A simple pre-procedural risk score for contrast-induced nephropathy among patients with chronic total occlusion undergoing percutaneous coronary intervention

Anemia and periprocedural complications determine contrast-associated acute kidney injury after recanalization of chronic coronary occlusions in chronic kidney disease

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO) particularly with pre-existing chronic kidney disease (CKD). The determinants of CA-AKI in patients with pre-existing CKD in an era of advanced strategies of CTO recanalization techniques need to be considered for a risk evaluation of the procedure.

METHODS

A consecutive cohort of 2504 recanalization procedures for a CTO between 2013 and 2022 was analyzed. Of these, 514 (20.5%) were done in patients with CKD (estimated glomerular filtration rate < 60 ml/min based on the most recently used CKD Epidemiology Collaboration equation).

RESULTS

The rate of patients classified to have CKD would be lower with 14.2% using the Cockcroft-Gault equation, and 18.1% using the modified Modification of Diet in Renal Disease equation. The technical success was high with 94.9% and 96.8% (p = 0.04) between patients with and without CKD. The incidence of CA-AKI was 9.9% versus 4.3% (p < 0.001). The major determinants of CA-AKI in patients with CKD were the presence of diabetes and a reduced ejection fraction, as well as periprocedural blood loss, whereas a higher baseline hemoglobin and the use of the radial approach prevented CA-AKI.

CONCLUSIONS

In patients with CKD CTO PCI could be performed successfully at a higher cost of CA-AKI. Correcting preprocedural anemia and avoiding intraprocedural blood loss may reduce the incidence of CA-AKI.

A Systematic Review of Periprocedural Risk Prediction Scores in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with high incidence of complications. We queried PubMed and the Cochrane Library (last search: October 26, 2022) for CTO PCI-specific periprocedural complication risk scores. We identified 8 CTO PCI-specific risk scores: (1) Angiographic coronary artery perforation (OPEN-CLEAN [Outcomes, Patient Health Status, and Efficiency iN (OPEN) Chronic Total Occlusion (CTO) Hybrid Procedures - CABG, Length (occlusion), EF <50%, Age, CalcificatioN] perforation, c-statistic 0.75): previous coronary artery bypass graft surgery, occlusion length 20 to 60 mm or ≥60 mm, left ventricular ejection fraction (LVEF) <50%, age 50 to 70 years or ≥70 years, heavy calcification. (2) Major adverse cardiovascular events (MACE) (PROGRESS-CTO complication, c-statistic 0.76): age >65 years, lesion length ≥23 mm, retrograde strategy, and (3) MACE (PROGRESS-CTO MACE, c-statistic 0.74): age ≥65 years, female gender, moderate/severe calcification, blunt/no stump, anterograde dissection and re-entry (ADR) or retrograde strategy. (4) All-cause mortality (PROGRESS-CTO mortality, c-statistic 0.80): age ≥65, moderate/severe calcification, LVEF ≤45%, ADR or retrograde strategy. (5) Perforation requiring pericardiocentesis (PROGRESS-CTO pericardiocentesis, c-statistic 0.78): age ≥65 years, moderate/severe calcification, female gender, ADR or retrograde strategy. (6) Acute myocardial infarction (PROGRESS-CTO acute myocardial infarction, c-statistic 0.72): previous coronary artery bypass graft surgery, atrial fibrillation, blunt/no stump. (7) Perforation requiring any treatment (PROGRESS-CTO perforation, c-statistic 0.74): age ≥65 years, moderate/severe calcification, blunt/no stump, ADR, or retrograde strategy. (8) Contrast-induced acute kidney injury (c-statistic 0.84): age ≥75, LVEF <40%, serum creatinine >1.5 mg/100 ml, serum albumin ≤30, 30<albumin≤40 or >40 g/L. There are 8 CTO PCI periprocedural risk scores that may facilitate risk assessment and procedural planning in patients who underwent CTO PCI.

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.

CTO in Contemporary PCI

Percutaneous Coronary Intervention (PCI) of Chronic Total Occlusions (CTO) represents the most challenging procedure in modern endovascular treatments. In recent years, the success rate of CTO PCI has substantially improved, owing to increasing operator expertise and advancements in CTO equipment and algorithms as well as the development of expert consensus documents. In this review, we summarize existing evidence for CTO PCI, its success/ risk prediction scoring tools, procedural principles and complications and provide an insight into the future role of CTO PCI.

