Cost-effectiveness analysis of stand-alone or combined non-invasive imaging tests for the diagnosis of stable coronary artery disease: results from the EVINCI study

The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: a clinical consensus statement from the European Association of Cardiovascular Imaging of the ESC

Since the 2009 publication of the stress echocardiography expert consensus of the European Association of Echocardiography, and after the 2016 advice of the American Society of Echocardiography-European Association of Cardiovascular Imaging for applications beyond coronary artery disease, new information has become available regarding stress echo. Until recently, the assessment of regional wall motion abnormality was the only universally practiced step of stress echo. In the state-of-the-art ABCDE protocol, regional wall motion abnormality remains the main step A, but at the same time, regional perfusion using ultrasound-contrast agents may be assessed. Diastolic function and pulmonary B-lines are assessed in step B; left ventricular contractile and preload reserve with volumetric echocardiography in step C; Doppler-based coronary flow velocity reserve in the left anterior descending coronary artery in step D; and ECG-based heart rate reserve in non-imaging step E. These five biomarkers converge, conceptually and methodologically, in the ABCDE protocol allowing comprehensive risk stratification of the vulnerable patient with chronic coronary syndromes. The present document summarizes current practice guidelines recommendations and training requirements and harmonizes the clinical guidelines of the European Society of Cardiology in many diverse cardiac conditions, from chronic coronary syndromes to valvular heart disease. The continuous refinement of imaging technology and the diffusion of ultrasound-contrast agents improve image quality, feasibility, and reader accuracy in assessing wall motion and perfusion, left ventricular volumes, and coronary flow velocity. Carotid imaging detects pre-obstructive atherosclerosis and improves risk prediction similarly to coronary atherosclerosis. The revolutionary impact of artificial intelligence on echocardiographic image acquisition and analysis makes stress echo more operator-independent and objective. Stress echo has unique features of low cost, versatility, and universal availability. It does not need ionizing radiation exposure and has near-zero carbon dioxide emissions. Stress echo is a convenient and sustainable choice for functional testing within and beyond coronary artery disease.

Economic and healthcare resource utilization assessments of PET imaging in Coronary Artery Disease diagnosis: a systematic review and discussion of opportunities for future economic evaluations

AIMS

This systematic literature review (SLR) consolidated economic and healthcare resource utilization (HCRU) evidence for positron emission tomography (PET) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) to inform future economic evaluations.

MATERIALS AND METHODS

An electronic search was conducted in MEDLINE, Embase, and Cochrane databases from 2012-2022. Economic and HCRU studies in adults who underwent PET- or SPECT-MPI for coronary artery disease (CAD) diagnosis were eligible. A qualitative methodological assessment of existing economic evaluations, HCRU, and downstream cardiac outcomes was completed. Exploratory meta-analyses of clinical outcomes were performed.

RESULTS

The search yielded 13,439 results, with 71 records included. Economic evaluations and comparative clinical trials were limited in number and outcome types (HCRU, downstream cardiac outcomes, and diagnostic performance) assessed. No studies included all outcome types and only one economic evaluation linked diagnostic performance to HCRU. The meta-analyses of comparative studies demonstrated significantly higher rates of early- and late-invasive coronary angiography and revascularization for PET- compared to SPECT-MPI; however, the rate of repeat testing was lower with PET-MPI. The rate of acute myocardial infarction was lower, albeit non-significant with PET- vs. SPECT-MPI.

LIMITATIONS AND CONCLUSIONS

This SLR identified economic and HCRU evaluations following PET- and SPECT-MPI for CAD diagnosis and determined that existing studies do not capture all pertinent outcome parameters or link diagnostic performance to downstream HCRU and cardiac outcomes, thus, resulting in simplified assessments of CAD burden. A limitation of this work relates to heterogeneity in study designs, patient populations, and follow-up times of existing studies. Resultingly, it was challenging to pool data in meta-analyses. Overall, this work provides a foundation for the development of comprehensive economic models for PET- and SPECT-MPI in CAD diagnosis, which should link diagnostic outcomes to HCRU and downstream cardiac events to capture the full CAD scope.

