Results: In total, 357 lncRNAs were found to be differentially expressed in PC-AKI. We identified lnc-HILPDA and lnc-PRND were conservative and remarkably upregulated in both kidneys and blood from rats and the blood of PC-AKI patients; these lncRNAs can precisely distinguish PC-AKI patients (area under the curve (AUC) values of 0.885 and 0.875, respectively). The combination of these two lncRNAs exhibited improved accuracy for predicting PC-AKI, with 100% sensitivity and 83.93% specificity. Time-course experiments showed that the significant difference was first noted in the blood of PC-AKI rats at 12 h for lnc-HILPDA and 24 h for lnc-PRND. Conclusion: Our study revealed that lnc-HILPDA and lnc-PRND may serve as the novel biomarkers for early detection and profoundly affect the clinical stratification and strategy guidance of PC-AKI.

[ESUR recommendations on the use of contrast media: Practice survey, review and commentary by CJN, FIRN and SFNDT]

Contrast media administration is classically considered to cause or worsen kidney failure. Recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. The present work evaluates the practice of French nephrologists, and provides a commentary on these recommendations based on an updated review of the literature. We conducted survey among French nephrologists, using an electronic questionnaire distributed by the Société Francophone de Néphrologie, Dialyse et Transplantation, the French Intensive care Renal Network and the Club des Jeunes Néphrologues. 266 responses were collected. The European Society of Urogenital Radiology guidelines are poorly known among the panel of nephrologists. Their practices differ from the guidelines by the more frequent and earlier implementation of measures to prevent renal failure post contrast media. In accordance with the guidelines, hydration is prescribed as a first-line preventive measure, mainly with saline and bicarbonate. Inhibitors of the renin-angiotensin-aldosterone system are frequently discontinued before an injection of contrast media, contrary to what is recommended. In conclusion, the European Society of Urogenital Radiology guidelines, which the working group endorses, but which are still too little known and applied in clinical nephrology in France, prompt nephrologists to lift some of the restrictions on the use of PCI as well as on the continuation of ARS inhibitors before injecting PCI.

Preventing a nonexistent entity: the curious case of contrast and acute kidney injury

PURPOSE OF REVIEW

In recent years, doubt has been cast on the existence of contrast-induced acute kidney injury. The skepticism has stemmed from observational studies from large administrative healthcare databases. Although they correctly call that contrast-induced acute kidney injury is less common than previously thought, they cannot completely exclude selection bias.

RECENT FINDINGS

Though less common than previously thought, contrast-induced acute kidney injury still exists. The only prophylactic method that remains valid is that of isotonic volume expansion, which is still deemed beneficial in high-risk patients. N-acetylcysteine and sodium bicarbonate are ineffective and their use should be abandoned.

SUMMARY

Contrast-induced kidney injury should be defined based on clinical grounds, not merely on biochemical numbers. More research to validate a clinical definition is necessary in order to accurately re-examine its incidence.

Coronary computed tomography angiography before on-pump cardiac surgery does not reduce the risk of postoperative acute kidney injury compared to coronary angiography

OBJECTIVES

Cardiac surgery and contrast media are both related to acute kidney injury. We investigated whether undergoing coronary computed tomography angiography, which uses less contrast medium, before on-pump cardiac surgery could reduce the risk of postoperative acute kidney injury compared to coronary angiography.

METHODS

In this retrospective study, 745 and 171 patients underwent coronary angiography and coronary computed tomography angiography, respectively, within 30 days before on-pump cardiac surgery. Postoperative acute kidney injury was defined according to Kidney Disease Improving Global Outcomes Definition and Staging criteria.

RESULTS

Age, hypertension, cardiopulmonary bypass time, and performing cardiac surgery within 24 h of preoperative angiography (odds ratio: 1.507, 95% confidence interval: 1.111‒2.045, P = 0.008) independently predicted postoperative acute kidney injury on multivariable analysis. After propensity score matching, the acute kidney injury incidence in coronary angiography and computed tomography angiography groups was 43% and 46%, respectively (P = 0.65), and the groups had similar intensive care unit stay (2 days vs. 2 days, P = 0.209), postoperative hospital stay (11 days vs. 12 days, P = 0.084), postoperative continuous renal replacement therapy use (0.6% vs 1.9%, P = 0.314), and in-hospital mortality (0 vs. 1.3%, P = 0.156). In-hospital outcomes were similar among patients who underwent preoperative coronary angiography or computed tomography angiography within 24 h before cardiac surgery.

