A novel risk score model for prediction of contrast-induced nephropathy after emergent percutaneous coronary intervention

The High-Sensitivity C-Reactive Protein to High-Density Lipoprotein Cholesterol Ratio and the Risk of Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention

Background

The high-sensitivity C-reactive protein to high-density lipoprotein cholesterol ratio (CHR) is a novel biomarker associated with coronary artery disease (CAD) risk. This study aimed to analyze the relationship between CHR and contrast-induced acute kidney injury (CI-AKI).

Methods

This retrospective cross-sectional research included 10,917 individuals who underwent PCI. CI-AKI was diagnosed using the Kidney Disease: Improving Global Outcomes (KIDIGO) standard. Univariate and multivariable logistic regression analyses were conducted to examine the association between CHR and CI-AKI, followed by a receiver operating characteristic (ROC) curve of participants to assess the clinical diagnostic performance of CHR on CI-AKI.

Results

A total of 1037 patients (9.50%) developed CI-AKI after PCI. The age of individuals averaged 64.1 ± 11.1 years old, with 2511 females (23.0%). A multivariate logistic regression study revealed that higher CHR levels were linked to higher CI-AKI incidence rates ([Q4 vs. Q1]: odds ratio (OR) = 1.89, 95% confidence interval (CI) [1.42 to 2.54], p < 0.001). A restricted cubic spline analysis revealed a linear association between CHR and CI-AKI. ROC analysis indicated that CHR was an excellent predictor of CI-AKI (area under ROC curve = 0.606, 95% CI [0.588 to 0.624]).

Conclusions

A high CHR level is strongly associated with increased CI-AKI incidence, suggesting that CHR may be an independent risk factor for CI-AKI.

Clinical Trial registration

NCT05050877. https://clinicaltrials.gov/study/NCT05050877?tab=results.

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.

Development and Validation of a Risk Model for Predicting Contrast-Associated Acute Kidney Injury in Patients With Cancer: Evaluation in Over 46,000 CT Examinations

BACKGROUND. Patients with cancer undergo frequent CT examinations with iodinated contrast media and may be uniquely predisposed to contrast-associated acute kidney injury (CA-AKI). OBJECTIVE. The purpose of this study was to develop and validate a model for predicting the risk of CA-AKI after contrast-enhanced CT in patients with cancer. METHODS. This retrospective study included 25,184 adult patients (12,153 men, 13,031 women; mean age, 62.3 ± 13.7 [SD] years) with cancer who underwent 46,593 contrast-enhanced CT examinations between January 1, 2016, and June 20, 2020, at one of three academic medical centers. Information was recorded regarding demographics, malignancy type, medication use, baseline laboratory values, and comorbid conditions. CA-AKI was defined as a 0.3-mg/dL or greater increase in serum creatinine level from baseline within 48 hours after CT or a 1.5-fold or greater increase in the peak measurement within 14 days after CT. Multivariable models accounting for correlated data were used to identify risk factors for CA-AKI. A risk score for predicting CA-AKI was generated in a development set (n = 30,926) and tested in a validation set (n = 15,667). RESULTS. CA-AKI occurred after 5.8% (2682/46,593) of CT examinations. The final multivariable model for predicting CA-AKI included hematologic malignancy, diuretic use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, chronic kidney disease (CKD) stage 3a, CKD stage 3b, CKD stage 4 or 5, serum albumin level less than 3.0 g/dL, platelet count less than 150 × 103/μL, 1+ or greater proteinuria on baseline urinalysis, diabetes mellitus, heart failure, and contrast medium volume 100 mL or greater. A risk score (range, 0-53 points) was generated with these variables. The most points (13) were for CKD stage 4 or 5 and for albumin level less than 3 g/dL. The frequency of CA-AKI progressively increased in higher risk categories. For example, in the validation set, CA-AKI occurred after 2.2% of CT examinations in the lowest risk category (score ≤ 4) and after 32.7% of CT examinations in the highest risk category (score ≥ 30). The Hosmer-Lemeshow test result indicated that the risk score was a good fit (p = .40). CONCLUSION. A risk model in which readily available clinical data are used to predict the likelihood of CA-AKI after contrast-enhanced CT in patients with cancer was developed and validated. CLINICAL IMPACT. The model may help facilitate appropriate implementation of preventive measures in the care of patients at high risk of CA-AKI.

