Prevalence and characteristics of coronary artery disease in a population with suspected ischemic heart disease using CT coronary angiography: correlations with cardiovascular risk factors and clinical presentation

Cardiac CT perfusion and FFRCTA: pathophysiological features in ischemic heart disease

Cardiac computed tomography (CCT) has rapidly evolved, becoming a powerful integrated tool for the evaluation of coronary artery disease (CAD), and being superior to other noninvasive methods due to its high accuracy and ability to simultaneously assess both lumen stenosis and atherosclerotic plaque burden. Furthermore, CCT is regarded as an effective gatekeeper for coronary angiography, and carries independent important prognostic information. In the last decade, the introduction of new functional CCT applications, namely CCT perfusion (CCTP) imaging and CT-derived fractional flow reserve (FFR_CTA), has opened the door for accurate assessment of the haemodynamic significance of stenoses. These new CCT technologies, thus, share the unique advantage of assessing both myocardial ischemia and patient-specific coronary artery anatomy, providing an integrated anatomical/functional analysis. In the present review, starting from the pathophysiology of myocardial ischemia, we evaluate the existing evidence for functional CCT imaging and its value in relation to alternative, well-established, non-invasive imaging modalities and invasive indices of ischemia (currently the gold-standard). The knowledge of clinical applications, benefits, and limitations of these new CCT technologies will allow efficient and optimal use in clinical practice in the near future.

Performance of a deep learning algorithm for the evaluation of CAD-RADS classification with CCTA

BACKGROUND AND AIMS

Artificial intelligence (AI) is increasing its role in diagnosis of patients with suspicious coronary artery disease. The aim of this manuscript is to develop a deep convolutional neural network (CNN) to classify coronary computed tomography angiography (CCTA) in the correct Coronary Artery Disease Reporting and Data System (CAD-RADS) category.

METHODS

Two hundred eighty eight patients who underwent clinically indicated CCTA were included in this single-center retrospective study. The CCTAs were stratified by CAD-RADS scores by expert readers and considered as reference standard. A deep CNN was designed and tested on the CCTA dataset and compared to on-site reading. The deep CNN analyzed the diagnostic accuracy of the following three Models based on CAD-RADS classification: Model A (CAD-RADS 0 vs CAD-RADS 1-2 vs CAD-RADS 3,4,5), Model 1 (CAD-RADS 0 vs CAD-RADS>0), Model 2 (CAD-RADS 0-2 vs CAD-RADS 3-5). Time of analysis for both physicians and CNN were recorded.

RESULTS

Model A showed a sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 47%, 74%, 77%, 46% and 60%, respectively. Model 1 showed a sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 66%, 91%, 92%, 63%, 86%, respectively. Conversely, Model 2 demonstrated the following sensitivity, specificity, negative predictive value, positive predictive value and accuracy: 82%, 58%, 74%, 69%, 71%, respectively. Time of analysis was significantly lower using CNN as compared to on-site reading (530.5 ± 179.1 vs 104.3 ± 1.4 sec, p=0.01) CONCLUSIONS: Deep CNN yielded accurate automated classification of patients with CAD-RADS.

Role of Cardiac Computed Tomography in the Evaluation of Coronary Artery Stenosis in Patients With Ascending Aorta Aneurysm Detected at Transthoracic Echocardiography

OBJECTIVE

The aim of our study was to evaluate the diagnostic performance of cardiac computed tomography (CCT) in the evaluation of coronary artery stenosis in patients with ascending aorta aneurysm detected at transthoracic echocardiography.

METHODS

We conducted a retrospective analysis of patients with an aneurysm 45 mm or greater at transthoracic echocardiography who underwent CCT from 2012 to 2014 in our hospital. We calculated the sensitivity, specificity, and positive and negative predictive values of CCT for the assessment of coronary artery stenosis (<50% or ≥50% stenosis) in patients who underwent conventional coronary angiography.

RESULTS

We included 104 patients (73 men, aged 64 [SD, 10.8] years) in our study. Obstructive coronary artery disease was found in 22.1% of patients. Sensitivity, specificity, and positive and negative predictive values of CCT for detecting significant stenoses were 100%, 98%, and 82% and 100% on a segment-by-segment analysis and 100%, 83%, and 65% and 100% on a per-patient analysis, respectively.

CONCLUSIONS

Cardiac computed tomography provides a comprehensive evaluation of ascending aorta aneurysms and coronary artery tree.

Ambient temperature and coronary heart disease mortality in Beijing, China: a time series study

BACKGROUND

Many studies have examined the association between ambient temperature and mortality. However, less evidence is available on the temperature effects on coronary heart disease (CHD) mortality, especially in China. In this study, we examined the relationship between ambient temperature and CHD mortality in Beijing, China during 2000 to 2011. In addition, we compared time series and time-stratified case-crossover models for the non-linear effects of temperature.

METHODS

We examined the effects of temperature on CHD mortality using both time series and time-stratified case-crossover models. We also assessed the effects of temperature on CHD mortality by subgroups: gender (female and male) and age (age > =65 and age < 65). We used a distributed lag non-linear model to examine the non-linear effects of temperature on CHD mortality up to 15 lag days. We used Akaike information criterion to assess the model fit for the two designs.