CONCLUSION

Although coronary computed tomography angiography uses less contrast medium, it does not reduce the risk of postoperative acute kidney injury or improve in-hospital outcomes compared to coronary angiography.

Customised weight-based volume contrast media protocol in CT of chest, abdomen and pelvis examination

INTRODUCTION

Fixed volume (FV) contrast media administration during CT examination is the standard practice in most healthcare institutions. We aim to validate a customised weight-based volume (WBV) method and compare it to the conventional FV methods, introduced in a regional setting.

METHODS

220 patients underwent CT of the chest, abdomen and pelvis (CAP) using a standard FV protocol, and subsequently, a customised 1.0 mL/kg WBV protocol within one year. Both image sets were assessed for contrast enhancement using CT attenuation at selected regions-of-interest (ROIs). The visual image quality was evaluated by three radiologists using a 4-point Likert scale. Quantitative CT attenuation was correlated with the visual quality assessment to determine the HU's enhancement indicative of the image quality grades. Contrast media usage was calculated to estimate cost-savings from both protocols.

RESULTS

Mean patient age was 61 ± 14 years, and weight was 56.1 ± 8.7 kg. FV protocol produced higher contrast enhancement than WBV, p < 0.001. CT images' overall contrast enhancement was negatively correlated with body weight for FV protocol while the WBV protocol produced more consistent enhancement across different body weight. More than 90% of the images from both protocols were graded "Excellent". WBV protocol also enabled a 28% cost reduction with cost savings of US$1238.

CONCLUSION

The customised WBV protocol produced CT images which were comparable to FV protocol for CT CAP examinations. A median CT value of 100 HU can be an indicator of good image quality for the WBV protocol.

Kidney and contrast media: Common viewpoint of the French Nephrology societies (SFNDT, FIRN, CJN) and the French Radiological Society (SFR) following ESUR guidelines

Contrast medium administration is classically considered to cause or worsen kidney failure, but recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. Kidney injury does not constitute a contra-indication to the administration of iodinated contrast medium, as long as the benefit-risk ratio justifies it. Intravenous hydration with 0.9% NaCl or 1.4% sodium bicarbonate is the only validated measure for the prevention of post-iodine contrast nephropathy. This is necessary for intravenous or intra-arterial administration of iodinated contrast agent without first renal pass when the glomerular filtration rate is less than 30mL/min/1.73m², for intra-arterial administration of iodinated contrast agent with first renal passage when the glomerular filtration rate is less than 45mL/min/1.73m², or in patients with acute renal failure. The use of iodinated contrast medium should allow the carrying out of relevant examinations based on an analysis of the benefit-risk ratio and the implementation of measures to prevent toxicity when necessary.

A High Triglyceride-Glucose Index Is Associated With Contrast-Induced Acute Kidney Injury in Chinese Patients With Type 2 Diabetes Mellitus

Background and Objectives

Triglyceride-glucose (TyG) is an emerging vital indicator of insulin resistance and is associated with increased risk of T2DM and cardiovascular events. We aimed to explore the TyG index and contrast-induced acute kidney injury (CI-AKI) in patients with type 2 diabetes who underwent coronary angiology.

Methods

This study enrolled 928 patients with suspected coronary artery disease who underwent coronary angiology or percutaneous coronary intervention in Zhongda hospital. Patient data were divided into quartiles according to the TyG index: group 1: TyG ≤ 8.62; group 2: 8.629.45. CI-AKI was diagnosed according to the KIDIGO criteria. Demographic data, hematological parameters, coronary angiology data, and medications were all recorded. We calculated the TyG index using the following formula: ln [fasting TG (mg/dL)×FPG (mg/dL)/2].

Results

Patients who developed CI-AKI exhibited significantly higher TyG index levels compared to patients who did not develop CI-AKI. The incidence of CI-AKI sharply increased with increasing TyG. Univariate and multivariate analysis identified TyG as an independent risk factor for CI-AKI. The AUC of the ROC curve was as high as 0.728 when the value of TyG was 8.88. The corresponding sensitivity was as high as 94.9%. Adding the variable TyG to the model for predicting CI-AKI risk further increased the predictive value of the model from 80.4% to 82%.