Economic, ethical, and environmental sustainability of cardiac imaging

Current cardiology guidelines assign a class of recommendation 1 for the diagnosis of chest pain to five imaging techniques based on either anatomic (coronary computed tomography angiography) or functional approaches, such as stress single-photon emission tomography, stress positron emission tomography, stress cardiovascular magnetic resonance, and stress echocardiography. The choice is left to the prescribing physician, based on local availability and expertise. However, the five techniques differ substantially in their cost, applicability based on patient characteristics, long-term risk, and environmental impact. The average European immediate cost ranges from 50 to 1000 euros. The radiation exposure ranges from 0 to 500 chest x-rays. The environmental footprint ranges from 3 to 300 kg of carbon dioxide emissions equivalent. The ethical code of the World Medical Association 2021 recommends the responsible use of healthcare money by doctors, with the minimization of potential damage to patients and the environment. The Euratom law 2013/directive 59 reinforces the justification principle and the optimization principle for medical radiation exposures, with the legal responsibility of both the referrer and the practitioner. A small cost, a minimal long-term risk, and a modest carbon emission per examination multiplied by billions of tests per year become an unaffordable economic burden in the short-term, significant population damage to public health over the years, and impacts on climate change in decades. The cardiology community may wish to adopt a more sustainable practice with affordable, radiation-optimized, and carbon-neutral practices for the benefit of patients, physicians, payers, and the planet.

Health Economic Analysis of CMR: A Systematic Review

INTRODUCTION

Uptake of cardiac magnetic resonance (CMR) in Australia has been limited by issues of cost and access. There is a need to inform future application of CMR by evaluating pertinent health economic literature. We sought to perform a systematic review on the health economic data as it pertains to CMR.

METHODS

Eight databases (biomedical/health economic) were searched for relevant articles highlighting economic evaluations of CMR. Following screening, studies that reported health economic outcomes (e.g., dollars saved, quality adjusted life years [QALY] and cost effectiveness ratios) were included. Data on cost effectiveness, clinical/disease characteristics, type of modelling were extracted and summarised.

RESULTS

Thirty-eight (38) articles informed the systematic review. Health economic models used to determine cost effectiveness included both trial-based studies (n=14) and Markov modelling (n=24). Comparative strategies ranged from nuclear imaging, stress echocardiography and invasive angiography. The disease states examined included coronary artery disease (23/38), acute coronary syndrome (3/38), heart failure (5/38) and miscellaneous (7/38). The majority of studies (n=29/38) demonstrated CMR as a strategy which is either economically dominant, cost-effective or cost-saving.

CONCLUSION

This systematic review demonstrates that CMR is cost-effective depending on diagnostic strategy, population and disease state. The lack of standardised protocols for application of CMR, economic models used and outcomes reported limits the ability to meta-analyse the available health economic data.

The Non-Invasive Diagnosis of Chronic Coronary Syndrome: A Focus on Stress Computed Tomography Perfusion and Stress Cardiac Magnetic Resonance

Coronary artery disease is still a major cause of death and morbidity worldwide. In the setting of chronic coronary disease, demonstration of inducible ischemia is mandatory to address treatment. Consequently, scientific and technological efforts were made in response to the request for non-invasive diagnostic tools with better sensitivity and specificity. To date, clinicians have at their disposal a wide range of stress-imaging techniques. Among others, stress cardiac magnetic resonance (S-CMR) and computed tomography perfusion (CTP) techniques both demonstrated their diagnostic efficacy and prognostic value in clinical trials when compared to other non-invasive ischemia-assessing techniques and invasive fractional flow reserve measurement techniques. Standardized protocols for both S-CMR and CTP usually imply the administration of vasodilator agents to induce hyperemia and contrast agents to depict perfusion defects. However, both methods have their own limitations, meaning that optimizing their performance still requires a patient-tailored approach. This review focuses on the characteristics, drawbacks, and future perspectives of these two techniques.

Cost-effectiveness of 82-Rubidium PET myocardial perfusion imaging for the diagnosis of myocardial ischemia depending on the prevalence of coronary artery disease

BACKGROUND

82-Rubidium-Positron emission tomography myocardial perfusion imaging (Rb-PET-MPI) offers higher diagnostic performance for the detection of myocardial ischemia compared to Tc-SPECT-MPI. The aim of this economic evaluation was to perform a cost-effectiveness analysis of Rb-PET-MPI versus Tc-SPECT-MPI in patients with suspected myocardial ischemia according to pretest probabilities (PTP) of obstructive coronary artery disease based on the results of the RUBIS Trial.

METHODS

Costs and effectiveness were calculated for all patients over 1 year and an incremental analysis of differences in costs and effectiveness in terms of diagnostic accuracy was performed. The uncertainty of the results was estimated using bootstrap. The analysis was conducted from the perspective of the French health care system with a time horizon of 12 months.

