Pre-procedural glucose levels and the risk for contrast-induced acute kidney injury in patients undergoing coronary angiography

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

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

Association of random glucose to albumin ratio with post-contrast acute kidney injury and clinical outcomes in patients with ST-elevation myocardial infarction

Purpose

Both glucose and albumin are associated with chronic inflammation, which plays a vital role in post-contrast acute kidney injury (PC-AKI). To explore the relationship between random glucose to albumin ratio (RAR) and the incidence of PC-AKI after percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI).

Patients and methods

STEMI patients who underwent PCI were consecutively enrolled from January, 01, 2010 to February, 28, 2020. All patients were categorized into T1, T2, and T3 groups, respectively, based on RAR value (RAR < 3.377; 3.377 ≤ RAR ≤ 4.579; RAR > 4.579). The primary outcome was the incidence of PC-AKI, and the incidence of major adverse clinical events (MACE) was the second endpoint. The association between RAR and PC-AKI was assessed by multivariable logistic regression analysis.

Results

A total of 2,924 patients with STEMI undergoing PCI were finally included. The incidence of PC-AKI increased with the increasing tertile of RAR (3.2% vs 4.8% vs 10.6%, P<0.001). Multivariable regression analysis demonstrated that RAR (as a continuous variable) was associated with the incidence of PC-AKI (adjusted odds ratio (OR) =1.10, 95% confidence interval (CI) =1.04 - 1.16, P<0.001) and in-hospital MACE (OR=1.07, 95% CI=1.02 - 1.14, P=0.012); RAR, as a categorical variable, was significantly associated with PC-AKI (T3 vs. T1, OR=1.70, 95% CI=1.08 - 2.67, P=0.021) and in-hospital MACE (T3 vs. T1, OR=1.63, 95% CI=1.02 - 2.60, P=0.041) in multivariable regression analyses. Receiver operating characteristic curve analysis showed that RAR exhibited a predictive value for PC-AKI (area under the curve (AUC)=0.666, 95% CI=0.625 - 0.708), and in-hospital MACE (AUC= 0.662, 95% CI =0.619 - 0.706).

Conclusions

The high value of RAR was significantly associated with the increasing risk of PC-AKI and in-hospital MACE after PCI in STEMI patients, and RAR offers a good predictive value for those outcomes.

The impact of the stress hyperglycemia ratio on the risk of contrast-associated acute kidney injury in patients undergoing coronary angiography: a large real-world cohort study

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is an important complication in the perioperative period of coronary angiography (CAG). Dysglycemia is closely associated with the occurrence of CA-AKI. However, the association between stress hyperglycemia and CA-AKI in patients undergoing CAG remains unclear. The study aims to investigate the association of the stress hyperglycemia ratio (SHR) and CA-AKI under CAG in a large real-world cohort.

METHODS

This was a retrospective observational study, and patients undergoing CAG were enrolled. SHR is calculated by dividing the random blood glucose with the estimated average glucose derived from the glycosylated hemoglobin (HbA1c), and subjects were divided into five groups according to SHR. The outcome was CA-AKI defined as an increase in serum creatinine of ≥ 0.3 mg/dL (26.5 μmol/L) or 1.5-fold higher than normal levels in 48 h. The association was assessed with logistic regression and restricted cubic spline analysis.

RESULTS

In 19,965 participants (men: 73.3%, mean age: 63.1 ± 10.8 years) undergoing CAG, a total of 1,621 CA-AKI cases occurred. There were reverse J-shaped associations between the SHR and CA-AKI after adjustment for other confounding factors. Moreover, SHR improved the predictive effectiveness of the traditional Mehran score (AUC 0.65 vs 0.63, P < 0.001), a predictive model of CA-AKI in patients undergoing percutaneous coronary intervention.

CONCLUSIONS

There were reverse J-shaped associations of SHR with CA-AKI risk among patients undergoing CAG, and the assessment of SHR before CAG may assist clinicians in identifying patients at higher risk of CA-AKI.

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.

Association between fasting stress hyperglycemia ratio and contrast-induced acute kidney injury in coronary angiography patients: a cross-sectional study

Aims

Stress hyperglycemia ratio (SHR), an emerging indicator of critical illness, exhibits a significant association with adverse cardiovascular outcomes. The primary aim of this research endeavor is to evaluate the association between fasting SHR and contrast-induced acute kidney injury (CI-AKI).

Methods

This cross-sectional study comprised 3,137 patients who underwent coronary angiography (CAG) or percutaneous coronary intervention (PCI). The calculation of fasting SHR involved dividing the admission fasting blood glucose by the estimated mean glucose obtained from glycosylated hemoglobin. CI-AKI was assessed based on elevated serum creatinine (Scr) levels. To investigate the relationship between fasting SHR and the proportion of SCr elevation, piecewise linear regression analysis was conducted. Modified Poisson's regression analysis was implemented to evaluate the correlation between fasting SHR and CI-AKI. Subgroup analysis and sensitivity analysis were conducted to explore result stability.

Results

Among the total population, 482 (15.4%) patients experienced CI-AKI. Piecewise linear regression analysis revealed significant associations between the proportion of SCr elevation and fasting SHR on both sides (≤ 0.8 and > 0.8) [β = -12.651, 95% CI (-23.281 to -2.022), P = 0.020; β = 8.274, 95% CI (4.176 to 12.372), P < 0.001]. The Modified Poisson's regression analysis demonstrated a statistically significant correlation between both the lowest and highest levels of fasting SHR and an increased incidence of CI-AKI [(SHR < 0.7 vs. 0.7 ≤ SHR < 0.9) β = 1.828, 95% CI (1.345 to 2.486), P < 0.001; (SHR ≥ 1.3 vs. 0.7 ≤ SHR < 0.9) β = 2.896, 95% CI (2.087 to 4.019), P < 0.001], which was further validated through subgroup and sensitivity analyses.

Conclusion

In populations undergoing CAG or PCI, both lowest and highest levels of fasting SHR were significantly associated with an increased occurrence of CI-AKI.

Serum total bilirubin level is associated with contrast induced nephropathy after primary percutaneous coronary intervention

Contrast Induced Nephropathy (CIN) is a major complication of angiographic procedures. Primary percutaneous coronary intervention (pPCI) is the preferred treatment for ST-segment elevation myocardial infarction (STEMI) but is associated with a risk of CIN. Oxidative stress and free radical damage play a role in the pathogenesis of CIN. Bilirubin has anti-inflammatory and antioxidant activity and has been shown to have a protective effect on endothelial cells. The present study aimed to assess the association between serum bilirubin level and development of CIN after pPCI. Sequential STEMI patients (n = 595) who underwent pPCI between January 2021 and December 2022 were enrolled. Among the participants, 116 (19.5%) developed CIN. Serum total bilirubin level was significantly lower in the CIN group (P = .001). In multivariate logistic regression analysis, serum bilirubin level was found as an independent predictor of CIN. Age, gender, contrast volume, and white blood cell count were other independent predictors of CIN. A higher serum bilirubin level is associated with a lower risk of CIN in the present study. In STEMI patients undergoing pPCI, serum bilirubin level may be helpful to predict the risk of CIN and may help ensure early initiation of preventive treatment and careful follow-up.

