Are iso-osmolar, as compared to low-osmolar, contrast media cost-effective in patients undergoing cardiac catheterization? An economic analysis

A Simplified Risk Score to Estimate the Risk of Contrast-Induced Nephropathy after Contrast Exposure

Introduction

Scores are available to predict the probability of contrast-induced nephropathy (CIN) after cardiac interventions, but not many scores are available for non-cardiac interventions and there are none for intravenous exposure to contrast. We designed this study to develop a simplified score to determine the probability of developing CIN in patients exposed to the parenteral contrast medium.

Methods

This was a prospective study of patients who received parenteral contrast. Of 1300 patients, the first 1000 comprised the derivation cohort and the next 300 comprised the validation cohort. The patient variables in the development cohort were studied using univariate analysis. Statistically significant individual variables were used as independent variables, and CIN was used as the dependent variable in the final multivariate logistic regression model. Then, the risk score was obtained and validated.

Results

The incidence of CIN was 3.8%. The risk factors, namely the presence of diabetes mellitus, e-GFR, and route and volume of contrast material were significantly associated with the risk of CIN (P < 0.05). The developed risk score had a sensitivity of 90.4% and specificity of 98.78%. The overall accuracy was 97.8%. The values of AUC of ROC in the development and validation datasets were high. This indicated that the predicted CIN risk score correlated well with the calibration and discriminative characteristics.

Conclusions

The route and volume of contrast administered, low e-GFR, and diabetes mellitus were the significant risk factors. The developed risk score exhibited very good sensitivity and specificity and excellent accuracy in predicting the probability of CIN.

Preventing a nonexistent entity: the curious case of contrast and acute kidney injury

PURPOSE OF REVIEW

In recent years, doubt has been cast on the existence of contrast-induced acute kidney injury. The skepticism has stemmed from observational studies from large administrative healthcare databases. Although they correctly call that contrast-induced acute kidney injury is less common than previously thought, they cannot completely exclude selection bias.

RECENT FINDINGS

Though less common than previously thought, contrast-induced acute kidney injury still exists. The only prophylactic method that remains valid is that of isotonic volume expansion, which is still deemed beneficial in high-risk patients. N-acetylcysteine and sodium bicarbonate are ineffective and their use should be abandoned.

SUMMARY

Contrast-induced kidney injury should be defined based on clinical grounds, not merely on biochemical numbers. More research to validate a clinical definition is necessary in order to accurately re-examine its incidence.

DyeVert™ PLUS EZ System for Preventing Contrast-Induced Acute Kidney Injury in Patients Undergoing Diagnostic Coronary Angiography and/or Percutaneous Coronary Intervention: A UK-Based Cost-Utility Analysis

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is a complication commonly associated with invasive angiographic procedures and is considered the leading cause of hospital-acquired acute kidney injury. CI-AKI can lead to a prolonged hospital stay, with a substantial economic impact, and increased mortality. The DyeVert™ PLUS EZ system (FDA approved and CE marked) is a device that has been developed to divert a portion of the theoretical injected contrast media volume (CMV), reducing the overall volume of contrast media injected and aortic reflux, and potentially improving long-term health outcomes.

OBJECTIVES

To assess the long-term costs and health outcomes associated with the introduction of the DyeVert™ PLUS EZ system into the UK health care service for the prevention of CI-AKI in a cohort of patients with chronic kidney disease (CKD) stage 3-4 undergoing diagnostic coronary angiography (DAG) and/or percutaneous coronary intervention (PCI), and to compare these costs and outcomes with those of the current practice.

METHODS

A de novo economic model was developed based on the current pathway of managing patients undergoing DAG and/or PCI and on evidence related to the clinical effectiveness of DyeVert™ in terms of its impact on relevant clinical outcomes and health service resource use. Clinical data used to populate the model were derived from the literature or were based on assumptions informed by expert clinical input. Costs included in the model were from the NHS and personal social services perspective and obtained from the literature and UK-based routine sources. Probabilistic distributions were assigned to the majority of model parameters so that a probabilistic analysis could be undertaken, while deterministic sensitivity analyses were also carried out to explore the impact of key parameter variation on the model results.

RESULTS

Base-case results indicate that the intervention leads to cost savings (- £435) and improved effectiveness (+ 0.028 QALYs) over the patient's lifetime compared with current practice. Output from the probabilistic analysis points to a high likelihood of the intervention being cost-effective across presented willingness-to-pay (WTP) thresholds. The overall long-term cost saving for the NHS associated with the introduction of the DyeVert™ PLUS EZ system is over £19.7 million for each annual cohort of patients. The cost savings are mainly driven by a lower risk of subsequent diseases and their associated costs.

CONCLUSIONS

The introduction of the DyeVert™ PLUS EZ system has the potential to reduce costs for the health care service and yield improved clinical outcomes for patients with CKD stage 3-4 undergoing angiographic procedures.