Cardiac computed tomography in patients with acute chest pain

Gender Differences in Epicardial Adipose Tissue and Plaque Composition by Coronary CT Angiography: Association with Cardiovascular Outcome

Background: To investigate gender differences in epicardial adipose tissue (EAT) and plaque composition by coronary CT angiography (CCTA) and the association with cardiovascular outcome. Methods: Data of 352 patients (64.2 ± 10.3 years, 38% female) with suspected coronary artery disease (CAD) who underwent CCTA were retrospectively analyzed. EAT volume and plaque composition from CCTA were compared between men and women. Major adverse cardiovascular events (MACE) were recorded from follow-up. Results: Men were more likely to have obstructive CAD, higher Agatston scores, and a larger total and non-calcified plaque burden. In addition, men displayed more adverse plaque characteristics and EAT volume compared to women (all p < 0.05). After a median follow-up of 5.1 years, MACE occurred in 8 women (6%) and 22 men (10%). In multivariable analysis, Agatston calcium score (HR 1.0008, p = 0.014), EAT volume (HR 1.067, p = 0.049), and low-attenuation plaque (HR 3.82, p = 0.036) were independent predictors for MACE in men, whereas only low-attenuation plaque (HR 2.42, p = 0.041) showed predictive value for events in women. Conclusion: Women demonstrated less overall plaque burden, fewer adverse plaque characteristics, and a smaller EAT volume compared to men. However, low-attenuation plaque is a predictor for MACE in both genders. Thus, a differentiated plaque analysis is warranted to understand gender differences of atherosclerosis to guide medical therapy and prevention strategies.

Clinical Evaluation of the Automatic Coronary Artery Disease Reporting and Data System (CAD-RADS) in Coronary Computed Tomography Angiography Using Convolutional Neural Networks

RATIONALE AND OBJECTIVES

The coronary artery disease reporting and data system (CAD-RADS™) was recently introduced to standardise reporting. We aimed to evaluate the utility of an automatic postprocessing and reporting system based on CAD-RADS™ in suspected coronary artery disease (CAD) patients.

MATERIALS AND METHODS

Clinical evaluation was performed in 346 patients who underwent coronary computed tomography angiography (CCTA). We compared deep learning (DL)-based CCTA with human readers for evaluation of CAD-RADS™ with commercially-available automated segmentation and manual postprocessing in a retrospective validation cohort.

RESULTS

Compared with invasive coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the DL model for diagnosis of CAD were 79.02%, 86.52%, 89.50%, 73.94%, and 82.08%, respectively. There was no significant difference between the DL-based and the reader-based CAD-RADS™ grading of CCTA results. Consistency testing showed that the Kappa value between the model and the readers was 0.775 (95% confidence interval [CI]: 0.728-0.823, p < 0.001), 0.802 (95% CI: 0.756-0.847, p < 0.001), and 0.796 (95% CI: 0.750-0.843, p < 0.001), respectively. This system reduces the time taken from 14.97 ± 1.80 min to 5.02 ± 0.8 min (p < 0.001).

CONCLUSION

The standardised reporting of DL-based CAD-RADS™ in CCTA can accurately and rapidly evaluate suspected CAD patients, and has good consistency with grading by radiologists.

Prognostic Value of Coronary Artery Disease-Reporting and Data System Score for Major Adverse Cardiac Events in Patients Attending the Emergency Department With Acute Chest Pain

OBJECTIVE

This study aimed to compare the prognostic performance of Coronary Artery Disease (CAD)-Reporting and Data System (CAD-RADS) score with those of clinical risk factors and the extent of CAD classification for predicting major adverse cardiac events in emergency department patients.

METHODS

A total of 779 patients with acute chest pain at low to intermediate risk for CAD underwent cardiac computed tomography angiography. The primary end point was early and late major adverse cardiac events. We developed the following models: model 1, clinical risk factors; model 2, clinical risk factors and CAD-RADS scores; model 3, clinical risk factors and extent of CAD.