Dynamic Changes in the Renal Function of Acute Myocardial Infarction Patients with Reduced eGFR After Emergency Percutaneous Coronary Intervention

Renal dysfunction greatly influences decision-making for emergency percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). This observational study investigated renal function changes and risk factors for renal injury in patients with AMI with reduced estimated glomerular filtration rate (eGFR) who underwent emergency PCI. The study included 85 patients with AMI with decreased eGFR who underwent emergency PCI, categorized into stage 2, 3, and 4 chronic kidney disease groups. Baseline data, laboratory indicators, coronary characteristics, and serum creatinine concentration were monitored at multiple time points. Renal injury was defined using two criteria: an increase in serum creatinine level by 0.3 mg/dL or a 50% increase from baseline. During the 1-year follow-up, renal injury incidence varied from 1.18% to 15.29%. The pattern showed an increasing trend in the 1st week after PCI, peaking at 1 week, followed by a decrease at 3 months, and another increase at one year. Low basal eGFR, high contrast agent dosage, and diabetes were associated with renal injury according to logistic regression analysis. The eGFR cutoff value of 35.475 mL/minute·1.73 m2 had a sensitivity of 83.05% and specificity of 57.69% for predicting renal injury based on receiver operating characteristic curve analysis. In summary, patients with AMI with basal eGFR lower than 35.475 mL/minute·1.73 m2 have a higher risk of renal injury after PCI. These findings emphasize the importance of assessing renal function and considering associated risk factors when deciding on emergency PCI for AMI with reduced eGFR.

Acute kidney injury in diabetes mellitus: Epidemiology, diagnostic, and therapeutic concepts

Acute kidney injury (AKI) and diabetes mellitus (DM) are public health problems that cause a high socioeconomic burden worldwide. In recent years, the landscape of AKI etiology has shifted: Emerging evidence has demonstrated that DM is an independent risk factor for the onset of AKI, while an alternative perspective considers AKI as a bona fide complication of DM. Therefore, it is necessary to systematically characterize the features of AKI in DM. In this review, we summarized the epidemiology of AKI in DM. While focusing on circulation- and tissue-specific microenvironment changes after DM, we described the active cellular and molecular mechanisms of increased kidney susceptibility to AKI under DM stress. We also reviewed the current diagnostic and therapeutic strategies for AKI in DM recommended in the clinic. Updated recognition of the epidemiology, pathophysiology, diagnosis, and medications of AKI in DM is believed to reveal a path to mitigate the frequency of AKI and DM comorbidity that will ultimately improve the quality of life in DM patients.

Investigation of the Effects of Stress Hyperglycemia Ratio and Preoperative Computed Tomographic Angiography on the Occurrence of Acute Kidney Injury in Diabetic Patients following Surgical Thromboembolectomy

Acute lower extremity ischemia (ALI) is a cardiovascular emergency resulting from embolic and thrombotic causes. Although endovascular techniques have advanced, surgical thromboembolectomy is still the gold standard. Emergency thromboembolectomy surgery involves an ischemia-reperfusion injury, which also poses a risk for acute renal injury (AKI). The stress hyperglycemia rate (SHR) has recently emerged as an important prognostic value in emergency cardiovascular events. In the present study, we aimed to analyze the impact of preoperative contrast-enhanced tomographic angiography (CTA) and the SHR value on postoperative AKI in emergency thromboembolectomy procedures in patients with insulin-dependent diabetes mellitus (DM). In this retrospective analysis, patients with DM who received emergency surgical thromboembolectomy after being hospitalized at our hospital with ALI between 20 October 2015, and 10 September 2022, were included. Patients were classified into two groups: Group 1 (N = 159), who did not develop AKI, and Group 2 (N = 45), who did. The 45 patients in Group 2 and the 159 patients in Group 1 had median ages of 59 (39-90) and 66 (37-93), respectively (p = 0.008). The percentage of patients in Group 2 with Rutherford class IIB and admission times longer than 6 h was higher (p = 0.003, p = 0.027, respectively). To determine the variables affecting AKI after surgical embolectomy procedures, multivariate logistic regression analysis was used. In multivariate analysis Model 1, age > 65 years (odds ratio [OR]: 1.425, 95% confidence interval [CI]: 1.230-1.980, p < 0.001), preoperative high creatinine (OR: 4.194, 95% CI: 2.890-6.156, p = 0.003), and Rutherford class (OR: 0.874, 95% CI: 0.692-0.990, p = 0.036) were determined as independent predictors for AKI. In Model 2, age > 65 years (OR: 1.224 CI: 1.090-1.679, p = 0.014), preoperative high creatinine (OR: 3.975, 95% CI: 2.660-5.486, p = 0.007), and SHR (OR: 2.142, CI: 1.134-3.968, p = 0.003), were determined as independent predictors for amputation. In conclusion, when an emergency thromboembolectomy operation is planned in insulin-dependent DM patients, renal risky groups can be identified, and renal protective measures can be taken. In addition, to reduce the renal risk, according to the suitability of the clinical conditions of the patients, the decision to perform a CTA with contrast can be taken by looking at the SHR value.

North American Practice-Based Recommendations for Transjugular Intrahepatic Portosystemic Shunts in Portal Hypertension

Complications of portal hypertension, including ascites, gastrointestinal bleeding, hepatic hydrothorax, and hepatic encephalopathy, are associated with significant morbidity and mortality. Despite few high-quality randomized controlled trials to guide therapeutic decisions, transjugular intrahepatic portosystemic shunt (TIPS) creation has emerged as a crucial therapeutic option to treat complications of portal hypertension. In North America, the decision to perform TIPS involves gastroenterologists, hepatologists, and interventional radiologists, but TIPS creation is performed by interventional radiologists. This is in contrast to other parts of the world where TIPS creation is performed primarily by hepatologists. Thus, the successful use of TIPS in North America is dependent on a multidisciplinary approach and technical expertise, so as to optimize outcomes. Recently, new procedural techniques, TIPS stent technology, and indications for TIPS have emerged. As a result, practices and outcomes vary greatly across institutions and significant knowledge gaps exist. In this consensus statement, the Advancing Liver Therapeutic Approaches group critically reviews the application of TIPS in the management of portal hypertension. Advancing Liver Therapeutic Approaches convened a multidisciplinary group of North American experts from hepatology, interventional radiology, transplant surgery, nephrology, cardiology, pulmonology, and hematology to critically review existing literature and develop practice-based recommendations for the use of TIPS in patients with any cause of portal hypertension in terms of candidate selection, procedural best practices and, post-TIPS management; and to develop areas of consensus for TIPS indications and the prevention of complications. Finally, future research directions are identified related to TIPS for the management of portal hypertension.

Construction of a Glycaemia-Based Signature for Predicting Acute Kidney Injury in Ischaemic Stroke Patients after Endovascular Treatment

Background: Hyperglycaemia is thought to be connected to worse functional outcomes after ischaemic stroke. However, the association between hyperglycaemia and acute kidney injury (AKI) after endovascular treatment (EVT) remains elusive. The purpose of this study was to investigate the influence of glycaemic on AKI after EVT. Methods: We retrospectively collected the clinical information of patients who underwent EVT from April 2015 to August 2021. Blood glucose after EVT was recorded as acute glycaemia. Chronic glucose levels were estimated by glycosylated haemoglobin (HbA1c) using the following formula: chronic glucose levels (mg/dL) = 28.7 × HbA1c (%) − 46.7. AKI was defined as an increase in maximum serum creatinine to ≥1.5 baseline. We evaluated the association of AKI with blood glucose. A nomogram was established to predict the risk of AKI, and its diagnostic efficiency was determined by decision curve analysis. Results: We enrolled 717 acute ischaemic stroke patients who underwent EVT. Of them, 205 (28.6%) experienced AKI. Acute glycaemia (OR: 1.007, 95% CI: 1.003−1.011, p < 0.001), the acute/chronic glycaemic ratio (OR: 4.455, 95% CI: 2.237−8.871, p < 0.001) and the difference between acute and chronic glycaemia (ΔA-C) (OR: 1.008, 95% CI: 1.004−1.013, p < 0.001) were associated with the incidence of AKI. Additionally, age, atrial fibrillation, ASITN/SIR collateral grading, postoperative mTICI scale, and admission NIHSS were also significantly correlated with AKI. We then created a glycaemia-based nomogram, and its concordance index was 0.743. The net benefit of the nomogram was further confirmed by decision curve analysis. Conclusions: The glycaemia-based nomogram may be used to predict AKI in ischaemic stroke patients receiving EVT.

