Relation of contrast-induced nephropathy to long-term mortality after percutaneous coronary intervention

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.

The effect of uric acid and albumin ratio in undergoing lower extremity endovascular interventions for peripheral arterial disease related contrast induced nephropathy

BACKGROUND

Among patients undergoing percutaneous vascular intervention, contrast-induced nephropathy (CIN) is associated with increased morbidity and mortality. Serum uric acid/albumin ratio (UAR) has emerged as a new marker associated with poor cardiovascular outcomes. We aimed to evaluate the relationship between UAR and CIN occurrence in patients treated for peripheral artery disease.

METHODS

Patients underwent percutaneous intervention due to peripheral artery disease were enrolled. The primary endpoint was development of contrast related nephropathy. Patients were divided into 2 groups according to the CIN occurrence.

RESULTS

A total of 663 patients were enrolled and mean age was 62 ± 10 years. After the intervention, 45 patients had CIN and 618 patients did not have CIN. Logistic regression analysis was performed to define the parameters of CIN. Male gender, diabetes, UAR, contrast volume, presence of coronary artery disease, and C-reactive protein levels were found significant in univariate analysis. However, only UAR was found significant in multivariate analysis (odds ratio 95% confidence interval: 3.426 (1.059-11.079), (P = 0.040)).Therefore, it is the only independent predictor for occurrence of CIN.

CONCLUSIONS

UAR is a reliable scoring system, which predicts CIN in such patient group. This score is not only cost-effective also simple, which can be easily applied into the clinical practice.

Identification of co-expressed central genes and transcription factors in acute myocardial infarction and diabetic nephropathy

BACKGROUND

Acute myocardial infarction (AMI) and diabetic nephropathy (DN) are common clinical co-morbidities, but they are challenging to manage and have poor prognoses. There is no research on the bioinformatics mechanisms of comorbidity, and this study aims to investigate such mechanisms.

METHODS

We downloaded the AMI data (GSE66360) and DN datasets (GSE30528 and GSE30529) from the Gene Expression Omnibus (GEO) platform. The GSE66360 dataset was divided into two parts: the training set and the validation set, and GSE30529 was used as the training set and GSE30528 as the validation set. After identifying the common differentially expressed genes (DEGs) in AMI and DN in the training set, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses and protein-protein interaction (PPI) network construction were performed. A sub-network graph was constructed by MCODE, and 15 hub genes were screened by the Cytohubba plugin. The screened hub genes were validated, and the 15 screened hub genes were subjected to GO, KEGG, Gene MANIA analysis, and transcription factor (TF) prediction. Finally, we performed TF differential analysis, enrichment analysis, and TF and gene regulatory network construction.

RESULTS

A total of 46 genes (43 up-regulated and 3 down-regulated) were identified for subsequent analysis. GO functional analysis emphasized the presence of genes mainly in the vesicle membrane and secretory granule membrane involved in antigen processing and presentation, lipopeptide binding, NAD + nucleosidase activity, and Toll-like receptor binding. The KEGG pathways analyzed were mainly in the phagosome, neutrophil extracellular trap formation, natural killer cell-mediated cytotoxicity, apoptosis, Fc gamma R-mediated phagocytosis, and Toll-like receptor signaling pathways. Eight co-expressed hub genes were identified and validated, namely TLR2, FCER1G, CD163, CTSS, CLEC4A, IGSF6, NCF2, and MS4A6A. Three transcription factors were identified and validated in AMI, namely NFKB1, HIF1A, and SPI1.

CONCLUSIONS

Our study reveals the common pathogenesis of AMI and DN. These common pathways and hub genes may provide new ideas for further mechanistic studies.

The Impact of Contrast-Associated Acute Kidney Injury on All-Cause Mortality in Older Patients After Coronary Angiography:A 7.5-year Follow-Up

Older patients (≥75 years) after coronary angiography constitute an increasing proportion, but only limited data are available regarding the prognosis of geriatric contrast-associated acute kidney injury (CA-AKI). Patients (≥75 years) undergoing coronary angiography between December 2010 and September 2013 were consecutively enrolled. CA-AKI was defined as an increase in serum creatinine of 25% or .5 mg/dL from the baseline within 48-72 h of contrast exposure. All-cause mortality was assessed during median 7.5 years (interquartile range [IQR] 6.7-8.7 years) follow-up period. In total, 571 patients aged >75 years undergoing coronary angiography were enrolled in a single center study; 82 (14.4%) patients had CA-AKI. The all-cause mortality during the median 7.5 years follow-up period was 22.0% in patients with CA-AKI and 13.1% in patients without CA-AKI (P = .015). After adjusting for potential confounding factors, the multivariable analysis indicated that CA-AKI was related to an increased risk of all-cause mortality during the median 7.5-year follow-up (hazard ratio [HR]: 2.46; 95% CI: 1.29-4.7; P = .006). CA-AKI is a significant and independent predictor of long-term mortality for patients aged over 75 years who underwent coronary angiography.

Effects of Low-Osmolar Contrast Media on Long-Term Renal Impairment After Coronary Angiography: Iohexol Versus Iopromide

To investigate the long-term effects of 2 commonly used low-osmolar contrast media, iohexol and iopromide, on renal function and survival in patients who underwent coronary angiography. A total of 14,141 cardiology patients from 2006 to 2013 were recruited, of whom 1,793 patients (679 patients on iohexol and 1,114 on iopromide) were evaluated for long-term renal impairment and 5,410 patients (1,679 patients on iohexol and 3,731 on iopromide) were admitted for survival analyses spanning as long as 15 years. Univariate and multivariate logistic regression were used to explore the risk factors for long-term renal impairment. Cox proportional hazard regression was used to investigate the risk factors affecting survival. Propensity score matching and inverse probability of treatment weighting were applied to balance the baseline clinical characteristics. Patients receiving iohexol demonstrated a greater occurrence of renal impairment compared with those who received iopromide. Such difference remained consistent both before and after propensity score matching or inverse probability of treatment weighting, with a statistical significance of p <0.05. Among clinical variables, receiving contrast-enhanced contrast tomography/magnetic resonance imaging during follow-up, antihypertensive medication usage, presence of proteinuria, and anemia were identified as risk factors for long-term renal impairment (p = 0.041, 0.049, 0.006, and 0.029, respectively). During survival analyses, the difference was insignificant after propensity score matching and inverse probability of treatment weighting. In conclusion, administration of iohexol was more likely to induce long-term renal impairment than iopromide, particularly among patients diagnosed with anemia and proteinuria and those taking antihypertensive medication and with additional contrast exposure. The all-cause mortality, however, showed no significant difference between iohexol and iopromide administration.

Clinical Outcomes of Patients with Chronic Kidney Disease Undergoing Percutaneous Coronary Interventions with a Novel Dynamic Coronary Roadmap System

Dynamic coronary roadmap (DCR) is a novel technology that creates a real-time overlay of the coronary arteries in percutaneous coronary intervention (PCI) and has the potential to reduce the contrast volume. However, the efficacy of DCR in terms of clinical outcomes in patients with chronic kidney disease (CKD) remains to be fully elucidated.This single center retrospective study enrolled 275 patients with CKD who underwent PCI, and divided them into a DCR group (n = 124) and Non-DCR group (n = 151). Propensity score matching was performed to minimize the differences in baseline characteristics in 113 patient pairs. The primary endpoint was a composite outcome of all-cause death, hospitalization for heart failure, nonfatal myocardial infarction, or the introductory rate of dialysis within 2 years. The secondary endpoints were contrast medium volume, the incidence of contrast-induced acute kidney injury (CI-AKI), and the introductory rate of dialysis within 2 years.Although there was no significant difference in the success rate (DCR group: 99.1% versus Non-DCR group: 98.2%; P = 0.561), contrast volume (92.20 mL versus 115.97 mL; P = 0.002) was significantly lower in the DCR group. CI-AKI incidence was 0.9% versus 6.2% in the DCR and Non-DCR groups, respectively (P = 0.031). The composite outcome defined as primary endpoint occurred in 10 patients in the DCR group and 20 patients in the Non-DCR group (8.8% versus 17.7%; P = 0.049).From the perspective of acute and long-term clinical outcomes, DCR use may be effective for patients with CKD.

