Diagnostic performance of deep learning-based coronary computed tomography angiography in detecting coronary artery stenosis

PURPOSE

To validate a fully automated, deep learning model based on coronary computed tomography angiography (CCTA) for the diagnosis of obstructive coronary artery disease (CAD) with stenosis ≥ 50%, which is commonly used as a clinical threshold for further testing and management. This model aims to improve diagnostic efficiency by automating the identification of significant coronary stenosis(≥ 50%).

METHODS

This multicenter clinical trial included patients been undergone CCTA from October 13, 2022, to February 28, 2023. CCTA data from suspected coronary artery disease (CAD) patients were retrospectively analyzed using deep learning-based software for comprehensive assessment, including coronary segmentation, lumen, and stenosis determination with comparison to the reference standard of consensus by three experts. This study utilized a multi-stage deep learning framework for coronary artery segmentation and stenosis analysis from CCTA images, consisting of several key components, including the 3D Multi-resolution Cascade Convolutional Neural Network (CNN), 3D Cascade-Locally Optimized Network, and Stenosis Analysis Network. The clinical trial registry number was NCT06172985.

RESULTS

A total of 1090 patients (mean age: 59.90 ± 11.51 years, 47.3% female) were included in this multicenter study. Artificial intelligence (AI) demonstrated excellent performance at the patient level, accurately diagnosing ≥ 50% stenosis by assessing each patient's coronary artery condition. The AI system showed high values for accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The values of the above statistics were 92.8%, 95.3%, 91.4%, 85.6%, and 97.3%, respectively. Excellent agreement was seen between expert readers and deep learning-determined maximal diameter stenosis for per-patient (kappa coefficients: 0.84, 95%CI: 0.81-0.88). Regarding diagnostic efficiency, comparing the AI with expert readers, the average reading time decreased from 5.94 min to 2.01 min (p < 0.001).

CONCLUSION

A novel AI-based assessment of CCTA can accurately and rapidly identify patients with coronary artery stenosis ≥ 50%, aiding in effective triage within the defined study population.

Representation of Older Adults and Women in Randomized Trials of Non-Invasive Imaging for Chest Pain

Background

Non-invasive imaging is widely used both for initial diagnosis and to guide management of ischemic heart disease (IHD). Older adults and women with IHD may have different responses to imaging as well as to treatments and outcomes that follow compared with younger adults and men. We aimed to study the representation of older adults and women in randomized controlled trials (RCT) of non-invasive imaging among patients with acute and stable chest pain.

Methods

We conducted a systematic search to identify RCTs evaluating non-invasive, imaging-guided diagnosis and management for IHD that were published before September 1, 2023. Participation-to-Prevalence Ratio (PPR) was estimated for women and age subgroups of <65, 65-74, ≥75 years. PPR of <0.8, 0.8-1.2, and >1.2 indicated underrepresentation, appropriate representation, and overrepresentation, respectively.

Results

Among 53 RCTs, sex and age breakdown were available in 53 (n=55,893) and 21 trials (n=35,503), respectively. The median age across all trials was 57.4 years [IQR: 55.0- 60.2]. Participants aged <65 years were overrepresented with a median PPR 2.13 [IQR: 1.73- 2.43], while those aged 65-74 years and ≥75 years were underrepresented with median PPRs of 0.74 [IQR: 0.56-0.83] and 0.21 [IQR: 0.11-0.33], respectively. Women were adequately represented with a median PPR of 1.2 [1.06-1.32].

Conclusion

While women were appropriately represented, adults 65 years or older, especially those ≥75 years, were under-represented in these trials. Future RCTs on non-invasive imaging should target enrollment of older adults to ensure generalizability of results to this growing population.

CLINICAL PERSPECTIVE

In a systematic review of 53 randomized controlled trials of non-invasive imaging for chest pain published before September 1, 2023 (n=55,893 participants), adults aged 65 years and older, especially those aged 75 years and above, were significantly underrepresented, whereas women had representation proportional to prevalence estimates. These findings highlight an urgent need to increase enrollment of older adults in future imaging trials to ensure broader applicability and relevance of study results.

Abstract Figure

Key messages and critical approach of the 2024 guidelines of the European Society of Cardiology on chronic coronary syndromes

The updated European Society of Cardiology (ESC) guidelines empower physicians to tailor treatment plans more effectively to individual patient characteristics, preferences, and responses. With a more flexible and individualized approach to angina management, it seems that the traditional stepwise approach may not be optimal for all patients. In addition, there is a significant shift in the diagnostic approach for chronic coronary syndromes (CCS). In this review, we mainly refer to key points and queries concerning the current ESC recommendations regarding the diagnostic approach and treatment of patients with stable angina, recommending practical directions to physicians managing patients with CCS.

Cardiac CT in the context of value-based care

Cardiac computed tomography (CCT) is often used synonymously with coronary CT angiography (CCTA) and coronary artery calcium scoring (CACS), but also encompasses the use of CT for the assessment of structural, valvular, and congenital heart disease, and other cardiovascular pathology. This paper looks at the role of cardiac CT in the context of value-based care and predominantly focuses on the role of cardiac CT in the assessment of coronary artery disease (CAD), as this is where most of the clinical use and evidence of value can be found. Critical questions as to the defining of quality health care using cardiac CT are highllighted and the wider use of CT for the assessment of non-coronary disease is commented on towards the end of the manuscript but does not yet have the same level of health economic and value-based evidence.

Combined strategy of upfront CTCA and optimal treatment for stable chest pain: rationale and design of the CLEAR-CAD trial

BACKGROUND

Patients with stable chest pain suspected of coronary artery disease (CAD) usually undergo multiple diagnostic tests to confirm or rule out obstructive CAD. Some tests may not effectively assess the presence of CAD, precluding optimal treatment. A diagnostic strategy of upfront computed tomography coronary angiography (CTCA) combined with optimal medical therapy (OMT) tailored to the extent of CAD may be superior to standard care in preventing major adverse cardiac events.

STUDY DESIGN

The CLEAR-CAD trial is a prospective, open-label, multicentre, randomised, superiority trial of an upfront CTCA-guided strategy in 6444 patients presenting in an outpatient setting with suspected CAD compared with standard care, in approximately 30 participating centres in the Netherlands. The upfront CTCA-guided strategy consists of an initial CTCA which is assessed using the Coronary Artery Disease-Reporting and Data System (CAD-RADS 2.0). In patients without CAD (CAD-RADS 0) no specific cardiac medication is mandated. Patients with non-obstructive CAD (CAD-RADS 1-2) are treated with preventive OMT. Patients with obstructive CAD (CAD-RADS ≥ 3) are treated with preventive and anti-anginal OMT; in the presence of pharmacologically refractory symptoms patients undergo selective revascularisation after non-invasive functional imaging for myocardial ischaemia (≥ 10%). Patients with significant left main or proximal left anterior descending coronary artery stenosis on CTCA undergo direct invasive coronary angiography and subsequent revascularisation. The primary endpoint is the composite of all-cause death and myocardial infarction.