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

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

Preoperative Fasting Blood Glucose Levels and the Risk of Contrast-Induced Nephropathy in Patients With Diabetes and Pre-diabetes Undergoing Coronary Arteriography or Percutaneous Coronary Intervention: A Cross-Sectional Study

Diabetes mellitus is an independent risk factor for contrast-induced nephropathy (CIN) in patients undergoing coronary arteriography/percutaneous coronary intervention (CAG/PCI). We evaluated whether preoperative fasting blood glucose (FBG) levels in diabetic and pre-diabetic patients who underwent CAG/PCI influenced the occurrence of CIN. From June 1, 2020, to February 28, 2021, 687 patients were divided into five groups based on their preoperative FBG levels. Blood samples were collected at admission and at 48 hours and 72 hours after the procedure to determine serum creatinine levels. The P value for trend was used to analyze the trend between preoperative FBG levels and the increased risk of CIN. Univariable and multivariable logistic regression analysis were used to exclude the influence of confounding factors, and some high-risk confounders were selected for subgroup analysis. The results of our cross-sectional study show that elevated preoperative FBG levels are independently associated with the risk of CIN in diabetic and pre-diabetic patients undergoing CAG/PCI. Furthermore, the incidence of CIN gradually increases with the rise in preoperative FBG levels. Patients with elevated preoperative FBG at admission should be carefully monitored and more active measures should be taken to prevent CIN.

Association Between Serum Osmolality and Acute Kidney Injury in Critically Ill Patients: A Retrospective Cohort Study

Purposes: Acute kidney injury (AKI) is a common complication in critically ill patients and is usually associated with poor outcomes. Serum osmolality has been validated in predicting critically ill patient mortality. However, data about the association between serum osmolality and AKI is still lacking in ICU. Therefore, the purpose of the present study was to investigate the association between early serum osmolality and the development of AKI in critically ill patients.

Methods: The present study was a retrospective cohort analysis based on the medical information mart for intensive care III (MIMIC-III) database. 20,160 patients were involved in this study and divided into six subgroups according to causes for ICU admission. The primary outcome was the incidence of AKI after ICU admission. The association between early serum osmolality and AKI was explored using univariate and multivariate logistic regression analyses.

Results: The normal range of serum osmolality was 285–300 mmol/L. High serum osmolality was defined as serum osmolality >300 mmol/L and low serum osmolality was defined as serum osmolality <285 mmol/L. Multivariate logistic regression indicated that high serum osmolality was independently associated with increased development of AKI with OR = 1.198 (95% CL = 1.199–1.479, P < 0.001) and low serum osmolality was also independently associated with increased development of AKI with OR = 1.332 (95% CL = 1.199–1.479, P < 0.001), compared with normal serum osmolality, respectively.

Conclusions: In critically ill patients, early high serum osmolality and low serum osmolality were both independently associated with an increased risk of development of AKI.

Usefulness of Adding Pre-procedural Glycemia to the Mehran Score to Enhance Its Ability to Predict Contrast-induced Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention Development and Validation of a Predictive Model

The Mehran score is the most widely accepted tool for predicting contrast-induced acute kidney injury (CI-AKI), a major complication of percutaneous coronary intervention (PCI). Similarly, abnormal fasting pre-procedural glycemia (FPG) represents a modifiable risk factor for CI-AKI, but it is not included in current risk models for CI-AKI prediction. We sought to analyze whether adding FPG to the Mehran score improves its ability to predict CI-AKI following PCI. We analyzed 671 consecutive patients undergoing PCI (age 69 [63,75] years, 23% females), regardless of their diabetic status, to derive a revised Mehran score obtained by including FPG in the original Mehran score (Derivation Cohort). The new risk model (GlyMehr) was externally validated in 673 consecutive patients (Validation Cohort) (age 69 [62,76] years, 21% females). In the Derivation Cohort, both FPG and the original Mehran score predicted CI-AKI (AUC 0.703 and 0.673, respectively). The GlyMehr score showed a better predictive ability when compared with the Mehran score both in the Derivation Cohort (AUC 0.749, 95%CI 0.662 to 0.836; p = 0.0016) and the Validation Cohort (AUC 0.848, 95%CI, 0.792 to 0.903; p = 0.0008). In the overall population (n = 1344), the GlyMehr score confirmed its independent and incremental predictive ability regardless of diabetic status (p ≤0.0034) or unstable/stable coronary syndromes (p ≤0.0272). In conclusion, adding FPG to the Mehran score significantly enhances our ability to predict CI-AKI. The GlyMehr score may contribute to improve the clinical management of patients undergoing PCI by identifying those at high risk of CI-AKI and potentially detecting modifiable risk factors.

Incidence of Acute Kidney Injury Is Lower in High-Risk Patients Undergoing Percutaneous Coronary Intervention Supported with Impella Compared to ECMO

Acute kidney injury (AKI) is a common complication post-PCI. Here, in a single-center observational registry, we compared the frequency of AKI in patients at elevated risk for AKI (based on Mehran risk stratification scoring) who underwent VA-ECMO- or Impella-supported high-risk PCI. A total of 28 patients scheduled for elective high-risk PCI with mechanical circulatory support were studied prospectively. All patients were turned down for surgery due to exceedingly high risk. Allocation to VA-ECMO (n=11) or Impella (n=17) was performed according to site-specific restrictions on the daily availability of the VA-ECMO platform as a prospective enrollment and performed prior to initiation of PCI. We analyzed AKI incidence as our primary endpoint, as well as PCI success, duration, and peripheral complications. All patients were successfully revascularized and had MCS weaned at the end of the procedure. Baseline GFR and procedural contrast media were similar. Despite similar risks for AKI as calculated by the Mehran score (35 ± 18.9 vs. 31 ± 16.6 %; p=0.55), patients supported by Impella during PCI demonstrated a reduced incidence of AKI (55 vs. 12 %; p=0.03). MCS-assisted high-risk PCI with VA-ECMO or Impella is feasible. However, Impella is associated with a shorter procedure time and a lower incidence of AKI.

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.

Relieving lipid accumulation through UCP1 suppresses the progression of acute kidney injury by promoting the AMPK/ULK1/autophagy pathway

Rationale: Acute kidney injury (AKI) is a serious clinical emergency with an acute onset, rapid progression, and poor prognosis. Recent evidence suggests that AKI is accompanied by significant metabolic abnormalities, including alterations in lipid metabolism. However, the specific changes in lipids in AKI, and their role and regulation mechanisms are currently unclear.

Methods: Quantitative metabolomics was performed in AKI models to reveal the differences of lipid metabolism-related products. Regulated pathway was detected by western blot, qRT-PCR, immunoblot analysis and immunohistochemistry.