RESULTS

The time series models had a better model fit than time-stratified case-crossover models. Both designs showed that the relationships between temperature and group-specific CHD mortality were non-linear. Extreme cold and hot temperatures significantly increased the risk of CHD mortality. Hot effects were acute and short-term, while cold effects were delayed by two days and lasted for five days. The old people and women were more sensitive to extreme cold and hot temperatures than young and men.

CONCLUSIONS

This study suggests that time series models performed better than time-stratified case-crossover models according to the model fit, even though they produced similar non-linear effects of temperature on CHD mortality. In addition, our findings indicate that extreme cold and hot temperatures increase the risk of CHD mortality in Beijing, China, particularly for women and old people.

Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR

Objectives

To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters.

Methods

Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced-steady state free precession) SAX sequence for MR, and evaluated using dedicated software.

Results

CT and MR images showed good agreement: LV EF (Ejection Fraction) (52 ± 14% for CT vs. 52 ± 14% for MR; r = 0.73; p > 0.05); RV EF (47 ± 12% for CT vs. 47 ± 12% for MR; r = 0.74; p > 0.05); LV EDV (End Diastolic Volume) (74 ± 21 ml/m² for CT vs. 76 ± 25 ml/m² for MR; r = 0.59; p > 0.05); RV EDV (84 ± 25 ml/m² for CT vs. 80 ± 23 ml/m² for MR; r = 0.58; p > 0.05); LV ESV (End Systolic Volume)(37 ± 19 ml/m² for CT vs. 38 ± 23 ml/m² for MR; r = 0.76; p > 0.05); RV ESV (46 ± 21 ml/m² for CT vs. 43 ± 18 ml/m² for MR; r = 0.70; p > 0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups.

Conclusions

Cardiac CT provides accurate and reproducible LV and RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR.

Key Points

• Cardiac-CT is able to provide Left and Right Ventricular function.

• Cardiac-CT is accurate as MR for LV and RV volume assessment.

• Cardiac-CT can provide accurate evaluation of coronary arteries and LV and RV function.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-011-2345-6) contains supplementary material, which is available to authorized users.

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography

PURPOSE

We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris.

MATERIALS AND METHODS

Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS).

RESULTS

Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05).

CONCLUSIONS

MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

Prevalence and impact of cardiovascular risk factors among patients presenting with acute coronary syndrome in the middle East

The authors explored the prevalence and impact of the cardiovascular risk factors (CVRFs) in patients presenting with acute coronary syndrome (ACS). During a five-month period in 2007, six adjacent Middle Eastern countries participated in the Gulf Registry of acute coronary events. CVRFs were identified on admission. Patients' characteristics and in-hospital outcomes were analyzed across the types of ACS. Among 6704 consecutive patients with ACS, 61% had non-ST elevation ACS (NSTEACS) and 39% had ST-elevation myocardial infarction (STEMI). Female sex, old age, diabetes mellitus, hypertension, dyslipidemia, and obesity were more prevalent in NSTEACS patients. STEMI patients were more likely to be smokers and less likely to be taking aspirin prior to the index admission. Chronic renal failure (CRF) and diabetes mellitus were independent predictors of in-hospital heart failure in NSTEACS, while CRF and hypertension were predictors of STEMI. Female sex and CRF were independent predictors of mortality in STEMI (odds ratio, 2.0; 95% confidence interval, 1.19-3.13 and odds ratio, 5.0; 95% confidence interval, 3.47-7.73, respectively). Assessment of the prevalence of CVRF in the acute coronary presentation is of important prognostic value for in-hospital morbidity and mortality. CVRF and its impact may differ according to ACS type, age, and sex. Coronary heart disease (CHD) is the leading cause of mortality and morbidity worldwide. To achieve a significant reduction in the prevalence of CHD, it is essential to adopt effective preventive strategies with adequate awareness of the epidemiology of cardiovascular risk factors (CVRFs).1 CVRFs include traditional and nontraditional factors. However, the US Preventive Services Task Force concluded that the evidence is insufficient to assess the balance of benefits and harms of using nontraditional risk factors.2,3 The World Health Organization has recognized obesity, hypertension, hypercholesterolemia, and smoking among the top10 traditional risk factors for premature death and morbidity.4 Since these risk factors are usually evident before developing CHD, knowledge of their prevalence in a given population allows the prediction of the likely burden of CHD.3 The American Heart Association has recognized many risk factors; some can be modified, treated, or controlled and some can not.5 The more risk factors present, the greater the likelihood of developing CHD. Currently, most reports for prevention of CHD are mainly derived from European centers and suggest that risk factors for CHD are varying from country to country.6 However, data from the Arab Middle East that evaluate the prevalence and impact of these risk factors in acute coronary events are scarce.4,7,8 We explore the prevalence of CVRFs in patients with acute coronary syndrome (ACS) who are living in the Arab Middle East and the impact of these factors on in-hospital heart failure (HF) and mortality. Copyright © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.

Coronary heart disease risk assessment and characterization of coronary artery disease using coronary CT angiography: comparison of asymptomatic and symptomatic groups

AIM

To evaluate the prevalence of coronary artery disease (CAD) in relation to risk of coronary heart disease (CHD) and assess plaque characteristics from coronary computed tomography (CT) angiography in asymptomatic and symptomatic patients.

MATERIALS AND METHODS

Three hundred and ninety consecutive patients [asymptomatic group, n=138; symptomatic group (atypical or non-anginal chest pain), n=252] were retrospectively enrolled. They were subsequently classified into three CHD risk categories, based on the National Cholesterol Education Program guidelines, and 10 year risks of coronary events were calculated using Framingham risk score. CT was evaluated for stenosis, plaque composition, and coronary calcium scores.

RESULTS

CAD was observed in 42% of the asymptomatic group and 62% of the symptomatic group. In the former, the prevalence of CAD in low-, moderate- and high-risk subgroups was 21.4, 47.4 and 65%, respectively, and was 33.3, 74.4, and 72.4% in the symptomatic group. Framingham 10-year risks of coronary events were significantly higher in patients with CAD than in normal participants, and receiver operating characteristics curves showed that discriminatory power was poor in the asymptomatic group and symptomatic men, and good in symptomatic women. Of the participants in the asymptomatic group, 12% exhibited only non-calcified plaques and of the symptomatic group, 7% exhibited only non-calcified plaques. The coronary calcium score was significantly higher for significant stenosis than for non-significant stenosis in both groups.

CONCLUSIONS

The prevalence of CAD was not negligible even in subgroups with low-to-moderate CHD risk. Additionally, the Framingham risk score was effective for predicting CAD only in symptomatic women. Coronary calcium scores correlated with significant stenosis; however, a sizeable percentage of both groups had only non-calcified plaques.

Role of 64-slice cardiac computed tomography in the evaluation of patients with non-ST-elevation acute coronary syndrome

PURPOSE

This study was done to evaluate the feasibility, sensitivity and specificity of 64-slice computed tomography (CT) in identifying haemodynamically significant (>50%) coronary artery stenoses in patients with suspected acute coronary syndrome (ACS) by correlating the CT findings with the clinical event and data provided by conventional coronary angiography (CCA).

MATERIALS AND METHODS

Sixty-four patients (38 men and 26 women; mean age 65 years; range+/-10 years) presenting to our hospital's emergency department with a clinical suspicion of ACS were studied with 64-slice CT followed by CCA within 24 h of arrival.

RESULTS

Two patients (3.1%) were excluded from the analysis due to artefacts. Per-patient analysis in the remaining 62 patients identified 24 cases (38.7%) of negative CT findings (no stenoses or stenoses <50%), 35 cases of positive CT findings (56.4%) with identification of the culprit lesion, two cases in which the culprit lesion was not identified and one patient with unconfirmed stenosis. Sensitivity and specificity were 94.6% and 96%, respectively. Per-vessel analysis (186 vessels) revealed 17 non-evaluable vessels (9.1%) due to motion artefacts, 61 vessels (32.8%) with stenosis >50%, seven overestimated vessels (3.7%) due to extensive calcifications, three vessels (1.6%) with underestimated stenosis and 98 vessels (52.6%) without stenosis. Sensitivity and specificity were 95.3% and 93.3%, respectively.

CONCLUSIONS

In this type of emergency, coronary CT angiography could lead to considerably lower healthcare costs by identifying patients without coronary disease and allowing immediate discharge without any need for further diagnostic procedures.

Choice strategy of different dose-saving protocols in 64-slice MDCT coronary angiography

PURPOSE

Multidetector-row computed tomography coronary angiography (MDCT-CA) produces high-level radiation dose because of submillimetre slice thickness and short scan time. As a result, manufacturers have produced different dose-saving protocols that may, however, reduce image quality and thus diagnostic accuracy. The aim of our study was to assess the diagnostic quality of MDCT-CA using different dose-saving protocols.

MATERIALS AND METHODS

Between April and August 2008, we examined 65 patients with 64-slice MDCT-CA: 6/65 using the step-and-shoot dose-saving protocol, 45/65 the cardiac dose right protocol and 14/65 using a standard protocol. Image quality was evaluated on a per-patient and per-segment basis, and the effective dose of each protocol was recorded.

RESULTS

In the per-patient analysis, image quality was excellent in 100% of the step-and-shoot protocols, in 91.1% of the cardiac dose right protocols and in 85.8% of the standard protocols. Effective dose to the patient considering the whole study (i.e. scout, calcium score, triggering and MDCT-CA) was 20.49 mSv in the standard protocol, 14.8 mSv in the cardiac dose right protocol and 6.63 mSv in the step-and-shoot protocol.

CONCLUSIONS

The radiologist should apply the appropriate protocol in relation to the clinical indications, type of patient and information required in order to spare as much dose as possible while maintaining high image quality.