RESULTS

The average cost of a Rb-PET-MPI-based strategy for the detection of myocardial ischemia was €219 lower than a SPECT-MPI-based strategy (€1192 (± 1834) vs €973 (± 1939), p < 0.01). The one-year incremental cost-effectiveness ratio was negative: - €2730 (money saved per additional accurate diagnosis) in patients presenting PTP > 15% for the Rb-PET-MPI vs. Tc-SPECT-MPI strategy. Analysis of the joint distribution of costs and outcomes found that the Rb-PET-MPI strategy had a 92% probability to be dominant (cost-saving and outcome-improving).

CONCLUSIONS

Rb-PET-MPI is cost-effective compared to Tc-SPECT-MPI for the detection of myocardial ischemia in patients with PTP > 15% of obstructive coronary artery disease.

TRIAL REGISTRATION

RUBIS Trial registration: NCT01679886, Registered 03 September 2012, https://clinicaltrials.gov/ct2/show/NCT01679886 .

Use of cardiac imaging in chronic coronary syndromes: the EURECA Imaging registry

BACKGROUND

The prospective, multicentre EURECA registry assessed the use of imaging and adoption of the European Society of Cardiology (ESC) Guidelines (GL) in patients with chronic coronary syndromes (CCS).

METHODS

Between May 2019 and March 2020, 5156 patients were recruited in 73 centres from 24 ESC member countries. The adoption of GL recommendations was evaluated according to clinical presentation and pre-test probability (PTP) of obstructive coronary artery disease (CAD).

RESULTS

The mean age of the population was 64 ± 11 years, 60% of patients were males, 42% had PTP >15%, 27% had previous CAD, and ejection fraction was <50% in 5%. Exercise ECG was performed in 32% of patients, stress imaging as the first choice in 40%, and computed tomography coronary angiography (CTCA) in 22%. Invasive coronary angiography (ICA) was the first or downstream test in 17% and 11%, respectively. Obstructive CAD was documented in 24% of patients, inducible ischaemia in 19%, and 13% of patients underwent revascularization. In 44% of patients, the overall diagnostic process did not adopt the GL. In these patients, referral to stress imaging (21% vs. 58%; P < 0.001) or CTCA (17% vs. 30%; P < 0.001) was less frequent, while exercise ECG (43% vs. 22%; P < 0.001) and ICA (48% vs. 15%; P < 0.001) were more frequently performed. The adoption of GL was associated with fewer ICA, higher proportion of diagnosis of obstructive CAD (60% vs. 39%, P < 0.001) and revascularization (54% vs. 37%, P < 0.001), higher quality of life, fewer additional testing, and longer times to late revascularization.

CONCLUSIONS

In patients with CCS, current clinical practice does not adopt GL recommendations on the use of diagnostic tests in a significant proportion of patients. When the diagnostic approach adopts GL recommendations, invasive procedures are less frequently used and the diagnostic yield and therapeutic utility are superior.

The Merits, Limitations, and Future Directions of Cost-Effectiveness Analysis in Cardiac MRI with a Focus on Coronary Artery Disease: A Literature Review

Cardiac magnetic resonance (CMR) imaging has a wide range of clinical applications with a high degree of accuracy for many myocardial pathologies. Recent literature has shown great utility of CMR in diagnosing many diseases, often changing the course of treatment. Despite this, it is often underutilized possibly due to perceived costs, limiting patient factors and comfort, and longer examination periods compared to other imaging modalities. In this regard, we conducted a literature review using keywords “Cost-Effectiveness” and “Cardiac MRI” and selected articles from the PubMed MEDLINE database that met our inclusion and exclusion criteria to examine the cost-effectiveness of CMR. Our search result yielded 17 articles included in our review. We found that CMR can be cost-effective in quality-adjusted life years (QALYs) in select patient populations with various cardiac pathologies. Specifically, the use of CMR in coronary artery disease (CAD) patients with a pretest probability below a certain threshold may be more cost-effective compared to patients with a higher pretest probability, although its use can be limited based on geographic location, professional society guidelines, and differing reimbursement patterns. In addition, a stepwise combination of different imaging modalities, with conjunction of AHA/ACC guidelines can further enhance the cost-effectiveness of CMR.