Characterization of Risk Prediction Models for Acute Kidney Injury: A Systematic Review and Meta-analysis

Importance

Despite the expansion of published prediction models for acute kidney injury (AKI), there is little evidence of uptake of these models beyond their local derivation nor data on their association with patient outcomes.

Objective

To systematically review published AKI prediction models across all clinical subsettings.

Data Sources

MEDLINE via PubMed (January 1946 to April 2021) and Embase (January 1947 to April 2021) were searched using medical subject headings and text words related to AKI and prediction models.

Study Selection

All studies that developed a prediction model for AKI, defined as a statistical model with at least 2 predictive variables to estimate future occurrence of AKI, were eligible for inclusion. There was no limitation on study populations or methodological designs.

Data Extraction and Synthesis

Two authors independently searched the literature, screened the studies, and extracted and analyzed the data following the Preferred Reporting Items for Systematic Review and Meta-analyses guideline. The data were pooled using a random-effects model, with subgroups defined by 4 clinical settings. Between-study heterogeneity was explored using multiple methods, and funnel plot analysis was used to identify publication bias.

Main Outcomes and Measures

C statistic was used to measure the discrimination of prediction models.

Results

Of the 6955 studies initially identified through literature searching, 150 studies, with 14.4 million participants, met the inclusion criteria. The study characteristics differed widely in design, population, AKI definition, and model performance assessments. The overall pooled C statistic was 0.80 (95% CI, 0.79-0.81), with pooled C statistics in different clinical subsettings ranging from 0.78 (95% CI, 0.75-0.80) to 0.82 (95% CI, 0.78-0.86). Between-study heterogeneity was high overall and in the different clinical settings (eg, contrast medium-associated AKI: I2 = 99.9%; P < .001), and multiple methods did not identify any clear sources. A high proportion of models had a high risk of bias (126 [84.4%]) according to the Prediction Model Risk Of Bias Assessment Tool.

Conclusions and Relevance

In this study, the discrimination of the published AKI prediction models was good, reflected by high C statistics; however, the wide variation in the clinical settings, populations, and predictive variables likely drives the highly heterogenous findings that limit clinical utility. Standardized procedures for development and validation of prediction models are urgently needed.

Development and evaluation of machine learning models and nomogram for the prediction of severe acute pancreatitis

BACKGROUND AND AIM

Severe acute pancreatitis (SAP) in patients progresses rapidly and can cause multiple organ failures associated with high mortality. We aimed to train a machine learning (ML) model and establish a nomogram that could identify SAP, early in the course of acute pancreatitis (AP).

METHODS

In this retrospective study, 631 patients with AP were enrolled in the training cohort. For predicting SAP early, five supervised ML models were employed, such as random forest (RF), K-nearest neighbors (KNN), and naive Bayes (NB), which were evaluated by accuracy (ACC) and the areas under the receiver operating characteristic curve (AUC). The nomogram was established, and the predictive ability was assessed by the calibration curve and AUC. They were externally validated by an independent cohort of 109 patients with AP.

RESULTS

In the training cohort, the AUC of RF, KNN, and NB models were 0.969, 0.954, and 0.951, respectively, while the AUC of the Bedside Index for Severity in Acute Pancreatitis (BISAP), Ranson and Glasgow scores were only 0.796, 0.847, and 0.837, respectively. In the validation cohort, the RF model also showed the highest AUC, which was 0.961. The AUC for the nomogram was 0.888 and 0.955 in the training and validation cohort, respectively.

CONCLUSIONS

Our findings suggested that the RF model exhibited the best predictive performance, and the nomogram provided a visual scoring model for clinical practice. Our models may serve as practical tools for facilitating personalized treatment options and improving clinical outcomes through pre-treatment stratification of patients with AP.

