Chest CT for triage during COVID-19 on the emergency department: myth or truth?

PURPOSE: We aimed to investigate the diagnostic performance of chest CT compared with first RT-PCR results in adult patients suspected of COVID-19 infection in an ED setting. We also constructed a predictive machine learning model based on chest CT and additional data to improve the diagnostic accuracy of chest CT. METHODS: This study's cohort consisted of 319 patients who underwent chest CT and RT-PCR testing at the ED. Patient characteristics, demographics, symptoms, vital signs, laboratory tests, and chest CT results (CO-RADS) were collected. With first RT-PCR as reference standard, the diagnostic performance of chest CT using the CO-RADS score was assessed. Additionally, a predictive machine learning model was constructed using logistic regression. RESULTS: Chest CT, with first RT-PCR as a reference, had a sensitivity, specificity, PPV, and NPV of 90.2%, 88.2%, 84.5%, and 92.7%, respectively. The prediction model with CO-RADS, ferritin, leucocyte count, CK, days of complaints, and diarrhea as predictors had a sensitivity, specificity, PPV, and NPV of 89.3%, 93.4%, 90.8%, and 92.3%, respectively. CONCLUSION: Chest CT, using the CO-RADS scoring system, is a sensitive and specific method that can aid in the diagnosis of COVID-19, especially if RT-PCR tests are scarce during an outbreak. Combining a predictive machine learning model could further improve the accuracy of diagnostic chest CT for COVID-19. Further candidate predictors should be analyzed to improve our model. However, RT-PCR should remain the primary standard of testing as up to 9% of RT-PCR positive patients are not diagnosed by chest CT or our machine learning model.

Prognostic value of coronary vessel dominance in relation to significant coronary artery disease determined with non-invasive computed tomography coronary angiography.

AIMS: Limited information is available regarding the relationship between coronary vessel dominance and prognosis. Therefore, the purpose of this study was to determine the prognostic value of coronary vessel dominance in relation to significant coronary artery disease (CAD) in patients referred for computed tomography coronary angiography (CTA). METHODS AND RESULTS: The study population consisted of 1425 patients (869 men, 57 ± 12 years) referred for CTA. To evaluate the impact of vessel dominance and significant CAD on CTA on outcome, patients were followed during a median period of 24 months for the occurrence of non-fatal myocardial infarction and all-cause mortality. The presence of a left dominant system was identified as a significant predictor for non-fatal myocardial infarction and all-cause mortality (HR: 3.20; 95% CI: 1.67-6.13, P < 0.001) and had incremental value over baseline risk factors and severity of CAD on CTA. In addition, in the subgroup of patients with significant CAD on CTA, patients with a left dominant system had a worse outcome compared with patients with a right dominant system (cumulative event rates: 9.5% and 35% at 3-year follow-up for a right and left dominant coronary artery system, respectively, log-rank P < 0.001). CONCLUSIONS: The presence of a left dominant system was identified as an independent predictor of non-fatal myocardial infarction and all-cause mortality, especially in patients with significant CAD on CTA. Therefore, the assessment of coronary vessel dominance on CTA may further enhance risk stratification beyond the assessment of significant CAD on CTA.

Influence of smoking on the prognostic value of cardiovascular computed tomography coronary angiography.

AIMS: Computed tomography coronary angiography (CTA) is an important non-invasive imaging modality increasingly used for the diagnosis and prognosis of coronary artery disease (CAD). The purpose of the current study was to determine the influence of smoking status on the prognostic value of CTA in patients with suspected or known CAD. METHODS AND RESULTS: In 1207 patients (57% male, age 57 ± 12 years) referred for CTA, the presence of significant CAD (≥ 50% stenosis) was determined. During follow-up (FU) the following events were recorded: all cause mortality, and non-fatal infarction. The prognostic value of CTA in smokers and non-smokers was compared using an interaction term in the Cox proportional hazard regression analysis. Significant CAD was observed in 327 patients (27%), and 273 patients (23%) were smokers. During a median FU time of 2.2 years, an event occurred in 50 patients. After correction for baseline characteristics including smoking in a multivariate model, significant CAD remained an independent predictor of events. Furthermore, a significant interaction (P < 0.05) was observed between significant CAD and smoking. The annualized event rate in smokers with significant CAD was 8.78% compared with 0.99% in smokers without significant CAD (P < 0.001). In non-smokers with significant CAD the annualized event rate was 2.07% compared with 1.01% in non-smokers without significant CAD (P= 0.058). CONCLUSION: The prognostic value of CTA was significantly influenced by smoking status. The event rates in patients with significant CAD were approximately four-fold higher in smokers compared with non-smokers. These findings suggest that smoking cessation needs to be aggressively pursued, especially in smokers with significant CAD.

Diabetes: prognostic value of CT coronary angiography--comparison with a nondiabetic population.

