Coronary CT angiography versus standard evaluation in acute chest pain

Precision emergency medicine

BACKGROUND

Precision health is a burgeoning scientific discipline that aims to incorporate individual variability in biological, behavioral, and social factors to develop personalized health solutions. To date, emergency medicine has not deeply engaged in the precision health movement. However, rapid advances in health technology, data science, and medical informatics offer new opportunities for emergency medicine to realize the promises of precision health.

METHODS

In this article, we conceptualize precision emergency medicine as an emerging paradigm and identify key drivers of its implementation into current and future clinical practice. We acknowledge important obstacles to the specialty-wide adoption of precision emergency medicine and offer solutions that conceive a successful path forward.

RESULTS

Precision emergency medicine is defined as the use of information and technology to deliver acute care effectively, efficiently, and authentically to individual patients and their communities. Key drivers and opportunities include leveraging human data, capitalizing on technology and digital tools, providing deliberate access to care, advancing population health, and reimagining provider education and roles. Overcoming challenges in equity, privacy, and cost is essential for success. We close with a call to action to proactively incorporate precision health into the clinical practice of emergency medicine, the training of future emergency physicians, and the research agenda of the specialty.

CONCLUSIONS

Precision emergency medicine leverages new technology and data-driven artificial intelligence to advance diagnostic testing, individualize patient care plans and therapeutics, and strategically refine the convergence of the health system and the community.

Left anterior descending coronary artery-left circumflex coronary artery bifurcation angle and severity of coronary artery disease; is there any correlation? A cross-sectional study

Background and Aims

The aim of this study is to evaluate the association of coronary computed tomography angiography derived (CCTA) plaque characteristics and the left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) bifurcation angle with severity of coronary artery disease (CAD).

Methods

All the stable patients with suspected CAD who underwent CCTA between January to December 2021 were included. Correlation between CCTA-derived aggregated plaque volume (APV), LAD-LCX angle, remodeling index (RI), coronary calcium score with Gensini score in conventional angiography were assessed. One hundred and twenty-two patients who underwent both CCTA and coronary angiography were analyzed.

Results

Our analysis showed that the median (percentile 25% to percentile 75%) of the APV, LAD-LCx angle, and calcium score were 31% (17%-47%), 58° (39°-89°), and 31 (0-186), respectively. Also, the mean ± SD of the RI was 1.05 ± 0.20. Significant correlation between LAD-LCx bifurcation angle (0.0001-0.684), APV (0.002-0.281), RI (0.0001-0.438), and calcium score (0.016-0.217) with Gensini score were detected. There was a linear correlation between the mean LAD-LCx bifurcation angle and the Gensini score. The sensitivity and specificity for the cut-off value of 47.5° for the LAD-LCX angle were 86.7% and 82.1%, respectively.

Conclusion

There is a direct correlation between the LAD-LCx angle and the Gensini score. In addition to plaque characteristics, anatomic-based CCTA-derived indices can be used to identify patients at higher risk for CAD.

Coronary computed tomography angiography for clinical practice

Coronary artery disease (CAD) is a common condition caused by the accumulation of atherosclerotic plaques. It can be classified into stable CAD or acute coronary syndrome. Coronary computed tomography angiography (CCTA) has a high negative predictive value and is used as the first examination for diagnosing stable CAD, particularly in patients at intermediate-to-high risk. CCTA is also adopted for diagnosing acute coronary syndrome, particularly in patients at low-to-intermediate risk. Myocardial ischemia does not always co-exist with coronary artery stenosis, and the positive predictive value of CCTA for myocardial ischemia is limited. However, CCTA has overcome this limitation with recent technological advancements such as CT perfusion and CT-fractional flow reserve. In addition, CCTA can be used to assess coronary artery plaques. Thus, the indications for CCTA have expanded, leading to an increased demand for radiologists. The CAD reporting and data system (CAD-RADS) 2.0 was recently proposed for standardizing CCTA reporting. This RADS evaluates and categorizes patients based on coronary artery stenosis and the overall amount of coronary artery plaque and links this to patient management. In this review, we aimed to review the major trials and guidelines for CCTA to understand its clinical role. Furthermore, we aimed to introduce the CAD-RADS 2.0 including the assessment of coronary artery stenosis, plaque, and other key findings, and highlight the steps for CCTA reporting. Finally, we aimed to present recent research trends including the perivascular fat attenuation index, artificial intelligence, and the advancements in CT technology.

Coronary Artery Disease: Role of Computed Tomography and Recent Advances

In this review, the authors summarize the role of coronary computed tomography angiography and coronary artery calcium scoring in different clinical presentations of chest pain and preventative care and discuss future directions and new technologies such as pericoronary fat inflammation and the growing footprint of artificial intelligence in cardiovascular medicine.

Prevalence and Outcomes of Patients With Acute Ischemic Stroke With Concomitant ST-Segment-Elevation Myocardial Infarction (Results From National Inpatient Sample 2016-2019)

BACKGROUND

Acute myocardial infarction may concomitantly occur with acute ischemic stroke. The prevalence, complications, and outcomes of acute ST-segment-elevation myocardial infarction (STEMI) in patients hospitalized with acute ischemic stroke are not well studied.

METHODS

We examined hospitalized patients with acute ischemic stroke who were included in the National Inpatient Sample from 2016 to 2019. Acute ischemic stroke and STEMI were defined by using the International Classification of Diseases-Tenth Revision diagnostic codes. Patients with Non-STEMI were excluded. The prevalence of complications and outcomes were expressed as percentages. Multivariable logistic regression analysis was used to examine the association of STEMI with a primary outcome of mortality and secondary outcomes. A subgroup analysis of patients with STEMI who underwent percutaneous coronary intervention was also performed.

RESULTS

Of the total (n=2 080 795) patients with acute ischemic stroke, 0.3% (n=6275; mean age, 70.5 years, 50.1% females, 69.5% White) also had STEMI diagnosed during the hospitalization. Of these, 1775 (28.3%) died in the STEMI group and 76 435 (3.7%) died in the group without STEMI. The most frequent complications in the STEMI group were acute kidney injury, intracranial hemorrhage, and ventricular arrhythmias. All secondary outcomes were associated with the diagnosis of STEMI (odds ratio [OR], 3.19 [95% CI, 2.82-3.6]; P≤0.001). STEMI was associated with mortality (OR, 8.37 [95% CI, 7.25-9.66]; P≤0.001) and intracranial hemorrhage (OR, 2.23 [95% CI, 1.84-2.70]; P≤0.001). Percutaneous coronary intervention was performed in 14.3% of STEMI subgroup patients. Percutaneous coronary intervention is not associated with mortality (OR, 0.93 [95% CI, 0.6-1.43]; P=0.7), and intracranial hemorrhage (OR, 1.54 [95% CI, 0.0.93-2.56]; P=0.1).

CONCLUSIONS

Patients with acute ischemic stroke with STEMI have a higher percentage of mortality. Percutaneous coronary intervention in the subgroup of patients with acute ischemic stroke with concomitant STEMI was not associated with increased odds of mortality and intracranial hemorrhage.

Limited Axial Interpretation of Coronary CT Angiography in the Emergency Department Setting

PURPOSE

Incorporating coronary CT angiographic (CCTA) imaging into emergency department (ED) workflows has been limited by the need for 24/7 real-time postprocessing. The aim of this study was to determine whether interpretation of transaxial CCTA images alone (limited axial interpretation [LI]) is noninferior to interpretation of combined transaxial and multiplanar reformation images (full interpretation [FI]) in assessing patients with acute chest pain in the ED.

METHODS

CCTA examinations from 74 patients were evaluated by two radiologists, one without dedicated CCTA training and one with basic CCTA experience. Each examination was evaluated three times in separate sessions, once by LI and twice by FI, in random order. Nineteen coronary artery segments were rated as having significant stenoses (≥50%) or not. Interreader agreement was assessed using Cohen's κ statistic. The primary analysis was whether the accuracy of LI for detecting significant stenosis was noninferior to that of FI at the patient level (margin = -10%). Secondary analyses included similar analyses of sensitivity and specificity, at both the patient and vessel levels.