Results: The present study systematically analyzes the changes in lipid composition in AKI for the first time and find that the degree of lipid accumulation was highly correlated with uncoupling protein 1 (UCP1). Importantly, relieving lipid accumulation in AKI by upregulating UCP1 can significantly inhibit the progression of AKI through promoting AMPK/ULK1/autophagy pathway.

Conclusions: The present findings suggest that lipid accumulation in AKI is directly regulated by UCP1, which can activate cell autophagy and thus significantly inhibit disease progression. It will provide new ideas and targets for the treatment of AKI.

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.

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.

Prognostic value of fasting glucose on the risk of heart failure and left ventricular systolic dysfunction in non-diabetic patients with ST-segment elevation myocardial infarction

Recent studies have shown that acute blood glucose elevation in patients with ST-segment elevation myocardial infarction (STEMI) suggests a poor prognosis. To investigate the effect of fasting blood glucose (FBG) on the risk of heart failure (HF) and left ventricular systolic dysfunction (LVSD) in non-diabetic patients undergoing primary percutaneous coronary intervention (PCI) for acute STEMI, we retrospectively recruited consecutive non-diabetic patients who underwent primary PCI for STEMI in our hospital from February 2003 to March 2015. The patients were divided into two groups according to the FBG level. A total of 623 patients were recruited with an age of 61.3 ± 12.9 years, of whom 514 (82.5%) were male. The HF risk (odds ratio 3.401, 95% confidence interval (CI) 2.144-5.395, P < 0.001) was significantly increased in patients with elevated FBG than those with normal FBG. Elevated FBG was also independently related to LVSD (β 1.513, 95%CI 1.282-1.785, P < 0.001) in a multiple logistics regression analysis. In conclusion, elevated FBG was independently associated with 30-day HF and LVSD risk in non-diabetic patients undergoing primary PCI for STEMI.

Pre-Procedural Hyperglycemia Increases the Risk of Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography: A Systematic Review and Meta-Analysis

BACKGROUND

Contrast-induced nephropathy (CIN) frequently occurs following coronary angiography (CAG) and is associated with worse outcomes, including both short and long-term mortality. Previous studies reported an association between procedural hyperglycemia (PH) and CIN, with or without diabetes mellitus (DM). We performed a systematic review and meta-analysis to explore the association of PH and CIN in patients undergoing CAG.

METHODS

We searched the databases of MEDLINE and EMBASE from inception to January 2020. Included studies investigated CIN incidence in patients undergoing CAG. Data from each study were combined using the random-effects model.

RESULTS

A total of eight studies were included in this meta-analysis. We found that PH was associated with an increased risk of CIN following CAG (pooled OR = 1.71, 95%CI:1.35-2.16, where PH was defined as ≥140 mg/dl; and pooled OR = 2.07, 95%CI:1.80-2.37, where PH was defined as ≥200 mg/dl). In subgroup analysis of non-diabetic patients and STEMI patients undergoing primary percutaneous coronary intervention, we found that PH was associated with an increased risk of CIN in both subgroups, where PH was defined as ≥140 mg/dl and ≥200mg/dl (p-value < 0.05).

CONCLUSIONS

Our meta-analysis demonstrated that PH significantly increases the risk of CIN following CAG, in both diabetic and non-diabetic populations. Further studies are needed to evaluate whether strict blood glucose control can reduce the incidence of CIN in this population.

Application of 17 Contrast-Induced Acute Kidney Injury Risk Prediction Models

INTRODUCTION

Contrast-induced acute kidney injury (CI-AKI) is a frequent complication of percutaneous coronary interventions (PCI). Various groups have developed and validated risk scores for CI-AKI. Although the majority of these risk scores achieve an adequate accuracy, their usability in clinical practice is limited and greatly debated.

OBJECTIVE

With the present study, we aimed to prospectively assess the diagnostic performance of recently published CI-AKI risk scores (up to 2018) in a cohort of patients undergoing PCI.

METHODS

We enrolled 1,247 consecutive patients (80% men, mean age 62 ± 10 years) treated with elective or urgent PCI. For each patient, we calculated the individual CI-AKI risk score based on 17 different risk models. CI-AKI was defined as an increase of ≥25% (liberal) or ≥0.5 mg/dL (strict) in pre-PCI serum creatinine 48 h after PCI.

RESULTS

CI-AKI definition and, therefore, CI-AKI incidence have a significant impact on risk model performance (median negative predictive value increased from 85 to 99%; median c-statistic increased from 0.516 to 0.603 using more strict definition criteria). All of the 17 published models were characterized by a weak-to-moderate discriminating ability mainly based on the identification of "true-negative" cases (median positive predictive value 19% with liberal criterion and 3% with strict criterion). In none of the models, c-statistic was >0.800 with either CI-AKI definition. Novel, different combinations of the >35 independent variables used in the published models either by down- or by up-scaling did not result in significant improvement in predictive performance.

CONCLUSIONS

The predictive ability of all models was similar and only modest, derived mainly by identifying true-negative cases. A new approach is probably needed by adding novel markers or periprocedural characteristics.

Artificial Intelligence in Acute Kidney Injury Risk Prediction

Acute kidney injury (AKI) is a frequent complication in hospitalized patients, which is associated with worse short and long-term outcomes. It is crucial to develop methods to identify patients at risk for AKI and to diagnose subclinical AKI in order to improve patient outcomes. The advances in clinical informatics and the increasing availability of electronic medical records have allowed for the development of artificial intelligence predictive models of risk estimation in AKI. In this review, we discussed the progress of AKI risk prediction from risk scores to electronic alerts to machine learning methods.

Serum osmolarity as a potential predictor for contrast-induced nephropathy following elective coronary angiography

BACKGROUND AND OBJECTIVES

Contrast-induced nephropathy (CIN) is a relatively common complication following primary coronary angiography (CAG) or percutaneous coronary intervention (PCI), especially in at-risk patients. The goal of this study is to evaluate the role of pre-procedural serum osmolarity as a risk factor for CIN in patients undergoing elective CAG for stable coronary artery disease (CAD).

MATERIALS AND METHODS

A total of 356 stable CAD patients scheduled to undergo CAG or PCI were included in this two-center study. Serum osmolarity was calculated on admission. CIN was defined according to the KDIGO criteria.

RESULTS

There were 45 (12.6%) patients who developed CIN 48-72 h after CAG or PCI. CIN patients had a higher prevalence of diabetes (51.1% in those with CIN vs 24.4% in those without CIN, p < 0.001), higher serum glucose (129 mg/dL in those with CIN vs 108 mg/dL in those without CIN, p < 0.001), blood urea nitrogen (22.4 mg/dL in those with CIN vs 19.0 mg/dL in those without CIN, p = 0.01) and serum osmolarity (294.2 mOsm in those with CIN vs 290.1 mOsm in those without CIN, p < 0.001) levels, had received a higher dose of contrast (250 mL in those with CIN vs 200 mL in those without CIN, p = 0.03) but had lower hemoglobin (12.9 g/dL in those with CIN vs 13.6 g/dL in those without CIN, p = 0.04) level. In multivariate analysis, serum osmolarity [odds ratio (OR) 1.11; 95% confidence interval (CI) 1.04-1.18 for each mOsm/L increase; p = 0.001], diabetes (OR 2.43, 95% CI 1.26-4.71; p = 0.01), C-reactive protein (OR 1.04, 95% CI 1.01-1.08 for each mg/dL increase; p = 0.02) and contrast volume (OR 34.66, 95% CI 1.25-962.22 for each L increase; p = 0.04) remained as independent predictors of CIN. Serum sodium, glucose and blood urea nitrogen contributed to the excess serum osmolarity of CIN patients.