Conclusions

High TyG is closely associated with increased incidence of CI-AKI, demonstrating that TyG is an independent risk factor for CI-AKI. TyG has potentially predictive value for CI-AKI and may play a crucial role in risk stratification in clinical practice.

Oral hydration compared to intravenous hydration in the prevention of post-contrast acute kidney injury in patients with chronic kidney disease stage IIIb: A phase III non-inferiority study (NICIR study)

OBJECTIVE

To evaluate the non-inferiority of oral hydration compared to intravenous (i.v.) hydration in the prevention of post-contrast acute kidney injury (PC-AKI) in patients with stage IIIb chronic kidney disease (CKD) referred for an elective contrast-enhanced computed tomography (CE-CT).

MATERIAL AND METHODS

This is a prospective, randomized, phase 3, parallel-group, open-label, non-inferiority trial. Patients were randomly assigned 1:1 to receive prophylaxis against PC-AKI either with oral hydration: 500 mL of water two hours before and 2000 mL during the 24 h after performing CE-CT or i.v. hydration: sodium bicarbonate (166 mmol/L) 3 mL/kg/h starting one hour before and sodium bicarbonate (166 mmol/L) 1 mL/kg/h during the first hour after CE-CT. 100 mL of non-ionic iodinated contrast was administered in all cases. The primary outcome was the proportion of PC-AKI in the first 48-72 h after CE-CT. Secondary outcomes were persistent PC-AKI, the need for hemodialysis, and the occurrence of adverse events related to prophylaxis.

RESULTS

Of 264 patients randomized between January 2018 and January 2019, 114 received oral hydration, and 114 received i.v. hydration and were evaluable. No significant differences were found (p > 0.05) between arms in clinical characteristics or risk factors. PC-AKI rate was 4.4 % (95 %CI: 1.4-9.9 %) in the oral hydration arm and 5.3 % (95 %CI: 2.0-11.1%) in the i.v. hydration arm. The persistent PC-AKI rate was 1.8 % (95 %CI: 0.2-6.2 %) in both arms. No patient required dialysis during the first month after CE-CT or had adverse effects related to the hydration regime.

CONCLUSION

In those with stage IIIb CKD referred for an elective CE-CT, we provide evidence of non-inferiority of oral hydration compared to i.v. hydration in the prevention of PC-AKI.

Cardiac Computed Tomography Perfusion: Contrast Agents, Challenges and Emerging Methodologies from Preclinical Research to the Clinics

Computed Tomography (CT) has long been regarded as a purely anatomical imaging modality. Recent advances on CT technology and Contrast Agents (CA) in both clinical and preclinical cardiac imaging offer opportunities for the use of CT in functional imaging. Combined with modern ECG-gating techniques, functional CT has now become a reality allowing a comprehensive evaluation of myocardial global and regional function, perfusion and coronary angiography. This article aims at reviewing the current status of cardiac CT perfusion and micro-CT perfusion with established and experimental scanners and contrast agents, from clinical practice to the experimental domain of investigations based on animal models of heart diseases.

Acute kidney injury: prevention, detection, and management. Summary of updated NICE guidance for adults receiving iodine-based contrast media

The National Institute for Health and Care Excellence (NICE) has recently updated the guideline for Acute kidney injury: prevention, detection and management (NG148), providing new recommendations on preventing acute kidney injury (AKI) in adults receiving intravenous iodine-based contrast media. The association between intravenous iodinated contrast media and AKI is controversial, particularly with widespread use of iso-osmolar agents. Associations between contrast media administration and AKI are largely based on observational studies, with inherent heterogeneity in patient populations, definitions applied, and timing of laboratory investigations. In an attempt to mitigate risk, kidney protection has typically been employed using intravenous volume expansion and/or oral acetylcysteine. Such interventions are in widespread use, despite lacking high-quality evidence of benefit. In the non-emergency setting, glomerular filtration rate (GFR) measurements should be obtained within the preceding 3 months before offering intravenous iodine-based contrast media. In the acute setting, adults should also have their risk of AKI assessed before offering intravenous iodine-based contrast media; however, this should not delay emergency imaging. Based on the evidence available from randomised controlled trials, the NICE committee recommends that oral hydration should be encouraged in adults at increased risk of AKI and that volume expansion with intravenous V fluids should only be considered for inpatients at particularly high risk.