Perspectives in noninvasive imaging for chronic coronary syndromes

Both the latest European guidelines on chronic coronary syndromes and the American guidelines on chest pain have underlined the importance of noninvasive imaging to select patients to be referred to invasive angiography. Nevertheless, although coronary stenosis has long been considered the main determinant of inducible ischemia and symptoms, growing evidence has demonstrated the importance of other underlying mechanisms (e.g., vasospasm, microvascular disease, energetic inefficiency). The search for a pathophysiology-driven treatment of these patients has therefore emerged as an important objective of multimodality imaging, integrating "anatomical" and "functional" information. We here provide an up-to-date guide for the choice and the interpretation of the currently available noninvasive anatomical and/or functional tests, focusing on emerging techniques (e.g., coronary flow velocity reserve, stress-cardiac magnetic resonance, hybrid imaging, functional-coronary computed tomography angiography, etc.), which could provide deeper pathophysiological insights to refine diagnostic and therapeutic pathways in the next future.

Cost-effectiveness in diagnosis of stable angina patients: a decision-analytical modelling approach

Objective

Given recent data on published diagnostic accuracies, this study sought to determine the most cost-effective diagnostic strategy for detection of significant coronary artery disease (CAD) in stable angina patients using invasive coronary angiography (ICA) and fractional flow reserve (FFR) as the reference standard.

Methods

A probabilistic decision-analytical model was developed which modelled a cohort of patients with stable angina. We investigated 17 diagnostic strategies between standalone and combination of different imaging tests to establish a correct diagnosis of CAD, using no testing as the baseline reference. These tests included CT coronary angiography (CTCA), stress echocardiography, CT-based FFR, single-photon emission computed tomography (SPECT), cardiovascular magnetic resonance (CMR), positron emission tomography, ICA, and ICA with FFR. Incremental cost-effectiveness ratios were calculated as the additional cost per correct diagnosis.

Results

SPECT followed by CTCA and ICA-FFR is the most cost-effective strategy between a cost-effectiveness threshold (CET) value of £1000–£3000 per correct diagnosis. CMR followed by CTCA and ICA-FFR is cost-effective within a CET range of £3000–£17 000 per correct diagnosis. CMR and ICA-FFR is cost-effective within a CET range of £17 000–£24 000. ICA-FFR as first line is the most-cost effective if the CET value exceeds the £24 000 per correct diagnosis. Sensitivity analysis showed that direct ICA-FFR may be cost-effective in patients with a high pre-test probability of CAD.

Conclusion

First-line testing with functional imaging is cost-effective at low to intermediate value of correct diagnosis in patients with low to intermediate risk of CAD. ICA is not cost effective although ICA-FFR may be at higher CET.

Changing Paradigms in the Diagnosis of Ischemic Heart Disease by Multimodality Imaging

Coronary artery disease (CAD) represents the most common cardiovascular disease, with high morbidity and mortality. Historically patients with chest pain of suspected coronary origin have been assessed with functional tests, capable to detect haemodynamic consequences of coronary obstructions through depiction of electrocardiographic changes, myocardial perfusion defects or regional wall motion abnormalities under stress condition. Stress echocardiography (SE), single-photon emission computed tomography (SPECT), positron emission tomography (PET) and cardiovascular magnetic resonance (CMR) represent the functional techniques currently available, and technical developments contributed to increased diagnostic performance of these techniques. More recently, cardiac computed tomography angiography (cCTA) has been developed as a non-invasive anatomical test for a direct visualisation of coronary vessels and detailed description of atherosclerotic burden. Cardiovascular imaging techniques have dramatically enhanced our knowledge regarding physiological aspects and myocardial implications of CAD. Recently, after the publication of important trials, international guidelines recognised these changes, updating indications and level of recommendations. This review aims to summarise current standards with main novelties and specific limitations, and a diagnostic algorithm for up-to-date clinical management is also proposed.

Economic Analysis of the CADScor System for Ruling Out Coronary Artery Disease in England

BACKGROUND

Coronary artery disease (CAD) is the most common type of heart and circulatory disease and is the leading cause of death worldwide. The current diagnostic pathway can lead to patient complications and is also extremely costly. A new medical device, the CADScor System (Acarix AB), was developed for the acoustic detection of CAD before patients undergo invasive diagnostic procedures.

OBJECTIVES

Our objective was to assess the cost utility of the CADScor System for the diagnosis of CAD at an early stage in the diagnostic testing pathway in England.

METHODS

A two-part economic model, consisting of a decision tree and Markov model, was developed to consider the cost utility (cost per quality-adjusted life-year [QALY] gained) of introducing the CADScor System for the diagnosis of CAD. The decision tree component explored the short-term costs and diagnostic outcomes associated with introduction of the test compared with the existing testing pathway. A Markov model was developed to explore the longer-term health and economic implications of the condition and original diagnosis, with costs and health effects estimated over different time horizons. Parameter uncertainty was explored in deterministic and probabilistic sensitivity analyses.