RESULTS

Interreader agreement for significant stenosis was good for both LI and FI (κ = 0.72 vs 0.70, P = .74). Average accuracy for significant stenosis at the patient level was 90.5% for LI and 91.9% for FI, with a difference of -1.4%. The accuracy of LI was noninferior to FI, because the confidence interval did not include the noninferiority margin. Noninferiority was also found for patient-level sensitivity and for accuracy, sensitivity, and specificity at the vessel level.

CONCLUSIONS

LI of the coronary arteries using transaxial CCTA images may be sufficient for the detection of significant coronary artery disease in the ED setting.

Automatic Coronary Artery Plaque Quantification and CAD-RADS Prediction Using Mesh Priors

Coronary artery disease (CAD) remains the leading cause of death worldwide. Patients with suspected CAD undergo coronary CT angiography (CCTA) to evaluate the risk of cardiovascular events and determine the treatment. Clinical analysis of coronary arteries in CCTA comprises the identification of atherosclerotic plaque, as well as the grading of any coronary artery stenosis typically obtained through the CAD-Reporting and Data System (CAD-RADS). This requires analysis of the coronary lumen and plaque. While voxel-wise segmentation is a commonly used approach in various segmentation tasks, it does not guarantee topologically plausible shapes. To address this, in this work, we propose to directly infer surface meshes for coronary artery lumen and plaque based on a centerline prior and use it in the downstream task of CAD-RADS scoring. The method is developed and evaluated using a total of 2407 CCTA scans. Our method achieved lesion-wise volume intraclass correlation coefficients of 0.98, 0.79, and 0.85 for calcified, non-calcified, and total plaque volume respectively. Patient-level CAD-RADS categorization was evaluated on a representative hold-out test set of 300 scans, for which the achieved linearly weighted kappa ( κ ) was 0.75. CAD-RADS categorization on the set of 658 scans from another hospital and scanner led to a κ of 0.71. The results demonstrate that direct inference of coronary artery meshes for lumen and plaque is feasible, and allows for the automated prediction of routinely performed CAD-RADS categorization.

FFRct use for acute chest pain triage in the emergency department: a cost-effectiveness analysis

AIMS

To model and assess the cost-effectiveness of CT-based fractional flow reserve (FFRct) for a population of low to intermediate risk patients for coronary artery disease (CAD) presenting to the emergency department (ED) with acute chest pain.

METHODS AND RESULTS

Using a decision tree model with a 1 year time horizon and from a health care perspective, two diagnostic pathways using FFRct are compared to current clinical routine combining coronary computed tomography angiography (CCTA) with an exercise test. Model data are drawn from the literature and nationally reported data. Outcomes are assessed as the number of avoided invasive coronary angiographies (ICAs) showing no obstructive CAD and quality of life (QoL) in a theoretical cohort of 1000 patients. Sensitivity analyses are performed to test the robustness of the results. Determining FFRct when CCTA is inconclusive is a cost-effective and dominant strategy with a potential saving of 198€/patient, 154 avoided unnecessary ICA showing no obstructive CAD (uICA)/1000 patients and an average improvement in QoL of 0.008 QALY/patient. With an additional 574€/patient, 8 avoided uICA/1000 patients and an improvement in QoL of 0.001 QALY/patient, a strategy where FFRct is always performed is cost-effective only when considering high cost-effectiveness thresholds.

CONCLUSIONS

For patients presenting to the ED with acute chest pain and a low to intermediate pre-test probability of CAD, a diagnostic strategy where FFRct is determined after an inconclusive CCTA is cost-effective. Clinical trials investigating both sensitivity and specificity of FFRct, as well as QoL associated with the use of this technology in this setting are warranted.

Coronary Artery Disease Assessment via On-Site CT Fractional Flow Reserve in Patients Undergoing Transcatheter Aortic Valve Replacement

Purpose To examine the clinical feasibility of workstation-based CT fractional flow reserve (CT-FFR) for coronary artery disease (CAD) evaluation during preprocedural planning in patients undergoing transcatheter aortic valve replacement (TAVR). Materials and Methods In this retrospective single-center study, 434 patients scheduled for TAVR between 2018 and 2020 were screened for study inclusion; a relevant proportion of patients (35.0% [152 of 434]) was not suitable for evaluation due to insufficient imaging properties. A total of 112 patients (mean age, 82.1 years ± 6.7 [SD]; 58 [52%] men) were included in the study. Invasive angiography findings, coronary CT angiography results, and Agatston score were acquired and compared with on-site CT-FFR computation for evaluation of CAD and prediction of major adverse cardiovascular events (MACE) within a 24-month follow-up. Results Hemodynamic relevant CAD, as suggested by CT-FFR of 0.80 or less, was found in 41 of 70 (59%) patients with stenosis of 50% or more. MACE occurred in 23 of 112 (20.5%) patients, from which 14 of 23 had stenoses with CT-FFR of 0.80 or less (hazard ratio [HR], 3.33; 95% CI: 1.56, 7.10; P = .002). CT-FFR remained a significant predictor of MACE after inclusion in a multivariable model with relevant covariables (HR, 2.89; 95% CI: 1.22, 6.86; P = .02). An Agatston score of 1000 Agatston units or more (HR, 2.25; 95% CI: 0.98, 5.21; P = .06) and stenoses of 50% or more determined via invasive angiography (HR, 0.94; 95% CI: 0.41, 2.17; P = .88) were not significant predictors of MACE. Conclusion Compared with conventional CAD markers, CT-FFR better predicted adverse outcomes after TAVR. A relevant portion of the screened cohort, however, was not suitable for CT-based CAD evaluation. Keywords: CT, Transcatheter Aortic Valve Implantation/Replacement (TAVI/TAVR), Cardiac, Coronary Arteries, Outcomes Analysis © RSNA, 2024 See also the commentary by Weir-McCall and Pugliese in this issue.

Post-infarction ventricular septal rupture complicated with cardiogenic shock and multiple organ hemorrhage: An autopsy case report

Ventricular septal rupture (VSR) is a catastrophic mechanical complication of acute myocardial infarction (AMI) that can result in acute heart failure. Delaying operative intervention frequently leads to cardiogenic shock and multi-organ failure. Here we report a case of massive anterior MI complicated with VSR that was discovered through cardiac Doppler ultrasound and suspected multiple organ hemorrhage. The patient showed signs of rapid cardiogenic shock and eventually died. The morphological changes of VSR and MI were identified during necropsy, and microscopic examinations of the heart, brain, and kidney revealed multiple organ hemorrhage. This autopsy case suggested that the complication of VSR caused by AMI results in a reduction of oxygen and nutrient content of the circulating blood throughout the body and, eventually, functional failure of multiple organs. We provide clinical and pathological evidence elucidating changes in multiple organs under the severe condition of post-infarction VSR and demonstrate the consequences of a lack of immediate surgery and sufficient medical intervention for a patient suffering from AMI with VSR.

Agreement among high-sensitivity cardiac troponin assays and non-invasive testing, clinical outcomes, and quality-of-care outcomes based on the 2020 European Society of Cardiology Guidelines

AIMS

Quality-of-care and safety of patients with suspected acute coronary syndrome (ACS) would benefit if management was independent of which high-sensitivity cardiac troponin (hs-cTn) assay was used for risk stratification. We aimed to determine the concordance of hs-cTn assays to risk-stratify patients with suspected ACS according to the European Society of Cardiology (ESC) 2020 Guidelines.

METHODS AND RESULTS

Blood samples were obtained at arrival and at 2 h from patients with suspected ACS using four hs-cTn assays. The patients were classified into rule-out/observe/rule-in strata based on the ESC 2020 Guidelines. Concordance was determined among the assays for rule-out/observe/rule-in strata. The prevalences of significant underlying disease (≥50% stenosis on coronary computed tomography or inducible myocardial ischaemia on stress testing) and adjudicated ACS, plus quality-of-care outcomes, were compared. Among 238 patients (52.7 ± 8.0 years; 40.3% female), the overall concordance across assays to classify patients into rule-out/observe/rule-in strata was 74.0% (176/238). Platforms significantly differed for rule-out (89.9 vs. 76.5 vs. 78.6 vs. 86.6%, P < 0.001) and observe strata (6.7 vs. 20.6 vs. 17.7 vs. 9.2%, P < 0.001), but not for rule-in strata (3.4 vs. 2.9 vs. 3.8 vs. 4.2%, P = 0.62). Among patients in ruled-out strata, 19.1-21.6% had significant underlying disease and 3.3-4.2% had ACS. The predicted disposition of patients and cost-of-care differed across the assays (all P < 0.001). When compared with observed strata, conventional troponin-based management and predicted quality-of-care outcomes significantly improved with hs-cTn-based strategies (direct discharge: 21.0 vs. 80.3-90.8%; cost-of-care: $3889 ± 4833 vs. $2578 ± 2896-2894 ± 4371, all P < 0.001).