Post-contrast Acute Kidney Injury After Emergent and Elective Percutaneous Coronary Intervention (from the CREDO-Kyoto PCI/CABG Registry Cohort 3)

Post-contrast acute kidney injury (PC-AKI) is a common complication after percutaneous coronary intervention (PCI). However, it is unclear whether or not the effects of PC-AKI on long-term clinical outcomes were different between emergent and elective procedures. Among patients enrolled in the CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Grafting) registry cohort 3, we identified 10,822 patients treated using PCI (emergent PCI stratum: n = 5,022 [46%] and elective PCI stratum: n = 5,860 [54%]). PC-AKI was defined as ≥0.3 mg/100 ml absolute or 1.5-fold relative increase of serum creatinine within 72 hours after PCI. The incidence of PC-AKI was significantly higher after emergent PCI than after elective PCI (10.5% vs 3.7%, p <0.001). In the multivariable logistic regression model, emergent PCI was the strongest independent risk factor for PC-AKI in the entire study population. The excess adjusted risk of patients with PC-AKI relative to those without remained significant for all-cause death in both the emergent and elective PCI strata (hazard ratio 1.87, 95% confidence interval 1.59 to 2.21, p <0.001 and hazard ratio 1.31, 95% confidence interval 1.03 to 1.68, p = 0.03, respectively). There was a significant interaction between the PCI setting (emergent and elective) and the effect of PC-AKI on all-cause death, with a greater magnitude of effect in the emergent PCI stratum than in the elective PCI stratum (p for interaction = 0.01). In conclusion, the incidence of PC-AKI was 2.8 times higher after emergent PCI than after elective PCI. The excess mortality risk of PC-AKI relative to no PC-AKI was greater after emergent PCI than after elective PCI.

An interpretable machine learning model for the prevention of contrast-induced nephropathy in patients undergoing lower extremity endovascular interventions for peripheral arterial disease

BACKGROUND

Contrast-induced nephropathy (CIN) is a postprocedural complication associated with increased morbidity and mortality. An important risk factor for development of CIN is renal impairment. Identification of patients at risk for acute renal failure will allow physicians to make appropriate decisions to minimize the incidence of CIN. We developed a machine learning model to stratify risk of acute renal failure that may assist in mitigating risk for CIN in patients with peripheral artery disease (PAD) undergoing endovascular interventions.

METHODS

We utilized the American College of Surgeons National Surgical Quality Improvement Program database to extract clinical and laboratory information associated with 14,444 patients who underwent lower extremity endovascular procedures between 2011 and 2018. Using 11,604 cases from 2011 to 2017 for training and 2840 cases from 2018 for testing, we developed a random forest model to predict risk of 30-day acute renal failure following infra-inguinal endovascular procedures.

RESULTS

Eight variables were identified as contributing optimally to model predictions, the most important being diabetes, preoperative BUN, and claudication. Using these variables, the model achieved an area under the receiver-operating characteristic (AU-ROC) curve of 0.81, accuracy of 0.83, sensitivity of 0.67, and specificity of 0.74. The model performed equally well on white and nonwhite patients (Delong p-value = 0.955) and patients age < 65 and patients age ≥ 65 (Delong p-value = 0.659).

CONCLUSIONS

We develop a model that fairly and accurately stratifies 30-day acute renal failure risk in patients undergoing lower extremity endovascular procedures for PAD. This model may assist in identifying patients who may benefit from strategies to prevent CIN.

The acute impact of baseline renal function and contrast medium volume/estimated glomerular filtration rate ratio on reduced renal function following endovascular abdominal aortic aneurysm repair

OBJECTIVE

The aim of this study was to determine the acute impact of baseline serum creatinine, estimated glomerular filtration rate (eGFR), and contrast medium volume (CMV) on the incidence of reduced renal function (RRF) after endovascular abdominal aortic aneurysm repair (EVAR). We aimed to determine if the CMV/eGFR ratio was a predictor of RRF.

METHODS

This study is a retrospective review of EVAR patients in the Society for Vascular Surgery/Vascular Quality Initiative (SVS/VQI) from January 2015 to August 2020. Reduced renal function was defined as > 0.3 mg/dl (26.5 μmol/L), 50% increase from baseline, and temporary or permanent dialysis. Receiver operator characteristic (ROC) curve analyses were conducted for serum creatinine, eGFR, contrast volume, fluid volume, and CMV/eGFR ratio. Two data sets (training and test) were developed followed by multivariate analyses.

RESULTS

SVS/VQI data for EVAR contained 38,701 records, of which 30,539 were divided into training (n = 18,283; 60%) and test (n = 12,256; 40%) data sets. RRF rate for the training set was 3.6% (n = 667) and 3.4% (n = 420) for the test data. RRF patients included more females (29.4 vs 19.0%, p < 0.001), were older in age (75.6 + 8.4 vs 73.3 + 8.7 years), had more congestive heart failure (22.3 vs 12.2%, p < 0.001), and more COPD (42.0 vs 34.2%, p < 0.001). An ROC analysis revealed that eGRF, creatinine, contrast, intravenous fluid, and contrast medium volume (CMV)/eGFR ratio were all significantly (p < 0.05) correlated with RRF. The eGFR and CMV/eGFR ratio had the largest area under the curve, (0.26) and (0.65), respectively, while fluid had the lowest (0.54). Negative predictive values were 93.7 (CMV/eGFR), 93.9 (creatinine), 94.2 (eGFR), 92.8 (contrast), and 92.6 (intravenous fluid). Multivariate analysis of the training data set resulted in the CMV/eGFR ratio as an independent predictor of RRF (odds ratio, OR: 1.9 with 95% CI: 1.6, 2.2, p < 0.015). For the test data, the CMV/eGFR ratio was an independent predictor of RRF (OR: 1.8, CI: 1.4 to 2.2, p < 0.001) as well as several other variables.

CONCLUSION

RRF after EVAR is a dreaded and potentially devastating complication. Baseline serum creatinine, eGFR, contrast medium volume, and the ratio (CMV/eGFR) were all significantly associated with RRF. The optimal cut-off value for the CMV/eGFR ratio, ≤ 2, provides an easy-to-use equation to provide a suggested contrast target based on initial renal function with caution applied for high-risk patients.

Revascularization in Patients With Non-ST Elevation Myocardial Infarction and Advanced Chronic Kidney Disease

OBJECTIVE

To investigate the impact of revascularization on long-term survival and renal outcome in non-ST-elevation myocardial infarction (NSTEMI) patients with severe chronic kidney disease (CKD).

PATIENTS AND METHODS

This study includes NSTEMI patients with an estimated glomerular filtration rate <30 mL/min per 1.73 m², including those on chronic hemodialysis who were identified from the multicenter Chang Gung Research Database from January 1, 2007, to December 31, 2017. Inverse probability of treatment weighting was used to generate comparable groups. The survival and the risk of progression to chronic hemodialysis between those receiving revascularization, either percutaneous coronary intervention or coronary artery bypass graft, and those receiving medical therapy during index hospitalization were compared.

RESULTS

A total of 2821 NSTEMI patients with severe CKD, including 1141 patients on chronic hemodialysis, were identified. Of these, 1149 patients received revascularization and 1672 received medical therapies. The differences in demographics, comorbidities, and presentations between groups were balanced after inverse probability of treatment weighting. After a mean follow-up of 1.82 years, revascularization was associated with a lower risk of all-cause mortality (adjusted HR, 0.61; 95% CI, 0.54-0.70). For non-dialysis-dependent patients who had survival to discharge, revascularization had a higher risk of progression to chronic hemodialysis (adjusted HR, 1.83; 95% CI, 1.49-2.26) after a mean follow-up of 2.3 years.

CONCLUSION

Revascularization was associated with a lower risk of all-cause mortality in NSTEMI patients with severe CKD. For non-dialysis-dependent patients who survived to discharge, revascularization was associated with a higher risk of progression to chronic hemodialysis.

Contrast-associated acute kidney injury after percutaneous coronary interventions in patients with acute coronary syndrome: a real-world study

Aim. To study the incidence of contrast-associated acute kidney injury (CA-AKI) in patients with various forms of the acute coronary syndrome (ACS). Materials and methods. An observational, open, single-center, prospective study included 83 patients with ACS with indications for percutaneous coronary intervention. Of these, 40 were included in the ST-segment elevation ACS group, and 43 patients were included in the non-ST-segment elevation ACS group. The study is registered at ClinicalTrials.gov as NCT04163484. Before the intervention, all patients had a general examination, ECG, complete blood count, blood chemistry, and blood coagulation tests. Later, 24 and 48 hours after the intervention, the serum creatinine (SC) trend was assessed. The primary endpoint was the development of in-hospital CA-AKI according to KDIGO criteria within 72 h or before hospital discharge. Results. An increase in SC level by 25% from the baseline was observed in 6 patients in each subgroup of ACS. A marked increase in SC by 50% and a decrease in glomerular filtration rate were reported only in 2 patients (one in each subgroup of ACS). Conclusion. The study showed that the incidence of CA-AKI in patients with ACS with ST-segment elevation was 2.3%, and in the group of patients with ACS without ST-segment elevation 2.5%.

