Coronary computed tomographic angiography (CCTA) in community hospitals: "current and emerging role"

Results of Computed Tomographic Coronary Angiography in Comparison with the Table of Pretest Probability of Chronic Coronary Syndrome

Aim        To compare results of computed tomography coronary angiography (CTCA) with a table of pretest probability of chronic coronary syndrome (CCS) taking into account the following key variants: abnormality, microvascular damage, nonobstructive or obstructive atherosclerotic damage.Material and methods        50 patients (39 men, 20 women) aged 30 to 67 years were evaluated with a computed tomography scanner PHILIPS Brilliance iCT SP 128. A high pretest probability of ischemic heart disease was found in 44 % of cases and medium in 40%.Results   According to CCS data, coronary artery (CA) pathology was not found in 28 % of patients. CA hypoplasia was observed in 4 % of patients. 22 % of patients had muscular bridges narrowing the CA lumen during systole by 40-50%. In 26 % of cases, CA had minimal and early stenoses. Moderate and pronounced stenoses were observed in 20% of cases. In one case, there was a total occlusion of the circumflex branch. Calcinates were found in 9.1 % of patients with muscular bridges, in 61.5 % of patients with minimal and early stenoses, and in 80% of patients with moderate and pronounced stenoses. In the group with "clean" CA and congenital defects, calcinates were absent. The mean value of pretest probability was the highest in the patient group with moderate and pronounced stenoses, 22.5±13.13. It was significantly higher than in the group with muscular bridges (р=0.045) and congenital pathology of CA (р=0.01). At the same time, this value did not significantly differ from the group with "clean" CA and the group with minimal and early stenoses. Based on the study results, 2 bypass surgeries and 5 CA stentings were performed.Conclusion            Thus, the table of pretest probability of ischemic heart disease does not provide a differential diagnosis and evaluation of the nature of CA damage as compared to results of CTCA.

Coronary Computed Tomographic Angiography Imaging as a Prognostic Indicator for Coronary Artery Disease: Data from a Lebanese Tertiary Center

Background:

Coronary artery disease (CAD) is a major cause of death and disability worldwide. Coronary computed tomographic angiography (CCTA) is a noninvasive imaging technique with a high negative predictive value (NPV). Most studies were done in developed countries, where the prevalence of CAD does not reflect the actual disease burden in developing countries, such as Lebanon.

Methods:

We retrospectively evaluated the prognostic value of CCTA in predicting acute myocardial events (AMEs) in 200 Lebanese patients. We determined if specific medical and radiological characteristics are linked with AME and looked for any association between the patient's medical risk factors and the type/location of detected atheromatous plaques. Patients' records were reviewed, and the follow-up period of 5–8 years ensued. Chi-square/Fisher test and Student's t-test were used, in addition to multinomial logistic regression to adjust for the confounding variables. P <0.05 was considered statistically significant.

Results:

Our study showed that CCTA had a NPV that reaches 97.9% in asymptomatic patients, a positive predictive value (PPV) of 76.4% for symptomatic patients, a sensitivity of 88.9%, and a specificity of 52.5%. AMEs were significantly increased in patients with a mixed plaque type and/or a moderate-to-severe lumen reduction on CCTA.

Conclusions:

CCTA is a sensitive modality for plaque detection and is found to have a remarkably high NPV for asymptomatic patients. A CCTA, along with a low pretest clinical probability of CAD, can be sufficient to rule out an AME for up to 8 years.

Coronary Artery Disease Detection by Machine Learning with Coronary Bifurcation Features

Background: Early accurate detection of coronary artery disease (CAD) is one of the most important medical research areas. Researchers are motivated to utilize machine learning techniques for quick and accurate detection of CAD. Methods: To obtain the high quality of features used for machine learning, we here extracted the coronary bifurcation features from the coronary computed tomography angiography (CCTA) images by using the morphometric method. The machine learning classifier algorithms, such as logistic regression (LR), decision tree (DT), linear discriminant analysis (LDA), k-nearest neighbors (k-NN), artificial neural network (ANN), and support vector machine (SVM) were applied for estimating the performance by using the measured features. Results: The results showed that in comparison with other machine learning methods, the polynomial-SVM with the use of the grid search optimization method had the best performance for the detection of CAD and had yielded the classification accuracy of 100.00%. Among six examined coronary bifurcation features, the exponent of vessel diameter (n) and the area expansion ratio (AER) were two key features in the detection of CAD. Conclusions: This study could aid the clinicians to detect CAD accurately, which may probably provide an alternative method for the non-invasive diagnosis in clinical.

Ultrasound Measurement of Carotid Intima-Media Thickness and Plaques in Predicting Coronary Artery Disease

Ultrasound measurement of carotid intima-media thickness (CIMT) and plaque thickness (PT) may be an additional tool for risk stratification of patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). The aim of this study was to evaluate the correlation of CIMT and PT with coronary artery disease (CAD) in risk stratification tests.This prospective observational study was conducted in an academic tertiary care ED. Carotid ultrasound measurements were obtained for emergency patients with suspected ACS. Carotid measurements included PT, mean CIMT and maximum CIMT. The correlations between carotid ultrasound and the results of coronary catheter angiography (CA), coronary computed tomography angiography (CCTA) and stress tests were identified. The convenience sample included 58 patients comprising 39 men and 19 women with a mean age of 60 ± 12 y. Twenty-two percent (13/58) of patients were positive for CAD, as indicated by results of the cardiac risk stratification tests. Presence of plaque correlated with CCTA findings, with a high specificity (92.8%) for a positive test. Max CIMT predicted abnormal CCTA (area under the curve [AUC] = 0.93, 95% confidence interval: 0.80-1). The correlations with stress test (0.78, 0.46-1) and CA (0.55, 0.28-0.82) were weaker. Presence of carotid plaque correlated significantly with findings of CAD on all risk stratification tests, but especially with CCTA. Carotid ultrasound could have a role in risk stratification in the ED, though more research is needed.