RESULTS

Base-case results indicated that the CADScor System would result in cost savings (- £131 per patient) and a marginal increase in QALYs (0.00001) over a 1-year time horizon. Probabilistic results indicated that the intervention had a > 99% probability of being cost effective at a willingness-to-pay threshold of £20,000 per QALY gained and 100% probability of being cost saving. Results from the deterministic sensitivity analyses indicated that variations in parameters related to the accuracy and cost of the CADScor System, and the prevalence of CAD, had the greatest impact on the overall results. The overall cost saving was estimated to be over £12.3 million per 100,000 eligible patient population.

CONCLUSIONS

The CADScor System is a potentially cost-saving test for the diagnosis of CAD. When initiated before the use of non-invasive cardiac imaging tests such as computed tomography coronary angiography, the test reduced costs to the healthcare service over various time horizons.

Coronary Revascularization in Patients With Stable Coronary Artery Disease: The Role of Imaging

In the last decades, the effective management of some cardiovascular risk factors in the general population has led to a progressive decrease in the prevalence of coronary artery disease (CAD). Nevertheless, coronary heart disease remains the major cause of death in developed and developing countries and chronic coronary syndromes (CCS) are still a major target of utilization of non-invasive cardiac imaging and invasive procedures. Current guidelines recommend the use of non-invasive imaging in patients with CCS to identify subjects at higher risk to be referred for invasive coronary angiography and possible revascularization. These recommendations are challenged by two opposite lines of evidence. Recent trials have somewhat questioned the efficacy of coronary revascularization as compared with optimal medical therapy in CCS. As a consequence the role of imaging in these patients and in in patients with ischemic cardiomyopathy is under debate. On the other hand, real-life data indicate that a consistent proportion of patients undergo invasive procedure and are revascularized without any previous non-invasive imaging characterization. On top of this, the impact of COVID-19 pandemic on the sanitary systems caused a change in the current management of patients with CAD. In the present review we will discuss these conflicting data analyzing the evidence which has been recently accumulated as well as the gaps of knowledge which should still be filled.

Performance of the coronary calcium score in an outpatient chest pain clinic and strategies for risk stratification

Background

Coronary artery calcium score (CAC) is an objective marker of atherosclerosis. The primary aim is to assess CAC as a risk classifier in stable coronary artery disease (CAD).

Hypothesis

CAC improves CAD risk prediction, compared to conventional risk scoring, even in the absence of cardiovascular risk factor inputs.

Methods

Outpatients presenting to a cardiology clinic (n = 3518) were divided into two cohorts: derivation (n = 2344 patients) and validation (n = 1174 patients). Adding logarithmic transformation of CAC, we built two logistic regression models: Model 1 with chest pain history and risk factors and Model 2 including chest pain history only without risk factors simulating patients with undiagnosed comorbidities. The CAD I Consortium Score (CCS) was the conventional reference risk score used. The primary outcome was the presence of coronary artery disease defined as any epicardial artery stenosis≥50% on CT coronary angiogram.

Results

Area under curve (AUC) of CCS in our validation cohort was 0.80. The AUC of Models 1 and 2 were significantly improved at 0.88 (95%CI 0.86–0.91) and 0.87 (95%CI 0.84–0.90), respectively. Integrated discriminant improvement was >15% for both models. At a pre‐specified cut‐off of ≤10% for excluding coronary artery disease, the sensitivity and specificity were 89.3% and 74.7% for Model 1, and 88.1% and 71.8% for Model 2.

Conclusion

CAC helps improve risk classification in patients with chest pain, even in the absence of prior risk factor screening.

Extracellular Vesicles in Diagnosing Chronic Coronary Syndromes the Bumpy Road to Clinical Implementation

Coronary artery disease (CAD), comprising both acute coronary syndromes (ACS) and chronic coronary syndromes (CCS), remains one of the most important killers throughout the entire world. ACS is often quickly diagnosed by either deviation on an electrocardiogram or elevated levels of troponin, but CCS appears to be more complicated. The most used noninvasive strategies to diagnose CCS are coronary computed tomography and perfusion imaging. Although both show reasonable accuracy (80–90%), these modalities are becoming more and more subject of debate due to costs, radiation and increasing inappropriate use in low-risk patients. A reliable, blood-based biomarker is not available for CCS but would be of great clinical importance. Extracellular vesicles (EVs) are lipid-bilayer membrane vesicles containing bioactive contents e.g., proteins, lipids and nucleic acids. EVs are often referred to as the “liquid biopsy” since their contents reflect changes in the condition of the cell they originate from. Although EVs are studied extensively for their role as biomarkers in the cardiovascular field during the last decade, they are still not incorporated into clinical practice in this field. This review provides an overview on EV biomarkers in CCS and discusses the clinical and technological aspects important for successful clinical application of EVs.