Patients with Different Stages of Chronic Kidney Disease Undergoing Intravenous Contrast-Enhanced Computed Tomography-The Incidence of Contrast-Associated Acute Kidney Injury

Introduction: Iodinated contrast medium (CM) is the third most common cause of acute kidney injury (AKI). However, the association is poorly known between the definitions of AKI between different stages of chronic kidney disease after intravenous CM administration. Methods: The dataset, covering a period of ~15 years (1 June 2008 to 31 March 2015), consisted of 20,018 non-dialytic adult patients who had received intravenous injections of non-ionic iso-osmolar CM, iodixanol, for enhanced computed tomography imaging. Contrast-associated AKI (CA-AKI), dialysis-required AKI, and mortality were analyzed. Results: A total of 12,271 participants were enrolled. CA-AKI increased significantly starting from stage 3A onward (p < 0.001). In summary, incidences of CA-AKI against different levels of chronic kidney disease were as follows: stage 1 (8.3%) = stage 2 (6.7%) < stage 3A (9.9%) < stage 3B (14.3%) < stage 4 (20.5%) = stage 5 (20.4%). The incidences of dialysis within 30 days were as follows: stage 1 (1%) = stage 2 (1.4%) = stage 3A (2.7%) < stage 3B (5.7%) < stage 4 (18%) < stage 5 (54.1%). The prediction of dialysis was good based on the baseline serum creatinine > 1.5 mg/dL (72.78% of sensitivity, 86.07% of specificity, 0.851 of area under curve) or baseline estimated glomerular filtration rate ≤ 38.49 mL/min/1.732 m2 (70.19% of sensitivity, 89.08% of specificity, 0.853 of area under curve). In multivariate Cox regression analysis model for CA-AKI, independent risk factors were stage 4 chronic kidney disease (p = 0.001) and shock (p = 0.001). Conclusion: Baseline serum creatinine and estimated glomerular filtration rate were good predictors for dialysis-required AKI. CA-AKI increased significantly since stage 3A chronic kidney disease. Stage 4 and 5 chronic kidney disease have the same risk for CA-AKI, but stage 5 chronic kidney disease has markedly higher risk for dialysis.

The Pathophysiology and the Management of Radiocontrast-Induced Nephropathy

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

A Comparison Between Two Definitions of Contrast-Associated Acute Kidney Injury for Long-Term Mortality in Elderly and Non-elderly Patients After Elective Percutaneous Coronary Intervention

Background: Contrast-associated acute kidney injury (CA-AKI) is responsible for a substantial proportion of the observed mortality that occurs after percutaneous coronary intervention (PCI), particularly in elderly patients. However, there has been significant and debate over whether the optimal definition of CA-AKI persists over prolonged periods due to variations in the prevalence and effects on prognosis. In this study, we aimed to identify whether different definitions of CA-AKI exert differential impacts on long-term mortality when compared between elderly and non-elderly patients receiving elective PCI. Methods: We prospectively investigated 5,587 consenting patients undergoing elective PCI between January 2012 and December 2018. We considered two classical definitions of CA-AKI from the European Society of Urogenital Radiology (ESUR) and the Acute Kidney Injury Network (AKIN). Multivariable Cox regression analysis was used to investigate the association between CA-AKI and long-term mortality. We also performed interaction and stratified analyses according to age (≤75 or >75 years). Results: The incidence of CA-AKI according to the ESUR and AKIN definitions was 18.7 and 6.1%, respectively. After a median follow-up of 2.1 years, multivariable Cox regression analysis indicated that CA-AKI according to the AKIN definition was a risk factor for long-term mortality in the overall population [hazard ratio (HR) = 2.20; 95% confidential interval (CI): 1.51-3.22; p < 0.001]; however, this was not the case for the ESUR definition (HR = 1.27; 95% CI: 0.92-1.76; p = 0.153). Further interaction analysis identified a significant interaction between age and the ESUR definition (p = 0.040). Stratified analyses also found an association between the ESUR definition and long-term mortality in patients >75 years of age (p = 0.011), but not in patients ≤75 years of age (p = 0.657). Conclusion: As a stringent definition of CA-AKI, the AKIN definition was significantly associated with long-term mortality in both non-elderly and elderly patients. However, in elderly patients, the more lenient definition provided by the ESUR was also significantly correlated with long-term mortality, which could sensitively identify high-risk elderly patients and may provide a better alternative.

Kidney Injury Molecule-1 Is Associated with Contrast-Induced Nephropathy in Elderly Patients with Non-STEMI

BACKGROUND

Contrast-induced nephropathy (CIN) is associated with an increased risk of major adverse cardiovascular events (MACE), and the association between CIN and oxidative mechanisms is well documented.

OBJECTIVE

This study aimed to evaluate the relationship between serum levels of kidney injury molecule-1 (KIM-1) and CIN in elderly patients with non-ST-segment elevation myocardial infarction (NSTEMI).

METHODS

This study included a total of 758 patients with NSTEMI, who underwent percutaneous coronary intervention (PCI); 15 developed CIN after PCI, and another 104 were the control group, matched for age > 65 years. Baseline to 48-to-72-hour laboratory values and clinical outcomes were recorded. Patients were followed during one year. P values of < 0.05 were considered significant.

RESULTS

CIN was observed in 12.60% of the patients. Serum KIM-1 was significantly higher in the CIN group than in the non-CIN group (14.02 [9.53 - 19.90] vs. 5.41 [3.41 - 9.03], p < 0.001). The Mehran score was significantly higher in the CIN group than in the non-CIN group (14 [5 - 22] vs. 5 [2 - 7], p = 0.001). MACE were significantly higher in the CIN group than in the non-CIN group (7 [46.70%] vs. 12 [11.50%], p = 0.001). Multivariate logistic regression analysis showed that baseline KIM-1 level (OR = 1.652, 95% CI: 1.20 - 2.27, p = 0.002) and Mehran score (OR = 1.457, 95% CI: 1.01 - 2.08, p = 0.039) were independent predictors of CIN in elderly patients with NSTEMI.

CONCLUSION

Baseline serum KIM-1 concentration and Mehran score are independent predictors of CIN in elderly patients with NSTEMI. Additionally, all-cause mortality, cardiovascular death, myocardial reinfarction, stroke, and MACE were significantly higher in the CIN group at one-year follow-up. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0).

Definition of acute kidney injury impacts prevalence and prognosis in ACS patients undergoing coronary angiography

Background

Development of acute kidney injury (AKI) in invasively managed patients with acute coronary syndrome (ACS) is associated with a markedly increased mortality risk. Different definitions of AKI are in use, leading to varying prevalence and outcome measurements. The aim of the present study is to analyze an ACS population undergoing coronary angiography for differences in AKI prevalence and outcome using four established AKI definitions.

Methods

944 patients (30% female) were enrolled in a prospective registry between 2003 and 2005 with 6-month all-cause mortality as outcome measure. Four established AKI definitions were used: an increase in serum creatinine (sCR) ≥ 1.5 fold, ≥ 0.3 mg/dl, and ≥ 0.5 mg/dl and a decrease in eGFR > 25% from baseline (AKIN 1, AKIN 2, CIN, and RIFLE definition groups, respectively).

Results

AKI rates varied widely between the different groups. Using the CIN definition, AKI frequency was lowest (4.4%), whereas it was highest if the RIFLE definition was applied (13.2%). AKIN 2 displayed a twofold higher AKI prevalence compared with AKIN 1 (10.2% vs. 5.3% (p < 0.001)). AKI was a strong risk factor for mid-term mortality, with distinctive variability between the definitions. The lowest mortality risk was found in the RIFLE group (HR 6.0; 95% CI 3.7–10.0; p < 0.001), whereas CIN revealed the highest risk (HR 16.7; 95% CI 9.9–28.1; p < 0.001).

Conclusion

Prevalence and outcome in ACS patients varied considerably depending on the AKI definition applied. To define patients with highest renal function-associated mortality risk, use of the CIN definition seems to have the highest prognostic relevance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01985-9.