Contrast-induced acute kidney injury and its contemporary prevention

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

Prevention and Management of AKI in ACS Patients Undergoing Invasive Treatments

PURPOSE OF REVIEW

Management of patients presenting with acute coronary syndrome (ACS) includes invasive procedures that may increase the risk of acute kidney injury (AKI). AKI adversely affects the outcomes of such procedures and complicates the management of ACS. We have summarized several strategies for the prevention and management of AKI in this critical patient group including in the pre-procedural, intraprocedural, and post-procedural settings.

RECENT FINDINGS

Definitive prevention and management strategies for AKI in patients presenting with ACS requiring invasive management can be confounded by the variation in data outcomes. Pre-procedural hydration with normal saline when accounting for time to catheterization, radial artery access, contrast stewardship, and close monitoring of renal function after catheterization should be implemented.

Endorsement of the TRIPOD statement and the reporting of studies developing contrast-induced nephropathy prediction models for the coronary angiography/percutaneous coronary intervention population: a cross-sectional study

OBJECTIVE

Clear and specific reporting of a research paper is essential for its validity and applicability. Some studies have revealed that the reporting of studies based on the clinical prediction models was generally insufficient based on the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist. However, the reporting of studies on contrast-induced nephropathy (CIN) prediction models in the coronary angiography (CAG)/percutaneous coronary intervention (PCI) population has not been thoroughly assessed. Thus, the aim is to evaluate the reporting of the studies on CIN prediction models for the CAG/PCI population using the TRIPOD checklist.

DESIGN

A cross-sectional study.

METHODS

PubMed and Embase were systematically searched from inception to 30 September 2021. Only the studies on the development of CIN prediction models for the CAG/PCI population were included. The data were extracted into a standardised spreadsheet designed in accordance with the 'TRIPOD Adherence Assessment Form'. The overall completeness of reporting of each model and each TRIPOD item were evaluated, and the reporting before and after the publication of the TRIPOD statement was compared. The linear relationship between model performance and TRIPOD adherence was also assessed.

RESULTS

We identified 36 studies that developed CIN prediction models for the CAG/PCI population. Median TRIPOD checklist adherence was 60% (34%-77%), and no significant improvement was found since the publication of the TRIPOD checklist (p=0.770). There was a significant difference in adherence to individual TRIPOD items, ranging from 0% to 100%. Moreover, most studies did not specify critical information within the Methods section. Only 5 studies (14%) explained how they arrived at the study size, and only 13 studies (36%) described how to handle missing data. In the Statistical analysis section, how the continuous predictors were modelled, the cut-points of categorical or categorised predictors, and the methods to choose the cut-points were only reported in 7 (19%), 6 (17%) and 1 (3%) of the studies, respectively. Nevertheless, no relationship was found between model performance and TRIPOD adherence in both the development and validation datasets (r=-0.260 and r=-0.069, respectively).

CONCLUSIONS

The reporting of CIN prediction models for the CAG/PCI population still needs to be improved based on the TRIPOD checklist. In order to promote further external validation and clinical application of the prediction models, more information should be provided in future studies.

CHA2DS2-VASc, a Simple Clinical Score Expanding Its Boundaries to Predict Contrast-Induced Acute Kidney Injury After Primary Percutaneous Coronary Interventions

Objective

Promising results of CHA₂DS₂-VASc score have been reported for the prediction of contrast-induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI). However, data of its predictive strength in the context of primary PCI are not available. Therefore, in this study, we have assessed predictive value of CHA₂DS₂-VASc score for CI-AKI after primary PCI.

Methods

This analytical cross-sectional study was conducted between January 2021 and June 2021 at the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan. Inclusion criteria of the study was consecutive adult patients who had undergone primary PCI. Baseline CHA₂DS₂-VASc score was calculated, and either a 25% or 0.5 mg/dL increase in post-procedure serum creatinine level as compared to baseline level was categorized as CI-AKI.

Results

A total of 691 patients were included, of which 82.1% (567) were male. CI-AKI after primary PCI was observed in 63 (9.1%) patients, out of which 66.7% (42) of patients had CHA₂DS₂-VASc score of ≥2. The area under the curve (AUC) for the score was 0.725 [0.662 to 0.788] with a sensitivity and specificity of 66.7% [63.1% to 70.2%] and 66.7% [53.7% to 78.1%], respectively, at a cut-off value of ≥2. In multivariable analysis, left ventricular ejection fraction ≤30% and CHA₂DS₂-VASc ≥2 were found to be independent predictors with adjusted odds ratios of 2.19 [1.06–4.5] and 2.13 [1.13–4.01], respectively.