Cardiac-CT and cardiac-MR cost-effectiveness: a literature review

Cardiovascular diseases are still among the first causes of death worldwide with a huge impact on healthcare systems. Within these conditions, the correct diagnosis of coronary artery disease with the most appropriate imaging-based evaluations is of utmost importance. The sustainability of the healthcare systems, considering the high economic burden of modern cardiac imaging equipments, makes cost-effective analysis an important tool, currently used for weighing different costs and health outcomes, when policy makers have to allocate funds and to prioritize interventions, getting the most out of their financial resources. This review aims at evaluating cost-effective analysis in the more recent literature, focused on the role of Calcium Score, coronary computed tomography angiography and cardiac magnetic resonance.

Plasma extracellular vesicle proteins are associated with stress-induced myocardial ischemia in women presenting with chest pain

Diagnosing stable ischemic heart disease (IHD) is challenging, especially in females. Currently, no blood test is available. Plasma extracellular vesicles (EV) are emerging as potential biomarker source. We therefore aimed to identify stress induced ischemia due to stable IHD with plasma extracellular vesicle protein levels in chest pain patients. We analyzed 450 patients suspected for stable IHD who were referred for ⁸²Rb PET/CT in the outpatient clinic. Blood samples were collected before PET/CT and plasma EVs were isolated in 3 plasma subfractions named: TEX, HDL, LDL. In total 6 proteins were quantified in each of these subfractions using immuno-bead assays. CD14 and CystatinC protein levels were independent significant predictors of stress-induced ischemia in the LDL and the HDL subfraction and SerpinC1 and SerpinG1 protein levels in the HDL fraction. Subgroup-analysis on sex revealed that these associations were completely attributed to the associations in women. None of the significant EV proteins remained significant in men. Plasma EV proteins levels are associated with the presence of stable IHD in females presenting with chest pain. This finding, if confirmed in larger cohort studies could be a crucial step in improving diagnostic assessment of women with suspected IHD.

Cost-effectiveness for imaging stable ischemic disease

Stable ischemic heart disease remains a major cause of morbidity and mortality. Although there are multiple imaging modalities to diagnose and/or assist in the clinical management, the most cost-effective approach remains unclear. We reviewed the relevant and recent evidence-based clinical studies and trials to suggest the most cost-effective approach to stable ischemic heart disease. The limitations of these studies are discussed. Incorporating the results of recent multicenter trials, we suggest that for appropriate patients with coronary artery disease with any degree of stenosis or presence of coronary calcium, optimal medical therapy may be most cost-effective. Invasive coronary angiography and/or coronary revascularization would be primarily for non-responders or >/=50% left main stenosis. Stress cardiac magnetic imaging would be performed for those patients with non-diagnostic coronary CT angiography from motion and non-responders from optimal medical therapy in non-diagnostic coronary CT angiography group from high coronary calcium. These paths seem to be safe and cost-effective but requires modeling for confirmation.

Anatomic or functional testing in stable patients with suspected CAD: contemporary role of cardiac CT in the ISCHEMIA trial era

One of the foundations of the management of patients with suspected coronary artery disease (CAD) is to avoid unnecessary invasive coronary angiography (ICA) referrals. However, the diagnostic yield of ICA following abnormal conventional stress testing is low. The ability of ischemia testing to predict subsequent myocardial infarction and death is currently being challenged, and more than half of cardiac events among stable patients with suspected CAD occur in those with normal functional tests. The optimal management of patients with stable CAD remains controversial and ischemia-driven interventions, though improving anginal symptoms, have failed to reduce the risk of hard cardiovascular events. In this context, there is an ongoing debate whether the initial diagnostic test among patients with stable suspected CAD should be a functional test or coronary computed tomography angiography. Aside from considering the specific characteristics of individual patients and local availability and conditions, the choice of the initial test relates to whether the objective concerns its role as gatekeeper for ICA, prognosis, or treatment decision-making. Therefore, the aim of this review is to provide a contemporary overview of these issues and discuss the emerging role of CCTA as the upfront imaging tool for most patients with suspected CAD.