Pentoxifylline for the prevention of contrast-induced nephropathy: systematic review and meta-analysis of randomised controlled trials

OBJECTIVES

To summarise current evidence on the use of pentoxifylline (PTX) to prevent contrast-induced nephropathy (CIN).

METHODS

The PubMed, Embase and CENTRAL databases were searched for randomised controlled trials including patients with and without PTX undergoing contrast media exposure. We analysed the incidence of CIN and serum creatinine changes before and after contrast media exposure. All statistical analyses were conducted with Review Manager V.5.3.

RESULTS

We finally enrolled in seven randomised controlled trials with a total of 1484 patients in this analysis. All of seven included studies were performed in patients undergoing angioplasty or stenting. The overall rates of CIN were 8.8% and 10.4% in the PTX groups and control groups, respectively. However, no significant reduction in the CIN rate was observed in the patients treated with PTX compared with the control groups (OR 0.81, 95% CI 0.57 to 1.13, I²=0, p=0.21). All studies reported no hospital mortality and the new requirement for dialysis during the trials.

CONCLUSION

Perioperative administration of PTX to patients undergoing angioplasty did not significantly reduce the development of CIN but showed some weak tendency of lower serum creatinine increase. Based on the available trials, the evidence does not support the administration of PTX for the prevention of CIN. More trials with larger sample sizes are needed to evaluate the role of PTX in CIN prevention.

Magnitude and associated factors of contrast induced nephropathy among patients undergoing coronary angiography and interventions at a cardiac referral hospital in Tanzania - a cross-sectional study

Introduction

contrast media are increasingly used in diagnostic and interventional procedures but are also known causes of acute kidney injury - a condition known as contrast induced nephropathy (CIN). We aimed to determine the magnitude and associated factors of CIN among patients undergoing coronary angiography and percutaneous coronary intervention at a cardiac referral hospital in Tanzania.

Methods

all adult patients undergoing elective coronary angiography and percutaneous coronary intervention at Jakaya Kikwete Cardiac Institute were consecutively enrolled between August 2017 and January 2018, if they fulfilled the inclusion criteria. Pre-procedure, 24- and 72-hours' post procedure serum creatinine was measured. CIN was defined as increase of ≥25% or absolute increase of ≥44μmol/L of serum creatinine within 72 hours following exposure to contrast media. Data analysis were done using SPSS Version 20. P-value of <0.05 was considered statistically significant.

Results

in total, 210 (94.6%) out of 222 patients seen during the study period fulfilled the inclusion criteria and were enrolled. Their mean (SD) age was 61.3 (10.9) years and 64.3% were men. Hypertension, diabetes, smoking and alcohol consumption was present in 86.7%, 37.7%, 12.4% and 37.6% respectively. The incidence of CIN was 19% within 72 hours post procedure. On multivariate logistic regression analysis, independent factors for developing CIN were history of heart failure (aOR=7.34), central obesity (aOR=3.12), triple vessel disease (aOR=10.14) and post procedure stay of ≥3 days (aOR=4.1), all p<0.05.

Conclusion

the incidence of CIN found in this population is high (19%) and is associated with heart failure, obesity, multi-vessel disease and longer post-procedure hospital stay.

Acute Kidney Injury After Repeated Exposure to Contrast Material for Coronary Angiography

Objective

To assess the incidence of contrast-associated acute kidney injury (CAAKI) after repeated exposure to contrast material for computed tomography (CT) and conventional coronary angiography within short intervals.

Methods

We studied 651 patients enrolled in the CorE-64 (November 5, 2005–January 30, 2007) and CORE320 (October 21, 2009–August 17, 2011) multicenter studies. Participants with suspected obstructive coronary heart disease were referred for diagnostic cardiac catheterization and underwent coronary CT angiography for research before invasive angiography. Nonionic, low-osmolality iodinated contrast material was used for all imaging.

Results

The median age of the patients was 62 years, and 190 (29%) were women. Major risk factors for acute kidney injury were present in 277 of 651 (43%) patients. The median interval between CT imaging and invasive angiography was 3.1 days (interquartile range, 0.9-8.0 days). The median volume of contrast material was 100 mL for each test. In 16 (2.5%) of 651 patients, CAAKI developed. Of these cases, 1 occurred after the CT scan, whereas 6 were documented after invasive angiography (compared with post-CT creatinine concentration assessment). In 9 patients, CAAKI was found in comparing creatinine concentration after completion of both tests with baseline values (but not compared with post-CT imaging).

Conclusion

Acute kidney injury after repeated exposure to iodinated contrast media within a few days is uncommon even in a population of patients with highly prevalent risk factors. Withholding of clinically indicated contrast-enhanced imaging may therefore not be justified in this setting.

What factors are Associated with the Development of Contras-induced Nephropathy in Elderly Patients with Acute Coronary Syndrome in Real Clinical Practice?

Aim. To study the factors associated with contrast-induced acute kidney injury in elderly patients with acute coronary syndrome (ACS).Material and Methods. A retrospective analysis of 514 electronic medical records of patients aged 75 years and over (38% men and 62% women) with confirmed acute coronary syndrome has been performed. The contrast-induced acute kidney injury was defined as an increase in serum creatinine ≥26.5 μmol/L in 48 h or as an increase in serum creatinine in 1.5 times within 7 days after the contrast media exposure. Patients were divided into contrast-induced acute kidney injury and non-contrast-induced acute kidney injury group. Clinical characteristics and in-hospital outcomes were extracted from patients' medical records. Procedural characteristics were obtained from laboratory database.Results. Angiographic intervention was performed in 74% of patients, 32% of them (more often in women, p=0.033) were diagnosed with contrast-induced acute kidney injury. Patients with contrast-induced acute kidney injury are characterized by a higher death rate (17% и 3%, p<0.001) and were more likely to have heart failure with reduced ejection fraction (34% и 21%, p=0.008) and acute heart failure (Killip class II-IV) (24% и 16%, p=0.015). The risk of developing contrast-induced acute kidney injury was related the volume of contrast medium administered.Conclusions. Prevention particular care should be taken to female patients older than 75 years with ACS, with a history of the chronic heart failure with reduced ejection fraction or acute heart failure (Killip class II-IV), and with a high volume of contrast media, highlighting that a perioperative comprehensive management strategy is needed to improve the prognosis.

[Contrast medium-induced acute kidney injury-Consensus paper of the working group "Heart and Kidney" of the German Cardiac Society and the German Society of Nephrology]

This consensus paper summarizes the expert consensus and recommendations of the working group "Heart and Kidney" of the German Cardiac Society (DGK) and the German Society of Nephrology (DGfN) on contrast medium-induced acute kidney injury. Potentially nephrotoxic contrast agents containing iodine are frequently used in interventional medicine and for computer tomography diagnostics. Acute kidney injury occurs in approximately 8-17% of patients exposed to contrast media. The risk factors and underlying pathophysiology are discussed and recommendations for the prophylaxis and treatment of contrast medium-induced acute nephropathy are presented.

Impact of contrast-induced acute kidney injury on the association between renin-angiotensin system inhibitors and long-term mortality in heart failure patients

INTRODUCTION

Renin-angiotensin system inhibitors (RASi) reduce mortality among heart failure (HF) patients, but their effect among those complicating contrast-induced acute kidney injury (CI-AKI) remains unexplored. We aimed to investigate whether the relationship between RASi prescription at discharge and mortality differs between HF patients with or without CI-AKI following coronary angiography (CAG).

METHODS

About 596 HF patients from an observational cohort were divided into a CI-AKI group (n = 104) and a non-CI-AKI group (n = 492) based on whether they had CI-AKI following CAG. The endpoint was all-cause mortality. Multivariable Cox regression was performed in each group to explore the associations between RASi at discharge and mortality.

RESULTS

During the median follow-up time of 2.26 (1.70; 3.24) years, higher mortality rate was observed in the CI-AKI group compared to the non-CI-AKI group (18.3% vs 8.9%, p = 0.002). Among HF patients with CI-AKI, after adjusting for confounding factors, the association was not significant between RASi prescription at discharge and mortality (HR: 0.39, 95%CI: 0.12-1.31, p = 0.128), while it was among those without CI-AKI (HR: 0.39, 95%CI: 0.18-0.84, p = 0.016).

CONCLUSION

RASi prescription at discharge for HF patients complicating CI-AKI tended to be ineffective, while it benefited those without CI-AKI. Further randomized evidence is needed to confirm this trend.