Conclusion

CHA₂DS₂-VASc score has a good predictive value for the prediction of CI-AKI after primary PCI. Criteria of CHA₂DS₂-VASc ≥2 can be used for the risk stratification of CI-AKI after primary PCI.

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.

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

Objective

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

Methods

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

Results

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

Conclusions

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

The Predictive Value of Myeloperoxidase for Contrast-Induced Nephropathy After Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction

Background

Higher serum myeloperoxidase (MPO) in patients with acute coronary syndrome is associated with adverse cardiovascular outcomes. Contrast-induced nephropathy (CIN) is associated with worse prognosis in patients with coronary artery disease following angiography. We have no idea whether patients with higher serum myeloperoxidase have a higher risk of CIN in acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Methods

This study involved 436 consecutive patients with AMI who had received PCI. Serum MPO levels were determined using enzyme-linked immunosorbent assay before administration of contrast media. Multivariate logistic regression analysis was used to analyze the independent risk factors for CIN after univariate analysis. The receiver operator characteristic (ROC) analysis was performed to evaluate the predictive value of MPO for CIN.

Results

Among the 436 patients, 79 individuals (18.1%) suffered CIN after the PCI procedure. Patients who developed CIN had significantly higher MPO levels compared to those who did not ([203.8 (150.6–276.2)] versus [138.5 (129.9–149.2)]; p<0.001). Multivariate logistic regression analysis revealed that MPO level (OR 1.023, 95% CI: 1.017–1.029, p<0.001) was an independent risk factor for the incidence of CIN after adjusting for the baseline information, blood indicators and angiography procedural parameters. The area under the ROC curve for predicting CIN of MPO was 0.848, and the optimum cutoff point of MPO was 147.38ug/L; the sensitivity and specificity were 82.3% and 72.3%, respectively.

Conclusion

The results show that MPO is independently associated with an increased risk of CIN with AMI patients undergoing PCI. Further studies are needed to verify these results.

Prediction Models for AKI in ICU: A Comparative Study

PURPOSE

To assess the performance of models for early prediction of acute kidney injury (AKI) in the Intensive Care Unit (ICU) setting.

PATIENTS AND METHODS

Data were collected from the Medical Information Mart for Intensive Care (MIMIC)-III database for all patients aged ≥18 years who had their serum creatinine (SCr) level measured for 72 h following ICU admission. Those with existing conditions of kidney disease upon ICU admission were excluded from our analyses. Seventeen predictor variables comprising patient demographics and physiological indicators were selected on the basis of the Kidney Disease Improving Global Outcomes (KDIGO) and medical literature. Six models from three types of methods were tested: Logistic Regression (LR), Support Vector Machines (SVM), Random Forest (RF), eXtreme Gradient Boosting (XGBoost), Light Gradient Boosting Decision Machine (LightGBM), and Convolutional Neural Network (CNN). The area under receiver operating characteristic curve (AUC), accuracy, precision, recall and F-measure (F1) were calculated for each model to evaluate performance.

RESULTS

We extracted the ICU records of 17,205 patients from MIMIC-III dataset. LightGBM had the best performance, with all evaluation indicators achieving the highest value (average AUC = 0.905, F1 = 0.897, recall = 0.836). XGBoost had the second best performance and LR, RF, SVM performed similarly (P = 0.082, 0.158 and 0.710, respectively) on AUC. The CNN model achieved the lowest score for accuracy, precision, F1 and AUC. SVM and LR had relatively low recall compared with that of the other models. The SCr level had the most significant effect on the early prediction of AKI onset in LR, RF, SVM and LightGBM.

CONCLUSION

LightGBM demonstrated the best capability for predicting AKI in the first 72 h of ICU admission. LightGBM and XGBoost showed great potential for clinical application owing to their high recall value. This study can provide references for artificial intelligence-powered clinical decision support systems for AKI early prediction in the ICU setting.

