Cost-effectiveness of computed tomography coronary angiography versus conventional invasive coronary angiography

Application and Performance of CT-Fractional Flow Reserve in Non-ST-Segment Elevation Myocardial Infarction

Only half of patients with non-ST-segment elevation myocardial infarction (NSTEMI) have obstructive coronary artery disease (CAD) on invasive coronary angiography (ICA). A non-invasive test that can safely rule out obstructive CAD therefore warrants investigation. Computed tomography fractional flow reserve (CT-FFR) enables hemodynamic interrogation of lesions identified on coronary computed tomography angiography (CCTA) but it has not been evaluated in NSTEMI. Inpatients with NSTEMI were recruited to undergo CCTA with CT-FFR prior to ICA. Blinded CT-FFR was performed using Siemens Frontiers cFFR, version 1.4. Invasive FFR was performed on all intermediate lesions with stenoses measuring >30% to <90%. The performance of CT-FFR and CTCA was compared to the gold-standard of ICA plus FFR. Forty patients (131 vessels) were included. The mean age was 61 ± 11 years and 75% were male. CT-FFR showed good correlation with invasive FFR (r = 0.78) and exhibited excellent diagnostic accuracy for obstructive CAD (defined as FFR<0.80 or angiographic stenosis >90%) on a per-vessel analysis, with a sensitivity of 87%, specificity 99%, positive predictive value (PPV) 97%, negative predictive value (NPV) 95% and area under the receiver operating curve (AUC) 0.93, which was superior to CCTA alone (sensitivity 82%, specificity 92%, PPV 82%, NPV 92%, AUC 0.87, p-value for AUC comparison = 0.04). On a per-patient analysis, CT-FFR had a diagnostic accuracy of 100%. In conclusion, CT-FFR provides additive diagnostic accuracy to CCTA in evaluating patients with NSTEMI and exhibits good correlation with invasive FFR.

Coronary Computed Tomographic Angiography to Optimize the Diagnostic Yield of Invasive Angiography for Low-Risk Patients Screened With Artificial Intelligence: Protocol for the CarDIA-AI Randomized Controlled Trial

BACKGROUND

Invasive coronary angiography (ICA) is the gold standard in the diagnosis of coronary artery disease (CAD). Being invasive, it carries rare but serious risks including myocardial infarction, stroke, major bleeding, and death. A large proportion of elective outpatients undergoing ICA have nonobstructive CAD, highlighting the suboptimal use of this test. Coronary computed tomographic angiography (CCTA) is a noninvasive option that provides similar information with less risk and is recommended as a first-line test for patients with low-to-intermediate risk of CAD. Leveraging artificial intelligence (AI) to appropriately direct patients to ICA or CCTA based on the predicted probability of disease may improve the efficiency and safety of diagnostic pathways.

OBJECTIVE

he CarDIA-AI (Coronary computed tomographic angiography to optimize the Diagnostic yield of Invasive Angiography for low-risk patients screened with Artificial Intelligence) study aims to evaluate whether AI-based risk assessment for obstructive CAD implemented within a centralized triage process can optimize the use of ICA in outpatients referred for nonurgent ICA.

METHODS

CarDIA-AI is a pragmatic, open-label, superior randomized controlled trial involving 2 Canadian cardiac centers. A total of 252 adults referred for elective outpatient ICA will be randomized 1:1 to usual care (directly proceeding to ICA) or to triage using an AI-based decision support tool. The AI-based decision support tool was developed using referral information from over 37,000 patients and uses a light gradient boosting machine model to predict the probability of obstructive CAD based on 42 clinically relevant predictors, including patient referral information, demographic characteristics, risk factors, and medical history. Participants in the intervention arm will have their ICA referral forms and medical charts reviewed, and select details entered into the decision support tool, which recommends CCTA or ICA based on the patient's predicted probability of obstructive CAD. All patients will receive the selected imaging modality within 6 weeks of referral and will be subsequently followed for 90 days. The primary outcome is the proportion of normal or nonobstructive CAD diagnosed via ICA and will be assessed using a 2-sided z test to compare the patients referred for cardiac investigation with normal or nonobstructive CAD diagnosed through ICA between the intervention and control groups. Secondary outcomes include the number of angiograms avoided and the diagnostic yield of ICA.

RESULTS

Recruitment began on January 9, 2025, and is expected to conclude in mid to late 2025. As of April 14, 2025, we have enrolled 81 participants. Data analysis will begin once data collection is completed. We expect to submit the results for publication in 2026.