The Utility of Echocardiography for Non-ST-Segment Elevation Myocardial Infarction: A Retrospective Study

Objective:

The objectives were to assess factors associated with a higher likelihood of predicting acute coronary atherothrombosis (ACA) in non-ST-segment elevation myocardial infarction (NSTEMI), evaluate the impact of adding echocardiographic data, and develop an algorithm that would reduce overutilization of emergent angiography.

Methods:

Data were retrospectively analyzed on a patient cohort presenting to an emergency department of an urban community hospital with NSTEMI from October 1, 2015, to July 31, 2018. The inclusion criterion was any adult patient with a first-time, primary diagnosis of NSTEMI without high-risk features. The main outcome variables were the presence of ACA on angiography.

Results:

Seventy-three patients with NSTEMI were included in this study. Logistic regression analysis identified the following independent variables useful for predicting ACA: age, wall motion abnormality on echo, and levels of low-density lipoprotein. The model’s overall fit was highly significant ( P = .0012).

Conclusion:

An integrative approach was demonstrated for the management of patients with NSTEMI presenting to the hospital. Although the positive predictive value of echo in predicting ACA was limited, when combined with demographic attributes and risk factors, it proved to be successful in determining the need for angiography in patients with NSTEMI.

The feasibility of 1-stop examination of coronary CT angiography and abdominal enhanced CT

This study aims to evaluate the feasibility of performing coronary computed tomography angiography (CCTA) and abdominal enhanced computed tomography (CT) with 1-time injection of the agent.CCTA images (right coronary artery, left anterior descending coronary artery, and left circumflex coronary artery) were collected from 20 patients who completed a 1-stop combined examination of CCTA and abdominal enhanced CT (group A), 20 patients who only underwent abdominal enhanced CT (group B1), and 20 patients who only underwent CCTA (group B2). These images were interpreted using the 5-point Likert scale system by 2 experienced radiologists, and abdominal images were observed for breathing artifact. CT value, signal-to-noise ratio (SNR), and CTDI were recorded and compare among the 3 groups.The difference in image quality of the coronary and total volume of the contrast agent between group A and group B1 was not statistical significant (P > .05). The CT value and SNR in group B1 (CCTA) (CT: 394.65 ± 59.23, SNR: 17.38 ± 4.13) increased, compare with Group A (CT: 360.35 ± 34.16, SNR: 13.76 ± 1.84, P = .03, .01), while CTDI was undifferentiated between group A (17.14 ± 6.20) and group B1 (18.38 ± 9.79) (P = .64). The difference in CT value and SNR at the arterial phase and CT value at the venous phase between group A (abdomen) and group B2 were statistically significant, the CTDI in group A (9.09 ± 1.05) increased, compared with group B2 (8.23 ± 1.33) (P = .03), and SNR at the venous phase in group B2 (12.50 ± 2.43) increased, compared with group A (10.89 ± 2.03) (P = .03).Revolution CT can capture full images and very rapidly switch to the scan mode, enabling a 1-stop axial CCTA and enhanced helical abdominal scan. The 1-stop combined scan resulted in a satisfactory image quality, which reduced the contrast agent dose and simplified the workflow.The 1-stop combined scan allows for the high success rate of the examination, reduces the number of examinations, and decreases the dose and risk of injection of the contrast agent. This would be helpful for patients to obtain diagnostic images in time.

Diagnostic Accuracy of Computed Tomography Angiography as Compared to Conventional Angiography in Patients Undergoing Noncoronary Cardiac Surgery

OBJECTIVE

To compare the diagnostic accuracy of multi-slice computed tomography (MSCT) angiography with conventional angiography in patients undergoing major noncoronary cardiac surgeries.

MATERIALS AND METHODS

We studied fifty major noncoronary cardiac surgery patients scheduled for invasive coronary angiography, 29 (58%) female and 21 (42%) male. Inclusion criteria of the study were age of the patients ≥40 years, having low or intermediate probability of coronary artery disease (CAD), left ventricular ejection fraction (LVEF) >35%, and patient giving informed consent for undergoing MSCT and conventional coronary angiography. The patients with LVEF <35%, high pretest probability of CAD, and hemodynamically unstable were excluded from the study.

RESULTS

The diagnostic accuracy of CT coronary angiography was evaluated regarding true positive, true negative values. The overall sensitivity and specificity of CT angiography technique was 100% (95% confidence interval [CI]: 39.76%-100%) and 91.30% (95% CI: 79.21%-97.58%). The positive (50%; 95% CI: 15.70%-84.30%) and negative predictive values (100%; 95% CI: 91.59%-100%) of CT angiography were also fairly high in these patients.

CONCLUSION

Our study suggests that this non-invasive technique may improve perioperative risk stratification in patients undegoing non-cardiac surgery.

Computed tomographic coronary angiography - is it ready as a screening tool for coronary artery disease?

Currently, there are no formal screening programmes for coronary artery disease (CAD). Computed tomographic coronary angiography (CTCA) has been suggested as a non-invasive and reliable method of atherosclerotic plaque assessment, with the potential for use in screening programmes. In this article, we briefly present the current understanding of atherosclerotic plaque formation, explain key technological aspects of CTCA and critique this method in the light of World Health Organisation (WHO) criteria for devising a screening programme. Current evolving and future insights are also considered. Overall, in our view, there is currently insufficient evidence to support the formal use of CTCA in a screening programme for CAD, although this viewpoint will undoubtedly evolve.