CONCLUSION

The CLEAR-CAD trial is the first randomised study to investigate the efficacy of a combined upfront CTCA-guided medical and selective revascularisation strategy in an outpatient setting with suspected CAD compared with standard care.

Computed Tomography Evaluation of Coronary Atherosclerosis: The Road Travelled, and What Lies Ahead

Coronary CT angiography (CCTA) is now endorsed by all major cardiology guidelines for the investigation of chest pain and assessment for coronary artery disease (CAD) in appropriately selected patients. CAD is a leading cause of morbidity and mortality. There is extensive literature to support CCTA diagnostic and prognostic value both for stable and acute symptoms. It enables rapid and cost-effective rule-out of CAD, and permits quantification and characterization of coronary plaque and associated significance. In this comprehensive review, we detail the road traveled as CCTA evolved to include quantitative assessment of plaque stenosis and extent, characterization of plaque characteristics including high-risk features, functional assessment including fractional flow reserve-CT (FFR-CT), and CT perfusion techniques. The state of current guideline recommendations and clinical applications are reviewed, as well as future directions in the rapidly advancing field of CT technology, including photon counting and applications of artificial intelligence (AI).

Evaluation of Noninvasive Diagnostic Techniques in Identifying Coronary Artery Disease: A Systematic Review

Background

Coronary artery disease (CAD) poses a significant global health burden, necessitating optimal diagnostic strategies for risk assessment and management. This study systematically reviews randomized controlled trials (RCTs) comparing different noninvasive imaging modalities for CAD evaluation, focusing on their subsequent invasive outcomes and major adverse cardiac events (MACEs).

Methods

A comprehensive electronic search was conducted across multiple databases, identifying 24 relevant RCTs published between 2010 and 2023. Key outcomes assessed included downstream referral to invasive testing, MACE rates, cost-effectiveness, and hospitalization outcomes.

Results

The majority of included RCTs focused on comparing coronary computed tomography angiography (CCTA) with alternative imaging techniques. While CCTA is often associated with increased invasiveness, it demonstrates slightly better MACE rates, cost-effectiveness, and hospitalization outcomes compared to other imaging modalities.

Conclusion

Continued investigation into alternative noninvasive diagnostic methods for CAD is essential to advance clinical practice and optimize patient care. By exploring new strategies beyond CCTA and leveraging technological innovations, health-care providers can improve diagnostic precision, mitigate procedural risks, and ultimately enhance outcomes for individuals with CAD.

Diagnosing Coronary Artery Disease in the Patient Presenting with Stable Ischemic Heart Disease: The Role of Anatomic versus Functional Testing

There are unique advantages and disadvantages to functional versus anatomic testing in the work-up of patients who present with symptoms suggestive of obstructive coronary artery disease. Evaluation of these individuals starts with an assessment of pre-test probability, which guides subsequent testing decisions. The choice between anatomic and functional testing depends on this pre-test probability. In general, anatomic testing has particular utility among younger individuals and women; while functional testing can be helpful to rule-in ischemia and guide revascularization decisions. Ultimately, selection of the most appropriate test should be individualized to the patient and clinical scenario.

Noninvasive imaging modalities in coronary artery disease: a meta analysis comparing coronary computed tomography angiography and standard of care

Introduction: Coronary artery disease has become a global pandemic and a major cause of death. The risk-factor calculation for coronary artery damage is an invasive procedure. Aim: To compare coronary computed tomography angiography (CCTA) with standard of care (SOC) to calculate need for revascularization, invasive coronary angiography as well as for myocardial infarction (MI) incidence and all-cause mortality. Methodology, results & conclusion: CCTA is significantly correlated with a reduction in MI episodes (RR = 0.752, 95% CI = 0.578-1.409; p < 0.033) and an increase in revascularizations (RR = 1.401, 95% CI = 1.315-1.492; p < 0.001) and invasive coronary angiography procedures (RR = 1.304, 95% CI = 1.208-1.409; p < 0.001). However, it was found that it did not affect all-cause mortality. On the contrary, standard care approaches were associated with greater rates of MI but lesser referrals for invasive coronary angiography and revascularization.

Evaluation of stable angina by coronary computed tomographic angiography versus standard of care: A systematic review and meta-analysis

INTRODUCTION

There is limited data comparing Coronary Computed Tomography Angiography (CCTA) versus the usual Standard of care (SOC) in patients with suspected stable coronary artery disease (CAD). We aimed to perform a systematic review and meta-analysis to compare CCTA versus SOC in patients with stable CAD.

METHODS

We searched multiple databases for randomized controlled trials (RCTs) comparing CCTA with SOC, which included various functional testing approaches for evaluating stable CAD. We used a random-effects model to calculate risk ratios (RRs) with 95 % confidence intervals (CIs). Outcomes included all-cause mortality, myocardial infarction (MI), hospitalization for unstable angina (UA), invasive angiography, revascularization, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG).

RESULTS

We identified 6 RCTs with 19,881 patients with stable CAD, of which 9995 underwent CCTA, and 9886 underwent SOC. There were no significant differences between CCTA and SOC in terms of all-cause mortality (RR: 0.91; 95 % CI: 0.70-1.19; p = 0.50), MI (RR: 0.78; 95 % CI: 0.58-1.05; p = 0.11), hospitalizations for UA (RR: 1.20; 95 % CI: 0.95-1.51;p = 0.12), invasive angiography (RR: 0.71; 95 % CI: 0.32-1.61; p = 0.42), revascularization (RR:1.25; 95 % CI: 0.83-1.89; p = 0.29), PCI (RR: 1.20; 95 % CI: 0.78-1.85; p = 0.40), and CABG rates (RR: 0.89; 95 % CI: 0.530-1.49; p = 0.65).

CONCLUSION

In patients with stable CAD, CCTA is associated with similar outcomes compared to the usual Standard of care. Given its potential to quickly rule out severe obstructive disease, its ability to provide non-invasive physiology and identify non-obstructive CAD with plaque information makes it an attractive addition to the available armamentarium to evaluate chest pain.

Non-Contrast and Contrast-Enhanced Cardiac Computed Tomography Imaging in the Diagnostic and Prognostic Evaluation of Coronary Artery Disease

In recent decades, cardiac computed tomography (CT) has emerged as a powerful non-invasive tool for risk stratification, as well as the detection and characterization of coronary artery disease (CAD), which remains the main cause of morbidity and mortality in the world. Advances in technology have favored the increasing use of cardiac CT by allowing better performance with lower radiation doses. Coronary artery calcium, as assessed by non-contrast CT, is considered to be the best marker of subclinical atherosclerosis, and its use is recommended for the refinement of risk assessment in low-to-intermediate risk individuals. In addition, coronary CT angiography (CCTA) has become a gate-keeper to invasive coronary angiography (ICA) and revascularization in patients with acute chest pain by allowing the assessment not only of the extent of lumen stenosis, but also of its hemodynamic significance if combined with the measurement of fractional flow reserve or perfusion imaging. Moreover, CCTA provides a unique incremental value over functional testing and ICA by imaging the vessel wall, thus allowing the assessment of plaque burden, composition, and instability features, in addition to perivascular adipose tissue attenuation, which is a marker of vascular inflammation. There exists the potential to identify the non-obstructive lesions at high risk of progression to plaque rupture by combining all of these measures.