RESULTS

The C-statistics revealed that both CAD-RADS score and CAD extent improved risk stratification over the clinical risk factors (C-index for early events: C-index: 0.901 vs 0.814 and 0.911 vs 0.814; C-index for late events: 0.897 vs 0.808 and 0.905 vs 0.808; all P < 0.05).

CONCLUSIONS

The CAD-RADS score had additional risk prediction benefits over clinical risk factors for emergency department patients.

Artificial Intelligence to Assist in Exclusion of Coronary Atherosclerosis During CCTA Evaluation of Chest Pain in the Emergency Department: Preparing an Application for Real-world Use

Coronary computed tomography angiography (CCTA) evaluation of chest pain patients in an emergency department (ED) is considered appropriate. While a "negative" CCTA interpretation supports direct patient discharge from an ED, labor-intensive analyses are required, with accuracy in jeopardy from distractions. We describe the development of an artificial intelligence (AI) algorithm and workflow for assisting qualified interpreting physicians in CCTA screening for total absence of coronary atherosclerosis. The two-phase approach consisted of (1) phase 1-development and preliminary testing of an algorithm for vessel-centerline extraction classification in a balanced study population (n = 500 with 50% disease prevalence) derived by retrospective random case selection, and (2) phase 2-simulated clinical Trialing of developed algorithm on a per-case (entire coronary artery tree) basis in a more "real-world" study population (n = 100 with 28% disease prevalence) from an ED chest pain series. This allowed pre-deployment evaluation of the AI-based CCTA screening application which provides vessel-by-vessel graphic display of algorithm inference results integrated into a clinically capable viewer. Algorithm performance evaluation used area under the receiver operating characteristic curve (AUC-ROC); confusion matrices reflected ground truth vs AI determinations. The vessel-based algorithm demonstrated strong performance with AUC-ROC = 0.96. In both phase 1 and phase 2, independent of disease prevalence differences, negative predictive values at the case level were very high at 95%. The rate of completion of the algorithm workflow process (96% with inference results in 55-80 s) in phase 2 depended on adequate image quality. There is potential for this AI application to assist in CCTA interpretation to help extricate atherosclerosis from chest pain presentations.

Reliability of coronary computed tomography angiography in acute coronary syndrome in an emergency setting

Background

Cardiovascular computed tomography (cardiovascular CT) is currently used as a fast non-invasive method for the visualization of coronary plaques and walls and the assessment of lumen stenosis severity. Previous studies demonstrated the high negative predictive value of CT for the exclusion of coronary lumen stenoses. In this study we hypothesize that coronary CT angiography (CTA) represents a reliable method as diagnostic procedure in acute coronary syndrome (ACS) even in emergency settings.

Methods

36 patients (51 lesions) with ACS who underwent cardiovascular CT, intravascular ultrasound (IVUS) and invasive coronary angiography (ICA) within 48 h were included. The percentage of coronary stenoses were measured and compared by three methods. Influence of available predictors that can potentially affect the measurement results was assessed.

Results

Cardiac CTA provided comparable results to IVUS (mean difference -0.45%, PPV: 98%, NPV: 75%). ICA tends to estimate lower stenoses degrees than cardiac CTA and IVUS (mean difference 13.19% and 13.64%, respectively). The final diagnosis and positive remodeling did not lead to any significant influence on measurements.

Conclusions

The cardiovascular CT results show that even in emergency settings it is possible to identify morphological changes as sequels of coronary artery sclerosis with comparable results to the reference method IVUS. Deviations of IVUS and cardiovascular CT from ICA are comparable and can to a large extent be explained by differences in the measurement technique.

A prospective cohort study of self-reported computerised medical history taking for acute chest pain: protocol of the CLEOS-Chest Pain Danderyd Study (CLEOS-CPDS)

INTRODUCTION

Management of acute chest pain focuses on diagnosis or safe rule-out of an acute coronary syndrome (ACS). We aim to determine the additional value of self-reported computerised history taking (CHT).