Use of the Thrombolysis in Myocardial Infarction Risk Index for Elderly Patients With ST-Segment Elevation Myocardial Infarction

Background: Thrombolysis in Myocardial Infarction (TIMI) Risk Index (TRI) is a simple risk assessment tool for patients with ST-segment elevation myocardial infarction (STEMI). However, its applicability to elderly patients with STEMI undergoing percutaneous coronary intervention (PCI) is uncertain. Methods: This was a retrospective analysis of elderly (≥60 years) patients who underwent PCI for STEMI from January 2010 to April 2016. TRI was calculated on admission using the following formula: heart rate × (age/10)²/systolic blood pressure. Discrimination and calibration of TRI for in-hospital events and 1 year mortality were analyzed. Results: Totally 1,054 patients were divided into three groups according to the tertiles of the TRI: <27 (n = 348), 27-36 (n = 360) and >36 (n = 346). The incidence of acute kidney injury (AKI; 7.8 vs. 8.6 vs. 24.0%, p < 0.001), AHF (3.5 vs. 6.6 vs. 16.2%, p < 0.001), in-hospital death (0.6 vs. 3.3 vs. 11.6%, p < 0.001) and MACEs (5.2 vs. 5.8 vs. 15.9%, p < 0.001) was significantly higher in the third tertile. TRI showed good discrimination for in-hospital death [area under the curve (AUC) = 0.804, p < 0.001; Hosmer-Lemeshow p = 0.302], which was superior to its prediction for AKI (AUC = 0.678, p < 0.001; Hosmer-Lemeshow p = 0.121), and in-hospital MACEs (AUC = 0.669, p < 0.001; Hosmer-Lemeshow p = 0.077). Receiver-operation characteristics curve showed that TRI > 42.0 had a sensitivity of 64.8% and specificity of 82.2% for predicting in-hospital death. Kaplan-Meier analysis showed that patients with TRI > 42.0 had higher 1 year mortality (Log-rank = 79.2, p < 0.001). Conclusion: TRI is suitable for risk stratification in elderly patients with STEMI undergoing PCI, and is thus of continuing value for an aging population.

Advances in the pathogenesis and prevention of contrast-induced nephropathy

With the increasing application of medical imaging contrast materials, contrast-induced nephropathy has become one of the leading causes of iatrogenic renal insufficiency. The underlying mechanism is associated with renal medullary hypoxia, direct toxicity of contrast agents, oxidative stress, apoptosis, immune/inflammation and epigenetic regulation in contrast-induced nephropathy. Up to date, there is no effective therapy for contrast-induced nephropathy, and thus risk predication and effective preventive strategies are keys to reduce the occurrence of contrast-induced nephropathy. It was found that the proper use of contrast medium, personalized hydration, and high-dose statins may reduce the occurrence of contrast-induced nephropathy, while antioxidants have not shown significant therapeutic benefits. Additionally, the role of remote ischemia preconditioning and vasodilators in the prevention of contrast-induced nephropathy needs further study. This review aims to discuss the incidence, pathogenesis, risk prediction, and preventive strategies for contrast-induced nephropathy.

Validation of pre-operative risk scores of contrast-induced acute kidney injury in a Chinese cohort

Background

Pre-operative risk scores are more valuable than post-procedure risk scores because of lacking effective treatment for contrast-induced acute kidney injury (CI-AKI). A number of pre-operative risk scores have been developed, but due to lack of effective external validation, most of them are also difficult to apply accurately in clinical practice. It is necessary to review and validate the published pre-operative risk scores for CI-AKI.

Materials and methods

We systematically searched PubMed and EMBASE databases for studies of CI-AKI pre-operative risk scores and assessed their calibration and discriminatory in a cohort of 2669 patients undergoing coronary angiography or percutaneous coronary intervention (PCI) from September 2007 to July 2017. The definitions of CI-AKI may affect the validation results, so three definition were included in this study, CI-AKI broad1 was defined as an increase in serum creatinine (Scr) of 44.2 μmol/L or 25%; CI-AKI broad2, an increase in Scr of 44.2 μmol/L or 50%; and CI-AKI-narrow, an increase in Scr of 44.2 μmol/L. The calibration of the model was assessed with the Hosmer-Lemeshow test and the discriminatory capacity was identified by C-statistic.