CONCLUSION

Serum osmolarity is a cheap and widely available marker that can reliably predict CIN after CAG or PCI. Future research should focus on determining a clinically optimal cutoff for serum osmolarity that would warrant preventive interventions. Furthermore, later research may investigate the role of serum osmolarity not only as a risk factor but also as a pathogenetic mechanism underlying CIN.

Impact of short term oral steroid use for intravenous contrast media hypersensitivity prophylaxis in diabetic patients undergoing nonemergent coronary angiography or interventions

OBJECTIVES

Oral steroids are routinely administered in the United States for prophylaxis of iodinated contrast media hypersensitivity (ICMH). We studied the impact of short-term steroid use in diabetic patients with ICMH undergoing nonemergent coronary angiography.

METHODS

We retrospectively analyzed records of diabetic patients with and without ICMH who underwent nonemergent coronary angiography at our center. Primary study endpoint was 30-day major adverse cardiac events (MACE) and secondary endpoints were pre- and postprocedure fasting blood glucose (FBG), highest in hospital blood glucose, pre- and postprocedure systolic blood pressure (SBP), and use of intravenous insulin and antihypertensive medications.

RESULTS

A total of 88 diabetics with ICMH (study group) and 76 diabetics without ICMH (control group) undergoing angiography were enrolled. Demographics and hemoglobin A1c values were similar in both groups. Preprocedural FBG was significantly higher in the study group. The study group had significantly higher post angiography FBG (239.93 + 96.88 mg/dl vs. 156.6 + 59.88 mg/dl) and greater use of intravenous (IV) insulin (67.27% vs. 32.43%). Further, those who received steroids had significantly higher systolic SBP postprocedure (146.16 + 25.35 mmHg vs. 130.8 + 21.59 mmHg), a higher incidence of severe hypertension and use of IV antihypertensive medications (80.95% vs. 19.05%) periprocedurally. There were no differences in 30-day MACE between groups.

CONCLUSION

Short-term steroid use for ICMH results in a significant increase in surrogate markers for adverse clinical events after coronary procedures. Study findings highlight the need for better periprocedural management of these patients and to limit steroid prophylaxis to those with only true ICMH.

Impact of blood glucose levels on the accuracy of urinary N-acety-β-D-glucosaminidase for acute kidney injury detection in critically ill adults: a multicenter, prospective, observational study

BACKGROUND

The performance of urinary N-acetyl-β-D-glucosaminidase (uNAG) for the detection of acute kidney injury (AKI) was controversial. uNAG is positively correlated with blood glucose levels. Hyperglycemia is common in the critically ill adults. The influence of blood glucose levels on the accuracy of uNAG in AKI detection has not yet been reported. The present study evaluated the effect of blood glucose levels on the diagnostic accuracy of uNAG to detect AKI.

METHODS

A total of 1585 critically ill adults in intensive care units at three university hospitals were recruited in this prospective observational study. uNAG, serum glucose, and glycosylated hemoglobin (HbA1c) were measured at ICU admission. Patients were categorized based on the history of diabetes and blood glucose levels. The performance of uNAG to detect AKI in different groups was assessed by the area under the receiver operator characteristic curve.

RESULTS

Four hundred and twelve patients developed AKI, of which 109 patients were severe AKI. uNAG was significantly correlated with the levels of serum glucose (P < 0.001) and HbA1c (P < 0.001). After stratification based on the serum glucose levels, no significant difference was observed in the AUC of uNAG in detecting AKI between any two groups (P > 0.05). Stratification for stress hyperglycemic demonstrated similar results.However, among non-diabetic patients, the optimal cut-off value of uNAG for detecting AKI was higher in stress hyperglycemic patients as compared to those without stress hyperglycemia.

CONCLUSIONS

The blood glucose levels did not significantly affect the performance of uNAG for AKI detection in critically ill adults. However, the optimal cut-off value of uNAG to detect AKIwas affected by stress hyperglycemia in non-diabetic patients.

Effects of hyperglycaemia and elevated glycosylated haemoglobin on contrast-induced nephropathy after coronary angiography

In patients undergoing percutaneous coronary intervention after acute myocardial infarction, hyperglycaemia on admission is associated with an increased risk of contrast-induced nephropathy (CIN). However, the effects of hyperglycaemia and elevated glycosylated haemoglobin (HbA1c) on CIN have remained to be fully elucidated. Therefore, a prospective cohort study was performed, comprising 258 patients who underwent coronary angiography between May 2017 and November 2017 at Zhongda Hospital affiliated with Southeast University (Nanjing, China). According to the diagnostic criteria for CIN (increase of serum creatinine by >44.2 µmol/l or by 25% within 48-72 h of using contrast agent), the patients were divided into two groups: CIN (45 cases) and non-CIN (213 cases). For all patients, the baseline data, medical history, laboratory parameters, medication history and intraoperative situation were recorded and assessed using single-factor analysis and multiple logistic regression analysis to analyse the risk factors of CIN. The incidence of CIN in the hyperglycaemia group (blood glucose on admission, >11.1 mmol/l) was 25%, compared with 13.8% in the non-hyperglycaemia group (P=0.026). Furthermore, the incidence of CIN in the elevated HbA1c group (HbA1c on admission, upper limit of normal) was 26.1%, compared with 14.3% in the group without elevated HbA1c (P=0.027). Hyperglycaemia was present on hospital admission in 84 of 258 patients (32.6%). The percentage of patients with elevated HbA1c was 26.7%. Age, estimated glomerular filtration rate, pre-operative blood cholesterol, hyperglycaemia on admission and elevated HbA1c were all identified to be associated with CIN. According to the multivariate logistic regression analysis, hyperglycaemia was an independent predictor of CIN (odds ratio, 2.815; 95% confidence interval, 1.042-4.581; P=0.029). In the acute coronary syndrome (ACS) and diabetes subgroups, hyperglycaemia was significantly associated with CIN. In the ACS subgroup, the incidence of CIN was 38.1%. It was indicated that hyperglycaemia is an independent risk factor for CIN, particularly in patients with ACS or diabetes. Trial registration no. ChiCTR-OOC-17011466.

Acute Kidney Injury in Diabetic Patients With Acute Myocardial Infarction: Role of Acute and Chronic Glycemia

Background

In acute myocardial infarction, acute hyperglycemia is a predictor of acute kidney injury (AKI), particularly in patients without diabetes mellitus. This emphasizes the importance of an acute glycemic rise rather than glycemia level at admission. We investigated whether, in diabetic patients with acute myocardial infarction, the combined evaluation of acute and chronic glycemic levels may have better prognostic value for AKI than admission glycemia.