Troponin in acute chest pain to risk stratify and guide effective use of computed tomography coronary angiography (TARGET-CTCA): a randomised controlled trial

BACKGROUND

The majority of patients with suspected acute coronary syndrome presenting to the emergency department will be discharged once myocardial infarction has been ruled out, although a proportion will have unrecognised coronary artery disease. In this setting, high-sensitivity cardiac troponin identifies those at increased risk of future cardiac events. In patients with intermediate cardiac troponin concentrations in whom myocardial infarction has been ruled out, this trial aims to investigate whether outpatient computed tomography coronary angiography (CTCA) reduces subsequent myocardial infarction or cardiac death.

METHODS

TARGET-CTCA is a multicentre prospective randomised open label with blinded endpoint parallel group event driven trial. After myocardial infarction and clear alternative diagnoses have been ruled out, participants with intermediate cardiac troponin concentrations (5 ng/L to 99th centile upper reference limit) will be randomised 1:1 to outpatient CTCA plus standard of care or standard of care alone. The primary endpoint is myocardial infarction or cardiac death. Secondary endpoints include clinical, patient-centred, process and cost-effectiveness. Recruitment of 2270 patients will give 90% power with a two-sided P value of 0.05 to detect a 40% relative risk reduction in the primary endpoint. Follow-up will continue until 97 primary outcome events have been accrued in the standard care arm with an estimated median follow-up of 36 months.

DISCUSSION

This randomised controlled trial will determine whether high-sensitivity cardiac troponin-guided CTCA can improve outcomes and reduce subsequent major adverse cardiac events in patients presenting to the emergency department who do not have myocardial infarction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03952351. Registered on May 16, 2019.

Diagnostic Strategies for the Assessment of Suspected Stable Coronary Artery Disease : A Systematic Review and Meta-analysis

BACKGROUND

There is uncertainty about which diagnostic strategy for detecting coronary artery disease (CAD) provides better outcomes.

PURPOSE

To compare the effect on clinical management and subsequent health effects of alternative diagnostic strategies for the initial assessment of suspected stable CAD.

DATA SOURCES

PubMed, Embase, and Cochrane Central Register of Controlled Trials.

STUDY SELECTION

Randomized clinical trials comparing diagnostic strategies for CAD detection among patients with symptoms suggestive of stable CAD.

DATA EXTRACTION

Three investigators independently extracted study data.

DATA SYNTHESIS

The strongest available evidence was for 3 of the 6 comparisons: coronary computed tomography angiography (CCTA) versus invasive coronary angiography (ICA) (4 trials), CCTA versus exercise electrocardiography (ECG) (2 trials), and CCTA versus stress single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) (5 trials). Compared with direct ICA referral, CCTA was associated with no difference in cardiovascular death and myocardial infarction (relative risk [RR], 0.84 [95% CI, 0.52 to 1.35]; low certainty) but less index ICA (RR, 0.23 [CI, 0.22 to 0.25]; high certainty) and index revascularization (RR, 0.71 [CI, 0.63 to 0.80]; moderate certainty). Moreover, CCTA was associated with a reduction in cardiovascular death and myocardial infarction compared with exercise ECG (RR, 0.66 [CI, 0.44 to 0.99]; moderate certainty) and SPECT-MPI (RR, 0.64 [CI, 0.45 to 0.90]; high certainty). However, CCTA was associated with more index revascularization (RR, 1.78 [CI, 1.33 to 2.38]; moderate certainty) but less downstream testing (RR, 0.56 [CI, 0.45 to 0.71]; very low certainty) than exercise ECG. Low-certainty evidence compared SPECT-MPI versus exercise ECG (2 trials), SPECT-MPI versus stress cardiovascular magnetic resonance imaging (1 trial), and stress echocardiography versus exercise ECG (1 trial).

LIMITATION

Most comparisons primarily rely on a single study, many studies were underpowered to detect potential differences in direct health outcomes, and individual patient data were lacking.

CONCLUSION

For the initial assessment of patients with suspected stable CAD, CCTA was associated with similar health effects to direct ICA referral, and with a health benefit compared with exercise ECG and SPECT-MPI. Further research is needed to better assess the relative performance of each diagnostic strategy.

PRIMARY FUNDING SOURCE

None. (PROSPERO: CRD42022329635).

Impact of design characteristics among studies comparing coronary computed tomography angiography to noninvasive functional testing in chronic coronary syndromes

BACKGROUND

Coronary computed tomography angiography (CCTA) is widely adopted to detect obstructive coronary artery disease (CAD) in patients with chronic coronary syndromes (CCS). However, it is unknown to which extent study-specific characteristics yield different conclusions.

METHODS

We summarized non-randomized and randomized studies comparing CCTA and noninvasive functional testing for CCS with information on the outcome of myocardial infarction (MI). We evaluated the differential effect according to study characteristics using random-effect meta-analysis with Hartung-Knapp-Sidik-Jonkman adjustments.

RESULTS

Fifteen studies (8 non-randomized, 7 randomized) were included. CCTA was associated with decrease in relative (odds ratio (OR) 0.54, 95%CI 0.47 to 0.62, P < .001) and absolute MI risk (risk difference (RD) -0.4%, 95%CI -0.6 to -0.1, P = .005). The results remained consistent among the non-randomized (RD -0.4%, 95%CI -0.7 to -0.1, P=.029), but not among the randomized trials where there was no difference in the observed risk (RD 0.2%, 95%CI -0.6 to 0.1, P = .158). CCTA was not associated with MI reduction in studies with clinical outcome definition (OR 0.77, 95%CI 0.41 to 1.44, P = .212), research driven follow-up (OR 0.54, 95%CI 0.24 to 1.21, P = .090), central event assessment (OR 0.63, 95%CI 0.21 to 1.86, P = .207), outcome adjudication (OR 0.74, 95%CI 0.24 to 2.23, P = .178), or at low-risk of bias (OR 0.74, 95%CI 0.24 to 2.23, P = .178).

CONCLUSIONS

Among studies of any design, CCTA was associated with lower risk of MI in CCS compared to noninvasive functional testing. This benefit was diminished among studies with clinical outcome definition, central outcome assessment/adjudication or at low-risk of bias.

Cardiac computed tomographic imaging in cardio-oncology: An expert consensus document of the Society of Cardiovascular Computed Tomography (SCCT). Endorsed by the International Cardio-Oncology Society (ICOS)

Cardio-Oncology is a rapidly growing sub-specialty of medicine, however, there is very limited guidance on the use of cardiac CT (CCT) in the care of Cardio-Oncology patients. In order to fill in the existing gaps, this Expert Consensus statement comprised of a multidisciplinary collaboration of experts in Cardiology, Radiology, Cardiovascular Multimodality Imaging, Cardio-Oncology, Oncology and Radiation Oncology aims to summarize current evidence for CCT applications in Cardio-Oncology and provide practice recommendations for clinicians.