METHODS AND ANALYSIS

Prospective cohort study design with self-reported, medical histories collected by a CHT programme (Clinical Expert Operating System, CLEOS) using a tablet. Women and men presenting with acute chest pain to the emergency department at Danderyd University Hospital (Stockholm, Sweden) are eligible. CHT will be compared with standard history taking for completeness of data required to calculate ACS risk scores such as History, ECG, Age, Risk factors and Troponin (HEART), Global Registry of Acute Coronary Events (GRACE), and Thrombolysis in Myocardial Infarction (TIMI). Clinical outcomes will be extracted from hospital electronic health records and national registries. The CLEOS-Chest Pain Danderyd Study project includes (1) a feasibility study of CHT, (2) a validation study of CHT as compared with standard history taking, (3) a paired diagnostic accuracy study using data from CHT and established risk scores, (4) a clinical utility study to evaluate the impact of CHT on the management of chest pain and the use of resources, and (5) data mining, aiming to generate an improved risk score for ACS. Primary outcomes will be analysed after 1000 patients, but to allow for subgroup analysis, the study intends to recruit 2000 or more patients. This ongoing project may lead to new and more effective ways for collecting thorough, accurate medical histories with important implications for clinical practice.

ETHICS AND DISSEMINATION

This study has been reviewed and approved by the Stockholm Regional Ethical Committee (now Swedish Ethical Review Authority). Results will be published, regardless of the outcome, in peer-reviewed international scientific journals.

TRIAL REGISTRATION NUMBER

This study is registered at https://www.clinicaltrials.gov (unique identifier: NCT03439449).

Inter-observer agreement of the Coronary Artery Disease Reporting and Data System (CAD-RADSTM) in patients with stable chest pain

Purpose

To assess inter-observer variability of the Coronary Artery Disease - Reporting and Data System (CAD-RADS) for classifying the degree of coronary artery stenosis in patients with stable chest pain.

Material and methods

A prospective study was conducted upon 96 patients with coronary artery disease, who underwent coronary computed tomography angiography (CTA). The images were classified using the CAD-RAD system according to the degree of stenosis, the presence of a modifier: graft (G), stent (S), vulnerable plaque (V), or non-diagnostic (n) and the associated coronary anomalies, and non-coronary cardiac and extra-cardiac findings. Image analysis was performed by two reviewers. Inter-observer agreement was assessed.

Results

There was excellent inter-observer agreement for CAD-RADS (k = 0.862), at 88.5%. There was excellent agreement for CAD-RADS 0 (k = 1.0), CAD-RADS 1 (k = 0.92), CAD-RADS 3 (k = 0.808), CAD-RADS 4 (k = 0.826), and CAD-RADS 5 (k = 0.833) and good agreement for CAD-RADS 2 (k = 0.76). There was excellent agreement for modifier G (k = 1.0) and modifier S (k = 1.0), good agreement for modifier N (k = 0.79), and moderate agreement for modifier V (k = 0.59). There was excellent agreement for associated coronary artery anomalies (k = 0.845), non-coronary cardiac findings (k = 0.857), and extra-cardiac findings (k = 0.81).

Conclusions

There is inter-observer agreement of CAD-RADS in categorising the degree of coronary arteries stenosis, and the modifier of the system and associated cardiac and extra-cardiac findings.

Emergency Computed Tomography Angiogram of the Chest, Abdomen, and Pelvis

In the setting of blunt trauma, the rapid assessment of internal injuries is essential to prevent potentially fatal outcomes. Computed tomography is a useful diagnostic tool for both screening and diagnosis. In addition to trauma, acute chest syndromes often warrant emergent computed tomographic angiography, looking for etiologies such as aortic aneurysms or complications of aortic aneurysms, or both, pulmonary emboli, as well as other acute vascular process like aortic dissection and Takayasu aortitis. With continued improvements in diagnostic imaging, computed tomographic angiography of the chest, abdominal and pelvis proves to be an effective modality to image the aorta and other major vascular structures.