Results

Of the 8 pre-operative risk scores for CI-AKI identified, 7 were single-center study and only 1 was based on multi-center study. In addition, 7 of the scores were just validated internally and only Chen score was externally validated. In the validation cohort of 2669 patients, the incidence of CI-AKI ranged from 3.0%(Liu) to 16.4%(Chen) for these scores. Furthermore, the incidence of CI-AKI was 6.59% (178) for CI-AKI broad1, 1.44% (39) for CI-AKI broad2, and 0.67% (18) for CI-AKI-narrow. For CI-AKI broads, C-statistics varied from 0.44 to 0.57. For CI-AKI-narrow, the Maioli score had the best discrimination and calibration, what’s more, the C-statistics of Maioli, Chen, Liu and Ghani was ≥0.7.

Conclusion

Most pre-operative risk scores were established based on single-center studies and most of them lacked external validation. For CI-AKI broads, the prediction accuracy of all risk scores was low. The Maioli score had the best discrimination and calibration, when using the CI-AKI-narrow definition.

Development and internal validation of a prediction model for hospital-acquired acute kidney injury

Background

Predictive models and clinical risk scores for hospital-acquired acute kidney injury (AKI) are mainly focused on critical and surgical patients. We have used the electronic clinical records from a tertiary care general hospital to develop a risk score for new-onset AKI in general inpatients that can be estimated automatically from clinical records.

Methods

A total of 47 466 patients met inclusion criteria within a 2-year period. Of these, 2385 (5.0%) developed hospital-acquired AKI. Step-wise regression modelling and Bayesian model averaging were used to develop the Madrid Acute Kidney Injury Prediction Score (MAKIPS), which contains 23 variables, all obtainable automatically from electronic clinical records at admission. Bootstrap resampling was employed for internal validation. To optimize calibration, a penalized logistic regression model was estimated by the least absolute shrinkage and selection operator (lasso) method of coefficient shrinkage after estimation.

Results

The area under the curve of the receiver operating characteristic curve of the MAKIPS score to predict hospital-acquired AKI at admission was 0.811. Among individual variables, the highest odds ratios, all >2.5, for hospital-acquired AKI were conferred by abdominal, cardiovascular or urological surgery followed by congestive heart failure. An online tool (http://www.bioestadistica.net/MAKIPS.aspx) will facilitate validation in other hospital environments.

Conclusions

MAKIPS is a new risk score to predict the risk of hospital-acquired AKI, based on variables present at admission in the electronic clinical records. This may help to identify patients who require specific monitoring because of a high risk of AKI.

Negative association between free triiodothyronine level and contrast-induced acute kidney injury in patients undergoing primary percutaneous coronary intervention

BACKGROUND

A low FT3 level is significantly associated with a variety of kidney disease and acute myocardial infarction (AMI). However, it remains unclear whether low FT3 is associated with CI-AKI in patients who underwent pPCI.

METHODS

Single-center retrospective study evaluated 363 STEMI patients undergoing pPCI. Patients were classfied into 2 groups, low FT3 group (FT3 < 3.1 pmol/L) and normal FT3 group (FT3 ≥ 3.1 pmol/L);CI-AKI was defined as an increase in the serum creatinine levels of ≥50% or 0.3 mg/dL above the baseline level within 48 h after contrast medium exposure.

RESULTS

Overall, 80(22.0%) patients had low FT3, and 59(16.3%) patients developed CI-AKI. The incidence of CI-AKI and in-hospital mortality was significantly higher in patients with low FT3 than normal (31.3% vs 12.0%; 15.0% vs 3.2%, respectively, both p < 0.0001). Multivariate logistic regression analysis indicated that low FT3 was an independent predictor of CI-AKI (odds ratio [OR] = 2.62, 95%CI:1.35-5.07, p < 0.05). In addition, low FT3 was associated with an increased risk of all-cause mortality during a mean follow-up period of 20 months (hazard ratio [HR] = 2.54, 95%CI:1.15-5.60, p < 0.05).

CONCLUSION

Low FT3 was associated with CI-AKI, short- and long-term mortality in STEMI patients after pPCI.

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.

Predictive Value of Hepatorenal Status in Contrast-Induced Nephropathy Among Patients Receiving Coronary Angiography and/or Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

Low serum albumin, high blood urea nitrogen (BUN), and uric acid are regarded closely related to the incidence of contrast-induced nephropathy (CIN), whereas it remains unclear whether they can function as predictors of CIN onset. The objective of this systematic review and meta-analysis was to explore the association between abovementioned indicators and CIN incidence rate in patients receiving coronary angiography (CAG) and/or intervention.

METHODS

Clinical studies were retrieved from the electronic databases of PubMed, EMBASE, Google Scholar, Clinical Trials, and ScienceDirect from their inception to July 13, 2018. Meta-analysis was performed on pooled eligible studies to determine whether these hepatorenal indicators were associated with CIN.

RESULTS

A total of 18 studies involving 16 171 patients were included in the meta-analysis. Pooled analysis results revealed that patients with hypoalbuminemia (odds ratio [OR] = 3.09, 95% confidence interval [CI] = 1.44-6.64, P = .004) and hyperuricemia (OR = 1.32, 95% CI = 1.15-1.50, P < .0001) both exhibited significantly higher CIN rates, regardless of the study design, renal function, and whether urgent clinical situation or not. However, there was no significant association between serum BUN and CIN risk.

CONCLUSION

Hypoalbuminemia and hyperuricemia are independently associated with the occurrence of CIN among the patients undergoing CAG and/or intervention.

Contrast-Induced Nephropathy and Long-Term Mortality After Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction

Abnormal hemodynamics is thought to contribute to the increased risk of contrast-induced nephropathy (CIN) and mortality. However, few studies focused on patients without abnormal hemodynamics (defined as hypotension, intra-aortic balloon pump usage) and reduced left ventricular ejection fraction (LVEF < 40%). Our study was to explore the impact of CIN on mortality in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) with relative stable hemodynamics. In this observational study, we included 696 patients with AMI undergoing PCI without reduced LVEF and abnormal hemodynamics. The end point was long-term, all-cause mortality. During the mean follow-up of 2.79 years, CIN was detected in 110 (15.8%) patients. The total all-cause mortality was higher in CIN group than that in non-CIN group (24% vs 3.4%, P < .001). In the multivariate Cox analysis, CIN was an independent predictor of worse outcomes (adjusted hazard ratio [HR]: 2.97, 95% confidence interval: 1.46-6.06, P < .001) and significantly associated with long-term mortality, so did renal insufficiency (adjusted HR: 4.40, P < .001) and use of β-blockers (adjusted HR: 0.33, P < .001). Among patients with AMI, CIN independently predicted long-term mortality following PCI, regardless of LVEF impairment and abnormal hemodynamics.

Growth differentiation factor-15 levels and the risk of contrast induced nephropathy in patients with acute myocardial infarction undergoing percutaneous coronary intervention: A retrospective observation study

Aims

To investigate the association between growth differentiation factor-15 (GDF-15) and contrast-induced nephropathy (CIN) in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI).

Methods

A total of 311 patients with AMI were studied retrospectively. All patients were divided into two groups according to the occurrence of CIN after PCI. Baseline clinical data were compared between two groups. Multivariate logistic regression analysis was used to identify the risk factors for CIN. Cox regression analysis was used to identify the association between GDF-15, CIN and short-term outcome.