Acute Kidney Injury Following Percutaneous Coronary Intervention for Acute Coronary Syndrome: Incidence, Aetiology, Risk Factors and Outcomes

We investigated the predictors, aetiology and long-term outcomes of acute kidney injury (AKI) following urgent percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Acute kidney injury occurred in 198 (7.2%) of 2917 patients: 14.1% of AKI cases were attributed to cardiogenic shock and 5.1% were classified as atheroembolic renal disease (AERD). Significant risk factors for AKI included age (odds ratio [OR] 1.05, 95% confidence limits [CI] 1.03-1.06), diabetes (OR 1.73, 95% CI 1.20-2.47), hypertension (OR 1.43, 95% CI 1.03-2.00), heart failure (OR 3.01, 95% CI 1.58-5.57), femoral access (OR 1.50, 95% CI 1.03-2.15), cardiogenic shock (OR 2.03, 95% CI 1.19-3.37) and ST-elevation myocardial infarction (STEMI) (OR 3.89, 95% CI 2.80-5.47). One-year mortality after AERD was 44.4% and renal replacement therapy (RRT) requirement 22.2% (compared with mortality 33.3% and RRT requirement 7.4%, respectively, in all other AKI patients). Mortality at 1 year was associated with AKI (OR 4.33, 95% CI 2.89-6.43), age (OR 1.08, 95% CI 1.06-1.09), heart failure (OR 1.92, 95% CI 1.05-3.44), femoral access (OR 2.05, 95% CI 1.41-2.95) and cardiogenic shock (OR 3.63, 95% CI 2.26-5.77). Acute kidney injury after urgent PCI is strongly associated with worse outcomes. Atheroembolic renal disease has a poor outcome and a high likelihood of long-term RRT requirement.

A preprocedural risk score predicts acute kidney injury following primary percutaneous coronary intervention

BACKGROUND

Reliable preprocedural risk scores for the prediction of Contrast-Induced Acute Kidney Injury (CI-AKI) following Percutaneous Coronary Intervention (pPCI) in patients with ST-elevation myocardial infarction (STEMI) are lacking. Aim of this study was to derive and validate a preprocedural Risk Score in this setting.

METHODS

Two prospectively enrolled patient cohorts were used for derivation and validation (n = 3,736). CI-AKI was defined as creatinine increase ≥0.5 mg/dl <72 h postpPCI. Odds ratios from multivariable logistic regression model were converted to an integer, whose sum represented the Risk Score.

RESULTS

Independent CI-AKI predictors were: diabetes, Killip class II-III (2 points each), age > 75 years, anterior MI (3 points), Killip class IV (4 points), estimated GFR < 60 ml/min/1.73m² (5 points). The Risk Score c-statistic was 0.84 in both cohorts. Compared with patients with Risk Score ≤ 4, the relative risks of CI-AKI among patients scoring 5-9 were 6.2 (derivation cohort) and 7.1 (validation cohort); among patients scoring ≥10, 19.8, and 21.4, respectively.

CONCLUSIONS

Among STEMI patients, a simple preprocedural Risk Score accurately and reproducibly predicted the risk of CI-AKI, identifying ¼ of patients with a seven-fold risk and 1/10 of patients with a 20-fold risk. This knowledge may help tailored strategies, including delaying revascularization of nonculprit vessels in patients at high risk of CI-AKI.

Impact of Chronic Kidney Disease on Chronic Total Occlusion Revascularization Outcomes: A Meta-Analysis

Objectives: To examine the impact of revascularization and associated clinical outcomes of chronic kidney disease (CKD) chronic total occlusion (CTO) and non-CKD CTO groups. Background: The influence of CKD on clinical outcomes after percutaneous coronary intervention (PCI) for CTO lesions is unknown, and there is no systemic review of this topic to date. Methods: We searched the PubMed, Embase, ProQuest, ScienceDirect, Cochrane Library, ClinicalKey, Web of Science, and ClinicalTrials Databases for articles published between 1 January 2010 and 31 March 2020. CKD was defined as estimated glomerular filtration rate of <60 mL/min/1.73 m² according to the Modification of Diet in Renal Disease formula. Data included demographics, lesion distributions, incidence of contrast-induced nephropathy (CIN), acute kidney injury (AKI), procedural success rate, mortality, and target lesion revascularization (TLR)/target vessel revascularization (TVR). Results: Six studies were ultimately included in this systematic review. A high prevalence (25.5%; range, 19.6–37.9%) of CKD was noted in the CTO population. In the non-CKD group, outcomes were better: less incidence of CIN or AKI (odds ratio (OR), 2.860; 95% confidence interval (CI), 1.775–4.608), higher procedural success rate (OR, 1.382; 95% CI, 1.036–1.843), and lower long-term mortality (OR, 4.502; 95% CI, 3.561–5.693). The incidence of TLR/TVR (OR, 1.118; 95% CI, 0.888–1.407) did not differ between groups. Conclusions: In the CKD CTO PCI population, a lower procedural success rate, a higher incidence of CIN or AKI, and higher in-hospital and long-term mortality rate were noted due to more complex lesions and more comorbidities. However, the incidence of TLR/TVR did not differ between groups.