Five-year follow-up of patients with radio-contrast-induced acute renal injury. Can intravenous sodium-bicarbonate improve long-term outcomes?

BACKGROUND/PURPOSE

Radiocontrast-induced acute kidney injury (RAKI) is a frequent complication during angiography and is associated with adverse prognosis. Most of the studies evaluating the long-term outcome of patients with RAKI are based on institutional registries. This is the first prospective study to evaluate the 5-year outcomes of patients with RAKI, and assess the effect of sodium bicarbonate (SB) in the long-term outcomes of patients with chronic kidney disease (CKD) undergoing non-emergent coronary angiography.

MATERIALS/METHODS

382 CKD stage III-IV patients undergoing elective non-emergent coronary angiography were randomized to SB (n = 192) or normal saline (NS) solution (n = 190). Incidence of RAKI, in-hospital, 1- and 5-year mortality and renal replacement therapy (RRT), and 5-year major adverse renal and cardiovascular events (MARCE) were compared between groups. Outcomes of patient with and without RAKI were compared after five-years of prospective follow-up. Multivariate predictors of RAKI and death at 5-years were determined.

RESULTS

The use of SB did not improve the incidence of RAKI, in-hospital outcomes, survival, and freedom from RRT or MARCE after 5-years of follow-up. Patients that developed RAKI had a significantly higher mortality at 1-year [8.9% Vs. 1.2%] and 5-years (36% Vs. 11%) (P < 0.01).

CONCLUSIONS

Hydration with SB showed no benefit compared to NS in preventing RAKI. The use of SB was not superior to NS after 5-years of follow-up regarding MARCE, survival or freedom of RRT. Five-year mortality among patients who developed RAKI remains high, and further research is needed to find the best preventive strategy for this high-risk group of patients.

SUMMARY

Radiocontrast-induced acute-kidney-injury (RAKI) is associated with poor long-term outcomes in observational and short-term studies. Hydration with sodium bicarbonate (SB) had been evaluated in the prevention of RAKI; but its long-term effect has not been evaluated. We randomized 382 high high-risk patients undergoing coronary angiography to SB or normal saline following them for five years. SB showed no benefit in preventing RAKI, decreasing major adverse renal and cardiovascular events, improving survival or freedom from dialysis after 5-years. This is the first study to follow patients with RAKI for a period of 5-years, showing a significantly higher mortality in this group of patients.

Glycemic variability as predictor of contrast-induced nephropathy in diabetic patients with acute myocardial infarction undergoing percutaneous coronary intervention

Background

Contrast-induced nephropathy (CIN) is a frequent complication in patients undergoing percutaneous coronary intervention (PCI). Diabetes mellitus (DM) and acute myocardial infarction (AMI) are associated with an increased risk of CIN. However, it remains unclear whether glycemic variability (GV) has the important prognostic significance of CIN in diabetic patients with AMI undergoing PCI. We conducted this study to investigate the independent prognostic value of the in-hospital GV in diabetic patients who presented with AMI and were treated with PCI.

Methods

The study group comprised 252 diabetic patients with AMI who underwent PCI and were assigned to CINand non-CIN groups. A continuous glucose monitoring system (CGMS) was used to determine the mean amplitude of glycemic excursion (MAGE), a representative index of GV. Independent risk factors for CIN were determined by multivariate logistic regression analysis (MLRA), and receiver-operating characteristic (ROC) analysis was used to measure the prognostic potential of GV.

Results

A total of 55 patients had CIN and they showed markedly elevated MAGE compared with the non-CIN group. MLRA revealed that MAGE had potential to independently predict CIN. The area under the ROC curve, optimal cut-point value, sensitivity and specificity for MAGE were 0.739, 2.95, 70.91% and 61.42%, respectively.

Conclusions

In diabetic AMI patients undergoing PCI, high GV is associated with increased risk of CIN.

Prophylactic hemodialysis following coronary angiography and one-year outcomes in non-dialysis patients with chronic kidney disease: A propensity-matched study

BACKGROUND/PURPOSE

Prophylactic hemodialysis after coronary angiography in patients with chronic kidney disease (CKD) prevents contrast nephropathy; however, the one-year outcomes are unclear. This study aimed to investigate the one-year outcomes of prophylactic hemodialysis against standard treatment in patients with CKD who underwent coronary angiography.

METHODS

A cohort study of 359 patients with CKD, coronary artery disease (CAD), and serum creatinine levels of 176.8-530.4 μmol/L, who were referred for elective coronary angiography was conducted. Propensity score matching identified 118 patient pairs for outcome comparisons. The hemodialysis group underwent prophylactic hemodialysis after coronary angiography, whereas the control group received standard treatment. The study's primary outcome was free from dialysis was considered the primary outcome, whereas the secondary outcome was overall survival. Unadjusted estimates of the probability of free from dialysis and overall survival were computed using Kaplan-Meier survival curves and log-rank tests. Cox proportional-hazards regression models were used in determining the risk factors associated with ESRD and mortality.

RESULTS

During a mean 9.3 months follow-up duration, the hemodialysis group had significantly better free from dialysis (85.6% vs. 64.4%; P = 0.002) and overall survival (85.4% vs. 78.5%; P = 0.008) rates than the control group. Cox proportional-hazards regression analyses of the propensity score-matched patients showed that the hemodialysis group had reduced risks for ESRD and mortality (hazard ratios, 0.32 and 0.48, respectively).

CONCLUSION

Prophylactic Hemodialysis following coronary angiography was associated with reduced ESRD and mortality risks in CKD patients with CAD, who did not routinely undergo dialysis.

Determinants of In-Hospital Mortality After Percutaneous Coronary Intervention: A Machine Learning Approach

Background

The ability to accurately predict the occurrence of in‐hospital death after percutaneous coronary intervention is important for clinical decision‐making. We sought to utilize the New York Percutaneous Coronary Intervention Reporting System in order to elucidate the determinants of in‐hospital mortality in patients undergoing percutaneous coronary intervention across New York State.

Methods and Results

We examined 479 804 patients undergoing percutaneous coronary intervention between 2004 and 2012, utilizing traditional and advanced machine learning algorithms to determine the most significant predictors of in‐hospital mortality. The entire data were randomly split into a training (80%) and a testing set (20%). Tuned hyperparameters were used to generate a trained model while the performance of the model was independently evaluated on the testing set after plotting a receiver‐operator characteristic curve and using the output measure of the area under the curve (AUC) and the associated 95% CIs. Mean age was 65.2±11.9 years and 68.5% were women. There were 2549 in‐hospital deaths within the patient population. A boosted ensemble algorithm (AdaBoost) had optimal discrimination with AUC of 0.927 (95% CI 0.923–0.929) compared with AUC of 0.913 for XGBoost (95% CI 0.906–0.919, P=0.02), AUC of 0.892 for Random Forest (95% CI 0.889–0.896, P<0.01), and AUC of 0.908 for logistic regression (95% CI 0.907–0.910, P<0.01). The 2 most significant predictors were age and ejection fraction.

Conclusions

A big data approach that utilizes advanced machine learning algorithms identifies new associations among risk factors and provides high accuracy for the prediction of in‐hospital mortality in patients undergoing percutaneous coronary intervention.

See Editorial by Garratt and Schneider

Experimental studies on computed tomographic peritoneography. Peritoneal and residual renal function tolerance to iodinated contrast media injected into the peritoneal cavity

Computed tomographic (CT) peritoneography has been widely used as reference standard to evaluate continuous ambulatory peritoneal dialysis-related complications. However, given the varying CT peritoneography approaches used across different institutions, there is no standard value for non-ionic iodinated contrast media (ICM) concentration. Few studies have currently investigated whether non-ionic iodinated contrast media (non-ionic ICM) affects peritoneal function or residual renal function (RRF). This study aimed to determine whether different non-ionic ICM concentrations affect peritoneum and RRF and attempted to evaluate CT peritoneography images to identify the optimal non-ionic ICM concentrations in animals. To this end, 25 male Sprague-Dawley rats were used to establish uraemic models, after which they were injected with a 40-mL mixture of peritoneal dialysate and iohexol at varying concentrations prior to CT peritoneography. Thereafter, two experienced radiologists blinded to the rat groupings evaluated image quality, peritoneal morphology and thickness were assessed using hematoxylin and eosin and Masson staining, and RRF was evaluated using serum creatinine levels hematoxylin and eosin staining of pathological kidney sections. Briefly, non-ionic ICM had negligible effects on the peritoneum and RRF. Our results suggest that a mixture containing 50 mL (350 mgI/mL) iohexol/2 L peritoneal dialysate can be used as reference in rats.