Clinical implementation of an emergency department coronary computed tomographic angiography protocol for triage of patients with suspected acute coronary syndrome

OBJECTIVES

To evaluate the efficiency and safety of emergency department (ED) coronary computed tomography angiography (CTA) during a 3-year clinical experience.

METHODS

Single-center registry of coronary CTA in consecutive ED patients with suspicion of acute coronary syndrome (ACS). The primary outcome was efficiency of coronary CTA defined as the length of hospitalization. Secondary endpoints of safety were defined as the rate of downstream testing, normalcy rates of invasive coronary angiography (ICA), absence of missed ACS, and major adverse cardiac events (MACE) during follow-up, and index radiation exposure.

RESULTS

One thousand twenty two consecutive patients were referred for clinical coronary CTA with suspicion of ACS. Overall, median time to discharge home was 10.5 (5.7-24.1) hours. Patient disposition was 42.7 % direct discharge from the ED, 43.2 % discharge from emergency unit, and 14.1 % hospital admission. ACS rate during index hospitalization was 9.1 %. One hundred ninety two patients underwent additional diagnostic imaging and 77 underwent ICA. The positive predictive value of CTA compared to ICA was 78.9 % (95 %-CI 68.1-87.5 %). Median CT radiation exposure was 4.0 (2.5-5.8) mSv. No ACS was missed; MACE at follow-up after negative CTA was 0.2 %.

CONCLUSIONS

Coronary CTA in an experienced tertiary care setting allows for efficient and safe management of patients with suspicion for ACS.

KEY POINTS

• ED Coronary CTA using advanced systems is associated with low radiation exposure. • Negative coronary CTA is associated with low rates of MACE. • CTA in ED patients enables short median time to discharge home. • CTA strategy is characterized by few downstream tests including unnecessary ICA.

Infarct characterization using CT

Myocardial infarction (MI) is a major cause of death and disability worldwide. The incidence is not expected to diminish, despite better prevention, diagnosis and treatment, because of the ageing population in industrialized countries and unhealthy lifestyles in developing countries. Nowadays it is highly requested an imaging tool able to evaluate MI and viability. Technology improvements determined an expansion of clinical indications from coronary plaque evaluation to functional applications (perfusion, ischemia and viability after MI) integrating additional phases and information in the mainstream examination. Cardiac computed tomography (CCT) and cardiac MR (CMR) employ different contrast media, but may characterize MI with overlapping imaging findings due to the similar kinetics and tissue distribution of gadolinium and iodinated contrast media. CCT may detect first-pass perfusion defects, dynamic perfusion after pharmacological stress, and delayed enhancement (DE) of non-viable territories.

MELAS Syndrome with Cardiac Involvement: A Multimodality Imaging Approach

A 49-year-old man presented with chest pain, dyspnea, and lactic acidosis. Left ventricular hypertrophy and myocardial fibrosis were detected. The sequencing of mitochondrial genome (mtDNA) revealed the presence of A to G mtDNA point mutation at position 3243 (m.3243A>G) in tRNA^Leu(UUR) gene. Diagnosis of cardiac involvement in a patient with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes syndrome (MELAS) was made. Due to increased risk of sudden cardiac death, cardioverter defibrillator was implanted.

[Multimodal imaging of ischemic heart diseases: A 2015 update]

Current realities and future possibilities of imaging in the ischemic heart diseases are very broad and constantly evolving, with the improvement of existing technologies and the introduction of new features such as dual-energy CT, strain ultrasound, multimodality fusion or perfusion MRI. Regular collaboration between prescribing clinicians, cardiologists, radiologists and nuclear radiologists is therefore essential to tailor the examination to the specific clinical question. The indications for each modality will therefore depend on its diagnostic performance, cost, acquisition and post-processing times and eventual radiation exposure. This review will detail principles and applications of current cardiac imaging examinations: echocardiography, nuclear medicine, MRI, CT and coronary angiography, emphasizing their current strengths and weaknesses in the ischemic heart diseases management.