CONCLUSION

Among individuals with suspected ACS, patient management may differ depending on which hs-cTn assay is utilized. More data are needed regarding the implications of inter-assay differences.

TRAIL REGISTRATION

NCT01084239.

Evaluation of stable chest pain following emergency department presentation: Impact of first-line cardiac computed tomography diagnostic strategy in an Australian setting

OBJECTIVE

International guidelines provide increasing support for computed tomography coronary angiography (CTCA) in investigating chest pain. A pathway utilising CTCA first-line for outpatient stable chest pain evaluation was implemented in an Australian ED.

METHODS

In pre-post design, the impact of the pathway was prospectively assessed over 6 months (August 2021 to January 2022) and compared with a 6-month pre-implementation group (February 2021 to July 2021). CTCA was recommended first-line in suspected stable cardiac chest pain, followed by chest pain clinic review. Predefined criteria were provided recommending functional testing in select patients. The impact of CTCA versus functional testing was evaluated. Data were obtained from digital medical records.

RESULTS

Three hundred and fifteen patients were included, 143 pre-implementation and 172 post-implementation. Characteristics were similar except age (pre-implementation: 58.9 ± 12.0 vs post-implementation: 62.8 ± 12.3 years, P = 0.004). Pathway-guided management resulted in higher first-line CTCA (73.3% vs 46.2%, P < 0.001), lower functional testing (30.2% vs 56.6%, P < 0.001) and lower proportion undergoing two non-invasive tests (4.7% vs 10.5%, P = 0.047), without increasing investigation costs or invasive coronary angiography (ICA) (pre-implementation: 13.3% vs post-implementation: 9.3%, P = 0.263). In patients undergoing CTCA, 40.7% had normal coronaries and 36.2% minimal/mild disease, with no difference in disease burden post-implementation. More medication changes occurred following CTCA compared with functional testing (aspirin: P = 0.005, statin: P < 0.001). In patients undergoing ICA, revascularisation to ICA ratio was higher following CTCA compared with functional testing (91.7% vs 18.2%, P < 0.001). No 30-day myocardial infarction or death occurred.

CONCLUSIONS

The pathway increased CTCA utilisation and reduced downstream investigations. CTCA was associated with medication changes and improved ICA efficiency.

Sex-disparities in chest pain workup: a retrospective cohort review of a university based clinical decision pathway

BACKGROUND

Females have historically lower rates of cardiovascular testing when compared to males. Clinical decision pathways (CDP) that utilize standardized risk-stratification methods may balance this disparity. We sought to determine whether clinical decision pathways could minimize sex-based differences in the non-invasive workup of chest pain in the emergency department (ED). Moreover, we evaluated whether the HEART score would minimize sex-based differences in risk-stratification.

METHODS

We conducted a retrospective cohort review of adult ED encounters for chest pain where CDP was employed. Primary outcome was any occurrence of non-invasive imaging (coronary CTA, stress imaging), invasive testing, intervention (PCI or CABG), or death. Secondary outcomes were 30-day major adverse cardiac events (MACE). We stratified HEART scores and primary/secondary outcomes by sex.

RESULTS

A total of 1078 charts met criteria for review. Mean age at presentation was 59 years. Females represented 47% of the population. Low, intermediate, and high-risk patients as determined by the HEART score were 17%, 65%, and 18% of the population, respectively, without any significant differences between males and females. Non-invasive testing was similar between males and females when stratified by risk. Males categorized as high risk underwent more coronary angiogram (33% vs. 16%, p = 0.01) and PCI (18% vs. 8%, p = 0.04) than high risk females, but this was not seen in patients categorized as low or intermediate risk. Males experienced more MACE than females (8% vs. 3%, p = 0.001).

CONCLUSIONS

We identified no sex-based differences in risk-stratification or non-invasive testing when the CDP was used. High risk males, however, underwent more coronary angiogram and PCI than high risk females, and consequently males experienced more overall MACE than females. This disparity may be explained by sex-based differences in the pathophysiology driving each patient's presentation.

[Benefits and drawbacks of CT scan as a triple rule-out exam in acute chest pain to exclude acute coronary syndrome, pulmonary embolism and aortic dissection]

Chest pain is one of the major causes for admission in the Emergency Room in most countries and one of the principal reasons for urgent consultation with a cardiologist or a general practitioner. After clinical examination and initial biological measurements, substantial patients require further explorations. CT scan allows the search for pulmonary embolism in the early stage of pulmonary arteries iodine contrast exploration. During the same exam at the systemic arterial phase, the search for aortic dissection or coronary artery disease is possible while exploring the later contrast in the aortic artery. This triple rule-out exam allows correct diagnosis in case of acute chest pain with suspected pulmonary embolism, aortic dissection and other acute aortic syndromes or acute coronary syndrome. But X-rays are substantially increased as well as iodine contrast agent quantity while exam quality is globally decreased. Artificial intelligence may play an important role in the development of this protocol.

Critical Appraisal of the Current Role of Myocardial Perfusion Imaging in the Management of Acute Chest Pain

This paper describes the evolution of nuclear cardiology techniques in the setting of acute coronary syndromes. Since the 1970s, the contribution of nuclear cardiology has been fundamental in delineating the physiopathology and diagnosis of acute myocardial infarction, when electrocardiogram (ECG) did not provide the diagnosis and when cardiac enzyme assessments were at a very early stage. In this clinical situation, at that time the role of pyrophosphate scintigraphy and antimyosin antibodies was important in ensuring diagnostic precision. However, these methods showed limitations and were abandoned in the late 80s and early 90s when therapeutic applications such as thrombolytic therapy, and primary-and rescue-percutaneous coronary intervention (PCI) were introduced. Beginning in the mid-80s, the introduction and widespread use of perfusion tracers such as 99mTc labelled compounds and technological advances such as SPECT, allowed to assess the efficacy of thrombolysis and early revascularization, as well as to assess in depth myocardial salvage. Currently, perfusion SPECT, especially using fast imaging techniques and dedicated cardiac SPECT with solid-state detectors, allows a quick confirmation or exclusion of acute coronary syndromes, particularly in low-to-intermediate likelihood of coronary artery disease (CAD), especially when there are absolute or relative contraindications to the use of coronary computed tomographic angiography (CCTA).

Diagnostic Impact of Hs-CRP and IL-6 for Acute Coronary Syndrome in Patients Admitted to the ED with Chest Pain: Added Value to the HEART Score?

Objective

To investigate whether hs-CRP and IL-6 provide additional diagnostic value beyond that achieved by the HEART score in patients with chest pain suggestive of acute coronary syndrome (ACS) admitted to the emergency department (ED).

Methods

This was a post hoc analysis using data from the RACING-MI study. Baseline data, including hs-CRP and IL-6 levels, were analyzed using the plasma from the biobank. A total of 818 patients with chest pain suggestive of ACS were included in this analysis. Of these, 98 were diagnosed with ACS (12%). Logistic regression was used to identify the independent predictors of ACS development in patients with chest pain.

Results

hs-CRP levels >2 mg/L were observed in 50% of all ACS cases. IL-6 levels >1.3 pg/mL were observed in 71% of all ACS cases. hs-CRP had a sensitivity of 50% and specificity of 51% for the diagnosis of ACS, whereas IL-6 had a sensitivity of 71% and specificity of 29%. The diagnostic likelihood ratios for ACS was 1.0 for hs-CRP>2 mg/L and IL-6 > 1.3 pg/mL, respectively. Logistic regression analysis revealed that age, male gender, and ongoing smoking were associated with ACS in patients with acute chest pain. No association was found between IL-6 or hs-CRP level and ACS. This was observed for both IL-6 and hs-CRP, whether assessed on a continuous scale or using prespecified cut-off values.