Clinical utility of coronary artery computed tomography angiography- What we know and What's new?

Coronary computed tomography (CT) angiography (CCTA) is increasingly recognized for diagnosing obstructive coronary artery disease (CAD) among patients presenting with chest pain. In this review, we summarize the utility of CCTA to determine luminal stenosis and identifying coronary plaques with high-risk features. We review different scoring systems that can quantify total plaque burden including how artificial intelligence can facilitate more detailed plaque assessment. We discuss how CCTA can also be used to detect the hemodynamic significance of CAD lesions (fractional flow reserve CT and CT perfusion) and also local factors outside the vessel wall that may predispose to plaque rupture (fat attenuation index and wall shear stress). We conclude with technological advances in imaging acquisition using photon counting CT and post-image processing techniques especially those that can mitigate blooming artifacts.

Efficacy of Coronary Computed Tomography Angiography Versus Nuclear Perfusion Stress in Preventing Downstream Imaging and Prolonged Inpatient Length of Stay in Low to Medium Risk Patients With Chest Pain

Background 

The first-line imaging for low to medium-risk patients presenting to the emergency department with stable chest pain is often a matter of debate. Chest pain is the second most common presentation to the emergency department. Non-invasive imaging has been useful in assisting in the diagnosis of coronary artery disease. 

Aim 

The aim of this study is to compare outcomes of Single Photon Emission Computed Tomography (SPECT) Nuclear Perfusion Stress and Coronary Computed Tomography Angiography (CCTA) performed in low to medium-risk patients and how they led to prolonged hospitalization and downstream testing.

Materials and methods

A total of 519 patients were selected for chart review using the following criteria: admitted for chest pain and older than 18 years of age. Those who presented with STEMI (ST-Elevation Myocardial Infarction) or non-(N)STEMI were excluded. Among these patients, four patients were excluded since their initial test was neither a CCTA nor SPECT Nuclear (NM) Perfusion Stress test. Another 30 patients were excluded based on HEART score (a clinical tool to stratify the risk of major adverse cardiac events) >7 and 111 patients with estimated glomerular filtration rate (eGFR) <60 were excluded. A total of 374 patients underwent analysis.

Results

Univariate data analysis of 374 patients demonstrated a higher percentage of patients with HEART scores 0-3 underwent CCTA (51.6% vs. 31.8% p=0.0250) when compared to patients with SPECT NM perfusion. Multivariable logistic regression revealed that the difference in length of stay between SPECT NM perfusion stress and CCTA was significant, patients with the CCTA test were less likely to have a length of stay ≥24 hours (odds ratio {OR}=0.41, p=0.0465) compared to patients with NM perfusion stress test.

Conclusion

This retrospective cohort study demonstrated that patients who underwent CCTA upon chest pain admission were more likely to have a decreased length of stay time to less than 24 hours. 

Role of Coronary CT Angiography in the Evaluation of Acute Chest Pain and Suspected or Confirmed Acute Coronary Syndrome

Advances in CT technology have resulted in improved imaging of the coronary anatomy in patients with stable coronary artery disease, using coronary CT angiography (CCTA). Recent data suggest that CCTA may play a role in higher risk patients, such as those evaluated in the emergency room with acute chest pain. Data thus far support the use of CCTA in low-risk patients with acute chest pain. Recent literature suggests that CCTA may play a role in the risk stratification of selected intermediate-risk patients. In this review, the authors discuss the emerging role of CCTA in higher risk patients, such as those with suspected or confirmed acute coronary syndrome (ACS). The excellent accuracy of CCTA in detecting obstructive coronary artery disease in patients with ACS is detailed, along with a highlighting of the safety of using CCTA in this setting. The authors also discuss the role for CCTA atheromatous plaque characterization, which is being increasingly recognized as an important predictor of clinical outcomes.

Cardiac CT angiography in current practice: An American society for preventive cardiology clinical practice statement✰

In this clinical practice statement, we represent a summary of the current evidence and clinical applications of cardiac computed tomography (CT) in evaluation of coronary artery disease (CAD), from an expert panel organized by the American Society for Preventive Cardiology (ASPC), and appraises the current use and indications of cardiac CT in clinical practice. Cardiac CT is emerging as a front line non-invasive diagnostic test for CAD, with evidence supporting the clinical utility of cardiac CT in diagnosis and prevention. CCTA offers several advantages beyond other testing modalities, due to its ability to identify and characterize coronary stenosis severity and pathophysiological changes in coronary atherosclerosis and stenosis, aiding in early diagnosis, prognosis and management of CAD. This document further explores the emerging applications of CCTA based on functional assessment using CT derived fractional flow reserve, peri‑coronary inflammation and artificial intelligence (AI) that can provide personalized risk assessment and guide targeted treatment. We sought to provide an expert consensus based on the latest evidence and best available clinical practice guidelines regarding the role of CCTA as an essential tool in cardiovascular prevention - applicable to risk assessment and early diagnosis and management, noting potential areas for future investigation.

The evolving role of coronary computed tomography in understanding sex differences in coronary atherosclerosis

Our understanding of sex differences in subclinical atherosclerosis and plaque composition and characteristics have greatly improved with the use of coronary computed tomography (CCTA) over the past years. CCTA has emerged as an important frontline diagnostic test for women, especially as we continue to understand the impact of non-obstructive atherosclerosis as well as diffuse, high risk plaque as precursors of acute cardiac events in women. Based on its ability to identify complex plaque morphology such as low attenuation plaque, high risk non calcified plaque, positive remodeling, fibrous cap, CCTA can be used to assess plaque characteristics. CCTA can avoid false positive of other imaging studies, if included earlier in assessment of ischemic symptoms. In the contemporary clinical setting, CCTA will prove useful in further understanding and managing cardiovascular disease in women and those without traditional obstructive coronary disease.

Clinical applications of cardiac computed tomography: a consensus paper of the European Association of Cardiovascular Imaging-part I

Cardiac computed tomography (CT) was introduced in the late 1990's. Since then, an increasing body of evidence on its clinical applications has rapidly emerged. From an initial emphasis on its technical efficiency and diagnostic accuracy, research around cardiac CT has now evolved towards outcomes-based studies that provide information on prognosis, safety, and cost. Thanks to the strong and compelling data generated by large, randomized control trials, the scientific societies have endorsed cardiac CT as pivotal diagnostic test for the management of appropriately selected patients with acute and chronic coronary syndrome. This consensus document endorsed by the European Association of Cardiovascular Imaging is divided into two parts and aims to provide a summary of the current evidence and to give updated indications on the appropriate use of cardiac CT in different clinical scenarios. This first part focuses on the most established applications of cardiac CT from primary prevention in asymptomatic patients, to the evaluation of patients with chronic coronary syndrome, acute chest pain, and previous coronary revascularization.

Computed tomography coronary angiography as the noninvasive in stable coronary artery disease? Long-term outcomes meta-analysis

Aim: To compare outcomes of coronary computed tomography angiography (CCTA) with that of functional testing (FT) in stable coronary artery disease. Methods: We searched PubMed, Embase, and Cochrane for randomized controlled trials (RCTs). A random-effects meta-analysis targeting all-cause death and nonfatal acute coronary syndromes was performed. Results: Eight RCTs enrolling 29,579 patients were included. Pooled relative risk (RR) for the primary end point was similar between CCTA and FT (RR = 0.97; 95% CI: 0.76-1.22). CCTA outperformed FT in nonfatal myocardial infarction (MI) (RR = 0.59; 95% CI: 0.41-0.83) and in downstream testing (OR: 0.47; 95% CI: 0.21-1.01). Conclusion: Updated data of stable coronary artery disease suggests that CCTA improved nonfatal MI and downstream testing.

Use of coronary artery calcium and coronary tomography angiography in the evaluation of ischemic heart disease

Over the years, significant technological advances have been made in the field of cardiac CT imaging which has led to the widespread use of the modality in the evaluation of ischemic and structural heart disease. The advent of newer scanning techniques has led to a reduction in scanning time as well as a reduction in the radiation and contrast media dose required - making these scans both convenient and safer to perform. Research has shown that coronary CT angiography has a high negative predictive value in the evaluation of patients with coronary artery disease. There is more recent evidence that coronary CTA has a positive impact on clinical outcomes as well. In this review article, we discuss the clinical applications of coronary CTA in the evaluation of patients with stable ischemic heart disease, the most recent studies evaluating the efficacy and limitations of the modality, the role of coronary calcium in cardiovascular risk prediction in asymptomatic patients and the future applications of the modality.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Troponin-Guided Coronary Computed Tomographic Angiography After Exclusion of Myocardial Infarction

BACKGROUND

Patients with suspected acute coronary syndrome in whom myocardial infarction has been excluded are at risk of future adverse cardiac events.

OBJECTIVES

This study evaluated the usefulness of high-sensitivity cardiac troponin I (hs-cTnI) to select patients for further investigation after myocardial infarction has been excluded.

METHODS

This is a prospective cohort study of patients presenting to the emergency department with suspected acute coronary syndrome and hs-cTnI concentrations below the sex-specific 99th percentile. Patients were recruited in a 2:1 fashion, stratified by peak hs-cTnI concentration above and below the risk stratification threshold of 5 ng/L. All patients underwent coronary computed tomography angiography (CCTA) after hospital discharge.

RESULTS

Overall, 250 patients were recruited (61.4 ± 12.2 years 31% women) in whom 62.4% (156 of 250 patients) had coronary artery disease (CAD). Patients with intermediate hs-cTnI concentrations (between 5 ng/L and the sex-specific 99th percentile) were more likely to have CAD than those with hs-cTnI concentrations <5 ng/L (71.9% [120 of 167 patients] vs 43.4% [36 of 83 patients]; odds ratio: 3.33; 95% CI: 1.92-5.78). Conversely, there was no association between anginal symptoms and CAD (63.2% [67 of 106 patients] vs 61.8% [89 of 144 patients]; odds ratio: 0.92; 95% CI: 0.48-1.76). Most patients with CAD did not have a previous diagnosis (53.2%; 83 of 156 patients) and were not on antiplatelet and statin therapies (63.5%; 99 of 156 patients) before they underwent CCTA.

CONCLUSIONS

In patients who had myocardial infarction excluded, CAD was 3× more likely in those with intermediate hs-cTnI concentrations compared with low hs-cTnI concentrations. In such patients, CCTA could help to identify those with occult CAD and to target preventative treatments, thereby improving clinical outcomes.

Coronary computed tomography angiography in patients with stable coronary artery disease

The treatment of coronary artery disease (CAD), which is defined by stable anatomical atherosclerotic and functional alterations of epicardial vessels or microcirculation, focuses on managing intermittent angina symptoms and preventing major adverse cardiovascular events with optimal medical therapy. When patients with known CAD present with angina and no acute coronary syndrome, they have historically been evaluated with a variety of noninvasive stress tests that utilize electrocardiography, radionuclide scintigraphy, echocardiography, or magnetic resonance imaging for determining the presence and extent of inducible myocardial ischemia. Patient event-free survival, however, is largely driven by the coronary atherosclerotic disease burden, which is not directly assessed by functional testing. Direct evaluation of coronary atherosclerotic disease by coronary computed tomography angiography (coronary CTA) has emerged as the first line noninvasive imaging modality as it improves diagnostic accuracy and positively influences clinical management. Compared to functional assessment of CAD, coronary CTA-guided management results in improved patient outcomes by facilitating prevention of myocardial infarction. Other strengths of coronary CTA include detailed atherosclerotic plaque characterization and the ability to assess functional significance of specific lesions, which may further improve risk assessment and prognosis and lead to more appropriate referrals for additional testing, such as invasive coronary angiography.

Coronary Computed Tomographic Angiography for Complete Assessment of Coronary Artery Disease: JACC State-of-the-Art Review

Coronary computed tomography angiography (CTA) has shown great technological improvements over the last 2 decades. High accuracy of CTA in detecting significant coronary stenosis has promoted CTA as a substitute for conventional invasive coronary angiography in patients with suspected coronary artery disease. In patients with coronary stenosis, CTA-derived physiological assessment is surrogate for intracoronary pressure and velocity wires, and renders possible decision-making about revascularization solely based on computed tomography. Computed tomography coronary anatomy with functionality assessment could potentially become a first line in diagnosis. Noninvasive imaging assessment of plaque burden and morphology is becoming a valuable substitute for intravascular imaging. Recently, wall shear stress and perivascular inflammation have been introduced. These assessments could support risk management for both primary and secondary cardiovascular prevention. Anatomy, functionality, and plaque composition by CTA tend to replace invasive assessment. Complete CTA assessment could provide a 1-stop-shop for diagnosis, risk management, and decision-making on treatment.

When More Is Better: Underused Advanced Imaging Exams That Can Improve Outcomes and Reduce Cost of Care

Appropriate use of resources is a tenet of care transformation efforts, with a national campaign to reduce low-value imaging. The next level of performance improvement is to bolster evidence-based screening, imaging surveillance, and diagnostic innovation, which can avert more costly, higher-risk elements of unnecessary care like emergent interventions. Clinical scenarios in which underused advanced imaging can improve outcomes and reduce total cost of care are reviewed, including abdominal aortic aneurysm surveillance, coronary artery disease diagnosis, and renal mass characterization. Reliable abdominal aortic aneurysm surveillance imaging reduces emergency surgery and can be driven by radiologists incorporating best practice standardized recommendations in imaging interpretations. Coronary computed tomography angiography in patients with stable and unstable chest pain can reduce downstream resource use while improving outcomes. Preoperative ^99mTc-sestamibi single-photon emission computed tomography (SPECT) reliably distinguishes oncocytoma from renal cell carcinoma to obviate unnecessary nephrectomy. As technological advances in diagnostic, molecular, and interventional radiology improve our ability to detect and cure disease, analyses of cost effectiveness will be critical to radiology leadership and sustainability in the transition to a value-based reimbursement model.

CT ​EvaLuation ​by ​ARtificial ​Intelligence ​For ​Atherosclerosis, Stenosis and Vascular ​MorphologY ​(CLARIFY): ​A ​Multi-center, international study

BACKGROUND

Atherosclerosis evaluation by coronary computed tomography angiography (CCTA) is promising for coronary artery disease (CAD) risk stratification, but time consuming and requires high expertise. Artificial Intelligence (AI) applied to CCTA for comprehensive CAD assessment may overcome these limitations. We hypothesized AI aided analysis allows for rapid, accurate evaluation of vessel morphology and stenosis.

METHODS

This was a multi-site study of 232 patients undergoing CCTA. Studies were analyzed by FDA-cleared software service that performs AI-driven coronary artery segmentation and labeling, lumen and vessel wall determination, plaque quantification and characterization with comparison to ground truth of consensus by three L3 readers. CCTAs were analyzed for: % maximal diameter stenosis, plaque volume and composition, presence of high-risk plaque and Coronary Artery Disease Reporting & Data System (CAD-RADS) category.

RESULTS

AI performance was excellent for accuracy, sensitivity, specificity, positive predictive value and negative predictive value as follows: >70% stenosis: 99.7%, 90.9%, 99.8%, 93.3%, 99.9%, respectively; >50% stenosis: 94.8%, 80.0%, 97.0, 80.0%, 97.0%, respectively. Bland-Altman plots depict agreement between expert reader and AI determined maximal diameter stenosis for per-vessel (mean difference -0.8%; 95% CI 13.8% to -15.3%) and per-patient (mean difference -2.3%; 95% CI 15.8% to -20.4%). L3 and AI agreed within one CAD-RADS category in 228/232 (98.3%) exams per-patient and 923/924 (99.9%) vessels on a per-vessel basis. There was a wide range of atherosclerosis in the coronary artery territories assessed by AI when stratified by CAD-RADS distribution.

CONCLUSIONS

AI-aided approach to CCTA interpretation determines coronary stenosis and CAD-RADS category in close agreement with consensus of L3 expert readers. There was a wide range of atherosclerosis identified through AI.

Prevalence of Abnormal Coronary Findings on Coronary Computed Tomography Angiography Among Young Adults Presenting With Chest Pain

PURPOSE

We evaluated the prevalence of coronary stenosis on coronary computed tomography angiography (CCTA) in patients aged 18 to 30 years, who presented to the emergency department with chest pain. We also examined the risk factors potentially associated with abnormal coronary findings on CCTA in this age group.

MATERIALS AND METHODS

A total of 884 patients were retrospectively evaluated. Indication for CCTA was guided by our hospital's chest pain protocol based on ACC/AHA guidelines. These were performed using the standard technique and interpreted based on CAD-RADS guidelines. Scans were identified as abnormal if atherosclerotic coronary artery disease (CAD), myocardial bridging (MB), or any anatomic coronary artery anomaly were present.

RESULTS

Twenty-two percent of patients had a coronary abnormality on CCTA. The most common abnormality was MB (17.3%), followed by CAD (4.4%) and coronary anomalies (1.5%). A small minority had stenosis (2.8%), most commonly caused by CAD. Most cases with stenosis were minimal to mild (72%) with 0.8% having coronary stenosis ≥50%. Age and male sex were risk factors for both coronary artery stenosis (odds ratio: 1.32 and 4.50, 95% confidence interval: 1.03-1.69, and 1.23-16.46, P=0.028 and 0.023, respectively) and CAD (odds ratio: 1.52 and 3.67, 95% confidence interval: 1.14-2.04, and 1.26-10.66, P=0.005 and 0.017, respectively).

CONCLUSIONS

Epicardial coronary stenosis is rarely the cause of chest pain among young adult patients presenting to the emergency department. Age and male sex were both risk factors for coronary artery stenosis/disease in this age group.

Can Computed Fractional Flow Reserve Coronary CT Angiography (FFRCT) Offer an Accurate Noninvasive Comparison to Invasive Coronary Angiography (ICA)? "The Noninvasive CATH." A Comprehensive Review

Invasive coronary angiography (ICA) serves as a very important tool in the diagnosis of coronary artery disease (CAD) and provides information for further intervention. Fractional Flow Reserve (FFR) at the time of ICA is the gold standard to analyze the hemodynamic and physiologic significance of moderate coronary stenosis. The dawn of coronary CT angiography (CTA) has helped in visualizing the anatomy of coronary arteries. Computed Fractional Flow Reserve (FFRCT) from such an imaging study shows promise in providing valuable data about physiology on top of the anatomy noninvasively; which can guide decision-making process for revascularization. This manuscript aims to review the accuracy of FFRCT obtained from a coronary CTA in the diagnosis of hemodynamically significant coronary artery stenosis and ruling out nonsignificant coronary artery stenosis when compared to the Gold standard of FFR obtained during ICA. We conducted a Medline search using various combinations of "FFRCT," "ICA" "noninvasive," "significant stenosis," and "CAD" to identify pivotal randomized trials published before May 1, 2020, for inclusion in this review. Concurrently, major practice guidelines, trial bibliographies, and pertinent reviews were examined to ensure inclusion of relevant trials. A consensus among the authors was used to choose items for narrative inclusion. The following section reviews data from pivotal trials to determine a noninvasive strategy in appropriate patients to accurately detect functionally significant stenosis. For these trials, the sensitivity, specificity, and accuracy are compared. Trials reviewed: CTA, FFRCT, ICA, CT-myocardial perfusion imaging. FFRCT is a novel noninvasive modality which localizes significant "ischemia-causing" stenosis (≤0.80) by means of crystal fluid dynamics eliminating the need for vasodilators. The analysis of FFRCT by DISCOVER FLOW, DeFACTO, NXT trials revealed high sensitivity, negative predictive value, and good accuracy. The ADVANCE registry showed significantly lower events of CV death or myocardial infarction with a negative FFRCT (>0.80 study). The PLATFORM trial showed significant reduction in negative ICA with negative FFRCT, thus ultimately reducing the number of unnecessary percutaneous coronary intervention. Decrease in healthcare costs was noted with FFRCT, decreasing downstream testing, and invasive procedures. FFRCT is a novel modality for analyzing significant stenosis in CAD noninvasively. The high sensitivity of this modality could make it a good rule out tool to avoid unnecessary intervention in physiologically insignificant lesions. Limitations of this modality include low specificity, double exposure to contrast, turnaround time, and upfront costs. Further query into this matter is warranted.

Prognostic value of cardiac CT

In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on coronary plaque morphology and composition with identification of specific high-risk plaque features, may further improve the risk stratification beyond the assessment of coronary stenosis. The development of new CCTA applications, such as stress myocardial CT perfusion and computational fluids dynamic applied to standard CCTA to derive CT-based fractional flow reserve (FFR) values have shown promising results to guide revascularization, potentially improving clinical outcomes in stable chest pain patients. In this review, starting from the role of CACS and moving beyond coronary stenosis, we evaluate the existing evidence of the prognostic effectiveness of the CCTA strategy in real-world clinical practice.

Noninvasive Imaging Risk Stratification with Computed Tomography Angiography for Coronary Artery Disease

The recent technological evolution of coronary computed tomography angiography (CTA) with improved sensitivity and high negative predictive value has extended its potential applications as a gatekeeper test before invasive coronary angiography. However, the definition of the most accurate diagnostic algorithms comprising CTA as a first-line strategy for ruling out coronary artery disease and the correct management of the patients according to the results of imaging tests still warrant better definition.

Non-invasive imaging of the coronary arteries

Non-invasive imaging of the coronary arteries is an enterprise in rapid development. From the research perspective, there is great demand for in vivo techniques that can reliably identify features of high-risk plaque that may offer insight into pathophysiological processes and act as surrogate indicators of response to therapeutic intervention. Meanwhile, there is clear clinical need for greater accuracy in diagnosis and prognostic stratification. Fortunately, ongoing technological improvements and emerging data from randomized clinical trials are helping make these elusive goals a reality. This review provides an update on the current status of non-invasive coronary imaging with computed tomography, magnetic resonance, and positron emission tomography with a focus on current clinical applications and future research directions.

SCOT-HEART trial: reshuffling our approach to stable ischemic heart disease

The role of diagnostic testing in triaging patients with stable ischemic heart disease continues to evolve towards recognizing the benefits of coronary CT angiography (CCTA) over functional testing. The SCOT-HEART (Scottish Computed Tomography of the HEART) trial highlights this paradigm shift finding a significant reduction of death from coronary heart disease or non-fatal myocardial infarction without a significant increased rate of invasive coronary angiography over a 5 year follow-up period when implementing CCTA with standard care vs standard care alone. The better negative predictive value and ability to identify nonobstructive coronary artery disease to optimize medical therapy highlight the benefits of a CCTA first strategy. With the advent of noninvasive fractional flow reserve (FFR) and widespread availability and ease of CT, CCTA continues to establish itself as a pivotal diagnostic exam for patients with stable ischemic heart disease. In this commentary, we review the SCOT-HEART trial and its impact on CCTA for patients with stable ischemic heart disease.

Exercise Electrocardiography and Computed Tomography Coronary Angiography for Patients With Suspected Stable Angina Pectoris: A Post Hoc Analysis of the Randomized SCOT-HEART Trial

Importance

Recent European guidance supports a diminished role for exercise electrocardiography (ECG) in the assessment of suspected stable angina.

Objective

To evaluate the utility of exercise ECG in contemporary practice and assess the value of combined functional and anatomical testing.

Design, Setting, and Participants

This is a post hoc analysis of the Scottish Computed Tomography of the Heart (SCOT-HEART) open-label randomized clinical trial, conducted in 12 cardiology chest pain clinics across Scotland for patients with suspected angina secondary to coronary heart disease. Between November 18, 2010, and September 24, 2014, 4146 patients aged 18 to 75 years with stable angina underwent clinical evaluation and 1417 of 1651 (86%) underwent exercise ECG prior to randomization. Statistical analysis was conducted from October 10 to November 5, 2019.

Interventions

Patients were randomized in a 1:1 ratio to receive standard care plus coronary computed tomography (CT) angiography or to receive standard care alone. The present analysis was limited to the 3283 patients who underwent exercise ECG alone or in combination with coronary CT angiography.

Main Outcomes and Measures

The primary clinical end point was death from coronary heart disease or nonfatal myocardial infarction at 5 years.

Results

Among the 3283 patients (1889 men; median age, 57.0 years [interquartile range, 50.0-64.0 years]), exercise ECG had a sensitivity of 39% and a specificity of 91% for detecting any obstructive coronary artery disease in those who underwent subsequent invasive angiography. Abnormal results of exercise ECG were associated with a 14.47-fold (95% CI, 10.00-20.41; P < .001) increase in coronary revascularization at 1 year and a 2.57-fold (95% CI, 1.38-4.63; P < .001) increase in mortality from coronary heart disease death at 5 years or in cases of nonfatal myocardial infarction at 5 years. Compared with exercise ECG alone, results of coronary CT angiography had a stronger association with 5-year coronary heart disease death or nonfatal myocardial infarction (hazard ratio, 10.63; 95% CI, 2.32-48.70; P = .002). The greatest numerical difference in outcome with CT angiography compared with exercise ECG alone was observed for those with inconclusive results of exercise ECG (5 of 285 [2%] vs 13 of 283 [5%]), although this was not statistically significant (log-rank P = .05).

Conclusions and Relevance

This study suggests that abnormal results of exercise ECG are associated with coronary revascularization and the future risk of adverse coronary events. However, coronary CT angiography more accurately detects coronary artery disease and is more strongly associated with future risk compared with exercise ECG.

Trial Registration

ClinicalTrials.gov Identifier: NCT01149590.

Outcomes of anatomical vs. functional testing for coronary artery disease : Lessons from the major trials

Management of patients presenting with suspected stable coronary artery disease (CAD) are challenging because estimation of pretest probability for obstructive CAD remains difficult. In addition, identification of those who benefit from coronary revascularization remains ineffective regardless of the wide array of noninvasive testing alternatives available. Functional testing, which has long been considered to be the test of choice to risk stratify these patients, shows modest agreement with CAD severity detected by invasive coronary angiography and has been reported to be ineffective in settings of low prevalence of obstructive CAD. A growing body of evidence demonstrates the excellent diagnostic accuracy as well as prognostic value of coronary computed tomography (CT) angiography especially in conjunction with noninvasive fractional flow reserve (FFR) testing, challenging the primary role of functional testing especially in patients without prior or known CAD. Landmark trials, including the Prospective Multicenter Imaging Study for Evaluation of chest pain (PROMISE) and Scottish Computed Tomography of the Heart (SCOT-HEART), have contributed to a better understanding of how coronary CT angiography may play a role in more efficient management and even improved health outcomes. The emerging role of coronary CT has been acknowledged by the 2019 Guidelines of the European Society of Cardiology recommending the use of CT as a first-line tool for the evaluation of patients with stable chest pain with a class I, level of evidence B recommendation. The purpose of this article is to provide an overview on existing evidence, clinical implication, limitations of available data, and remaining questions to be answered by future research.

Long-Term Prognostic Role of Computed Tomography Coronary Angiography for Stable Angina

Purpose of review

Chest pain is a common presentation, and there are a wide variety of ways in which it can be investigated and treated. There is growing interest in whether the way we reach a diagnosis of angina can affect the long-term prognosis. In addition to its unparalleled negative predictive value, computed tomography coronary angiography (CCTA) gives anatomical information on the extent and severity of coronary artery disease. This article discusses recent research into the ability of CCTA to predict and improve long-term prognosis for patients with stable angina.

Recent findings

Results from retrospective studies, randomised controlled trials and meta-analyses all suggest that initial investigation with computed tomography coronary angiography confers a prognostic benefit. In addition, the most recent studies have shown that the assessment of plaque burden and plaque constituents is predictive of long-term outcomes.

Summary

Management of stable chest pain should be guided by a CCTA-based approach. Future research should focus on whether incorporating plaque analysis strategies into clinical practice confers additional benefit.

Primacy of coronary CT angiography as the gatekeeper for the cardiac catheterization laboratory

Determining the underlying etiology of chest pain remains a mainstay of modern cardiological practice and is focused on identifying coronary artery disease to improve both symptoms and prognosis. In the current age of multi-modality imaging, the expanding repertoire of tests has subjected clinicians to a tyranny of choices. In whom should we perform further investigations? What non-invasive modality should be used? Which test is the best gatekeeper for invasive coronary angiography? In this week's American Heart Journal, Houssany-Pissot and colleagues present real-world data from a large French cohort of patients who present with suspected stable coronary artery disease undergoing invasive coronary angiography. Their findings demonstrate that compared to functional testing, coronary computed tomography angiography is associated with fewer normal invasive coronary angiograms and more patients with actionable disease. Moreover, this was apparent irrespective of the pre-test probability of obstructive coronary artery disease. The consistency of this study with data from randomised trials and observational registries leads us to agree that computed tomography has primacy as gatekeeper for the cardiac catheter laboratory irrespective of the level of pre-test probability. This latest addition to the growing and large body of evidence does beg the question of why guidelines do not now recommend CCTA as the first line test of choice for the non-invasive investigation of all patients with stable coronary artery disease?

Comparison of coronary CT angiography versus functional imaging for CABG patients: A resource utilization analysis

AIMS

The impact of anatomical versus functional testing in patients with prior coronary artery bypass surgery (CABG) is poorly defined. We therefore sought to determine the rates of downstream investigations and the attendant healthcare costs in CABG patients undergoing CCTA versus SPECT.

METHODS AND RESULTS

2754 consecutive CABG patients were imaged by SPECT (2163) or CCTA (591). 425 patients (15.4%) underwent downstream testing which was more common in those imaged with CCTA versus SPECT (23.18% vs 13.31% respectively, p < 0.01). When a propensity score adjustment was made for differences in baseline characteristics, the findings in downstream testing persisted (p < 0.01). When patients who subsequently underwent repeat revascularization (arguably the highest risk patients) were removed from the analysis, downstream testing remained more frequent in CCTA (12.7%) versus SPECT imaged patients (8.8%) (p = 0.01). Costs of downstream tests per patient were two-fold greater in the CCTA group in comparison to the SPECT group ($366.79 ± 29.59 vs $167.35 ± 10.12 respectively, p < 0.01). Conversely, total costs which included the index costs were less in the CCTA group, $764.66 ± 29.59 versus $1396.73 ± 1012 for the SPECT cohort, p < 0.0001).

CONCLUSIONS

Index imaging with SPECT versus CCTA in CABG patients was associated with fewer downstream tests, less ICA, less repeat revascularization but greater expense. Cost however is only part of the decision making process that determines an optimal index test. Until CCTA demonstrates improved risk stratification over SPECT in CABG patients it is likely SPECT will remain the preferred first imaging test.

Is Physiologic Stress Test with Imaging Comparable to Anatomic Examination of Coronary Arteries by Coronary Computed Tomography Angiography to Investigate Coronary Artery Disease? - A Systematic Review and Meta-Analysis

Objective Coronary computed tomography angiography (CCTA) is a noninvasive diagnostic modality that remains underutilized compared to functional stress testing (ST) for investigating coronary artery disease (CAD). Several patients are misdiagnosed with noncardiac chest pain (CP) that eventually die from a cardiovascular event in subsequent years. We compared CCTA to ST to investigate CP. Methods We searched MEDLINE, PubMed, Cochrane Library, and Embase from January 1, 2007 to July 1, 2018 for randomized controlled trials (RCTs) comparing CCTA to ST in patients who presented with acute or stable CP. We used Review Manager (RevMan) [Computer program] Version 5.3 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014) for review and analysis. Results We included 16 RCTs enrolling 21,210 patients; there were more patients with hyperlipidemia and older patients in the ST arm compared to the CCTA arm. There was no difference in mortality: 103 in the CCTA arm vs. 110 in the ST arm (risk ratio [RR] = 0.93, 95% confidence interval [CI] = 0.71-1.21, P = .58, and I² = 0%). A significant reduction was seen in myocardial infarctions (MIs) after CCTA compared to ST: 115 vs. 156 (RR = 0.71, CI = 0.56-0.91, P < .006, I²=0%). On subgroup analysis, the CCTA arm had fewer MIs vs. the ST with imaging subgroup (RR = 0.70, CI = 0.54-0.89, P = .004, I² = 0%) and stable CP subgroup (RR = 0.66, CI = 0.50-0.88, P = .004, I² = 0%). The CCTA arm showed significantly higher invasive coronary angiograms and revascularizations and significantly reduced follow-up testing and recurrent hospital visits. A trend towards increased unstable anginas was seen in the CCTA arm. Conclusions Our analysis showed a significant reduction in downstream MIs, hospital visits, and follow-up testing when CCTA is used to investigate CAD with no difference in mortality.

Adoption of coronary artery disease - Reporting and Data System (CAD-RADS™) and observed impact on medical therapy and systolic blood pressure control

BACKGROUND

CAD-RADS was developed to standardize communication of per-patient maximal stenosis on coronary CT angiography (CCTA) and provide treatment recommendations and may impact primary prevention care and resource utilization. The authors sought to evaluate CAD-RADS adoption on preventive medical therapy and risk factor control amongst a mixed provider population.

METHODS

Statins, aspirin (ASA), systolic blood pressure and, when available, lipid panel changes were abstracted for 1796 total patients undergoing CCTA in the 12 months before (non-standard reporting, NSR, cohort) and after adoption of the CAD-RADS reporting template. Only initiation of a medication in a treatment naïve patient, escalation from baseline dose, or transition to a higher potency was considered an escalation/initiation in lipid therapy.

RESULTS

The CAD-RADS reporting template was utilized in 83.7% (751/897) of CCTAs after the CAD-RADS adoption period. After adjusting for any coronary artery disease (CAD) on CCTA, statin initiation/escalation was more commonly observed in the CAD-RADS cohort (aOR 1.46; 95%CI 1.12-1.90, p = 0.005), driven by higher rates of new statin initiation (aOR 1.79; 95%CI 1.23-2.58, p = 0.002). This resulted in a higher observed rates of total cholesterol improvement in the CAD-RADS cohort (58% vs 49%, p = 0.016). New ASA initiation was similar between reporting templates after adjustment for CAD on CCTA (aOR 1.40; 95%CI 0.97-2.02, p = 0.069). The ordering provider's specialty (cardiology vs non-cardiology) did not significantly impact the observed differences in initiation/escalation of statins and ASA (pinteraction = NS).

CONCLUSIONS

Adoption of CAD-RADS reporting was associated with increased utilization of preventive medications, regardless of ordering provider specialty.