CONCLUSIONS

CarDIA-AI will be the first randomized controlled trial using AI to optimize patient selection for CCTA versus ICA, potentially improving diagnostic efficiency, avoiding unnecessary complications of ICA, and improving health care resource usage.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06648239; https://clinicaltrials.gov/study/NCT06648239/.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/71726.

Diagnostic accuracy of late gadolinium enhancement cardiac MRI for coronary artery disease in patients with reduced left ventricular ejection fraction

BACKGROUND

Identifying significant coronary artery disease (CAD) in patients with reduced left ventricular ejection fraction (rLVEF) is essential for guiding therapeutic decisions, including medical management, device implantation and potential revascularisation. Prior studies suggested that rest cardiac MRI (CMR) with late gadolinium enhancement (LGE) could reliably detect significant CAD. We aimed to evaluate the diagnostic accuracy of rest LGE-CMR for predicting significant CAD in rLVEF patients.

METHODS

In this prospective, multicentre cohort study across 10 centres, adults with new-onset rLVEF≤45% without obvious cause were included. All patients underwent rest CMR and coronary angiography. Independent, blinded committees reviewed images. Significant CAD was defined as ≥70% stenosis in major coronary arteries. Ischaemic scars were identified on CMR as subendocardial LGE. The primary outcome was the sensitivity of CMR in detecting significant CAD.

RESULTS

Among 380 patients (median age 63 years, 68% male), significant CAD was present in 49 (13%). CMR identified ischaemic scars in 106 (28%). The sensitivity of CMR for detecting significant CAD was 57% (95% CI: 43% to 71%), specificity 76% (95% CI: 72% to 81%), positive predictive value 26% (95% CI: 18% to 35%) and negative predictive value 92% (95% CI: 89% to 95%). A CMR-first strategy would have missed 43% of significant CAD cases, many requiring revascularisation (86% of missed cases).

CONCLUSIONS

In this large, prospective multicentre study with independent image review, rest LGE-CMR demonstrated limited sensitivity for detecting significant CAD in patients with rLVEF. Relying solely on CMR could lead to missed diagnoses and undertreatment. CMR should be integrated with other diagnostic tools to optimise care in this population.

TRIAL REGISTRATION NUMBER

NCT03231189.

European Society of Cardiology: the 2023 Atlas of Cardiovascular Disease Statistics

This report from the European Society of Cardiology (ESC) Atlas Project updates and expands upon the 2021 report in presenting cardiovascular disease (CVD) statistics for the ESC member countries. This paper examines inequalities in cardiovascular healthcare and outcomes in ESC member countries utilizing mortality and risk factor data from the World Health Organization and the Global Burden of Disease study with additional economic data from the World Bank. Cardiovascular healthcare data were collected by questionnaire circulated to the national cardiac societies of ESC member countries. Statistics pertaining to 2022, or latest available year, are presented. New material in this report includes contemporary estimates of the economic burden of CVD and mortality statistics for a range of CVD phenotypes. CVD accounts for 11% of the EU's total healthcare expenditure. It remains the most common cause of death in ESC member countries with over 3 million deaths per year. Proportionately more deaths from CVD occur in middle-income compared with high-income countries in both females (53% vs. 34%) and males (46% vs. 30%). Between 1990 and 2021, median age-standardized mortality rates (ASMRs) for CVD decreased by median >50% in high-income ESC member countries but in middle-income countries the median decrease was <12%. These inequalities between middle- and high-income ESC member countries likely reflect heterogeneous exposures to a range of environmental, socioeconomic, and clinical risk factors. The 2023 survey suggests that treatment factors may also contribute with middle-income countries reporting lower rates per million of percutaneous coronary intervention (1355 vs. 2330), transcatheter aortic valve implantation (4.0 vs. 153.4) and pacemaker implantation (147.0 vs. 831.9) compared with high-income countries. The ESC Atlas 2023 report shows continuing inequalities in the epidemiology and management of CVD between middle-income and high-income ESC member countries. These inequalities are exemplified by the changes in CVD ASMRs during the last 30 years. In the high-income ESC member countries, ASMRs have been in steep decline during this period but in the middle-income countries declines have been very small. There is now an important need for targeted action to reduce the burden of CVD, particularly in those countries where the burden is greatest.

Could Computed Tomography Coronary Angiography Replace Invasive Coronary Angiography as a First-Line Diagnostic Investigation in Suspected Acute Coronary Syndromes? A Decision-Analytic Model

BACKGROUND

The implementation of high-sensitivity cardiac troponin (hs-cTn) assays into clinical practice has resulted in the identification of a novel cohort of patients with modestly increased troponin concentrations. Subsequent increases in rates of coronary angiography have been observed, without significant increases in rates of coronary revascularisation. Computed tomography coronary angiography (CTCA) is a non-invasive investigation that offers the opportunity to decouple investigation from the impetus to revascularise, and may provide an alternative, more risk-appropriate initial investigative strategy for the cohort with low to moderate hs-cTn increases. This analysis seeks to define the threshold of pre-test probability of coronary revascularisation in patients with suspected acute coronary syndrome at which a strategy of initial CTCA is safe and a more cost-effective approach than standard invasive coronary angiography (ICA).

METHODS

A cost-benefit evaluation was conducted using a decision-analytic model. The primary outcome measure was the incremental cost-effectiveness ratio (ICER) of CTCA in comparison with ICA as an initial diagnostic investigation for patients with hs-cTnT levels between 5 and 100 ng/L. Secondary outcome measures of costs, patient outcomes, and quality-adjusted life years were analysed.

RESULTS

Median base case ICER over 1,000 trials was $17,163 AUD but demonstrated large variability. Sensitivity analysis demonstrated that CTCA was cost-effective until the probability of requiring revascularisation was ∼60%, beyond which point CTCA was associated with higher costs and poorer outcomes than ICA.

CONCLUSIONS

Computed tomography coronary angiography may be a cost-effective first-line investigation for patients with moderate hs-cTnT rises until/up to a 60% pre-test probability for receiving coronary revascularisation. To objectively assess the optimal circumstances of cost-effectiveness, prospective evaluation incorporating the estimated probability of revascularisation will be required.

Economical aspects of coronary angiography for diagnostic purposes: a Belgian perspective

Coronary angiography (CA) is an increasing diagnostic procedure in Belgium. The aim of this analysis was to look at the financial aspects of CA in a large tertiary Belgium hospital to establish if current reimbursement is appropriate. For the analysis of costs we considered the use of the catheterisation laboratory, personnel costs and material costs during multiple weekly periods in the spring of 2023. We calculated that one cathlab needs to perform 8.21 CA's to equal incomes with costs. To allow for a small positive income (200€) for the hospital/cardiologist 9 procedures per cathlab day are required. Our hospital performs a 7 (mean) ± 0.75 (standard deviation) of CA's per cathlab day and therefore does not reach this financial break-even point. Our calculations are on the safe side, since coronary physiological interrogation with fractional flow reserve (FFR) was excluded from this analysis. Nevertheless, this is a cost-effective technique for which no extra reimbursement is foreseen in the current Belgium system.

The Cost Effectiveness of Coronary CT Angiography and the Effective Utilization of CT-Fractional Flow Reserve in the Diagnosis of Coronary Artery Disease

Given the high global disease burden of coronary artery disease (CAD), a major problem facing healthcare economic policy is identifying the most cost-effective diagnostic strategy for patients with suspected CAD. The aim of this review is to assess the long-term cost-effectiveness of coronary computed tomography angiography (CCTA) when compared with other diagnostic modalities and to define the cost and effective diagnostic utilization of computed tomography-fractional flow reserve (CT-FFR). A search was conducted through the MEDLINE database using PubMed with 16 of 119 manuscripts fitting the inclusion and exclusion criteria for review. An analysis of the data included in this review suggests that CCTA is a cost-effective strategy for both low risk acute chest pain patients presenting to the emergency department (ED) and low-to-intermediate risk stable chest pain outpatients. For patients with intermediate-to-high risk, CT-FFR is superior to CCTA in identifying clinically significant stenosis. In low-to-intermediate risk patients, CCTA provides a cost-effective diagnostic strategy with the potential to reduce economic burden and improve long-term health outcomes. CT-FFR should be utilized in intermediate-to-high risk patients with stenosis of uncertain clinical significance. Long-term analysis of cost-effectiveness and diagnostic utility is needed to determine the optimal balance between the cost-effectiveness and diagnostic utility of CT-FFR.

CT angiography compared to invasive angiography for stable coronary disease as predictors of major adverse cardiovascular events- A systematic review and meta-analysis

BACKGROUND

Computational tomography coronary angiography (CTCA) is increasingly the diagnostic test of choice for investigating patients with stable anginal symptoms.

OBJECTIVES

We sought to conduct a systematic review and meta-analysis comparing CTCA with invasive coronary angiography (ICA) with regards to major adverse cardiovascular events (MACE), procedural complications and rates of revascularisation.

METHODS

We conducted a systematic review and meta-analysis in line with the PRISMA statement. A literature search was conducted using PubMed, MEDLINE Ovid and Embase, with three studies included in meta-analysis. Statistical analysis was undertaken using Review Manager 5.3 for MacOS software and outcomes expressed as odds ratio, with 95% confidence intervals and sensitivity analysis was conducted.

RESULTS

A total of 5662 patients were included in this study level meta-analysis. There was no difference in MACE between CT and angiography [2.97% v 3.45%, fixed-effect model, OR: 0.84 (0.62-1.14), p = 0.26, I² 0%] and no difference found in rates of myocardial infarction, death or stroke. CTCA was associated with a reduced rate of revascularisation [12.6% v 18.3%, fixed-effects model, OR: 0.64 (0.55-0.75), p<0.00001, I² =0%]. However, CTCA was not associated with a significantly lower complication rate [0.5% v 1.72%, random effects model, OR: 0.52 (0.06-4.38), p = 0.55, I² 52%].

CONCLUSION

CTCA is a safe strategy for investigating patients with stable angina with no associated increase in MACE but a reduction in revascularisation rates.

Prediction of coronary heart disease in rural Chinese adults: a cross sectional study

Background

Coronary heart disease (CHD) is a common cardiovascular disease with high morbidity and mortality in China. The CHD risk prediction model has a great value in early prevention and diagnosis.

Methods

In this study, CHD risk prediction models among rural residents in Xinxiang County were constructed using Random Forest (RF), Support Vector Machine (SVM), and the least absolute shrinkage and selection operator (LASSO) regression algorithms with identified 16 influencing factors.

Results

Results demonstrated that the CHD model using the RF classifier performed best both on the training set and test set, with the highest area under the curve (AUC = 1 and 0.9711), accuracy (one and 0.9389), sensitivity (one and 0.8725), specificity (one and 0.9771), precision (one and 0.9563), F1-score (one and 0.9125), and Matthews correlation coefficient (MCC = one and 0.8678), followed by the SVM (AUC = 0.9860 and 0.9589) and the LASSO classifier (AUC = 0.9733 and 0.9587). Besides, the RF model also had an increase in the net reclassification index (NRI) and integrated discrimination improvement (IDI) values, and achieved a greater net benefit in the decision curve analysis (DCA) compared with the SVM and LASSO models.

Conclusion

The CHD risk prediction model constructed by the RF algorithm in this study is conducive to the early diagnosis of CHD in rural residents of Xinxiang County, Henan Province.

Sustainability of paediatric radiology in Italy

Italy is the sixth most populous country in Europe and has the second highest average life expectancy, reaching 79.4 years for men and 84.5 for women. However, Italy has one of the lowest total fertility rates in the world: in 2018 it was 1.3 births per woman, with the population older than 65 comprising more than 30%, and those younger-than-19 less than 15%. Older people are the main concern of the Italian health system. Weighted coefficients for the allocation of funds favour older adults. As confirmed by our study, paediatric radiology is expensive, and the reimbursement based on Italian adult rates is not sufficient. The negative impact on the budget discourages the diffusion of paediatric radiology both in the private practices that provide services paid for by the state government and in the public hospitals. The 501 paediatric hospital units in Italy are not homogeneously distributed throughout the national territory. Furthermore, in Italy there are 12 highly specialised children's hospitals whose competences were defined in 2005 by the Ministry of Health. Paediatric radiology is not included among the highly qualified specialties. The quality gap in paediatric radiology between children's hospitals and general hospitals, the latter often without paediatric radiologists, is evident in daily practice with misdiagnoses and investigations not carried out.

Cardiovascular Magnetic Resonance May Avoid Unnecessary Coronary Angiography in Patients With Unexplained Left Ventricular Systolic Dysfunction: A Retrospective Diagnostic Pilot Study

BACKGROUND

Coronary angiography (CA) is usually performed in patients with reduced left ventricular ejection fraction (LVEF) to search ischemic cardiomyopathy. Our aim was to examine the agreement between CA and cardiovascular magnetic resonance (CMR) imaging among a cohort of patients with unexplained reduced LVEF, and estimate what would have been the consequences of using CMR imaging as the first-line examination.

METHODS

Three hundred five patients with unexplained reduced LVEF of ≤45% who underwent both CA and CMR imaging were retrospectively registered. Patients were classified as CMR⁺ or CMR^- according to presence or absence of myocardial ischemic scar, and classified CA⁺ or CA^- according to presence or absence of significant coronary artery disease.

RESULTS

CMR⁺ (n = 89) included all 54 CA⁺ patients, except 2 with distal coronary artery disease in whom no revascularization was proposed. Among the 247 CA^- patients, 15% were CMR⁺. CMR imaging had 96% sensitivity, 85% specificity, 99% negative predictive value, and 58% positive predictive value for detecting CA⁺ patients. Revascularization was performed in 6.5% of the patients (all CMR⁺). Performing CA only for CMR⁺ patients would have decreased the number of CAs by 71%.

CONCLUSIONS

In reduced LVEF, performing CA only in CMR⁺ patients may significantly decrease the number of unnecessary CAs performed, without missing any patients requiring revascularization.

A micro-costing evaluation of lobectomy by thoracotomy versus thoracoscopy

Background

Two surgical strategies called video-assisted thoracoscopy surgery (VATS) and thoracotomy are used for lobectomy following lung cancer diagnosis. The aim of this study was to assess the total cost of each technique (thoracotomy and VATS) during hospitalization in France.

Methods

A micro-costing methodology from the hospital perspective was implemented to assess the hospitalization costs, using direct observations, interviews, and data collection based on medical records in four hospitals. The average real cost of each technique was compared.

Results

From the hospital perspective, VATS was more expensive than thoracotomy but the difference was not significant (€6,941.30 vs. €5,950.11).

Conclusions

According to this micro-costing study, thoracotomy seems to be the less expensive technique for the hospital. Our data will be included in a cost-utility analysis to assess the medico-economic impact of the VATS strategy.

Cost-effectiveness analysis of new generation coronary CT scanners for difficult-to-image patients

AIMS

New generation dual-source coronary CT (NGCCT) scanners with more than 64 slices were evaluated for patients with (known) or suspected of coronary artery disease (CAD) who are difficult to image: obese, coronary calcium score > 400, arrhythmias, previous revascularization, heart rate > 65 beats per minute, and intolerance of betablocker. A cost-effectiveness analysis of NGCCT compared with invasive coronary angiography (ICA) was performed for these difficult-to-image patients for England and Wales.

METHODS AND RESULTS

Five models (diagnostic decision model, four Markov models for CAD progression, stroke, radiation and general population) were integrated to estimate the cost-effectiveness of NGCCT for both suspected and known CAD populations. The lifetime costs and effects from the National Health Service perspective were estimated for three strategies: (1) patients diagnosed using ICA, (2) using NGCCT, and (3) patients diagnosed using a combination of NGCCT and, if positive, followed by ICA. In the suspected population, the strategy where patients only undergo a NGCCT is a cost-effective option at accepted cost-effectiveness thresholds. The strategy of using NGCCT in combination with ICA is the most favourable strategy for patients with known CAD. The most influential factors behind these results are the percentage of patients being misclassified (a function of both diagnostic accuracy and the prior likelihood), the complication rates of the procedures, and the cost price of a NGCCT scan.

CONCLUSION

The use of NGCCT might be considered cost-effective in both populations since it is cost-saving compared to ICA and generates similar effects.

Acceptance of Combined Coronary CT Angiography and Myocardial CT Perfusion versus Conventional Coronary Angiography in Patients with Coronary Stents--Intraindividual Comparison

Objectives

To evaluate how well patients with coronary stents accept combined coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) compared with conventional coronary angiography (CCA).

Background

While combined CTA and CTP may improve diagnostic accuracy compared with CTA alone, patient acceptance of CTA/CTP remains to be defined.

Methods

A total of 90 patients with coronary stents prospectively underwent CTA/CTP (both with contrast agent, CTP with adenosine) and CCA as part of the CARS-320 study. In this group, an intraindividual comparison of patient acceptance of CTA, CTP, and CCA was performed.

Results

CTP was experienced to be significantly more painful than CTA (p<0.001) and was associated with a higher frequency of dyspnea (p<0.001). Comparison of CTA/CTP with CCA revealed no significant differences in terms of pain (p = 0.141) and comfort (p = 0.377). Concern before CTA/CTP and CCA and overall satisfaction were likewise not significantly different (p = 0.097 and p = 0.123, respectively). Nevertheless, about two thirds (n = 60, 68%) preferred CTA/CTP to CCA (p<0.001). Moreover, patients felt less helpless during CTA/CTP than during CCA (p = 0.026). Lack of invasiveness and absence of pain were the most frequently mentioned advantages of CTA/CTP over CCA in our patient population.

Conclusions

CCA and combined CTA/CTP are equally well accepted by patients; however, more patients prefer CTA/CTP. CTP was associated with more intense pain than CTA and more frequently caused dyspnea than CTA alone.

Trial Registration

ClinicalTrials.gov NCT00967876