The role of thiol levels in predicting contrast-induced nephropathy in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention

OBJECTIVE:

Contrast-induced nephropathy (CIN) is a common complication of diagnostic or interventional procedures that may arise from administration of intravascular contrast media. Recent studies have reported the thiol-disulfide ratio as a novel oxidative stress marker. Therefore, we investigated the role of thiol levels in predicting CIN in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PCI).

METHODS:

A total of 302 patients were enrolled in the study. CIN was defined as an increase in serum creatinine concentration ≥0.5 mg/dL compared with the admission value or a >25% relative rise during the first 48–72 hours after the procedure. To evaluate the relationship between thiol levels and CIN, the patients were divided into a CIN group and a non-CIN group.

RESULTS:

CIN occurred in 44 (15%) patients. Native thiol (274.8±84.7 μmol/L vs. 220.8±97.1 μmol/L, p=0.001) and total thiol (305.4±89.7 μmol/L vs. 260.1±102.1 μmol/L, p=0.009) levels were higher in patients within the non-CIN group. Disulfide (15.8±6.6 μmol/L vs. 19.6±8.4 μmol/L, p=0.002) levels, and mean disulfide/total thiol ratios (8.4±3.7 vs. 5.9±3.1, p=0.001) were higher in patients with CIN (+) group. In univariate analysis, the initial native thiol, total thiol, disulfide levels, and disulfide/total thiol ratio were found to have prognostic significance in the development of CIN. In the multivariate regression analysis, only the disulfide/total thiol ratio (OR=1.190; 95% CI: 1.090–1.300; p=0.001) was significantly and independently associated with CIN. The cutoff value of the disulfide/total thiol ratio to predict CIN on admission in patients with STEMI who underwent primary PCI was 7, with a sensitivity of 68.2% and a specificity of 79.8%.

CONCLUSION:

Our results suggest that thiol/disulfide homeostasis could be a good biochemical risk marker for CIN in STEMI patients who underwent primary PCI.

Efficacy of Oral Nicorandil to Prevent Contrast-Induced Nephropathy in Patients with Chronic Renal Dysfunction Undergoing an Elective Coronary Procedure

Objectives: This prospective, randomized study was to investigate the role of nicorandil in the prevention of contrast-induced nephropathy (CIN) in patients with chronic renal dysfunction undergoing an elective coronary procedure. Methods: A total of 252 eligible patients were enrolled in this study and allocated into the control group (n = 125) or nicorandil group (n = 127). Both groups received the standard hydration treatment, and patients in the nicorandil group were orally administrated 10 mg of nicorandil (t.i.d.) beginning 2 days before and continuing for 2 days after an elective coronary procedure. Serum creatinine (SCr) and cystatin C (CysC) were measured at 24 h before and 24, 48, and 72 h after the procedure. The occurrences of CIN and adverse events within 1 year were recorded. Results: The nicorandil group had relatively lower SCr and CysC levels and a higher eGFR at 24 and 48 h after the procedure than the control group (p < 0.05). The incidence of CIN was significantly decreased in the nicorandil group compared to the control group. The multivariate logistic regression model revealed that nicorandil treatment was an independent protective factor for CIN (OR 0.669, 95% CI 0.522–0.857, p = 0.001). The multivariate COX proportional hazard model showed that nicorandil treatment was an independent protective predictor for adverse events (HR 0.881, 95% CI 0.781–0.993, p = 0.037). Conclusions: Nicorandil could exhibit a protective effect against CIN in patients with chronic renal dysfunction undergoing an elective coronary procedure and reduce the adverse events within 1 year after the procedure, which is superior to hydration treatment only.

A simple risk score model for predicting contrast-induced nephropathy after coronary angiography in patients with diabetes

BACKGROUND

Contrast-induced nephropathy (CIN) is a common complication in patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI) and associated with poor outcome. Some previous studies have already set up models to predict CIN, but there is no model for patients with diabetes mellitus (DM) especially. Therefore, we aim to develop and validate a simple risk score for predicting the risk of CIN in patients with DM undergoing CAG/PCI.

METHODS

A total of 1157 consecutive patients with DM undergoing CAG/PCI were randomly assigned to a development cohort (n = 771) and a validation cohort (n = 386). The primary endpoint was CIN, which was defined as an absolute increase in serum creatinine (SCr) by 0.5 mg/dL from the baseline within 48-72 h after contrast exposure. The independent predictors for CIN were identified by multivariate logistic regression, and the discrimination and calibration of the risk score were assessed by ROC curve and Hosmer-Lemeshow test, respectively.

RESULTS

The overall incidence of CIN was 45 (3.9%). The new simple risk score (Chen score), which included four independent variables (age > 75 years, acute myocardial infarction, SCr > 1.5 mg/dL, the use of intra-aortic balloon pump), exhibited a similar discrimination and predictive ability on CIN (AUC 0.813, 0.843, 0.796, P > 0.05, respectively), mortality (AUC 0.735, 0.771, 0.826, respectively) and MACEs when being compared with the classical Mehran or ACEF risk score.

CONCLUSION

Our data suggest that the new simple risk score might be a good tool for predicting CIN in patients with DM undergoing CAG/PCI.

Nephrotoxicity of gadolinium-based contrast in the setting of renal artery intervention: retrospective analysis with 10-year follow-up

PURPOSE

We aimed to determine the incidence rate and potential risk factors for postcontrast acute kidney injury (PC-AKI) as well as the long-term clinical implications on dialysis and mortality in patients with chronic kidney disease (CKD) who underwent renal artery stent placement exclusively with gadolinium-based contrast agents.

METHODS

This retrospective study reviewed 412 patients with CKD who underwent renal artery stent placement. Sixty-eight patients underwent intervention exclusively with gadolinium-based contrast agents and were analyzed. Criteria for PC-AKI included either an absolute serum creatinine increase >0.3 mg/dL or percentage increase in serum creatinine >50% within 48 hours of intervention. Logistic regression analysis was performed to identify risk factors for PC-AKI. The cumulative proportion of patients who died or went on to hemodialysis was determined using Kaplan-Meier survival analysis.

RESULTS

The incidence of PC-AKI was 14.7%. The rate of AKI decreased for every 1 unit increase in glomerular filtration rate ( GFR, odds ratio [OR]=0.91, P = 0.047). Prehydration was associated with a lower PC-AKI rate (OR=0.17; P = 0.015). Acute kidney injury after intervention was associated with an increased rate of dialysis (Hazard ratio [HR]=4.51, P = 0.002) and mortality (HR=2.52; P = 0.027).

CONCLUSION

Gadolinium-based contrast agents are potentially nephrotoxic when used for endovascular intervention in patients with CKD. The risk of PC-AKI increased with lower GFR and decreased with prehydration. Dialysis and mortality risk were increased in patients who developed PC-AKI.

The role of nuclear factor erythroid-2-related factor 2 expression in radiocontrast-induced nephropathy

Radiocontrast-induced nephropathy (CIN) is the third most common cause of acute renal failure. The pathophysiology of CIN is related to tubular injury caused by oxidative stress, and nuclear factor erythroid-2-related factor 2 (Nrf2) is critical in coordinating intracellular antioxidative processes. We thus investigated the role of Nrf2 in CIN. CIN was established in mice and in NRK-52E cells via iohexol administration according to the protocols of previous studies. To determine the role of Nrf2 in CIN, Nrf2 expression was reduced in vivo using Nrf2 knockout (KO) mice (B6.129 × 1-Nfe2 l2tm1Ywk/J) and in vitro with siRNA treatment targeting Nrf2. Increased Nrf2 expression was observed after iohexol treatment both in vivo and in vitro. Serum creatinine at 24 h after iohexol injection was significantly higher in KO mice than in wild-type (WT) mice. Histologic examination showed that iohexol-induced tubular vacuolization and structural disruption were aggravated in Nrf2 KO mice. Significant increases in apoptosis and F4/80(+) inflammatory cell infiltration were demonstrated in KO mice compared to WT mice. In addition, the increase in reactive oxygen species after iohexol treatment was augmented by Nrf2 inhibition both in vivo and in vitro. Nrf2 may be implicated in the pathogenesis of CIN via the modulation of antioxidant, anti-apoptotic, and anti-inflammatory processes.