Conclusion

Among the 818 patients admitted to the ED with chest pain suggestive of ACS, neither hs-CRP nor IL-6 provided an independent added diagnostic value. Our results suggest that inflammatory markers have limited diagnostic value in detecting patients with ACS in the ED.

Artificial intelligence-based opportunistic detection of coronary artery stenosis on aortic computed tomography angiography in emergency department patients with acute chest pain

Aims

To evaluate a deep-learning model (DLM) for detecting coronary stenoses in emergency room patients with acute chest pain (ACP) explored with electrocardiogram-gated aortic computed tomography angiography (CTA) to rule out aortic dissection.

Methods and results

This retrospective study included 217 emergency room patients (41% female, mean age 67.2 years) presenting with ACP and evaluated by aortic CTA at our institution. Computed tomography angiography was assessed by two readers, who rated the coronary arteries as 1 (no stenosis), 2 (<50% stenosis), or 3 (≥50% stenosis). Computed tomography angiography was categorized as high quality (HQ), if all three main coronary arteries were analysable and low quality (LQ) otherwise. Curvilinear coronary images were rated by a DLM using the same system. Per-patient and per-vessel analyses were conducted. One hundred and twenty-one patients had HQ and 96 LQ CTA. Sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of the DLM in patients with high-quality image for detecting ≥50% stenoses were 100, 62, 59, 100, and 75% at the patient level and 98, 79, 57, 99, and 84% at the vessel level, respectively. Sensitivity was lower (79%) for detecting ≥50% stenoses at the vessel level in patients with low-quality image. Diagnostic accuracy was 84% in both groups. All 12 patients with acute coronary syndrome (ACS) and stenoses by invasive coronary angiography (ICA) were rated 3 by the DLM.

Conclusion

A DLM demonstrated high NPV for significant coronary artery stenosis in patients with ACP. All patients with ACS and stenoses by ICA were identified by the DLM.

Role of computed tomography cardiac angiography in acute chest pain syndromes

Use of CT coronary angiography (CTCA) to evaluate chest pain has rapidly increased over the recent years. While its utility in the diagnosis of coronary artery disease in stable chest pain syndromes is clear and is strongly endorsed by international guidelines, the role of CTCA in the acute setting is less certain. In the low-risk setting, CTCA has been shown to be accurate, safe and efficient but inherent low rates of adverse events in this population and the advent of high-sensitivity troponin testing have left little room for CTCA to show any short-term clinical benefit.In higher-risk populations, CTCA has potential to fulfil a gatekeeper role to invasive angiography. The high negative predictive value of CTCA is maintained while also identifying non-obstructive coronary disease and alternative diagnoses in the substantial group of patients presenting with chest pain who do not have type 1 myocardial infarction. For those with obstructive coronary disease, CTCA provides accurate assessment of stenosis severity, characterisation of high-risk plaque and findings associated with perivascular inflammation. This may allow more appropriate selection of patients to proceed to invasive management with no disadvantage in outcomes and can provide a more comprehensive risk stratification to guide both acute and long-term management than routine invasive angiography.

Comparative Effectiveness of Coronary CT Angiography and Standard of Care for Evaluating Acute Chest Pain: A Living Systematic Review and Meta-Analysis

Purpose

To perform a living systematic review and meta-analysis of randomized controlled trials comparing the effectiveness of coronary CT angiography (CCTA) and standard of care (SOC) in the evaluation of acute chest pain (ACP).

Materials and Methods

Multiple electronic databases were systematically searched, with the most recent search conducted on October 31, 2022. Studies were stratified into two groups according to the pretest probability for acute coronary syndrome (group 1 with predominantly low-to-intermediate risk vs group 2 with high risk). A meta-regression analysis was also conducted using participant risk, type of SOC used, and the use or nonuse of high-sensitivity troponins as independent variables.

Results

The final analysis included 22 randomized controlled trials (9379 total participants; 4956 assigned to CCTA arms and 4423 to SOC arms). There was a 14% reduction in the length of stay and a 17% reduction in immediate costs for the CCTA arm compared with the SOC arm. In group 1, the length of stay was 17% shorter and costs were 21% lower using CCTA. There was no evidence of differences in referrals to invasive coronary angiography, myocardial infarction, mortality, rate of hospitalization, further stress testing, or readmissions between CCTA and SOC arms. There were more revascularizations (relative risk, 1.45) and medication changes (relative risk, 1.33) in participants with low-to-intermediate acute coronary syndrome risk and increased radiation exposure in high-risk participants (mean difference, 7.24 mSv) in the CCTA arm compared with the SOC arm. The meta-regression analysis found significant differences between CCTA and SOC arms for rate of hospitalization, further stress testing, and medication changes depending on the type of SOC (P < .05).

Conclusion

The results support the use of CCTA as a safe, rapid, and less expensive in the short term strategy to exclude acute coronary syndrome in low- to intermediate-risk patients presenting with acute chest pain.Keywords: Acute Coronary Syndrome, Chest Pain, Emergency Department, Coronary Computed Tomography, Usual Care Supplemental material is available for this article. Published under a CC BY 4.0 license.

Moving toward Precision Medicine in Acute Coronary Syndromes: A Multimodal Assessment of Non-Culprit Lesions

Patients with acute coronary syndrome and multivessel disease experience several recurrent adverse events that lead to poor outcomes. Given the complexity of treating these patients, and the extremely high risk of long-term adverse events, the assessment of non-culprit lesions becomes crucial. Recently, two trials have shown a possible clinical benefit into treat non-culprit lesions using a fraction flow reserve (FFR)-guided approach, compared to culprit-lesion-only PCI. However, the most recent FLOW Evaluation to Guide Revascularization in Multivessel ST-elevation Myocardial Infarction (FLOWER-MI) trial did not show a benefit of the use of FFR-guided PCI compared to an angiography-guided approach. Otherwise, intracoronary imaging using optical coherence tomography (OCT), intravascular ultrasound (IVUS), or near-infrared spectroscopy (NIRS) could provide both quantitative and qualitative assessments of non-culprit lesions. Different studies have shown how the characterization of coronary lesions with intracoronary imaging could lead to clinical benefits in these peculiar group of patients. Moreover, non-invasive evaluations of NCLs have begun to take ground in this context, but more insights through adequately powered and designed studies are needed. The aim of this review is to outline the available techniques, both invasive and non-invasive, for the assessment of multivessel disease in patients with STEMI, and to provide a systematic guidance on the assessment and approach to these patients.

Impact of immune checkpoint inhibitors on atherosclerosis progression in patients with lung cancer

BACKGROUND

Patients with lung cancer face a heightened risk of atherosclerosis-related cardiovascular events. Despite the strong scientific rationale, there is currently a lack of clinical evidence examining the impact of immune checkpoint inhibitors (ICIs) on the advancement of atherosclerosis in patients with lung cancer. The objective of our study was to investigate whether there is a correlation between ICIs and the accelerated progression of atherosclerosis among individuals with lung cancer.

METHODS

In this case-control (2:1 matched by age and gender) study, total, non-calcified, and calcified plaque volumes were measured in the thoracic aorta using sequential contrast-enhanced chest CT scans. Univariate and multivariate rank-based estimation regression models were developed to estimate the effect of ICI therapy on plaque progression in 40 cases (ICI) and 20 controls (non-ICI).

RESULTS

The patients had a median age of 66 years (IQR: 58-69), with 50% of them being women. At baseline, there were no significant differences in plaque volumes between the groups, and their cardiovascular risk profiles were similar. However, the annual progression rate for non-calcified plaque volume was 7 times higher in the ICI group compared with the controls (11.2% vs 1.6% per year, p=0.001). Conversely, the controls showed a greater progression in calcified plaque volume compared with the ICI group (25% vs 2% per year, p=0.017). In a multivariate model that considered cardiovascular risk factors, the use of an ICI was associated with a more substantial progression of non-calcified plaque volume. Additionally, individuals treated with combination ICI therapy exhibited greater plaque progression.