Methods and Results

At admission, we prospectively measured glycemia and estimated average chronic glucose levels (mg/dL) using glycosylated hemoglobin (HbA_1c), according to the following formula: 28.7×HbA_1c (%)−46.7. We evaluated the association with AKI of the acute/chronic glycemic ratio and of the difference between acute and chronic glycemia (Δ_A−C). We enrolled 474 diabetic patients with acute myocardial infarction. Of them, 77 (16%) experienced AKI. The incidence of AKI increased in parallel with the acute/chronic glycemic ratio (12%, 14%, 22%; P=0.02 for trend) and Δ_A−C (13%, 13%, 23%; P=0.01) but not with admission glycemic tertiles (P=0.22). At receiver operating characteristic analysis, the acute/chronic glycemic ratio (area under the curve: 0.62 [95% confidence interval, 0.55–0.69]; P=0.001) and Δ_A−C (area under the curve: 0.62 [95% confidence interval, 0.54–0.69]; P=0.002) accurately predicted AKI, without difference in the area under the curve between them (P=0.53). At reclassification analysis, the addition of the acute/chronic glycemic ratio and Δ_A−C to acute glycemia allowed proper AKI risk prediction in 16% of patients.

Conclusions

In diabetic patients with acute myocardial infarction, AKI is better predicted by the combined evaluation of acute and chronic glycemic values than by assessment of admission glycemia alone.

Association of Preprocedural Hyperglycemia With Contrast-Induced Acute Kidney Injury and Poor Outcomes After Emergency Percutaneous Coronary Intervention

We investigated whether preprocedural hyperglycemia was associated with contrast-induced acute kidney injury (CI-AKI) and long-term outcomes in patients with acute coronary syndrome (ACS) who underwent emergency percutaneous coronary intervention (PCI). Patients (n = 558) with ACS who underwent emergency PCI were consecutively enrolled. Preprocedural hyperglycemia was defined as glucose levels >198 mg/dL (11 mmol/L). The primary outcome was CI-AKI (≥0.3 mg/dL absolute or ≥50% relative serum creatinine increase 48 hours after contrast medium exposure). Overall, 103 (18.5%) patients had preprocedural hyperglycemia and 89 (15.9%) patients developed CI-AKI. The incidence of CI-AKI was significantly higher in patients with hyperglycemia than without (28.2% vs 13.2%; P < .01). Multivariate analysis indicated that preprocedural hyperglycemia was an independent predictor of CI-AKI (odds ratio = 1.971, 95% confidence interval [CI]: 1.129-3.441; P < .05). In addition, preprocedural hyperglycemia was associated with an increased risk of all-cause mortality during the 2-year follow-up (hazard ratio = 2.440, 95% CI: 1.394-4.273; P = .002). Preprocedural hyperglycemia is a significant and independent predictor of CI-AKI and long-term outcomes.

Are There Modifiable Risk Factors to Improve AKI?

Acute kidney injury (AKI) is a common critical syndrome, with high morbidity and mortality. Patients with AKI typically have an adverse prognosis, from incident chronic kidney disease (CKD), progression to end-stage renal disease (ESRD), subsequent cardiovascular disease, and ultimately death. However, there is currently no effective therapy for AKI. Early detection of risk factors for AKI may offer a good approach to prevention or early intervention. Traditional risk factors include extreme age, many common comorbid diseases, such as preexisting CKD, some specific exposures, such as sepsis, and exposure to some nephrotoxic agents. Recently, several novel risk factors for AKI, such as hyperuricemia, hypoalbuminemia, obesity, anemia, and hyperglycemia, have been identified. The underlying mechanisms between these nontraditional risk factors and AKI and whether their correction can reduce AKI occurrence remain to be clarified. This review describes the current epidemiology of AKI, summarizes its outcome, outlines the traditional risk profile, and finally highlights some recently identified novel risk factors.

Preprocedural Prediction Model for Contrast-Induced Nephropathy Patients

Background

Several models have been developed for prediction of contrast‐induced nephropathy (CIN); however, they only contain patients receiving intra‐arterial contrast media for coronary angiographic procedures, which represent a small proportion of all contrast procedures. In addition, most of them evaluate radiological interventional procedure‐related variables. So it is necessary for us to develop a model for prediction of CIN before radiological procedures among patients administered contrast media.

Methods and Results

A total of 8800 patients undergoing contrast administration were randomly assigned in a 4:1 ratio to development and validation data sets. CIN was defined as an increase of 25% and/or 0.5 mg/dL in serum creatinine within 72 hours above the baseline value. Preprocedural clinical variables were used to develop the prediction model from the training data set by the machine learning method of random forest, and 5‐fold cross‐validation was used to evaluate the prediction accuracies of the model. Finally we tested this model in the validation data set. The incidence of CIN was 13.38%. We built a prediction model with 13 preprocedural variables selected from 83 variables. The model obtained an area under the receiver‐operating characteristic (ROC) curve (AUC) of 0.907 and gave prediction accuracy of 80.8%, sensitivity of 82.7%, specificity of 78.8%, and Matthews correlation coefficient of 61.5%. For the first time, 3 new factors are included in the model: the decreased sodium concentration, the INR value, and the preprocedural glucose level.

Conclusions

The newly established model shows excellent predictive ability of CIN development and thereby provides preventative measures for CIN.

HDL Cholesterol Level Is Associated with Contrast Induced Acute Kidney Injury in Chronic Kidney Disease Patients Undergoing PCI

Chronic kidney disease (CKD) is a significant risk factor for contrast induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI). This study included 1592 CKD patients extracted from a prospective multicenter, all comer-based registry of patients undergoing PCI. In multivariate logistic analysis for CI-AKI development, a significant linear trend was observed between the quartiles of HDL-C (quartile 1 vs. 2: odds ratio [OR], 0.716; 95% confidence interval [CI], 0.421-1.219; quartile 1 vs. 3: OR, 0.534; 95% CI, 0.301-0.947; quartile 1 vs. 4: OR, 0.173; 95% CI, 0.079-0.377; P for trend < 0.001). HDL-C quartiles were also negatively correlated with the incidence of CI-AKI; 19.0%, 12.1%, 8.7%, and 3.7% for quartile 1(Q1) (<34 mg/dL), Q2 (34-40 mg/dL), Q3 (40-48 mg/dL), and Q4 (>48 mg/dL) respectively (P < 0.001 overall and for the trend). Multivariate Cox regression analysis for the long term mortality, the highest HDL-C quartile was associated with decreased mortality compared with the lowest HDL-C quartile (hazard ratio [HR] 0.516, 95% CI, 0.320-0.832, P = 0.007). Our study suggests more intensive strategies should be considered for preventing CI-AKI in CKD patients with low serum HDL-C level who is planned for PCI.

Relationship between pre-procedural microalbuminuria and renal functional changes after coronary computed tomography in diabetic patients

BACKGROUND

Diabetes is one of the risks for development of contrast-induced nephropathy (CIN). The percentage change in cystatin C (CyC), a recent new reliable marker for detecting subtle renal dysfunction, of ≥10% for 24h after procedure is an independent predictor for developing CIN. Urinary microalbumin is one of the markers for preclinical nephropathy in diabetic patients. We investigated the relationship between pre-procedural urinary microalbumin and renal functional changes using CyC after coronary computed tomography angiography (CCTA) in diabetic patients.

METHODS

Two hundred and six patients with diabetes scheduled for CCTA were enrolled. The serum creatinine and CyC levels were measured before and 24h after CCTA. The percentage change in CyC (%CyC) and absolute change in estimated glomerular filtration rate (eGFR) from pre- to post-procedure were calculated. The pre-procedural urinary microalbumin was measured. The patients were classified into 2 groups as follows: group A comprised 93 patients with pre-procedural urinary microalbumin of ≥30mg/g creatinine; and group B comprised 113 patients with one of <30mg/g creatinine.