Preprocedure Planning for Chronic Total Occlusion Percutaneous Coronary Intervention: The Separation Is in the Preparation

To perform chronic total occlusion percutaneous coronary intervention safely, efficiently, and successfully, adequate time must be dedicated to thorough preprocedural planning. This process should encompass a patient encounter, becoming fully familiarized with the patient's clinical traits, a detailed review of coronary anatomy, laying out an algorithmic procedural approach and making any relevant plans for actions that will enhance intraprocedural safety.

Contrast-associated acute kidney injury: An update of risk factors, risk factor scores, and preventive measures

As lifespans lengthen, age-related diseases such as cardiovascular disease and diabetes are becoming more prevalent. Correspondingly, the use of contrast agents for medical imaging is also becoming more common, and there is increasing awareness of contrast-associated acute kidney injury (CA-AKI). There is no specific treatment for CA-AKI, and clinicians currently focus on prevention, interventions that alter its pathogenesis, and identification of risk factors. Although the incidence of CA-AKI is low in the general population, the risk of CA-AKI can reach 20% to 30% in patients with multiple risk factors. Many models have been applied in the clinic to assess the risk factors for CA-AKI, enable identification of high-risk groups, and improve clinical management. Hypotonic or isotonic contrast media are recommended to prevent CA-AKI in high-risk patients. Patients with risk factors should avoid using contrast media multiple times within a short period of time. All nephrotoxic drugs should be stopped at least 24 h before the administration of contrast media in high-risk populations, and adequate hydration is recommended for all patients. This review summarizes the pathophysiology of CA-AKI and the progress in diagnosis and differential diagnosis; updates the risk factors and risk factor scoring systems; reviews the latest advances related to prevention and treatment; discusses current problems in epidemiological studies; and highlights the importance of identifying high-risk subjects to control modifiable risk factors and use of a rating scale to estimate the risk and implement appropriate prevention strategies.

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.

Performance of a pre-procedural Mehran score to predict acute kidney injury after percutaneous coronary intervention

AIM

Acute kidney injury (AKI) is a known complication of patients undergoing cardiac catheterization or percutaneous coronary interventions (PCI).The Mehran score was developed to identify patients at risk for AKI after cardiac catheterization or PCI, but its use of contrast volume as part of the score calculation limits its application prior to the procedure. In this study, we evaluated the utility of a modified Mehran score that utilizes only pre-procedural data by excluding contrast volume.

METHODS

This was done in a retrospective fashion using data from patients who received PCI at our institution between July 2015 and December 2017 by evaluating the discriminative ability of the scoring systems for predicting outcomes through a receiver-operator characteristic curve analysis.

RESULTS

One thousand five hundred and seven patients were included in the study. A total of 70 (4.6%) patients developed AKI. The removal of contrast volume from the Mehran score resulted in a small loss of discrimination with AUROC 0.73 vs 0.74, P = .01 for the pre-procedural Mehran and the original Mehran, respectively. When compared to the original score, the pre-procedural Mehran score had a four-category net discrimination index (NRI) of -0.10 and an integrated discrimination index (IDI) for of -0.12.

CONCLUSION

Despite a small loss in discrimination, there was no difference in the four-category net discrimination index between the two scores. The pre-procedural modified Mehran score is a useful clinical predictor of the risk of AKI in patients undergoing PCI.

Acute kidney injury prediction models: current concepts and future strategies

PURPOSE OF REVIEW

Acute kidney injury (AKI) is a critical condition associated with poor patient outcomes. We aimed to review the current concepts and future strategies regarding AKI risk prediction models.

RECENT FINDINGS

Recent studies have shown that AKI occurs frequently in patients with common risk factors and certain medical conditions. Prediction models for AKI risk have been reported in medical fields such as critical care medicine, surgery, nephrotoxic agent exposure, and others. However, practical, generalizable, externally validated, and robust AKI prediction models remain relatively rare. Further efforts to develop AKI prediction models based on comprehensive clinical data, artificial intelligence, improved delivery of care, and novel biomarkers may help improve patient outcomes through precise AKI risk prediction.

SUMMARY

This brief review provides insights for current concepts for AKI prediction model development. In addition, by overviewing the recent AKI prediction models in various medical fields, future strategies to construct advanced AKI prediction models are suggested.

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.

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.

Current approaches for treatment of coronary chronic occlusions

Introduction: Coronary chronic total occlusions (CTO) represent a challenging subset in interventional cardiology.Areas covered: During the last decade, improvements in materials, techniques, and meticulous pre-procedural lesion assessment have increased the success rate in CTO lesions. Several scores have been developed to address overall lesion evaluation and help select the most appropriate treatment strategy. In addition, specific algorithms such as the hybrid algorithm have been introduced to provide a framework for CTO operators and a rapid management of the various challenging aspects of the procedure. The hybrid approach requires operator's ability to switch from one treatment strategy to another when the first one appears to be unsuccessful. Adequate training and operators' experience remain crucial to improve the likelihood of success.Expert opinion: The aim of this review is to provide insights and guidance for operators on current approaches for treatment of CTO and complication management.

ADVANCIS Score Predicts Acute Kidney Injury After Percutaneous Coronary Intervention for Acute Coronary Syndrome

Acute kidney injury (AKI), a common and crucial complication of acute coronary syndrome (ACS) after receiving percutaneous coronary intervention (PCI), is associated with increased mortality and adverse outcomes. This study aimed to develop and validate a risk prediction model for incident AKI after PCI for ACS. We included 82,186 patients admitted for ACS and receiving PCI between 1997 and 2011 from the Taiwan National Health Insurance Research Database and randomly divided them into a training cohort (n = 57,630) and validation cohort (n = 24,656) for risk model development and validation, respectively. Risk factor analysis revealed that age, diabetes mellitus, ventilator use, prior AKI, number of intervened vessels, chronic kidney disease (CKD), intra-aortic balloon pump (IABP) use, cardiogenic shock, female sex, prior stroke, peripheral arterial disease, hypertension, and heart failure were significant risk factors for incident AKI after PCI for ACS. The reduced model, ADVANCIS, comprised 8 clinical parameters (age, diabetes mellitus, ventilator use, prior AKI, number of intervened vessels, CKD, IABP use, cardiogenic shock), with a score scale ranging from 0 to 22, and performed comparably with the full model (area under the receiver operating characteristic curve, 87.4% vs 87.9%). An ADVANCIS score of ≥6 was associated with higher in-hospital mortality risk. In conclusion, the ADVANCIS score is a novel, simple, robust tool for predicting the risk of incident AKI after PCI for ACS, and it can aid in risk stratification to monitor patient care.

Percutaneous Coronary Intervention of Chronic Total Occlusions in Patients With Low Left Ventricular Ejection Fraction

OBJECTIVES

The study sought to assess the outcome of percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) in patients with low left ventricular ejection fraction (LVEF) (≤35%).

BACKGROUND

Data regarding the outcome of PCI in patients with low LVEF affected by CTO are scarcely reported.

METHODS

The authors performed a prospective longitudinal multicenter study including consecutive patients undergoing elective PCI of CTOs. Patients were subdivided into 3 groups: group 1 (LVEF ≥50%), group 2 (LVEF 35% to 50%), and group 3 (LVEF ≤35%).

RESULTS

A total of 839 patients (mean 64.6 ± 10.5 years of age, 87.7% men) underwent CTO PCI attempts. Baseline LVEF ≤35% was present in 72 (8.6%) patients. The angiographic success was high (overall 93.6%) and similar among the 3 groups (93.5% vs. 94.4% vs. 91.7%, respectively; all p = NS). In group 3, no periprocedural complications of CTO PCI were observed. Mean clinical follow-up of 16.3 ± 8.2 months duration was available in 781 (93.1%) patients including those with LVEF ≤35%. At 2 years, major cardiac and cerebrovascular events (MACCE) free survival was similar in the 3 groups (86% vs. 82.8% vs. 75.2%; all p = NS). In patients with LVEF ≤35%, LVEF improved significantly in the presence of a successful CTO PCI from 29.1 ± 3.4% to 41.6 ± 7.9% (p < 0.001).

CONCLUSIONS

In CTO patients with low LVEF, PCI could represent a safe and effective revascularization strategy achieving good midterm outcome and LVEF improvement.

Pre-Procedural Risk Score of Contrast-Induced Nephropathy in Elderly Patients Undergoing Elective Coronary Angiography

To establish a scoring model to predict the risk of contrast-induced nephropathy (CIN) in elderly patients undergoing elective coronary angiography (CAG).A total of 1286 patients aged > 65 years who had undergone elective CAG between August 2009 and February 2013 were enrolled in this study. They were randomly (3:2) assigned to a development (n = 756) or validation dataset (n = 530). Independent predictors of CIN were identified by using logistic regression and were assigned a weighted integer, which was used to establish a score model.CIN incidence in the development set was 6.3%. The risk score model contained 3 variables (with the weighted integer): age > 75 years (1.5), creatinine clearance (CrCl) < 60 mL/minute (1), and congestive heart failure (CHF) (1.5). CIN incidence was 3.1%, 9.1%, and 29.0% in the low-risk group (≤ 1), moderate risk group (1 - 3), and high-risk group (≥ 3), respectively. The risk model demonstrated good prediction value in the development (c-statistic = 0.727) and validation (c-statistic = 0.695) datasets. Compared to the non-CIN group, the CIN group had a significantly higher rate of inhospital major adverse cardiac events (P < 0.01).The risk score model with 3 variables, namely age > 75 years, CrCl < 60 mL/minute, and CHF, is a clinical prediction tool for CIN in elderly patients before elective CAG. CIN is one of the independent risk factors of major adverse cardiac events (MACE).

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.

Approach to CTO Intervention: Overview of Techniques

OPINION STATEMENT

Successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has been associated with significant clinical benefits, but remains technically demanding. Failure to cross the CTO with a guidewire is the most common cause of CTO PCI failure. CTO crossing can be achieved in the antegrade or retrograde direction and can be accomplished by maintaining true lumen position throughout or via subintimal dissection/reentry techniques. A procedural plan should be created prior to the procedure through careful angiographic review of four key parameters: (a) morphology of the proximal occlusion cap; (b) length of the occlusion; (c) quality of the distal vessel and presence of bifurcation at the distal cap; and (d) suitability of collateral circulation for retrograde crossing. Dual coronary injection is recommended in all cases with contralateral collaterals for detailed characterization of the lesion. If one approach fails to progress, a quick transition to the next approach is encouraged to maximize efficacy and efficiency. Procedural complications, including vessel perforation, may occur more frequently in CTO as compared with non-CTO PCI; hence, availability of necessary equipment and expertise in treating such complications are essential.

Risk prediction models for contrast induced nephropathy: systematic review

OBJECTIVES

To look at the available literature on validated prediction models for contrast induced nephropathy and describe their characteristics.

DESIGN

Systematic review.

DATA SOURCES

Medline, Embase, and CINAHL (cumulative index to nursing and allied health literature) databases.

REVIEW METHODS

Databases searched from inception to 2015, and the retrieved reference lists hand searched. Dual reviews were conducted to identify studies published in the English language of prediction models tested with patients that included derivation and validation cohorts. Data were extracted on baseline patient characteristics, procedural characteristics, modelling methods, metrics of model performance, risk of bias, and clinical usefulness. Eligible studies evaluated characteristics of predictive models that identified patients at risk of contrast induced nephropathy among adults undergoing a diagnostic or interventional procedure using conventional radiocontrast media (media used for computed tomography or angiography, and not gadolinium based contrast).

RESULTS

16 studies were identified, describing 12 prediction models. Substantial interstudy heterogeneity was identified, as a result of different clinical settings, cointerventions, and the timing of creatinine measurement to define contrast induced nephropathy. Ten models were validated internally and six were validated externally. Discrimination varied in studies that were validated internally (C statistic 0.61-0.95) and externally (0.57-0.86). Only one study presented reclassification indices. The majority of higher performing models included measures of pre-existing chronic kidney disease, age, diabetes, heart failure or impaired ejection fraction, and hypotension or shock. No prediction model evaluated its effect on clinical decision making or patient outcomes.

CONCLUSIONS

Most predictive models for contrast induced nephropathy in clinical use have modest ability, and are only relevant to patients receiving contrast for coronary angiography. Further research is needed to develop models that can better inform patient centred decision making, as well as improve the use of prevention strategies for contrast induced nephropathy.