CONCLUSIONS

ICI therapy was associated with more non-calcified plaque progression. These findings underscore the importance of conducting studies aimed at identifying the underlying mechanisms responsible for plaque advancement in patients undergoing ICI treatment.

TRIAL REGISTRATION NUMBER

NCT04430712.

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.

Impact of HEART Score Decision Aid on Coronary Computed Tomography Angiography Utilization and Diagnostic Yield in the Emergency Department

OBJECTIVE

Emergency physicians are challenged to efficiently and reliably risk stratify patients presenting with chest pain (CP) to optimize diagnostic testing and avoid unnecessary hospital admissions. The objective of our study was to evaluate the impact of a HEART score-based decision aid (HSDA) integrated in the electronic health record on coronary computed tomography angiography (CCTA) utilization and diagnostic yield in adult emergency department (ED) CP patients with suspected acute coronary syndrome.

METHODS

We conducted a before and after study to determine whether implementation of a mandatory computerized HSDA would reduce CCTA utilization in ED CP patients and improve the diagnostic yield of obstructive coronary artery disease (CAD) (≥50%). We included all adult ED CP patients with suspected acute coronary syndrome during the first 6 months of 2018 (before) and 2020 (after) at a large academic center. CCTA utilization and obstructive CAD yield were compared in patients before and after implementing the HSDA using χ2 tests. Secondarily, we assessed the association of HEART scores and CCTA results.

RESULTS

Of the 3095 CP patients during the before study period, 733 underwent CCTA. Of the 2692 CP patients during the after study period, 339 underwent CCTA. CCTA utilization before and after HSDA was 23.4% [95% confidence interval (95% CI), 22.2-25.2] and 12.6% (95% CI, 11.4-13.0), respectively; mean difference was 11.1% (95% CI, 0.9-13.0). Among 1072 patients undergoing CCTA, mean (SD) age and percent females before versus after HSDA were 54 (11) versus 56 (11) years and 50% versus 49%, respectively. We included 1014 patients (686 before and 328 after) for the yield analysis. Obstructive CAD was present in 15% (95% CI, 12.7-17.9) and 20.1% (95% CI, 16.1-24.7) before and after HSDA, respectively; mean difference was 4.9% (95% CI, 0.1-10.1).

CONCLUSIONS

Implementation of a mandatory electronic health record HSDA aid reduced ED CCTA utilization by half and improved the diagnostic yield.

Characteristics and key differences between patient populations receiving imaging modalities for coronary artery disease diagnosis in the US

BACKGROUND

There are limited data on the impact of imaging modality selection for the assessment of coronary artery disease (CAD) risk on downstream resource utilisation. This study sought to identify differences between patient populations in the US undergoing stress echocardiography, single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), positron emission tomography (PET) MPI, and coronary computed tomography angiography (cCTA) for the assessment of CAD risk, and associated physician referral patterns.

METHODS

Claims and electronic health records data for 2.5 million US patients who received stress echocardiography, cCTA, SPECT MPI or PET MPI between January 2016 and March 2018, from the Decision Resources Group Real-World Evidence US Data Repository, were analysed. Patients were stratified into suspected and existing CAD cohorts, and further stratified by pre-test risk and presence and recency of interventions or acute cardiac events (within 1-2 years pre-index test). Linear and logistic regression were used to compare numeric and categorical variables.

RESULTS

Physicians were more likely to refer patients to standalone SPECT MPI (77%) and stress echocardiography (18%) than PET MPI (3%) and cCTA (2%). Overall, 43% of physicians referred more than 90% of their patients to standalone SPECT MPI. Just 3%, 1% and 1% of physicians referred more than 90% of their patients to stress echocardiography, PET MPI or cCTA. At the aggregated imaging level, patients who underwent stress echocardiography or cCTA had similar comorbidity profiles. Comorbidity profiles were also similar for patients who underwent SPECT MPI and PET MPI.

CONCLUSION

Most patients underwent SPECT MPI at the index date, with very few undergoing PET MPI or cCTA. Patients who underwent cCTA at the index date were more likely to undergo additional imaging tests compared with those who underwent other imaging modalities. Further evidence is needed to understand factors influencing imaging test selection across patient populations.

Epicardial adipose tissue and obstructive coronary artery disease in acute chest pain: the EPIC-ACS study

Aims

We tested the hypothesis that epicardial adipose tissue (EAT) quantification improves the prediction of the presence of obstructive coronary artery disease (CAD) in patients presenting with acute chest pain to the emergency department.

Methods and results

Within this prospective observational cohort study, we included 657 consecutive patients (mean age 58.06 ± 18.04 years, 53% male) presenting to the emergency department with acute chest pain suggestive of acute coronary syndrome between December 2018 and August 2020. Patients with ST-elevation myocardial infarction, haemodynamic instability, or known CAD were excluded. As part of the initial workup, we performed bedside echocardiography for quantification of EAT thickness by a dedicated study physician, blinded to all patient characteristics. Treating physicians remained unaware of the results of the EAT assessment. The primary endpoint was defined as the presence of obstructive CAD, as detected in subsequent invasive coronary angiography. Patients reaching the primary endpoint had significantly more EAT than patients without obstructive CAD (7.90 ± 2.56 mm vs. 3.96 ± 1.91 mm, P < 0.0001). In a multivariable regression analysis, a 1 mm increase in EAT thickness was associated with a nearby two-fold increased odds of the presence of obstructive CAD [1.87 (1.64-2.12), P < 0.0001]. Adding EAT to a multivariable model of the GRACE score, cardiac biomarkers and traditional risk factors significantly improved the area under the receiver operating characteristic curve (0.759-0.901, P < 0.0001).

Conclusion

Epicardial adipose tissue strongly and independently predicts the presence of obstructive CAD in patients presenting with acute chest pain to the emergency department. Our results suggest that the assessment of EAT may improve diagnostic algorithms of patients with acute chest pain.

Evolution of Stress Echocardiogram in the Era of CT Angiography

The ideal diagnostic modality for acute chest pain is a highly debated topic in the cardiovascular community. With the rapid rise of coronary computed tomography angiography (CTA) and the fall of functional testing, stress echocardiography (SE) is at a delicate crossroads. Though there are many advantages of coronary CTA, it is not without its flaws. The exact realm of SE needs to be clearly defined, as well as which patients need diagnostic testing. The emergence of additional parameters will propel the evolution of modern SE. In this review article, we explore the role of SE, guidelines, comparison of SE versus CTA, and additional parameters in the coronary CTA era.

In search of new gatekeepers: coronary CT (Computed Tomography) in acute coronary syndrome

Coronary computed tomography (CCT) is a non-invasive imaging method that allows visualization of the epicardial coronary arteries. The diagnostic and prognostic role of CCT has been demonstrated by various randomized trials to such an extent that it has been included as a Class I, level of evidence B recommendation in the latest European Society of Cardiology (ESC) guidelines for the diagnosis of chronic coronary syndrome in patients at intermediate-low cardiovascular risk. In addition to the anatomical evaluation, the CCT allows to evaluate the presence of high-risk characteristics of the atherosclerotic plaque (napkin-ring sign, positive remodelling, spotty calcification, and low-attenuation plaque), thus discriminating the stability of the atheromatous pathology. Furthermore, among the potential of cardiac CT in the emergency department, the possibility of making a triple rule-out must be underlined, excluding three potential big killers as the cause of acute chest pain: acute coronary syndrome, pulmonary embolism, and aortic dissection. Various randomized clinical studies have demonstrated that the prognosis of the patient with chronic coronary artery disease (CAD) improves only if a haemodynamically significant stenosis is treated, generally investigated with invasive fractional flow reserve (FFR); CCT technological advances have made it possible to create an algorithm for calculating the FFR-CT, an index of haemodynamic significance of coronary stenosis, whose correlation with the invasive FFR data and, consequently, with the prognosis has been demonstrated of patients with CAD.