Contrast-Induced Nephropathy and Long-Term Clinical Outcomes Following Percutaneous Coronary Intervention in Patients With Advanced Renal Dysfunction (Estimated Glomerular Filtration Rate <30 ml/min/1.73 m2)

The incidence of contrast-induced nephropathy (CIN) increases with the progression of renal dysfunction. Recent reports have shown that percutaneous coronary intervention (PCI) can be safely performed even in patients with advanced renal dysfunction by appropriate CIN-prevention strategies. However, data are limited regarding the occurrence and prognostic influence of CIN in patients with advanced renal dysfunction. We examined the data obtained from 323 consecutive patients with advanced renal dysfunction (eGFR <30 ml/min/1.73 m²) who underwent PCI at 5 hospitals. CIN was defined as a ≥25% increase in baseline serum creatinine levels and/or a ≥0.5 mg/dl increase in absolute serum creatinine levels within 72 hours after PCI. Incidence of all-cause death and the initiation of permanent dialysis were examined during follow-up. The prevalence of emergency/urgent PCI was 53.3%. Intravascular ultrasound was used in 266 patients (82.4%), and the volume of contrast used was 71.7 ± 57.2 ml. CIN was observed in 31 patients (9.7%). The median follow-up duration was 656 days (interquartile range 257-1143 days). The cumulative rates of all-cause death or the initiation of permanent dialysis, all-cause death, and the initiation of permanent dialysis were 38.1%, 25.9%, and 18.2%, respectively, at 2 years. A comparison between patients with and without CIN showed no significant intergroup differences in the occurrence of the aforementioned events. In conclusion, the incidence of CIN was not high in Japanese patients with advanced renal dysfunction in routine clinical practice. Whereas, the long-term prognosis following PCI is observed to be poor in this studied population, and CIN did not show a significant prognostic influence.

Association of the blood urea nitrogen-to-left ventricular ejection fraction ratio with contrast-induced nephropathy in patients with acute coronary syndrome who underwent percutaneous coronary intervention

AIM

We investigated the predictive value of the blood urea nitrogen-to-left ventricular ejection fraction ratio (BUNEFr) to evaluate the risk of contrast-induced nephropathy (CIN) in acute coronary syndrome (ACS) patients who were treated with percutaneous coronary intervention (PCI).

METHODS

A total of 1010 ACS patients undergoing PCI were included in this study. The serum creatinine level was measured before and within 48-72 h of contrast medium administration. Contrast-induced nephropathy was defined as an absolute increase of 0.3 mg/dL or a relative increase of 25% from baseline serum creatinine within 48-72 h of contrast medium exposure. To evaluate the relation between BUNEFr and CIN, the patients were divided into a CIN group and a no-CIN group.

RESULTS

A total of 74 patients developed CIN (7.3%). Patients with CIN were older and had a higher BUNEFr than those without. Multivariate analysis showed that age, hypotension or positive inotrope support, history of stroke, contrast volume, and BUNEFr (OR 10.59, 95% CI 2.803-40.070, p = 0.001) were independent predictors of CIN. For the development of CIN, the AUC of a multivariable model that included hypotension or positive inotrope support, history of stroke, and contrast volume was 0.813 (95% CI 0.758-0.857, p < 0.001). When BUNEFr was added to a multivariable model, the AUC was 0.859 (95% CI 0.814-0.894, z = 3.204, difference p = 0.0014). Moreover, the addition of BUNEFr to a multivariable model was associated with a significant net reclassification improvement estimated at 49.4% (p < 0.001) and an integrated discrimination improvement of 0.044 (p = 0.0138).

CONCLUSION

The BUNEFr may be a useful new predictor of CIN in ACS patients treated with PCI. The inclusion of BUNEFr in a multivariable model could allow improved risk classification in these patients regarding the development of CIN.

Impact of Chronic Kidney Disease on Utilization of Coronary Angiography and Percutaneous Coronary Intervention, and Their Outcomes in Patients With Non-ST Elevation Myocardial Infarction

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease. Coronary angiography (CAG) and percutaneous coronary intervention (PCI) are frequently performed in patients presenting with a non-ST elevation myocardial infarction (NSTEMI). Utilizing the National Inpatient Sample database, we assessed the trends in utilization of CAG, PCI, and coronary artery bypass grafting in 3,654,586 admissions with NSTEMI from 2001 to 2012. The rates of CAG were 54%, 36.1%, and 45.9%, respectively, in patients with normal renal function, patients with CKD not on renal replacement therapy (RRT), and patients with CKD requiring RRT. The in-hospital mortality for patients with NSTEMI was significantly higher in patients with CKD-3.9% in patients without CKD, 6.9% in CKD patients not on RRT, and 8.6% in CKD patients needing RRT. In a propensity-matched cohort of 126,740 NSTEMI admissions, CKD was associated with increased in-hospital mortality (7.9% vs 5.3%, p <0.001), acute kidney injury (34.3 % vs 10.6%, p <0.001), lower use of CAG (37.8% vs 46.4%, p <0.001), and PCI (16.2% vs 20.8, p <0.001), higher hospital costs ($17,333 vs $15,583, p <0.001), and a longer length of stay (6.8 days vs 5.5 days, p <0.001). PCI was associated with decreased mortality (odds ratio of 0.31 ± 0.01, p <0.001) in all the 3 groups. In conclusion, CKD is a marker of adverse outcomes in patients with NSTEMI. Although CAG and PCI were associated improved outcomes, they remain underutilized in these patients.

Contrast-induced Nephropathy Following Percutaneous Coronary Intervention at a Tertiary Cardiac Center in Nepal

Background

Contrast-induced nephropathy (CIN) is one of the leading causes of morbidity and mortality including increased financial burden in high risk patients undergoing percutaneous coronary intervention (PCI).

Methods

This is an observational prospective study. We aimed to study the incidence of CIN in Nepalese populations and compare the outcome to international reprinted values with coronary artery disease (CAD) undergoing PCI. All consecutive patients with CAD undergoing PCI between February 2010 and July 2010 were enrolled in the study.

Results

One hundred fifty-two patients were enrolled in the study during six months period. Twenty (13.20%) patients developed CIN following PCI. Out of them 70% were diabetics and 30% were non-diabetics. Mean age of patients was 58.5 ± 23 years; male:female ratio was 2.7:1. Mean contrast volume injected was 160.3  ±  78.3  mL. Diabetic patients 21.8% (14/64) had significant CIN compared to non-diabetic patients 6.8% (6/88) following PCI (<0.01).

Conclusions

CIN is a common complication following PCI especially in diabetics. Despite the use of iodinated material we had similar incidence of CIN comparing the incidence of CIN among various radiocontrast compounds used to visualize vessels. None of the patients received hemodialysis as compared to available studies and there was no observed mortality.

Acute Kidney Injury and mortality prognosis in Acute Coronary Syndrome patients: A meta-analysis

AIM

The aim of this study is to provide a robust estimate of mortality risk in acute coronary syndrome (ACS)-associated acute kidney injury (AKI) to inform clinical practice and policy.

METHODS

A meta-analysis of cohort studies evaluating outcomes of ACS and which reported AKI and AKI-associated mortality. Studies were excluded if they incorporated patients not admitted through the emergency department (i.e. for elective procedures), were limited to cardiogenic shock or cardiac arrest, or relied on registry data for outcomes without further adjudication. The predictor was ACS-associated AKI and outcomes early (30 day or in-hospital) mortality and late-mortality (post-hospital discharge).

RESULTS

Thirty-six studies with 37 unique cohorts comprising 100 476 patients were included. The pooled rate of ACS-associated AKI was 15.8%. In 32 cohorts reporting early mortality, the crude early mortality rate was 15.0% amongst those with AKI compared with 2.0% amongst those without AKI. The pooled estimate of the relative risk of AKI-associated early mortality was 4.1 (95% confidence interval: 3.3 to 5.0) with high heterogeneity between studies (I ²  = 84% (61% to 88%)). When heterogeneity was accounted for mathematically using credibility ceilings, the risk of mortality was lower, but still clinically significant (3.1 (2.6 to 3.6)). In 19 cohorts reporting late mortality (1 to 10 years), the relative risk of AKI-associated mortality was 2.6 (2.0 to 3.3) with moderate heterogeneity (I ²  = 65 % [35% to 88%]). Following application of credibility ceiling relative risk estimate dropped to 2.2 (1.9 to 2.6).