Results

There were 80 patients in CIN group (average age was 71.60 ± 13.00 years; 67.5% male) and 231 patients in non-CIN group (average age was 63.80 ± 11.70 years; 71.9%male). The concentration of GDF-15 in CIN group was higher than that of non-CIN group (1232 ± 366.6 ng/L vs. 939.20 ± 309.6 ng/L, P <0.001). According to GDF-15 quartiles, patients were divided into four groups. Multivariate logistic model indicated that the highest quartile(Q4) was significantly associated with an increased risk of CIN compared with lower level of GDF-15 (Q1, Q2 and Q3) (OR : 3.572, 1.803–7.078, P < 0.001). Of 243 patients who could calculate the ACEF risk score, area under the curve (AUC) of GDF-15 was 0.793, 95%CI: 0.729–0.856, P < 0.001, while AUC of ACEF was 0.708, 95%CI: 0.630–0.786, P < 0.001. Using 10% and 30% as arbitrary thresholds to define patients at low, intermediate, and high risk, GDF-15 achieved a net reclassification improvement (NRI) of 0.32 (95%CI: 0.123–0.518, P = 0.001) compared with the ACEF risk score. Cox regression model showed that high concentration of GDF-15 (Q4) was significantly associated with an increased risk of all-cause mortality and major adverse clinical events (MACE) (HR: 8.434, 95%CI: 2.650–26.837, P <0.001; HR: 3.562, 95%CI: 1.658–7.652, P = 0.001) compared with low level of GDF-15 (Q1, Q2 and Q3). CIN was an independent predictor of all-cause mortality and MACE in AMI patients (HR: 3.535, 95%CI: 1.135–11.005, P = 0.029; HR: 5.154, 95%CI: 2.228–11.925, P <0.001).

Conclusion

GDF-15 levels increased in CIN group in AMI patients underwent PCI. GDF-15 was an independent risk factor for CIN in AMI patients underwent PCI. GDF-15 level and CIN are independent risk factors for all-cause mortality and MACE in short-term follow-ups.

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

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

Monocyte to High-Density Lipoprotein Ratio Predicts Contrast-Induced Nephropathy in Patients With Acute Coronary Syndrome

Contrast-induced nephropathy (CIN) is associated with worse prognosis in patients with acute coronary syndrome (ACS). Early identification and intervention for patients with a high risk of CIN are very important to improve clinical outcomes. Inflammation plays important role in the development of CIN in the setting of ACS. The monocyte to high-density lipoprotein ratio (MHR) is a novel inflammatory marker. Bleeding is also associated with worse prognosis in such patients. We aimed to investigate whether the preprocedural MHR had a predictive role for CIN development in such patients. In addition, using the thrombolysis in myocardial infarction classification, we aimed to assess whether there was any relationship between bleeding and CIN. A total of 647 patients (496 males; age: 63.3 ± 12.7 years) with ACS who underwent percutaneous coronary intervention (PCI) were included in the study. Seventy patients (10.8%) had developed CIN. Age, diabetes mellitus, contrast volume, estimated glomerular filtration rate, and MHR were independent predictors for CIN. Preprocedural MHR may be used as a simple marker of CIN. It may help with the early identification of patients with ACS who underwent PCI who are at high risk of CIN thus allowing the planning of protective measures.

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.

Development of a preprocedure nomogram for predicting contrast-induced acute kidney injury after coronary angiography or percutaneous coronary intervention

Most of the risk models for predicting contrast-induced acute kidney injury (CI-AKI) are available for postcontrast exposure prediction, thus have limited values in practice. We aimed to develop a novel nomogram based on preprocedural features for early prediction of CI-AKI in patients after coronary angiography (CAG) or percutaneous coronary intervention (PCI). A total of 245 patients were retrospectively reviewed from January 2015 to January 2017. Least absolute shrinkage and selection operator (Lasso) regression model was applied to select most strong predictors for CI-AKI. The CI-AKI risk score was calculated for each patient as a linear combination of selected predictors that were weighted by their respective coefficients. The discrimination of nomogram was assessed by C-statistic. The occurrence of CI-AKI was 13.9% (34 out of 245). We identified ten predictors including sex, diabetes mellitus, lactate dehydrogenase level, C-reactive protein, years since drinking, chronic kidney disease (CKD), stage of CKD, stroke, acute myocardial infarction, and systolic blood pressure. The CI-AKI prediction nomogram obtained good discrimination (C-statistic, 0.718, 95%CI: 0.637-0.800, p = 7.23 × 10^-5). The cutoff value of CI-AKI risk score was -1.953. Accordingly, the novel nomogram we developed is a simple and accurate tool for preprocedural prediction of CI-AKI in patients undergoing CAG or PCI.