Pericoronary Adipose Tissue Radiomics from Coronary Computed Tomography Angiography Identifies Vulnerable Plaques

Pericoronary adipose tissue (PCAT) features on Computed Tomography (CT) have been shown to reflect local inflammation and increased cardiovascular risk. Our goal was to determine whether PCAT radiomics extracted from coronary CT angiography (CCTA) images are associated with intravascular optical coherence tomography (IVOCT)-identified vulnerable-plaque characteristics (e.g., microchannels (MC) and thin-cap fibroatheroma (TCFA)). The CCTA and IVOCT images of 30 lesions from 25 patients were registered. The vessels with vulnerable plaques were identified from the registered IVOCT images. The PCAT-radiomics features were extracted from the CCTA images for the lesion region of interest (PCAT-LOI) and the entire vessel (PCAT-Vessel). We extracted 1356 radiomic features, including intensity (first-order), shape, and texture features. The features were reduced using standard approaches (e.g., high feature correlation). Using stratified three-fold cross-validation with 1000 repeats, we determined the ability of PCAT-radiomics features from CCTA to predict IVOCT vulnerable-plaque characteristics. In the identification of TCFA lesions, the PCAT-LOI and PCAT-Vessel radiomics models performed comparably (Area Under the Curve (AUC) ± standard deviation 0.78 ± 0.13, 0.77 ± 0.14). For the identification of MC lesions, the PCAT-Vessel radiomics model (0.89 ± 0.09) was moderately better associated than the PCAT-LOI model (0.83 ± 0.12). In addition, both the PCAT-LOI and the PCAT-Vessel radiomics model identified coronary vessels thought to be highly vulnerable to a similar standard (i.e., both TCFA and MC; 0.88 ± 0.10, 0.91 ± 0.09). The most favorable radiomic features tended to be those describing the texture and size of the PCAT. The application of PCAT radiomics can identify coronary vessels with TCFA or MC, consistent with IVOCT. Furthermore, the use of CCTA radiomics may improve risk stratification by noninvasively detecting vulnerable-plaque characteristics that are only visible with IVOCT.

Opportunities and Challenges of Computed Tomography Coronary Angiography in the Investigation of Chest Pain in the Emergency Department-A Narrative Review

Chest pain is one of the most common presentations to emergency departments. However, only 5.1% will be diagnosed with an acute coronary syndrome, representing considerable time and expense in the diagnosis and investigation of the patients eventually found not to be suffering from an acute coronary syndrome. PubMed and Medline databases were searched with variations of the terms "chest pain", "emergency department", "computed tomography coronary angiography". After review, 52 articles were included. Computed tomography coronary angiography (CTCA) is a class I endorsement for investigating chest pain in major international societal guidelines. CTCA offers excellent sensitivity and negative predictive value in identifying patients with coronary disease, with prognostic data impacting patient management. If CTCA is to be applied to all comers, it is pertinent to discuss the advantages and potential pitfalls if use in the Australian system is to be increased.

Coronary CTA for Acute Chest Pain in the Emergency Department: Comparison of 64-Detector Row Single-Source and Third-Generation Dual-Source Scanners

Background: When performing coronary CTA in the emergency department (ED), a contemporary scanner with improved temporal resolution may eliminate the need to administer beta blockers for heart rate (HR) control, thereby expediting workup. Objective: To compare ED length-of-stay (LOS), image quality, frequency of nondiagnostic examinations, and other clinical outcomes between patients undergoing coronary CTA in the ED by a single-source CT (SSCT) scanner with HR control versus a dual-source CT (DSCT) scanner without HR control. Methods: This retrospective study included 509 patients (mean age, 52.1±15.1 years; 283 men, 226 women) at low-to-intermediate risk for acute coronary syndrome who underwent coronary CTA for acute chest pain during off hours in a single ED from March 1, 2020 to April 25, 2022. A total of 205 patients initially underwent CTA using a 64-detector SSCT with HR control (oral beta-blocker administration if HR was >65 beats per minute); following scanner replacement on April 26, 2021, 304 patients underwent CTA using a third-generation DSCT without HR control. Groups were compared in terms of ED LOS and CT completion time (time from ordering of CTA to completion of acquisition) using propensity score matching, and additional endpoints including image quality and nondiagnostic examinations based on radiology reports. Results: DSCT group, compared with SSCT group, showed no significant difference in median ED LOS (505 vs 457 minutes; P=.37), but shorter median CT completion time (95 vs 117 minutes; P<.001); based on mediation analysis, 89% of reduction in CT completion time for DSCT was attributed to absence of HR control. DSCT group, compared with SSCT group, showed higher frequency of examinations with good or excellent image quality (87.8% vs 60.0%, P<.001) and lower frequency of nondiagnostic examinations (1.6% vs 6.3%, P=.01), but no significant difference in frequencies of emergent cardiology consultation, invasive angiography, ED disposition, or coronary revascularization (all P>.05). No patient in either group experienced 30-day all-cause mortality or major adverse cardiovascular event. Conclusion: Use of a DSCT scanner for coronary CTA can eliminate need for beta-blocker administration for HR control while decreasing nondiagnostic examinations. Clinical Impact: A DSCT scanner can expedite clinical processes in the ED.

Non-invasive coronary imaging in elderly population

Age is a non-modifiable cardiovascular risk factor, which leads to development and progression of chronic conditions, such as coronary artery disease, by promoting atherosclerosis. Aging is responsible for morphological structure changes of the coronary arteries and specific atherosclerotic plaque features, which can be studied with non-invasive coronary imaging techniques, particularly coronary CT angiography. The aim of this review is to evaluate current knowledge on this technique applied to the elderly population, and to describe CAD manifestation and plaque features of coronary atherosclerosis in this particular set of patients. We also discuss the clinical implication of frailty assessment and customization of diagnostic strategies in order to shift the approach from disease-centered to patient-centered care.

Role of cardiac imaging in acute chest pain

Chest pain is the second most common complaint in the emergency department. The need to diagnose the cause of chest pain in a timely manner and appropriately direct care is crucial. This article discusses the role of imaging in acute chest pain, after first differentiating chest pain into cardiac and non-cardiac causes with upfront clinical and biochemical assessment. The role of non-invasive imaging including point-of-care ultrasound, echocardiography, myocardial perfusion imaging, cardiac MRI, coronary computed tomography angiography and novel cardiac CT applications are discussed. Updates in the literature regarding the role of coronary plaque imaging in acute chest pain are reviewed, as are ongoing challenges and future directions. This includes a discussion on the yield of diagnostic testing in low-risk acute chest pain cohorts vs intermediate-high risk cohorts. The incremental value of further testing in the former is low, which is reflected in contemporary guidelines that discourage the use of costly diagnostic tests in these cohorts. In the latter cohort, emerging evidence has shown specifically the role coronary computed tomography angiography could play in reducing the need for invasive coronary angiography in selective patients where the true probability of acute coronary syndrome is thought to be low. Real-world considerations such as accessibility and affordability are also discussed in the paper because while guidelines offer clinicians the flexibility of evidence-based choice, physician decision must necessarily be made in consideration of real-world constraints.

Coronary computed tomography angiography in the evaluation of acute chest pain in patients with elevated high sensitive cardiac troponin I (hs-cTn) level

Aims CCTA is a well-established and safe imaging modality for the diagnosis of CAD and is gate keeping for invasive coronary angiography (ICA). We aimed to examine CCTA performance in patients presenting with ACP and dynamic hs-cTn elevation compatible with MI but not exceeding 7 folds of the URL. We also examined the performance of GRACE and PTP consortium scores in this population of patients.

Outcomes of Functional Testing Versus Invasive Cardiac Catheterization for the Evaluation of Intermediate Severity Coronary Stenosis Detected on Cardiac Computed Tomography Angiography

INTRODUCTION

The aim of this study was to evaluate the effectiveness of functional testing in comparison to invasive coronary angiography (ICA) among acute chest pain patients whose first diagnostic modality was a coronary computed tomography angiogram (CCTA) and were found to have intermediate coronary stenosis, defined as 50%-70% luminal stenosis.

METHODS

We conducted a retrospective review of 4763 acute chest pain patients ≥18 years old who received a CCTA as the initial diagnostic modality. Of these, 118 patients met enrollment criteria and proceeded to either stress test (80/118) or directly to ICA (38/118). The primary outcome was 30-day major adverse cardiac event, consisting of acute myocardial infarction, urgent revascularization, or death.

RESULTS

There was no difference in 30-day major adverse cardiac event among patients who underwent initial stress testing versus directly referred to ICA (0% vs. 2.6%, P = 0.322) following CCTA. The rate of revascularization without acute myocardial infarction was significantly higher among those who underwent ICA versus stress test [36.8% vs. 3.8%, P < 0.0001; adjusted odds ratio: 9.6, 95% confidence interval, 1.8-49.6]. Patients who underwent ICA had a higher rate of catheterization without revascularization within 30 days of the index admission in comparison to those who underwent initial stress testing (55.3% vs. 12.5%, P < 0.0001; adjusted odds ratio: 26.7, 95% confidence interval, 6.6-109.5).

CONCLUSION

Among patients with intermediate coronary stenosis on CCTA, a functional stress test compared with ICA may prevent unnecessary revascularization and improve cardiac catheterization yield without negatively affecting the 30-day patient safety profile.

Contemporary Chest Pain Evaluation: The Australian Case for Cardiac CT

Computed tomography coronary angiography (CTCA) is a non-invasive diagnostic modality that provides a comprehensive anatomical assessment of the coronary arteries and coronary atherosclerosis, including plaque burden, composition and morphology. The past decade has witnessed an increase in the role of CTCA for evaluating patients with both stable and acute chest pain, and recent international guidelines have provided increasing support for a first line CTCA diagnostic strategy in select patients. CTCA offers some advantages over current functional tests in the detection of obstructive and non-obstructive coronary artery disease, as well as for ruling out obstructive coronary artery disease. Recent randomised trials have also shown that CTCA improves prognostication and guides the use of guideline-directed preventive therapies, leading to improved clinical outcomes. CTCA technology advances such as fractional flow reserve, plaque quantification and perivascular fat inflammation potentially allow for more personalised risk assessment and targeted therapies. Further studies evaluating demand, supply, and cost-effectiveness of CTCA for evaluating chest pain are required in Australia. This discussion paper revisits the evidence supporting the use of CTCA, provides an overview of its implications and limitations, and considers its potential role for chest pain evaluation pathways in Australia.

DiFiR-CT: Distance field representation to resolve motion artifacts in computed tomography

BACKGROUND

Motion during data acquisition leads to artifacts in computed tomography (CT) reconstructions. In cases such as cardiac imaging, not only is motion unavoidable, but evaluating the motion of the object is of clinical interest. Reducing motion artifacts has typically been achieved by developing systems with faster gantry rotation or via algorithms which measure and/or estimate the displacement. However, these approaches have had limited success due to both physical constraints as well as the challenge of estimating non-rigid, temporally varying, and patient-specific motion fields.

PURPOSE

To develop a novel reconstruction method which generates time-resolved, artifact-free images without estimation or explicit modeling of the motion.

METHODS

We describe an analysis-by-synthesis approach which progressively regresses a solution consistent with the acquired sinogram. In our method, we focus on the movement of object boundaries. Not only are the boundaries the source of image artifacts, but object boundaries can simultaneously be used to represent both the object as well as its motion over time without the need for an explicit motion model. We represent the object boundaries via a signed distance function (SDF) which can be efficiently modeled using neural networks. As a result, optimization can be performed under spatial and temporal smoothness constraints without the need for explicit motion estimation.

RESULTS

We illustrate the utility of DiFiR-CT in three imaging scenarios with increasing motion complexity: translation of a small circle, heart-like change in an ellipse's diameter, and a complex topological deformation. Compared to filtered backprojection, DiFiR-CT provides high quality image reconstruction for all three motions without hyperparameter tuning or change to the architecture. We also evaluate DiFiR-CT's robustness to noise in the acquired sinogram and found its reconstruction to be accurate across a wide range of noise levels. Lastly, we demonstrate how the approach could be used for multi-intensity scenes and illustrate the importance of the initial segmentation providing a realistic initialization. Code and supplemental movies are available at https://kunalmgupta.github.io/projects/DiFiR-CT.html.

CONCLUSIONS

Projection data can be used to accurately estimate a temporally-evolving scene without the need for explicit motion estimation using a neural implicit representation and analysis-by-synthesis approach.

2022 use of coronary computed tomographic angiography for patients presenting with acute chest pain to the emergency department: An expert consensus document of the Society of cardiovascular computed tomography (SCCT): Endorsed by the American College of Radiology (ACR) and North American Society for cardiovascular Imaging (NASCI)

Coronary computed tomography angiography (CTA) improves the quality of care for patients presenting with acute chest pain (ACP) to the emergency department (ED), particularly in patients with low to intermediate likelihood of acute coronary syndrome (ACS). The Society of Cardiovascular Computed Tomography Guidelines Committee was formed to develop recommendations for acquiring, interpreting, and reporting of coronary CTA to ensure appropriate, safe, and efficient use of this modality. Because of the increasing use of coronary CTA testing for the evaluation of ACP patients, the Committee has been charged with the development of the present document to assist physicians and technologists. These recommendations were produced as an educational tool for practitioners evaluating acute chest pain patients in the ED, in the interest of developing systematic standards of practice for coronary CTA based on the best available data or broad expert consensus. Due to the highly variable nature of medical care, approaches to patient selection, preparation, protocol selection, interpretation or reporting that differs from these guidelines may represent an appropriate variation based on a legitimate assessment of an individual patient's needs.

Cost-effectiveness of rapid assessment of potential ischaemic heart disease with CT coronary angiography

OBJECTIVES

To estimate the cost-effectiveness of early CT coronary angiography (CTCA) for intermediate risk patients with suspected acute coronary syndrome (ACS), compared with standard care METHODS: We performed within-trial economic analysis using data from the RAPID-CTCA randomised trial, and long-term modelling of cost-effectiveness using secondary data sources to estimate the cost-effectiveness of early CTCA compared with standard care for patients with suspected ACS attending acute hospitals in the UK. Cost-effectiveness was estimated as the incremental cost per quality-adjusted life year (QALY) gained, and the probability of each strategy being cost-effective at varying willingness-to-pay per QALY gained.

RESULTS

The within-trial analysis showed that there were no demonstrable differences in costs or QALYs between early CTCA and standard care, with point estimates suggesting higher costs (£7414 vs £6845: mean difference £569, 95% CI -£208 to £1335; p=0.1521) and lower QALYs (0.749 vs 0.758, mean difference -0.009, 95% CI -0.026 to 0.010; p=0.377) in the CTCA arm. The long-term economic analysis suggested that, on average, CTCA was slightly less effective than standard care alone with 0.025 quality-adjusted life years lost per patient treated and was more expensive with additional costs of £481 per patient treated. At a threshold of £20 000 per QALY, CTCA has 24% probability of being cost-effective.

CONCLUSIONS

There are no demonstrable differences in within-trial costs and QALYs, and long-term cost-effectiveness modelling suggested higher long-term costs with CTCA and uncertain effect on long-term QALYs, making routine use of CTCA for suspected ACS unlikely to be a cost-effective use of NHS resources.

Coronary CT and timing of invasive coronary angiography in patients ≥75 years old with non-ST segment elevation acute coronary syndromes

BACKGROUND

The ability of coronary CT angiography (cCTA) to rule out significant coronary artery disease (CAD) in older patients with non-ST segment elevation acute coronary syndromes (NSTEACS) is unclear since valid cCTA analysis may be limited by extensive coronary artery calcification. In addition, the effect of very early invasive coronary angiography (ICA) with possible revascularisation is debated.

METHODS

This is a posthoc analysis of patients ≥75 years included in the Very Early vs Standard Care Invasive Examination and Treatment of Patients with Non-ST-Segment Elevation Acute Coronary Syndrome Trial. cCTA was performed prior to the ICA. The diagnostic accuracy of cCTA was investigated. Presence of a coronary artery stenosis ≥50% by subsequent ICA was used as reference. Patients were randomised to a very early (within 12 hours of diagnosis) or a standard ICA (within 48-72 hours of diagnosis). The primary composite endpoint was 5-year all-cause mortality, non-fatal recurrent myocardial infarction or hospital admission for refractory myocardial ischaemia or heart failure.