RESULTS

The %CyC, fasting plasma glucose levels, and HbA1c were significantly greater in group A than in group B. The absolute change in eGFR was significantly less in group A than in group B. A significant correlation was seen between urinary microalbumin and %CyC (r=0.49, p<0.0001). Multivariate regression analysis revealed that pre-procedural urinary microalbumin and HbA1c were independent predictors for a %CyC≥10% (OR: 1.030, 95% CI: 1.020-1.039, p=0.008; and OR: 1.011, 95% CI: 1.007-1.016, p=0.004, respectively). The optimal cut-off value of a pre-procedural urinary microalbumin level was 64mg/g creatinine for predicting a %CyC≥10% using receiver-operating characteristic curve analysis with a sensitivity, specificity, and area under the curve of 56%, 88%, and 0.72, respectively.

CONCLUSIONS

Renal functional changes should be paid attention to after CCTA, particularly in diabetic patients exhibiting elevated pre-procedural urinary microalbumin even though they indicate preserved eGFR.

Carotid and cerebral CT angiography using low volume of iodinated contrast material and low tube voltage

PURPOSE

To evaluate image quality of carotid computed tomography angiography (CTA) using a low voltage (80kV) and low amount of iodinated contrast material.

MATERIALS-METHODS

A total of 101 patients referred for carotid CTA were randomly assigned to receive a specific protocol. In group A patients received intravenous administration of contrast material at a dose of 1mL/kg and CTA examinations were performed at 100kV. In group B, patients received intravenous administration of contrast material at a dose of 0.5mL/kg and CTA examinations were performed at 80kV. The same nonionic iodinated contrast material containing 370mg of iodine per mL was used in both groups. Attenuation values were measured from the center of specific arterial segments using regions of interest. Attenuation values above 300HU were accepted as significant. Institutional review board approval was obtained.

RESULTS

A total of 50 patients were included in group A (38 men, 12 women; mean age, 63.56 years±13.18 [SD]) and 51 patients in group B (33 men, 18 women; mean age, 59.60 years±16.63 [SD]). A total of 1615 arterial segments (1515 common carotid artery-middle cerebral artery and 101 aortic arches) were analyzed. Venous contamination was not observed in either group. The mean attenuation values of all arterial segments in both groups were greater than 300HU. Mean arterial attenuation value in group B (499.22HU±97.25 [SD]) was significantly greater than in group A (374.36HU±73.79 [SD]) (P<0.01). Hemodynamically significant stenosis (grade III stenosis or >70%) was detected in 2 segments in group A and in 3 segments in group B, while grade IV stenosis (occlusion) was detected in 2 segments in group B. Distal common carotid artery dissection was detected in 1 patient and aortic dissection was detected in 1 patient in group B. Total dose-length product (DLP) value was significantly greater in group A (225.74mGy·cm±21.80 [SD]) than in group B (116.60mGy·cm±21.22 [SD]) (P<0.01). The mean tube current was similar in group A (2013.11mAs±195.92 [SD]) and in group B (2096.64 mAs±309.03 [SD]) (P<0.05).

CONCLUSION

Carotid and cerebral CTA examinations using 128-section CT can be successfully obtained using an imaging protocol that combines low voltage and 50% reduction in the volume of iodinated contrast material. This provides good image quality with low radiation dose.

Impact of post-procedural hyperglycemia on acute kidney injury after transcatheter aortic valve implantation

BACKGROUND

Post-operative hyperglycemia, in individuals with and without diabetes, has been identified as a predictor of acute kidney injury (AKI) in patients following cardiac surgery. Whether or not this is also true for patients undergoing transcatheter aortic valve implantation (TAVI) is unknown.

OBJECTIVES

To evaluate whether post-procedural glucose levels are associated with AKI after TAVI.

METHODS AND RESULTS

A total of 422 consecutive patients undergoing transfemoral TAVI were included in the analysis. For each patient, plasma glucose levels were assessed at hospital admission, 4h after the procedure and daily during hospitalization. Post-procedural hyperglycemia was defined as 2 consecutive blood glucose readings ≥150mg/dL in the 72-hour period following TAVI. AKI was defined according to the VARC consensus report regarding standardized endpoint definitions. Overall, 137 (32.5%) patients developed post-procedural hyperglycemia and 138 (33%) patients developed AKI. Hyperglycemia was associated with a 2-fold higher incidence of AKI than in patients without hyperglycemia (48% vs. 25%, p<0.001). In-hospital mortality was higher in patients with hyperglycemia than in those without hyperglycemia (9.6% vs. 1.8%, p<0.001). In-hospital mortality rate was also higher in patients who developed AKI (12.7% vs. 2.7%, p<0.001). Patients with acute hyperglycemia that developed AKI had the highest in-hospital and long-term mortality rate (15% and 38%). Post-procedural hyperglycemia was an independent predictor of AKI.

CONCLUSIONS

Post-procedural hyperglycemia is associated with a higher incidence of AKI and mortality after TAVI. Randomized controlled trials are needed to determine whether meticulous post-procedural glycemic control following TAVI impacts upon clinical outcomes.

Short-Term High-Dose Vitamin E to Prevent Contrast Medium-Induced Acute Kidney Injury in Patients With Chronic Kidney Disease Undergoing Elective Coronary Angiography: A Randomized Placebo-Controlled Trial

Background

Contrast medium–induced acute kidney injury (CIAKI) is a leading cause of acquired renal impairment. The effects of antioxidants have been conflicting regarding the prevention of CIAKI. We performed a study of vitamin E use to decrease CIAKI in patients undergoing elective coronary angiography.

Methods and Results

In a placebo‐controlled randomized trial at 2 centers in Iran, 300 patients with chronic kidney disease—defined as estimated glomerular filtration rate <60 mL/min per 1.73 m²—were randomized 1:1 to receive 0.9% saline infusion 12 hours prior to and after intervention combined with 600 mg vitamin E 12 hours before plus 400 mg vitamin E 2 hours before coronary angiography or to receive placebo. The primary end point was the development of CIAKI, defined as an increase ≥0.5 mg/dL or ≥25% in serum creatinine that peaked within 72 hours. Based on an intention‐to‐treat analysis, CIAKI developed in 10 (6.7%) and 21 (14.1%) patients in the vitamin E and placebo groups, respectively (P=0.037). Change in white blood cell count from baseline to peak value was greater in the vitamin E group compared with the placebo group (−500 [−1500 to 200] versus 100 [−900 to 600]×10³/mL, P=0.001). In multivariate analysis, vitamin E (odds ratio 0.408, 95% CI 0.170–0.982, P=0.045) and baseline Mehran score (odds ratio 1.257, 95% CI 1.007–1.569; P=0.043) predicted CIAKI.

Conclusions

Prophylactic short‐term high‐dose vitamin E combined with 0.9% saline infusion is superior to placebo for prevention of CIAKI in patients undergoing elective coronary angiography.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02070679.