CONCLUSIONS

Acute coronary syndrome-associated AKI is associated with more than a three-fold increase in early mortality and more than two-fold in long-term mortality.

Race, contrast-induced nephropathy and long-term outcomes after coronary and peripheral angiography and intervention

BACKGROUND

Contrast-induced nephropathy (CIN) is a complication of diagnostic angiography and percutaneous coronary and endovascular intervention. We investigated the effect of race on the development of CIN.

METHODS

We studied 4070 predominantly male patients undergoing peripheral and coronary angiography and percutaneous coronary and endovascular intervention. We analyzed the incidence of CIN at 72 h, of renal dysfunction at 3 months as well as the long-term incidence of hemodialysis and of death.

RESULTS

The mean age was 67.2 years. CIN occurred in 92 (7.1%) Caucasian patients and in 42 (6.6%) non-Caucasians at 72 h after the procedure (odds ratio [OR] 1.08, 95% confidence interval [CI] 0.74-1.57; P = 0.69). At 3 months, renal dysfunction was seen in 231 (11.24%) Caucasian patients versus 121 (11.52%) of the non-Caucasian group (OR 0.97, CI 0.77-1.23; P = 0.81). After a follow-up of 5 years, of the 4070 patients, 17 patients (0.64%) of the Caucasian group were placed on dialysis versus 27 (1.88%) of the non-Caucasian group (OR 0.34, 0.18-0.62; P = 0.0004) and 535 (20.28%) of the Caucasian patients had died compared to 293 (20.44%) of the non-Caucasian group (OR = 0.99, 95% CI 0.85-1.17; P = 0.94).

CONCLUSIONS

In this cohort of patients, race was not associated with the development of CIN at 72 h, or the development of renal dysfunction at 3 months post angiography or intervention. In the long-term, the rate of initiation of dialysis was significantly lower in the Caucasian patients but mortality was not.

Clinical Implications of Contrast-Induced Nephropathy in Patients Without Baseline Renal Dysfunction Undergoing Coronary Angiography

BACKGROUND

The clinical implications of different definitions of contrast-induced nephropathy (CIN) in patients without baseline renal dysfunction are not well defined.

METHODS

Consecutive patients at a single centre without baseline renal dysfunction (estimated glomerular filtration rate, eGFR≥60ml/min/1.73m²) undergoing coronary angiography or percutaneous coronary intervention (PCI), were systematically evaluated for long-term risk of mortality following CIN using two broad definitions: an absolute increase from baseline in serum creatinine (SCr) ≥0.3mg/dl (mild to severe absolute CIN) and a relative increase from baseline of 25% (mild to severe relative CIN) within 72hours.

RESULT

Of 2,823 subjects alive before discharge following coronary angiography there were 320 episodes of mild to severe relative CIN (11.3%) and 125 of mild to severe absolute CIN (4.4%). During a median follow-up of 2.3years, 73 patients (3.2%) died. After adjustment for confounders, mild to severe absolute CIN was associated with an adjusted hazard ratio (HR) (95% confidence interval) for all-cause mortality of 3.31 (1.74-6.30) (p<0.0001) and relative CIN with an adjusted HR of 1.92 (1.09, 3.38) (p=0.024). The risk of mortality rose with severity of CIN. Two commonly used definitions of CIN combining absolute and relative terms (increase ≥ 0.3mg/dl or 50%, and ≥ 0.5mg/dl or 25% from the baseline) confirmed these results.

CONCLUSION

Among patients without baseline renal dysfunction undergoing coronary angiography, the incidence of CIN can range widely depending on definition. Absolute CIN is less common than relative CIN. Regardless of definition, CIN is associated with a markedly increased risk of long-term mortality. This finding requires confirmation in multicentre studies.

RenalGuard system to prevent contrast-induced acute kidney injury in Japanese patients with renal dysfunction; RESPECT KIDNEY study

Increasing the urine flow rate (UFR) reduces the toxic effect of contrast media. Use of the RenalGuard system enables the achievement of a high UFR by maintaining intravascular volume and prevents the development of contrast-induced acute kidney injury (CI-AKI). However, the efficacy and safety of RenalGuard system have not yet been evaluated in Japan. This multicenter prospective study evaluated the efficacy and safety of the RenalGuard therapy in preventing CI-AKI development in 60 Japanese patients with renal dysfunction [estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m²] undergoing catheter procedures. Baseline eGFR and Mehran's CIN (contrast-induced nephropathy) risk score were 35.1 ± 8.5 mL/min/1.73 m² and 11.7 ± 4.3, respectively. Regardless of this high-risk profile, the incidence of CI-AKI was 8.6% (5/58) compared with the 26.1% incidence estimated by the CIN risk score. Moreover, two-sided 95% (Fisher's) exact confidence interval was 2.9-19.0 and its upper limit (i.e., 19.0) was less than the prespecified threshold incidence of 25.0. Univariate logistic regression analysis demonstrated that the UFR during catheter procedure was one of the most important factor associated with CI-AKI (odds ratio 0.99, confidence interval 0.98-1.00, p = 0.03). In conclusion, RenalGuard therapy may prevent CI-AKI development in Japanese patients with renal dysfunction. Further large-scale prospective multicenter studies are necessary to confirm our findings.

Impact of Transient or Persistent Contrast-induced Nephropathy on Long-term Mortality After Elective Percutaneous Coronary Intervention

Contrast-induced nephropathy (CIN) is associated with increased long-term mortality. However, it is still controversial whether CIN is the cause of increased mortality or merely a marker of high-risk patients. The current study population included 5,516 patients who underwent their first elective percutaneous coronary intervention (PCI) in the Coronary REvascularization Demonstrating Outcome Study in Kyoto registry cohort-2. CIN was defined as an elevation in the peak serum creatinine (SCr) of ≥0.5 mg/dl from the baseline within 5 days after PCI. CIN, seen in 218 patients (4.0%), was independently associated with an increased long-term mortality risk (hazard ratio [HR] 1.43, 95% confidence interval [CI],1.11 to 1.83; p = 0.005). SCr data at 1 year (180 to 550 days) after PCI were available in 3,986 patients, who were subdivided into persistent CIN (follow-up SCr elevation ≥0.5 mg/dl: n = 50 [1.3%]), transient CIN (follow-up SCr elevation <0.5 mg/dl: n = 90 [2.3%]), and non-CIN (n = 3,846 [96.5%]). In the landmark analysis at 1 year after PCI, 524 patients (13.1%) died during a median follow-up of 1,521 days. After adjustment for the 37 confounders, persistent CIN, but not transient CIN, was significantly correlated with a higher long-term mortality risk compared with non-CIN (HR 1.84, 95% CI 1.12 to 3.03; p = 0.02, and HR 1.11, 95% CI 0.71 to 1.76; p = 0.6, respectively). In conclusion, only persistent CIN was independently associated with increased long-term mortality.

Predictors and Outcomes of Postcontrast Acute Kidney Injury after Endovascular Renal Artery Intervention

PURPOSE

To determine incidence, predictors, and clinical outcomes of postcontrast acute kidney injury (PC-AKI) following renal artery stent placement for atherosclerotic renal artery stenosis.

MATERIALS AND METHODS

This retrospective study reviewed 1,052 patients who underwent renal artery stent placement for atherosclerotic renal artery stenosis; 437 patients with follow-up data were included. Mean age was 73.6 years ± 8.3. PC-AKI was defined as absolute serum creatinine increase ≥ 0.3 mg/dL or percentage increase in serum creatinine ≥ 50% within 48 hours of intervention. Logistic regression analysis was performed to identify risk factors for PC-AKI. The cumulative proportion of patients who died or went on to hemodialysis was determined using Kaplan-Meier survival analysis.

RESULTS

Mean follow-up was 71.1 months ± 68.4. PC-AKI developed in 26 patients (5.9%). Patients with PC-AKI had significantly higher levels of baseline proteinuria compared with patients without PC-AKI (odds ratio = 1.38; 95% confidence interval, 1.11-1.72; P = .004). Hydration before intervention, chronic kidney disease stage, baseline glomerular filtration rate, statin medications, contrast volume, and iodine load were not associated with higher rates of PC-AKI. Dialysis-free survival and mortality rates were not significantly different between patients with and without PC-AKI (P = .50 and P = .17, respectively).

CONCLUSIONS

Elevated baseline proteinuria was the only predictor for PC-AKI in patients undergoing renal artery stent placement. Patients who developed PC-AKI were not at greater risk for hemodialysis or death.