RESULTS

Of 452 (21%) patients ≥75 years, 161 (35.6%) underwent cCTA. 19% of cCTAs excluded significant CAD. The negative predictive value (NPV) of cCTA was 94% (95% CI 79 to 99) and the sensitivity 98% (95% CI 94 to 100). No significant differences in the frequency of primary endpoints were seen in patients randomised to very early ICA (at 5-year follow-up, n=100 (46.9%) vs 122 (51.0%), log-rank p=0.357).

CONCLUSION

In patients ≥75 years with NSTEACS, cCTA before ICA showed a high NPV. A very early ICA <12 hours of diagnosis did not significantly improve long-term clinical outcomes.

Serial troponin-T and long-term outcomes in suspected acute coronary syndrome

BACKGROUND

Long-term prognostic implications of serial high-sensitivity troponin concentrations in subjects with suspected acute coronary syndrome are unknown.

METHODS AND RESULTS

Individuals with a first diagnosis of myocardial infarction, unstable angina, observation for suspected myocardial infarction, or chest pain from 2012 through 2019 who underwent two high-sensitivity troponin-T (hsTnT) measurements 1-7 h apart were identified through Danish national registries. Absolute and relative risks for death at days 0-30 and 31-365, stratified for whether subjects had normal or elevated hsTnT concentrations, and whether these concentrations changed by <20%, > 20 to 50%, or >50% in either direction from first to second measurement, were calculated through multivariable logistic regression with average treatment effect modeling. Of the 28 902 individuals included, 2.8% had died at 30 days, whereas 4.9% of those who had survived the first 30 days died between days 31-365. The standardized risk of death was highest among subjects with two elevated hsTnT concentrations (0-30 days: 4.3%, 31-365 days: 7.2%). In this group, mortality was significantly higher in those with a > 20 to 50% or >50% rise from first to second measurement, though only at 30 days. The risk of death was very low in subjects with two normal hsTnT concentrations (0-30 days: 0.1%, 31-365 days: 0.9%) and did not depend on relative or absolute changes between measurements.

CONCLUSIONS

Individuals with suspected acute coronary syndrome and two consecutively elevated hsTnT concentrations consistently had the highest risk of death. Mortality was very low in subjects with two normal hsTnT concentrations, irrespective of changes between measurements.

Deep Learning Analysis of Chest Radiographs to Triage Patients with Acute Chest Pain Syndrome

Background Patients presenting to the emergency department (ED) with acute chest pain (ACP) syndrome undergo additional testing to exclude acute coronary syndrome (ACS), pulmonary embolism (PE), or aortic dissection (AD), often yielding negative results. Purpose To assess whether deep learning (DL) analysis of the initial chest radiograph may help triage patients with ACP syndrome more efficiently. Materials and Methods This retrospective study used electronic health records of patients with ACP syndrome at presentation who underwent a combination of chest radiography and additional cardiovascular or pulmonary imaging or stress tests at two hospitals (Massachusetts General Hospital [MGH], Brigham and Women's Hospital [BWH]) between January 2005 and December 2015. A DL model was trained on 23 005 patients from MGH to predict a 30-day composite end point of ACS, PE, AD, and all-cause mortality based on chest radiographs. Area under the receiver operating characteristic curve (AUC) was used to compare performance between models (model 1: age + sex; model 2: model 1 + conventional troponin or d-dimer positivity; model 3: model 2 + DL predictions) in internal and external test sets from MGH and BWH, respectively. Results At MGH, 5750 patients (mean age, 59 years ± 17 [SD]; 3329 men, 2421 women) were evaluated. Model 3, which included DL predictions, significantly improved discrimination of those with the composite outcome compared with models 2 and 1 (AUC, 0.85 [95% CI: 0.84, 0.86] vs 0.76 [95% CI: 0.74, 0.77] vs 0.62 [95% CI: 0.60 0.64], respectively; P < .001 for all). When using a sensitivity threshold of 99%, 14% (813 of 5750) of patients could be deferred from cardiovascular or pulmonary testing for differential diagnosis of ACP syndrome using model 3 compared with 2% (98 of 5750) of patients using model 2 (P < .001). Model 3 maintained its diagnostic performance in different age, sex, race, and ethnicity groups. In external validation at BWH (22 764 patients; mean age, 57 years ± 17; 11 470 women), trends were similar and improved after fine tuning. Conclusion Deep learning analysis of chest radiographs may facilitate more efficient triage of patients with acute chest pain syndrome in the emergency department. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Goo in this issue.

Pericoronary adipose tissue radiomics from coronary CT angiography identifies vulnerable plaques characteristics in intravascular OCT

Pericoronary adipose tissue (PCAT) features on CT have been shown to reflect local inflammation, and signals increased cardiovascular risk. Our goal was to determine if PCAT radiomics extracted from coronary CT angiography (CCTA) images are associated with intravascular optical coherence tomography (IVOCT)-identified vulnerable plaque characteristics (e.g., microchannels [MC] and thin-cap fibroatheroma [TCFA]). CCTA and IVOCT images of 30 lesions from 25 patients were registered. Vessels with vulnerable plaques were identified from the registered IVOCT images. PCAT radiomics features were extracted from CCTA images for the lesion region of interest (PCAT-LOI) and the entire vessel (PCAT-Vessel). We extracted 1356 radiomics features, including intensity (first-order), shape, and texture features. Features were reduced using standard approaches (e.g., high feature correlation). Using stratified three-fold cross-validation with 1000 repeats, we determined the ability of PCAT radiomics features from CCTA to predict IVOCT vulnerable plaque characteristics. In identification of TCFA lesions, PCAT-LOI and PCAT-Vessel radiomics models performed comparably (AUC±standard deviation 0.78±0.13, 0.77±0.14). For identification of MC lesions, PCAT-Vessel radiomics model (0.89±0.09) was moderately better associated than that of PCAT-LOI model (0.83±0.12). Both PCAT-LOI and PCAT-Vessel radiomics models also similarly identified coronary vessels thought to be highly vulnerable (i.e., both TCFA and MC) (0.88±0.10, 0.91±0.09). Favorable radiomics features tended to be those describing texture and size of PCAT. PCAT radiomics can identify coronary vessels with TCFA or MC, consistent with IVOCT. CCTA radiomics may improve risk stratification by noninvasively detecting vulnerable plaque characteristics that are only visible with IVOCT.

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.

Abnormal epicardial coronary vasomotor reactivity is associated with altered outcomes

BACKGROUND

The prevalence and significance of abnormal epicardial coronary vasomotor reactivity (ACVR) in patients with symptoms compatible with myocardial ischaemia remains ill-defined. Our diagnostic strategy is to perform a provocative test (PT) in every patient presenting with chest pain at rest, for whom coronary angiography does not reveal significant epicardial coronary artery disease (≥70% stenosis by visual assessment).

AIM

To evaluate such a strategy in terms of incidence of ACVR, PT safety and patient outcomes.

METHODS

The present study was a retrospective observational study with a median clinical follow-up of 5years. The primary outcome was incidence of ACVR in patients with PT. Risk factors for ACVR and clinical follow-up were obtained, and the rate of major adverse cardiovascular and cerebrovascular events (MACCE; death, cardiovascular mortality, myocardial infarction, stroke and coronary revascularization) was reported.

RESULTS

ACVR was documented in 294 (12.4%) of the 2379 patients with PT, out of the 13,654 patients undergoing angiography. Patients with ACVR were more often female (43.9% vs. 30.0%; P<0.0001), current smokers (37.4% vs. 8.7%; P<0.0001) and had a suspected acute coronary syndrome (36.7% vs. 29.1%; P=0.005) at admittance compared with patients without ACVR. During clinical follow-up, MACCE occurred more frequently in patients with (9.8%) than in those without (3.7%) ACVR (hazard ratio [HR] 4.15, 95% confidence interval [CI] 2.62-6.57; P<0.0001), including more myocardial infarctions (4.0% vs. 0.4%; HR 17.8, 95% CI 6.41-49.5; P<0.0001) and more myocardial revascularizations (6.1% vs. 1.1%; HR 9.36, 95% CI 4.67-18.74; P<0.0001) compared with patients with normal PT at baseline.

CONCLUSIONS

ACVR is frequent in patients with symptoms compatible with myocardial ischaemia at rest, with no significant coronary stenosis. PT is a safe strategy to identify a population at high risk of recurrent ischaemic events.