Preventing Contrast-induced Renal Failure: A Guide

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

Diabetic Kidney Disease: A Syndrome Rather Than a Single Disease

The term "diabetic kidney" has recently been proposed to encompass the various lesions, involving all kidney structures that characterize protean kidney damage in patients with diabetes. While glomerular diseases may follow the stepwise progression that was described several decades ago, the tenet that proteinuria identifies diabetic nephropathy is disputed today and should be limited to glomerular lesions. Improvements in glycemic control may have contributed to a decrease in the prevalence of glomerular lesions, initially described as hallmarks of diabetic nephropathy, and revealed other types of renal damage, mainly related to vasculature and interstitium, and these types usually present with little or no proteinuria. Whilst glomerular damage is the hallmark of microvascular lesions, ischemic nephropathies, renal infarction, and cholesterol emboli syndrome are the result of macrovascular involvement, and the presence of underlying renal damage sets the stage for acute infections and drug-induced kidney injuries. Impairment of the phagocytic response can cause severe and unusual forms of acute and chronic pyelonephritis. It is thus concluded that screening for albuminuria, which is useful for detecting "glomerular diabetic nephropathy", does not identify all potential nephropathies in diabetes patients. As diabetes is a risk factor for all forms of kidney disease, diagnosis in diabetic patients should include the same combination of biochemical, clinical, and imaging tests as employed in non-diabetic subjects, but with the specific consideration that chronic kidney disease (CKD) may develop more rapidly and severely in diabetic patients.

Glycemic Variability Assessed by Continuous Glucose Monitoring and Short-Term Outcome in Diabetic Patients Undergoing Percutaneous Coronary Intervention: An Observational Pilot Study

Poor glycemic control is associated with unfavorable outcome in patients undergoing percutaneous coronary intervention (PCI), irrespective of diabetes mellitus. However a complete assessment of glycemic status may not be fully described by glycated hemoglobin or fasting blood glucose levels, whereas daily glycemic fluctuations may influence cardiovascular risk and have even more deleterious effects than sustained hyperglycemia. Thus, this paper investigated the effectiveness of a continuous glucose monitoring (CGM), registering the mean level of glycemic values but also the extent of glucose excursions during coronary revascularization, in detecting periprocedural outcome such as renal or myocardial damage, assessed by serum creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and troponin I levels. High glycemic variability (GV) has been associated with worse postprocedural creatinine and NGAL variations. Moreover, GV, and predominantly hypoglycemic variations, has been observed to increase in patients with periprocedural myocardial infarction. Thus, our study investigated the usefulness of CGM in the setting of PCI where an optimal glycemic control should be achieved in order to prevent complications and improve outcome.

Pre-diabetes and the risk of contrast induced nephropathy in patients undergoing coronary angiography or percutaneous intervention

BACKGROUND

Contrast induced nephropathy (CIN) is a complication of coronary angiography/percutaneous intervention (PCI). It is known that diabetes is an independent risk factor for CIN, but we have no data regarding the association between CIN and glycemic levels in patients without diabetes. Aim of our study was to evaluate whether high level of glycated-haemoglobin in patients without diabetes is associated with an increased risk of CIN.

METHODS

A total of 1324 patients without diabetes, undergoing elective/urgent coronary angiography/angioplasty were divided according to quartiles of baseline glycated-haemoglobin. CIN was defined as an absolute ≥ 0.5mg/dL or a relative ≥ 25% increase in creatinine level at 24-48 h after the procedure.

RESULTS

Patients with elevated glycated-haemoglobin were older, with hypertension, metabolic syndromes, previous history of AMI, PCI and CABG. They had higher gycaemia, fasting-glycaemia and triglycerides but lower HDL-cholesterol. Patients with higher glycated-haemoglobin were more often on therapy with statins, diuretics and calcium-antagonist at admission, had higher basal, 24 and 48 h creatinine, lower creatinine clearance and lower ejection fraction. They had the highest incidence of PCI and contrast volume-eGFR rate. CIN occurred in 10.6% of patients with a linear association with glycated-haemoglobin (p=0.001). No relationship was found between glycaemia/fasting glycaemia at admission and CIN. The multivariate analysis confirmed the association between elevated glycated haemoglobin (above the median value 5.7%) and the risk of CIN after adjustment for baseline confounding factors (Adjusted OR [95% CI]=1.69 [1.14-2.51], p=0.009). In fact, the results were consistent in major high-risk subgroups.

CONCLUSION

This is the first study showing that among patients without diabetes undergoing coronary angiography/PCI elevated glycated-haemoglobin but not glucose levels is independently associated with the risk of CIN.

Contrast-Induced Nephropathy: Definitions, Epidemiology, and Implications

Contrast-induced nephropathy, now termed contrast-induced acute kidney injury (CI-AKI), has been a long-recognized complication of administering intravascular iodinated contrast. This article reviews the newest literature on subclinical CI-AKI detected by novel biomarkers, and clinical CI-AKI recognized by an increase in serum creatinine and a reduction in urine output. Both components of CI-AKI are associated with adverse outcomes, including in-hospital complications, increased length of stay, need for renal replacement therapy, rehospitalization, permanent loss in renal filtration function, and death.

Red Cell Distribution Width Predicts Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome

We investigated the relationship between red cell distribution width (RDW) and contrast-induced nephropathy (CIN) in patients (aged 61 ± 12, 69% men) with acute coronary syndrome (ACS). Consecutive patients diagnosed with ACS (n = 662) who underwent percutaneous coronary intervention (PCI) were included in the study. Patients were divided into 2 groups: CIN and no CIN. Contrast-induced nephropathy was defined as an increase in serum creatinine level of ≥0.5 mg/dL or ≥25% above baseline within 72 hours after PCI. Contrast-induced nephropathy occurred in 81 (12.2%) patients. Red cell distribution width, creatinine, and high-sensitivity C-reactive protein levels were significantly higher in the CIN group than in the no-CIN group. Multivariate regression analysis revealed that baseline RDW level (odds ratio 1.379, 95% confidence interval 1.084-1.753, P = .009), age ( P = .025), creatinine ( P = .004), and left ventricular ejection fraction ( P = .011) were independent risk factors for the development of CIN. In conclusion, increased RDW levels are independently associated with a greater risk of CIN in patients undergoing PCI for ACS.

Association between Glycosylated Haemoglobin Level and Contrast-Induced Acute Kidney Injury in Patients with Type 2 Diabetes Mellitus

BACKGROUND

There are several reports suggesting that admission hyperglycaemia increases the risk of contrast-induced acute kidney injury (CI-AKI). However, it is not clear whether there has been an association between long-standing poor glycaemic control and the incidence of CI-AKI. The purpose of this study was to examine the impact of poor glycaemic control or elevated glycosylated haemoglobin (HbA1c) on the incidence of CI-AKI in patients with type 2 diabetes mellitus (T2DM).

METHODS

The present study prospectively enrolled 133 patients with T2DM undergoing elective coronary angiography (CAG) and/or intervention. All patients had an estimated glomerular filtration rate (eGFR) of ≥60 ml/min/1.73 m(2). Patients were divided into two groups: those with an optimal HbA1c (<7%) and those with an elevated HbA1c (≥7%). All had similar baseline characteristics and were hydrated appropriately. The outcome was assessed by the incidence of CI-AKI.

RESULTS

CI-AKI occurred in 2 of 41 patients (4.9%) with optimal HbA1c levels and 5 of 92 patients (5.4%) with elevated HbA1c levels (p = 0.89). The cutoff point of HbA1c was set at 6.5%, but no statistically significant difference between the two groups was observed [1 of 24 patients (4.1%) vs. 6 of 109 patients (5.5%), p = 0.79]. However, despite a high variability in the incidence of CI-AKI, there was no statistically significant difference between the two groups when varying CI-AKI definitions were considered.

CONCLUSION

An elevated HbA1c level is not associated with a higher incidence of CI-AKI compared to optimal HbA1c levels in patients with T2DM (patients with an eGFR of ≥60 ml/min/1.73 m(2)) undergoing CAG and/or intervention.

Hemodynamic and tubular changes induced by contrast media

The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI.