Use of the contrast volume or grams of iodine-to-creatinine clearance ratio to predict mortality after percutaneous coronary intervention

Absolute zero-contrast percutaneous coronary interventions: An intravascular ultrasound-guided case series and literature review

PURPOSE

Contrast media (CM)-associated adverse effects including mainly acute kidney injury and hypersensitivity reactions still remain a significant treatment burden to vulnerable patients requiring percutaneous coronary intervention (PCI). The complete omission of CM administration accompanied by intravascular ultrasound (IVUS) guidance may offer an appropriate revascularization treatment.

METHODS

We hereby present a case series of four patients with challenging coronary lesions and relative/absolute contraindications to CM use [(hypersensitivity reaction owning to CM, history of contrast-induced acute kidney injury, solitary kidney, or advanced chronic kidney disease (CKD)] who underwent absolute zero-contrast IVUS-guided PCI following a predetermined protocol.

RESULTS

The initial diagnostic angiography was reviewed for landmark identification, and multiple guidewires created a metallic road map providing additional landmarks and protected side branches. IVUS imaging was performed to determine lesion length, reference segments and landing zones, assess stent expansion/apposition and identify major complications. All procedures were successfully completed without any CM administration, renal function deterioration, pericardial effusion, or stent edge dissection.

CONCLUSIONS

We demonstrated the feasibility of absolute zero-contrast IVUS-guided PCI in patients with complex coronary lesions susceptible to CM-associated adverse effects. Since the safety of this strategy is well-documented in patients with CKD and challenging lesions morphology even in acute settings, evidence-based validation of this approach is capable of changing the otherwise conservative treatment of vulnerable patients where even minimum doses of CM may have detrimental effects.

SUMMARY FOR THE ANNOTATED TABLE OF CONTENTS

Patients with vulnerable renal function as well as former hypersensitivity reaction to contrast media encounter a significant treatment burden regarding coronary artery disease. Zero-contrast IVUS-guided strategy based on a predetermined protocol provides a feasible alternative approach in patients susceptible to contrast media-associated adverse effects even in the presence of complex coronary lesions.

Predicting Contrast-induced Renal Complications

Chronic kidney disease is an independent risk factor for the development of coronary artery disease and overlaps with other risk factors such as hypertension and diabetes. Percutaneous coronary intervention is a cornerstone of therapy for coronary artery disease and requires contrast media, which can lead to renal injury. Identifying patients at risk for contrast-associated acute kidney injury (CA-AKI) is critical for preventing kidney damage, which is associated with both short- and long-term mortality. Determination of the potential risk for CA-AKI and a new need for dialysis using validated risk prediction tools identifies patients at high risk for this complication. Identification of patients at risk for renal injury after contrast exposure is the first critical step in prevention. Contrast media volume, age and sex of the patient, a history of chronic kidney disease and/or diabetes, clinical presentation, and hemodynamic and volume status are factors known to predict incident contrast-induced nephropathy. Recognition of at-risk patient subpopulations allows for targeted, efficient, and cost-effective strategies to reduce the risk of renal complications resulting from contrast media exposure.

Management of Patients With Kidney Disease in Need of Cardiovascular Catheterization: A Scientific Workshop Cosponsored by the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions

Patients with chronic kidney disease (CKD) are at an increased risk of developing cardiovascular disease (CVD), whereas those with established CVD are at risk of incident or progressive CKD. Compared with individuals with normal or near normal kidney function, there are fewer data to guide the management of patients with CVD and CKD. As a joint effort between the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions, a workshop and subsequent review of the published literature was held. The present document summarizes the best practice recommendations of the working group and highlights areas for further investigation.

Association Between Contrast Volume-to-Creatinine Clearance Ratio and the Risk of Perioperative Myocardial Infarction After Elective Percutaneous Coronary Intervention

Although the use of iodinated contrast for percutaneous coronary intervention (PCI) has known toxicity issues, the association between the contrast volume-to-creatinine clearance (V/CrCl) ratio and perioperative myocardial infarction (PMI) is unclear. The present study is aimed to investigate the predictive value of V/CrCl ratio on the incidence of PMI, and to determine a relatively safe contrast media V/CrCl ratio cut-off value to prevent PMI undergoing elective PCI. The V/CrCl ratio were obtained from 5970 patients undergoing elective PCI for single-vessel lesions. Cardiac troponin I (cTnI) were measured at baseline, 8, 16, and 24 hours after PCI. PMI was defined as postprocedural > 5 × upper limit of normal. Receiver operating characteristic (ROC) curves were performed to identify the optimal sensitivity for the V/CrCl range. Multivariate regression model were used to assess the association between V/CrCl ratios and PMI. Eight hundred and ninety-seven patients (15.0%) developed PMI. There was a significant association between higher V/CrCl ratio and the development of PMI (P < 0.001 for the trend). ROC curve analysis indicated that V/CrCl ratio of 2.05 was a discriminator for PMI (area under the curve = 0.674). After adjusting for other potential risk factors, V/CrCl ratio > 2.05 remained significant associated with PMI (odds ratio, 1.921; 95% confidence interval, 1.311-2.815; P = 0.001). The finding of this study suggests the importance of minimizing the contrast media dose to avoid PMI development. Use of a contrast media dose based on renal function with a V/CrCl value < 2.05 might be valuable in preventing PMI.

Safety and feasibility of intravascular ultrasound guided zero-contrast percutaneous coronary intervention-A prospective study

BACKGROUND

There are published reports of safety and feasibility of percutaneous coronary intervention (PCI) without contrast, using intravascular ultrasound (IVUS) and coronary physiology guidance in chronic kidney disease population. We prospectively evaluated the safety and feasibility of zero-contrast PCI technique.

METHODS

In this prospective study, we hypothesized that PCI is feasible without contrast, using IVUS guidance alone without mandatory coronary physiology to rule out slow-flow or no-flow at the end of PCI in a population at risk of contrast-induced acute kidney injury (CI-AKI). In this study, we included 31 vessels in 27 patients at risk of CI-AKI and assessed the primary outcome of technical success at the end of PCI. Major adverse cardio-cerebro vascular events (MACCE) and percent change in estimated glomerular filtration rate(eGFR) one month after PCI were the secondary outcomes of the study.

RESULTS

The primary outcome was met in 87.1%(n = 27) of the procedures. Technical failure was seen in 12.9%(n = 4) of the procedures. None of the patients developed MACCE at one-month follow-up. The median percent change in eGFR at one-month follow-up was -8.19%(-24.40%, +0.92%). There was no newer initiation of renal replacement therapy at one-month follow-up.

CONCLUSIONS

Zero-contrast PCI is safe and feasible in selective coronary anatomies with IVUS guidance. Coronary physiology is not mandatory to rule out slow-flow or no-flow at the end of procedure. Contrast may be needed to tide over the crisis during the possible complications, namely slow-flow, geographical miss and intraprocedural thrombus.

Hydration for prevention of kidney injury after primary coronary intervention for acute myocardial infarction: a randomised clinical trial

OBJECTIVE

To evaluate the efficacy of aggressive hydration compared with general hydration for contrast-induced acute kidney injury (CI-AKI) prevention among patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI).

METHODS

The Aggressive hydraTion in patients with STEMI undergoing pPCI to prevenT Contrast-Induced Acute Kidney Injury study is an open-label, randomised controlled study at 15 teaching hospitals in China. A total of 560 adult patients were randomly assigned (1:1) to receive aggressive hydration or general hydration treatment. Aggressive hydration group received preprocedural loading dose of 125/250 mL normal saline within 30 min, followed by postprocedural hydration performed for 4 hours under left ventricular end-diastolic pressure guidance and additional hydration until 24 hours after pPCI. General hydration group received ≤500 mL 0.9% saline at 1 mL/kg/hour for 6 hours after randomisation. The primary end point is CI-AKI, defined as a >25% or 0.5 mg/dL increased in serum creatinine from baseline during the first 48-72 hours after primary angioplasty. The safety end point is acute heart failure.

RESULTS

From July 2014 to May 2018, 469 patients were enrolled in the final analysis. CI-AKI occurred less frequently in aggressive hydration group than in general hydration group (21.8% vs 31.1%; risk ratio (RR) 0.70, 95% CI 0.52 to 0.96). Acute heart failure did not significantly differ between the aggressive hydration group and the general hydration group (8.1% vs 6.4%, RR 1.13, 95% CI 0.66 to 2.44). Several subgroup analysis showed the better effect of aggressive hydration in CI-AKI prevention in male, renal insufficient and non-anterior myocardial infarction participants.

CONCLUSIONS

Comparing with general hydration, the peri-operative aggressive hydration seems to be safe and effective in preventing CI-AKI among patients with STEMI undergoing pPCI.

The relationship between hyperuricemia and contrast-induced acute kidney injury undergoing primary percutaneous coronary intervention: secondary analysis protocol for the ATTEMPT RESCIND-1 study

Background

Contrast-induced acute kidney injury (CI-AKI) contributes toward unfavorable clinical outcomes after primary percutaneous coronary intervention (pPCI). We will assess whether hyperuricemia is an independent predictor of CI-AKI and outcomes in patients undergoing pPCI.

Methods/design

Our study is a secondary analysis for the database from ATTEMPT study, enrolling 560 ST-segment elevation myocardial infarction (STEMI) patients undergoing pPCI. Patients will be divided into 2 groups according to the admission serum uric acid (SUA) level. Hyperuricemia will be defined as a SUA level > 7 mg/dL (417 mmol/L) in males and > 6 mg/dL (357 mmol/L) in females. The primary endpoint was CI-AKI, defined as > 25% or 0.5 mg/dL increase in serum creatinine from baseline during the first 48–72 h post-procedurally. Multivariate analyses for CI-AKI and long-term mortality will be performed using the logistic regression and Cox regression analyses, respectively.

Discussion

This study will determine the predictive value of hyperuricemia for the development of CI-AKI and outcomes in patients with STEMI undergoing pPCI. We predict that hyperuricemia will be associated with a risk of CI-AKI in patients with pPCI. Furthermore, after adjusting for other variables, long-term mortality after pPCI may be higher in those with hyperuricemia than in those with normouricemia. Results of this study may provide scientific evidence for the effect of hyperuricemia on CI-AKI and long-term outcomes, thereby offering the potential possibility of lowering SUA on the development of CI-AKI and outcomes.

Trial registration

ClinicalTrials.gov NCT02067195, Registered on 20 February 2014.

Predicting Contrast-Induced Renal Complications

Chronic kidney disease is a major risk factor for developing coronary artery disease, serving as an independent risk factor while overlapping with other risk factors. Percutaneous coronary intervention is a cornerstone of therapy for coronary artery disease and requires contrast media, which can contribute to renal injury. Identifying patients at risk for contrast-induced nephropathy is critical for preventing renal injury, which is associated with short- and long-term mortality. Determination of the potential risk for contrast-induced nephropathy and a new need for dialysis using validated risk prediction tools is a method of identifying patients at high risk for this complication.

Statistical analysis plan for aggressive hydraTion in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention to prevenT contrast-induced nephropathy (ATTEMPT) study

Background

The ATTEMPT study is a multicenter, randomized controlled trial which is investigator-based and open label in nature. For the study, 560 patients with ST-segment elevation myocardial infarction (STEMI) underwent primary percutaneous coronary intervention (pPCI) have been randomized (1:1) for treatment with periprocedural aggressive hydration (treatment group) or general hydration (control group). To improve the quality of the study’s analysis and to minimize analysis bias based on the study’s findings.

Methods

The design of the statistical analysis plan (SAP) was created by chief investigators and statisticians and received permission from the aggressive hydraTion in patients with ST-Elevation Myocardial infarction undergoing Primary percutaneous coronary intervention to prevenT contrast-induced nephropathy (ATTEMPT) management committee. Treatment allocation and research data were reviewed by the Data Safety and Monitoring Committee and researchers were kept blind. We produced data shells based on a pre-existing published protocol and produced detailed descriptions of statistical analyses. This study includes primary, secondary and safety endpoints. Relevant statistical comparisons were planned and discussed in a transparent manner. They are publicly available, verifiable and were determined prior to the data collection process being completed.

Results

We developed a SAP for the ATTEMPT study and an outline and list of mock tables were also created. We produced descriptions of analyses of baseline characteristics, patient care approaches, efficacy measures, and outcomes. This study defined five previously specified subgroups and compared the statistics of groups within these subgroups.

Conclusions

This SAP has been developed for the ATTEMPT study and has high-quality standards of internal validity to minimize analysis bias.

Trial registration

ClinicalTrials.gov number, NCT02067195.

Carbon dioxide-angiography for patients with peripheral arterial disease at risk of contrast-induced nephropathy

Patients with peripheral arterial disease (PAD) and critical limb ischemia are at risk for limb amputation and require urgent management to restore blood flow. Patients with PAD often have several comorbidities, including chronic kidney disease, diabetes mellitus, and hypertension. Diagnostic and interventional angiography using iodinated contrast agents provides excellent image resolution but can be associated with contrast-induced nephropathy (CIN). The use of carbon dioxide (CO₂) as a contrast agent reduces the volume of iodine contrast required for angiography and reduces the incidence of CIN. However, CO₂ angiography has been underutilized due to concerns regarding safety and image quality. Modern CO₂ delivery systems with advanced digital subtraction angiography techniques and hybrid angiography have improved imaging accuracy and reduced the incidence of CIN. Awareness of the need for optimal imaging conditions, contraindications, and potential complications have improved the safety of CO₂ angiography. This review aims to highlight current technological advances in the delivery of CO₂ in vascular angiography for patients with PAD and critical limb ischemia, which result in limb preservation while preventing kidney damage.

Development and Validation of a Model for Predicting the Risk of Acute Kidney Injury Associated With Contrast Volume Levels During Percutaneous Coronary Intervention

Importance

Determining the association of contrast volume during percutaneous coronary intervention (PCI) with the risk of acute kidney injury (AKI) is important for optimizing PCI safety.

Objective

To quantify how the risk of AKI is associated with contrast volume, accounting for the possibility of nonlinearity and heterogeneity among different baseline risks.

Design, Setting, and Participants

This prognostic study used data from the American College of Cardiology National Cardiovascular Data Registry CathPCI Registry for 1694 US hospitals. Derivation analysis included 2 076 694 individuals who underwent PCI from July 1, 2011, to June 30, 2015. Validation analysis included 961 863 individuals who underwent PCI from July 1, 2015, to March 31, 2017. Data analysis took place from July 2018 to May 2019.

Exposure

Contrast volume during PCI.

Main Outcomes and Measures

Acute kidney injury was defined using 3 thresholds for preprocedure to postprocedure creatinine level increase (ie, ≥0.3 mg/dL, ≥0.5 mg/dL, and ≥1.0 mg/dL). A model quantifying the association of contrast volume with AKI was developed, and the existence of nonlinearity and heterogeneity were examined by likelihood ratio tests. The model was derived in the training set (a random 50% of the derivation cohort), and performance was evaluated in the test set (the remaining 50% of the derivation cohort) and an independent validation set by area under the receiver operating characteristic curve (AUC) and calibration slope of observed vs predicted risks.

Results

The 2 076 694 patients in the derivation set had a mean (SD) age of 65.1 (12.1) years, and 662 525 (31.9%) were women; 133 306 (6.4%) had creatinine level increases of at least 0.3 mg/dL, 66 626 (3.2%) had creatinine level increases of at least 0.5 mg/dL, and 28 378 (1.4%) had creatinine level increases of at least 1.0 mg/dL. In the validation set of 961 843 patients (mean [SD] age, 65.7 [12.1] years; 305 577 [31.8%] women), these rates were 62 913 (6.5%), 34 229 (3.6%), and 15 555 (1.6%), respectively. The association of contrast volume and AKI risk was nonlinear (χ226 = 1436.2; P < .001) and varied by preprocedural risk (χ220 = 105.6; P < .001). In the test set, the model yielded an AUC of 0.777 (95% CI, 0.775-0.779) for predicting risk of a creatinine level increase of at least 0.3 mg/dL, 0.839 (95% CI, 0.837-0.841) for predicting risk of a creatinine level increase of at least 0.5 mg/dL, and 0.870 (95% CI, 0.867-0.873) for predicting risk of a creatinine level increase of at least 1.0 mg/dL; it achieved a calibration slope of 0.998 (95% CI, 0.989-1.007), 0.999 (95% CI, 0.989-1.008), and 0.986 (95% CI, 0.973-0.998), respectively, for the AKI severity levels. The model had similar performance in the validation set (creatinine level increase of ≥0.3 mg/dL: AUC, 0.794; 95% CI, 0.792-0.795; calibration slope, 1.039; 95% CI, 1.030-1.047; creatinine level increase of ≥0.5 mg/dL: AUC, 0.845; 95% CI, 0.843-0.848; calibration slope, 1.063; 95% CI, 1.054-1.074; creatinine level increase of ≥1.0 mg/dL: AUC, 0.872; 95% CI, 0.869-0.875; calibration slope, 1.103; 95% CI, 1.089-1.117).

Conclusions and Relevance

The association of contrast volume with AKI risk is complex, varies by baseline risk, and can be predicted by a model. Future research to evaluate the effect of the model on AKI is needed.

Efficacy of post-procedural oral hydration volume on risk of contrast-induced acute kidney injury following primary percutaneous coronary intervention: study protocol for a randomized controlled trial

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) contributes toward unfavorable clinical outcomes. Oral hydration with water is inexpensive and it may be effective in the prevention of CI-AKI, but its efficacy among patients undergoing primary percutaneous coronary intervention (PCI) remains unknown.

METHODS/DESIGN

Our study is a secondary analysis on the database from the ATTEMPT study. We enrolled ST-elevation myocardial infarction (STEMI) patients undergoing primary PCI. Eligible patients received peri-procedural aggressive (left ventricular end-diastolic pressure-guided) or routine (≤ 500 mL) intravenous hydration with an isotonic solution (0.9% NaCl) with randomization. The primary endpoint was CI-AKI, defined as a > 25% or 0.5 mg/dL increase in serum creatinine from baseline during the first 48-72 h post-procedurally. All patients drank unrestricted amounts of fluids freely, the volume of which was recorded until 24 h following primary PCI. Oral hydration volume/weight (OHV/W) ratios were calculated. The association between post-procedural oral hydration (quartiles) and CI-AKI was assessed using multivariable analysis controlling for confounders, including intravenous hydration strategies.

DISCUSSION

Our study determined the effects of post-procedural oral hydration on CI-AKI following primary PCI, which is a potential strategy for CI-AKI prevention among patients with STEMI at very high risk.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02067195 . Registered on 21 February 2014.

Imaging Evaluation for the Detection of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement

Subclinical leaflet thrombosis has been increasingly recognized as a common imaging finding after surgical or transcatheter aortic valve replacement (TAVR) in recent studies. This finding has raised concerns over TAVR valve durability and debates on optimal postprocedural antithrombotic regime. Hypoattenuated leaflet thickening (HALT) and the associated reduced leaflet motion (RELM) were noted as computed tomography hallmarks of the phenomenon. The coexistence of HALT and significant RELM has been suggested as a threshold for reporting of subclinical leaflet thrombosis. This methodology may contribute to the standardization of reporting for research collaboration, hence the better understanding and management of this common yet largely unknown phenomenon.

The effect of establishing pre-angiography thresholds on contrast utilization

INTRODUCTION

Contrast induced nephropathy is linked to contrast utilization and strategies for minimizing renal injury are incorporated into many laboratories that perform coronary angiography. Contrast limits have been described, below which there is minimal incremental increase in the risk of renal injury. Whether a priori acknowledgement of these limits as part of a contrast "Time-Out" reduces contrast utilization has not been established. In this study, we investigate the effect of verbalizing pre-angiography and ½ time contrast thresholds on contrast utilization and associated clinical outcomes.

METHODS

We retrospectively reviewed 5265 cases of coronary angiography (984 with contrast thresholds defined pre-procedure compared to 4281 without pre-defined contrast thresholds). There were two primary endpoints: (1) proportion of procedures that utilized an amount of contrast ≤ threshold, and (2) median difference between amount of contrast utilized and the contrast threshold. Secondary outcomes incorporated indices of renal function, and included changes in serum creatinine levels, eGFR, and CKD stage.

RESULTS

Compared to pre-"Time-Out" group, the post-"Time-Out" group had a higher proportion of procedures with contrast ≤ stated contrast threshold (88% vs 84%, P < 0.002), and a lower amount of total contrast volume (88 mL [IQR 60-136] versus 78 mL [IQR 53-119]). The post-"Time-Out" group also had a lower incidence of any increase in post-procedure serum creatinine (45% vs 36%; P = 0.04), and a larger median decrease of pre- to post-procedure eGFR (P = 0.04).

CONCLUSION

Acknowledgement of contrast threshold as part of a contrast "Time-Out" is associated with reduced overall contrast utilization, and likely minimizes risks of contrast-induced nephropathy.

Balancing the risks and benefits of using emergency diagnostic radiocontrast studies to diagnose life-threatening illness in critically ill patients: a decision analysis

Diagnosis of many life-threatening illnesses, including acute pulmonary embolism, aortic dissection, and ischaemic bowel disease, requires confirmatory radiological imaging with radiocontrast. It is well established that radiocontrast can induce acute kidney injury, especially in patients with pre-existing renal impairment. The decision to proceed with a radiological study with radiocontrast to confirm or exclude a life-threatening, but potentially reversible, illness in patients with renal impairment is difficult. Theoretically, a radiocontrast study will be justifiable provided its benefits outweigh its harms. Using published prognostic data of contrast-induced nephropathy (CIN), this decision analysis aimed to assess whether a certain threshold of pre-test probability of a life-threatening illness is needed before a radiocontrast study can be justified for patients with different levels of renal impairment. In critically ill patients presenting with a life-threatening illness with hypotension requiring vasopressors or inotropes, the risk of CIN (defined by an increment in plasma creatinine of 40 µmol/l) and the associated attributable mortality after using 50 to 100 ml of radiocontrast was about 30% and 4%, respectively, for patients with baseline plasma creatinine concentrations <400 µmol/l. The risk of CIN and its associated attributable mortality increased substantially and exceeded 80% and 10%, respectively, if patients also had diabetes mellitus and their baseline plasma creatinine concentrations were >400 µmol/l. In the latter high-risk patients, using a radiocontrast study to diagnose or exclude a life-threatening illness could only be justified if the life-threatening illness was readily treatable and the pre-test probability of having such disease was greater than 15%-20%.

A New Preprocedure Risk Score for Predicting Contrast-Induced Acute Kidney Injury

BACKGROUND

Most of the risk models for predicting contrast-induced acute kidney injury (CI-AKI) are available for only postcontrast exposure prediction; however, prediction before the procedure is more valuable in practice. This study aimed to develop a risk scoring system based on preprocedural characteristics for early prediction of CI-AKI in patients after coronary angiography or percutaneous coronary intervention (PCI).

METHODS

We prospectively recruited 1777 consecutive patients who were randomized in an approximate 3:2 ratio to create a development data set (n = 1076) and a validation data set (n = 701). A risk score model based on preprocedural risk factors was developed using stepwise logistic regression. Validation was performed by bootstrap and split-sample methods.

RESULTS

The occurrence of CI-AKI was 5.97% (106 of 1777), 5.95% (64 of 1076), and 5.99% (42 of 701) in the overall, developmental, and validation data sets, respectively. The risk score was developed with 5 prognostic factors (age, serum creatinine levels, N-terminal pro b-type natriuretic peptide levels, high-sensitivity C-reactive protein, and primary PCI), ranged from 0-36, and was well calibrated (Hosmer-Lemeshow χ² = 4.162; P = 0.842). Good discrimination was obtained both in the developmental and validation data sets (C-statistic, 0.809 and 0.798, respectively). The risk score was highly and positively associated with CI-AKI (P for trend < 0.001) in-hospital and long-term outcomes.

CONCLUSIONS

The novel risk score model we developed is a simple and accurate tool for early/preprocedural prediction of CI-AKI in patients undergoing coronary angiography or PCI. This tool allows assessment of the risk of CI-AKI before contrast exposure, allowing for timely initiation of appropriate preventive measures.

Contrast Volume to Cystatin C-Based Glomerular Filtration Ratio Predicts the Risk of Contrast-Induced Nephropathy After Cardiac Catheterization

Cystatin C is considered to be a better alternative to creatinine for estimating glomerular filtration rate (GFR). The aim of this study was to investigate whether a contrast volume to estimated GFR based on cystatin C (V/eGFRcys) is a better predictor of contrast-induced nephropathy (CIN). We enrolled 1195 consecutive patients undergoing elective cardiac catheterization. Receiver–operating characteristic (ROC) curves were used to identify the optimal cutoff value of V/eGFRcys for detecting CIN. Multivariate regression models were used to evaluate whether V/eGFRcys is an independent risk factor for CIN. A total of 19 (1.6%) patients developed CIN. There was a significant association between a higher V/eGFRcys ratio and CIN risk ( P = .008). A ROC curve analysis indicated that a V/eGFRcys ratio of 2.29 was a fair discriminator for CIN. After adjusting for other known CIN risk factors, V/eGFRcys ratios >2.29 remained significantly associated with CIN (odds ratio = 2.93, 95% confidence interval: 1.02-8.44, P = .047). In conclusion, a V/eGFRcys >2.29 was a significant and independent predictor of CIN after cardiac catheterization.

Incidence of Renal Failure Requiring Hemodialysis Following Transcatheter Aortic Valve Replacement

OBJECTIVE

Studies have shown that iodinated radiocontrast use is associated with acute renal failure especially in the presence of chronic kidney disease and multiple factors modulate this risk. The purpose of this meta-analysis is to compare the incidence of renal failure requiring hemodialysis between transfemoral (TF) and transapical (TA) transcatheter aortic valve replacement using the Edwards valve.

METHODS

The PubMed database was searched from January 2000 through December 2014. A total of 10 studies (n = 2,459) comparing TF (n = 1,268) and TA (n = 1,191) TAVR procedures using the Edwards valve were included. Variables of interest were baseline logistic EuroSCORE, prevalence of diabetes mellitus, hypertension, peripheral arterial disease, chronic kidney disease and amount of contrast used. The primary endpoint was incidence of renal failure requiring hemodialysis. The odds ratio and 95% CI were computed and P < 0.05 was considered as the level of significance.

RESULTS

The logistic EuroSCORE was significantly higher in TA compared to TF (P = 0.001) TAVR. The amount of contrast (mL) used was significantly higher in the TF group compared to the TA group (mean difference: 36.9, CI: 25.7-48.1, P < 0.001). The incidence of hemodialysis following the procedure was significantly higher in the TA group compared to TF group (odds ratio = 4.3, CI: 2.4-7.8, P < 0.00001).

CONCLUSIONS

This meta-analysis suggests that despite the lower amount of contrast used in TA-TAVR, the incidence of renal failure requiring hemodialysis was higher with the Edwards valve. This suggests that the incidence of renal failure requiring hemodialysis after TAVR is associated with baseline comorbidities in the TA-TAVR group rather than the volume of contrast used.

Safe limits of contrast vary with hydration volume for prevention of contrast-induced nephropathy after coronary angiography among patients with a relatively low risk of contrast-induced nephropathy

BACKGROUND

Few studies have investigated the safe limits of contrast to prevent contrast-induced nephropathy (CIN) based on hydration data. We aimed to investigate the relative safe maximum contrast volume adjusted for hydration volume in a population with a relatively low risk of CIN.

METHODS AND RESULTS

The ratios of contrast volume-to-creatinine clearance (V/CrCl) and hydration volume to body weight (HV/W) were determined in patients undergoing cardiac catheterization. Receiver-operator characteristic curve analysis based on the maximum Youden index was used to identify the optimal cutoff for V/CrCl in all patients and in HV/W subgroups. Eighty-six of 3273 (2.6%) patients with mean CrCl 71.89±27.02 mL/min developed CIN. Receiver-operator characteristic curve analysis indicated that a V/CrCl ratio of 2.44 was a fair discriminator for CIN in all patients (sensitivity, 73.3%; specificity, 70.4%). After adjustment for other confounders, V/CrCl >2.44 continued to be significantly associated with CIN (adjusted odds ratio, 4.12; P<0.001) and the risk of death (adjusted hazard ratio, 2.62; P<0.001). The mean HV/W was 12.18±7.40. We divided the patients into 2 groups (HV/W ≤12 and >12 mL/kg). The best cutoff value for V/CrCl was 1.87 (sensitivity, 67.9%; specificity, 64.4%; adjusted odds ratio, 3.24; P=0.011) in the insufficient hydration subgroup (HV/W, ≤12 mL/kg; CIN, 1.32%) and 2.93 (sensitivity, 69.0%; specificity, 65.0%; adjusted odds ratio, 3.04; P=0.004) in the sufficient hydration subgroup (HV/W, >12 mL/kg; CIN, 5.00%).

CONCLUSIONS

The V/CrCl ratio adjusted for HV/W may be a more reliable predictor of CIN and even long-term outcomes after cardiac catheterization. We also found a higher best cutoff value for V/CrCl to predict CIN in patients with a relatively sufficient hydration status, which may be beneficial during decision-making about contrast dose limits in relatively low-risk patients with different hydration statuses.

Percutaneous coronary intervention for chronic total occlusion improved prognosis in patients with renal insufficiency at high risk of contrast-induced nephropathy

We investigated whether attempted percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) would improve the prognosis in patients with renal insufficiency at high risk of contrast-induced nephropathy (CIN). We analyzed 2,330 consecutive patients with renal insufficiency with or without CTOs who underwent coronary angiography or PCI from prospectively collected data. The long-term death and risk of CIN were evaluated among three groups: patients without CTOs (group A, n = 1,829), patients with un-attempted PCI for CTOs (group B, n = 142), and patients who underwent attempted PCI for CTOs (group C, n = 359). Overall, group B and group C (successful rate, 89%) patients had similar renal function and were not significantly associated with an increased risk of CIN (adjusted odds ratio [OR] = 0.88, 95% confidence interval [CI]: 0.41–1.93, P = 0.758). During a 2.33-year period (median), multivariate analysis demonstrated that attempted PCI for CTOs was independently associated with lower mortality (adjusted hazard ratio for death: 0.38, 95% CI: 0.18–0.83; P = 0.015). Attempted PCI for CTOs improved the long-term prognosis in patients with high-risk renal insufficiency and did not increase the risk of CIN.

Aggressive hydraTion in patients with ST-Elevation Myocardial infarction undergoing Primary percutaneous coronary intervention to prevenT contrast-induced nephropathy (ATTEMPT): Study design and protocol for the randomized, controlled trial, the ATTEMPT, RESCIND 1 (First study for REduction of contraSt-induCed nephropathy followINg carDiac catheterization) trial

Adequate hydration is recommended for acute ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) to prevent contrast-induced nephropathy (CIN). However, the optimal hydration regimen has not been well established in these high-risk patients. The objective of this study is to evaluate the efficacy of a preprocedural loading dose plus postprocedural aggressive hydration with normal saline guided by the left ventricular end-diastolic pressure (LVEDP) compared with general hydration for CIN prevention. The ATTEMPT study is a multicenter, open-label, investigator-driven, randomized controlled trial in China. Approximately 560 patients with STEMI undergoing primary PCI will be randomized (1:1) to receive either periprocedural general hydration (control group) or aggressive hydration (treatment group). Patients in the control group receive periprocedural general hydration with ≤500 mL normal saline (within 6 hours) at a normal rate (0.5 or 1 mL/kg · h). Patients in the treatment group receive a preprocedural loading dose (125/250 mL) of normal saline within 30 minutes and intravenous hydration at a normal rate until LVEDP is available, followed by postprocedural aggressive hydration guided by LVEDP for 4 hours and then continuous intravascular hydration at the normal rate until 24 hours after PCI. The primary end point is CIN, defined as a >25% or 0.5-mg/dL increase in serum creatinine from baseline during the first 48 to 72 hours after procedure. The ATTEMPT study has the potential to identify optimal hydration regimens for STEMI patients undergoing PCI.

Multi-phase rotational angiography of the left ventricle to assist ablations: feasibility and accuracy of novel imaging

AIMS

Interventional left ventricular (LV) procedures integrating static 3D anatomy visualization are subject to mismatch with dynamic catheter movements due to prominent LV motion. We aimed to evaluate the accuracy of a recently developed acquisition and post-processing protocol for low radiation dose LV multi-phase rotational angiography (4DRA) in patients.

METHODS AND RESULTS

4DRA image acquisition of the LV was performed as investigational acquisition in patients undergoing left-sided ablation (11 men; BMI = 24.7 ± 2.5 kg/m²). Iodine contrast was injected in the LA, while pacing from the RA at a cycle length of 700 ms. 4DRA acquisition and reconstruction were possible in all 11 studies. Reconstructed images were post-processed using streak artefact reduction algorithms and an interphase registration-based filtering method, increasing contrast-to-noise ratio by a factor 8.2 ± 2.1. This enabled semi-automatic segmentation, yielding LV models of five equidistant phases per cardiac cycle. For evaluation, off-line 4DRA fluoroscopy registration was performed, and the 4DRA LV contours of the different phases were compared with the contours of five corresponding phases of biplane LV angiography, acquired in identical circumstances. Of the distances between these contours, 95% were <4 mm in both incidences. Effective radiation dose for 4DRA, calculated by patient-specific Monte-Carlo simulation, was 5.1 ± 1.1 mSv.

CONCLUSION

Creation of 4DRA LV models in man is feasible at near-physiological heart rate and with clinically acceptable radiation dose. They showed high accuracy with respect to LV angiography in RAO and LAO. The presented technology not only opens perspectives for full cardiac cycle dynamic anatomical guidance during interventional procedures, but also for 3DRA without need for very rapid pacing.

Contrast-induced nephropathy following chronic total occlusion percutaneous coronary intervention in patients with chronic kidney disease

OBJECTIVES

Contrast-induced nephropathy (CIN) has not been systematically studied in high-risk patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO).

METHODS

We prospectively observed 515 consecutive patients with CKD undergoing PCI. Patients were divided into three groups: patients who underwent attempted PCI for CTO (group A, n = 85), patients who did not receive PCI for CTO (group B, n = 45) and patients without CTO (group C, n = 385).

RESULTS

CIN developed in 55 patients (10.68 %). Group A patients received a larger CM dose than group B or group C (p = 0.024). The intravenous hydration volume, age and CIN Mehran score were not significantly different between the three groups. The incidence of CIN was 9.4 % for group A, 6.7 % for group B and 11.4 % for group C (p = 0.344). In-hospital mortality and required renal replacement therapy (p = 0.325) were not significantly different between the groups. Multivariate analysis showed that after adjusting for potential confounding factors, the odds ratio for CIN was 1.03 (p = 0.944) for group A and 0.64 for group B (p = 0.489) compared to group C.

CONCLUSIONS

Attempts to achieve recanalization of CTO in patients with CKD might not increase the risk of CIN if appropriate preventative measures are taken.

KEY POINTS

• Contrast-induced nephropathy can increase morbidity and mortality • Chronic kidney disease patients are at the greatest risk of CIN • Patients with CKD undergoing CTO-PCI are common • Incidence of CIN has not been reported in CKD patients • CTO-PCI in CKD patients might not increase the risk of CIN.

Predictors of outcomes of contrast-induced acute kidney injury after percutaneous coronary intervention in patients with chronic kidney disease

Contrast-induced acute kidney injury (CI-AKI) is a serious complication that is difficult to predict in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI). The aim of this study was to investigate predictors and clinical outcomes of CI-AKI in patients with CKD after PCI. A total of 297 patients with CKD who underwent PCI from September 2006 to December 2011 were enrolled. CI-AKI was defined as serum creatinine level either ≥25% or ≥0.5 mg/dl from baseline within 72 hours after PCI. The primary outcome was all-cause death. The median follow-up duration was 26 months (interquartile range 12 to 40), and CI-AKI occurred in 55 patients (19%). In multivariate logistic regression analyses, the development of CI-AKI was associated with female gender, left ventricular systolic dysfunction, acute myocardial infarction, PCI for left main disease, serum hemoglobin level, and a contrast volume to creatinine clearance ratio >6.0. The development of CI-AKI was significantly associated with increased in-hospital mortality (18.2% vs 3.7%, p = 0.001). Cox proportional-hazard analysis showed that the incidence of all-cause death was significantly higher in patients who developed CI-AKI than in those without CI-AKI (41.8% vs 16.1%, adjusted hazard ratio 3.0, 95% confidence interval 1.6 to 5.6, p <0.001). In conclusion, female gender, left ventricular systolic dysfunction, acute myocardial infarction, PCI for left main disease, serum hemoglobin level, and contrast volume to creatinine clearance ratio >6.0 are independent predictors of CI-AKI. The development of CI-AKI is significantly associated with increased in-hospital and long-term adverse clinical outcomes in patients with CKD undergoing PCI.

Intravascular ultrasound guidance to minimize the use of iodine contrast in percutaneous coronary intervention: the MOZART (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy) randomized controlled trial

OBJECTIVES

The aim of this study was to evaluate the impact of intravascular ultrasound (IVUS) guidance on the final volume of contrast agent used in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND

To date, few approaches have been described to reduce the final dose of contrast agent in PCIs. We hypothesized that IVUS might serve as an alternative imaging tool to angiography in many steps during PCI, thereby reducing the use of iodine contrast.

METHODS

A total of 83 patients were randomized to angiography-guided PCI or IVUS-guided PCI; both groups were treated according to a pre-defined meticulous procedural strategy. The primary endpoint was the total volume contrast agent used during PCI. Patients were followed clinically for an average of 4 months.

RESULTS

The median total volume of contrast was 64.5 ml (interquartile range [IQR]: 42.8 to 97.0 ml; minimum, 19 ml; maximum, 170 ml) in the angiography-guided group versus 20.0 ml (IQR: 12.5 to 30.0 ml; minimum, 3 ml; maximum, 54 ml) in the IVUS-guided group (p < 0.001). Similarly, the median volume of contrast/creatinine clearance ratio was significantly lower among patients treated with IVUS-guided PCI (1.0 [IQR: 0.6 to 1.9] vs. 0.4 [IQR: 0.2 to 0.6, respectively; p < 0.001). In-hospital and 4-month outcomes were not different between patients randomized to angiography-guided and IVUS-guided PCI.

CONCLUSIONS

Thoughtful and extensive use of IVUS as the primary imaging tool to guide PCI is safe and markedly reduces the volume of iodine contrast compared with angiography-alone guidance. The use of IVUS should be considered for patients at high risk of contrast-induced acute kidney injury or volume overload undergoing coronary angioplasty. (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy [MOZART]; NCT01947335).

Contrast Volume-to-Creatinine Clearance Ratio Predicts the Risk of Contrast-Induced Nephropathy After Percutaneous Coronary Intervention in Patients With Reduced Ejection Fraction

We determined a relatively safe contrast media volume-to-creatinine clearance (V/CrCl) cutoff value to avoid contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) in patients (n = 111) with reduced ejection fraction (<40%). Improved prediction of CIN in these patients would be useful. Multivariate regression models were used to evaluate whether V/CrCl is an independent risk factor for CIN. Nine (8.1%) patients developed CIN. The V/CrCl was significantly (P = .023) higher in patients with CIN than in those without. The incidence of CIN in patients with the highest tertile of V/CrCl was significantly higher than the middle and lowest tertiles (18.4% vs. 2.7% and 2.8%; P = .013). After adjusting for other potential risk factors, a V/CrCl ≥3.87 remained significantly associated with risk of CIN. A V/CrCl <3.87 might be valuable in predicting the risk of CIN in patients with reduced ejection fraction undergoing PCI.

Predicting Contrast-induced Renal Complications in the Catheterization Laboratory

Risk scores should undergo 3 analytical phases before they are suitable for adoption in clinical practice, namely, derivation, external validation, and assessment of effect on clinical outcomes of use of the risk score in a so-called impact study. Major risk factors for renal complications after percutaneous coronary intervention are pre-existing chronic kidney disease, diabetes mellitus, use of a high contrast dose, and hemodynamic instability. Unfortunately, only 3 of these 10 risk scores have undergone external validation. As a result, there is a great need for further research on the already designed risk scores.

Nonpharmacological strategies to prevent contrast-induced acute kidney injury

Contrast-induced AKI (CI-AKI) has been one of the leading causes for hospital-acquired AKI and is associated with independent risk for adverse clinical outcomes including morbidity and mortality. The aim of this review is to provide a brief summary of the studies that focus on nonpharmacological strategies to prevent CI-AKI, including routine identification of at-risk patients, use of appropriate hydration regimens, withdrawal of nephrotoxic drugs, selection of low-osmolar contrast media or isoosmolar contrast media, and using the minimum volume of contrast media as possible. There is no need to schedule dialysis in relation to injection of contrast media or injection of contrast agent in relation to dialysis program. Hemodialysis cannot protect the poorly functioning kidney against CI-AKI.