PURPOSE: To evaluate the prognostic value of multidetector computed tomographic (CT) coronary angiography in a diabetic population known to have or suspected of having coronary artery disease (CAD) compared with that in nondiabetic individuals. MATERIALS AND METHODS: Institutional review board approval and patient informed consent were obtained. Three hundred thirteen patients with type 2 diabetes mellitus (DM) and 303 patients without DM underwent unenhanced 64-detector row CT, at which a calcium score was obtained, followed by CT angiography. Multidetector CT coronary angiograms were retrospectively classified as normal, showing nonobstructive CAD (50% luminal narrowing). During follow-up after CT angiography, major events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization) and total events (major events plus coronary revascularizations) were recorded for each patient. Cox proportional hazards analysis and Kaplan-Meier analysis were used to compare survival rates. RESULTS: In the group of 313 patients with DM, there were 213 men, and the mean age was 62 years +/- 11 (standard deviation). In the group of 303 patients without DM, there were 203 men, and the mean age was 63 years +/- 11. The mean number of diseased segments (5.6 vs 4.4, P = .001) and the rate of obstructive CAD (51% vs 37%, P < .001) were higher in patients with DM. Patients were followed up for a mean of 20 months +/- 5.4 (range, 6-44 months). At multivariate analysis, DM (P < .001) and evidence of obstructive CAD (P < .001) were independent predictors of outcome. Obstructive CAD remained a significant multivariate predictor for both patients with DM and patients without DM. In both patients with DM and patients without DM with absence of disease, the event rate was 0%. The event rate increased to 36% in patients without DM but with obstructive CAD and was highest (47%) in patients with DM and obstructive CAD. CONCLUSION: In both patients with DM and patients without DM, multidetector CT coronary angiography provides incremental prognostic information over baseline clinical variables, and the absence of atherosclerosis at CT coronary angiography is associated with an excellent prognosis. Multidetector CT coronary angiography might be a clinically useful tool for improving risk stratification in both patients with DM and patients without DM.

Incremental value of subclinical left ventricular systolic dysfunction for the identification of patients with obstructive coronary artery disease.

BACKGROUND: Left ventricular (LV) diastolic dysfunction and subclinical systolic dysfunction may be markers of coronary artery disease (CAD). However, whether these markers are useful for prediction of obstructive CAD is unknown. METHODS: A total of 182 consecutive outpatients (54 +/- 10 years, 59% males) without known CAD and overt LV systolic dysfunction underwent 64-slice multislice computed tomography (MSCT) coronary angiography and echocardiography. The MSCT angiograms showing atherosclerosis were classified as showing obstructive (> or =50% luminal narrowing) CAD or not. Conventional echocardiographic parameters of LV systolic and diastolic function were obtained; in addition, (1) global longitudinal strain (GLS) and strain rate (indices of systolic function) and (2) global strain rate during the isovolumic relaxation period and during early diastolic filling (indices of diastolic function) were assessed using speckle-tracking echocardiography. In addition, the pretest likelihood of obstructive CAD was assessed using the Duke Clinical Score. RESULTS: Based on MSCT, 32% of patients were classified as having no CAD, whereas 33% showed nonobstructive CAD and the remaining 35% had obstructive CAD. Multivariate analysis of clinical and echocardiographic characteristics showed that only high pretest likelihood of CAD (odds ratio [OR] 3.21, 95% 1.02-10.09, P = .046), diastolic dysfunction (OR 3.72, 95% CI 1.44-9.57, P = .006), and GLS (OR 1.97, 95% CI 1.43-2.71, P < .001) were associated with obstructive CAD. A value of GLS > or =-17.4 yielded high sensitivity and specificity in identifying patients with obstructive CAD (83% and 77%, respectively), providing a significant incremental value over pretest likelihood of CAD and diastolic dysfunction. CONCLUSIONS: The GLS impairment aids detection of patients without overt LV systolic dysfunction having obstructive CAD.

Incremental prognostic value of left ventricular function analysis over non-invasive coronary angiography with multidetector computed tomography.

BACKGROUND: The purpose of this study was to determine the prognostic value of computed tomography coronary angiography (CTA)-derived left ventricular (LV) function analysis and to assess its incremental prognostic value over the detection of significant stenosis using CTA. METHODS: In 728 patients (400 males, mean age 55 ± 12 years) with known or suspected CAD, the presence of significant stenosis (≥ 50% stenosis) and LV function were assessed using CTA. LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV), and LV ejection fraction (LVEF) were calculated. LV function was assessed as a continuous variable and using cutoff values (LVEDV > 215 mL, LVESV > 90 mL, LVEF < 49%). The following events were combined in a composite end-point: all-cause mortality, non-fatal myocardial infarction, and unstable angina pectoris requiring hospitalization. RESULTS: On CTA, a significant stenosis was observed in 221 patients (30%). During follow-up [median 765 days, 25-75th percentile: 493-978] an event occurred in 45 patients (6.2%). After multivariate correction for clinical risk factors and CTA, LVEF < 49% and LVESV > 90 mL were independent predictors of events with an incremental prognostic value over clinical risk factors and CTA. CONCLUSIONS: The present results suggest that LV function analysis provides independent and incremental prognostic information beyond anatomic assessment of CAD using CTA.

Incremental prognostic value of multi-slice computed tomography coronary angiography over coronary artery calcium scoring in patients with suspected coronary artery disease.

AIMS: The purpose of this study was to assess the relationship between calcium scoring (CS) and multi-slice computed tomography coronary angiography (MSCTA) and to determine if MSCTA has an incremental prognostic value to CS. METHODS AND RESULTS: In 432 patients (59% male, age 58 +/- 11 years) referred for cardiac evaluation owing to suspected coronary artery disease (CAD), CS and 64-slice MSCTA were performed. The following events were combined in a composite endpoint: all-cause mortality, non-fatal infarction, and unstable angina requiring revascularization. CS was 0 in 147 (34%) patients, CS 1-99 was present in 122 (28%), CS 100-399 in 75 (17%), CS 400-999 in 56 (13%), and CS > or = 1000 in 32 (7%). MSCTA was normal in 133 (31%) patients, MSCTA 30-50% stenosis was observed in 190 (44%), and MSCTA > or =50% stenosis in 109 (25%). During follow-up [median 670 days (25th-75th percentile: 418-895)], an event occurred in 21 patients (4.9%). After multivariate correction for CS, MSCTA > or = 50% stenosis, the number of diseased segments, obstructive segments, and non-calcified plaques were independent predictors with an incremental prognostic value to CS. CONCLUSION: MSCTA provides additional information to CS regarding stenosis severity and plaque composition. This additional information was shown to translate into incremental prognostic value over CS.

Real-time 3-dimensional echocardiography early after acute myocardial infarction: incremental value of echo-contrast for assessment of left ventricular function.

BACKGROUND: Accurate and reproducible assessment of left ventricular (LV) systolic function is important in patients with acute myocardial infarction (AMI). Real-time 3-dimensional echocardiography (RT3DE) is an accurate technique, but it relies heavily on good image quality. The aim of the present study was to evaluate the incremental value of contrast-enhanced RT3DE. METHODS: A total of 140 consecutive patients (58 +/- 11 years, 78% men) with ST-elevation AMI clinically underwent nonenhanced and contrast-enhanced RT3DE within 24 hours from AMI to evaluate global and regional LV systolic function. Endocardial border definition was graded for each of the 16 LV segments as follows: 0 = border invisible, 1 = border visualized only partially, and 2 = complete visualization of the border. Three image-quality groups (good, fair, and uninterpretable) were identified. Left ventricular volumes and ejection fraction were measured off-line. Wall motion was graded for each visible segment as follows: 1 = normal, 2 = hypokinetic, 3 = akinetic, and 4 = dyskinetic. RESULTS: During contrast-enhanced RT3DE, as compared with nonenhanced RT3DE, the number of segments with complete visualization of the endocardial border increased from 66% to 84% (P < .001); and the number of patients with a good-quality echocardiogram increased from 59% to 94% (P < .001). Intra- and interobserver agreement for assessment of global and regional LV systolic function improved during contrast-enhanced RT3DE, as compared with nonenhanced RT3DE. CONCLUSIONS: Assessment of LV systolic function in AMI patients with RT3DE is frequently hampered by suboptimal echocardiographic quality. Contrast-enhanced RT3DE is of incremental value, improving the endocardial border visualization and the reproducibility of LV function assessment.

Type 2 diabetes is associated with more advanced coronary atherosclerosis on multislice computed tomography and virtual histology intravascular ultrasound.

BACKGROUND: Data on coronary plaque observations on multi-slice computed tomography (MSCT) in patients with type 2 diabetes are scarce. METHODS AND RESULTS: In total, 60 patients (19 with diabetes) underwent 64-slice MSCT, followed by conventional coronary angiography with intravascular ultrasound (IVUS). Non-invasively, the extent of coronary atherosclerosis and 3 plaque types (non-calcified, calcified, mixed) were visually evaluated on MSCT. Invasively, plaque burden was assessed on gray-scale IVUS. Plaque composition was evaluated on virtual histology intravascular ultrasound (VH IVUS). Concerning geometrical plaque data, diabetic patients showed more plaques on MSCT (7.1 +/- 3.2 vs 4.9 +/- 3.2 in non-diabetic patients, P = .01). On gray-scale IVUS, diabetes was associated with a larger plaque burden (48.7 +/- 10.7% vs 40.0 +/- 12.1%, P = .003). Concerning plaque composition, diabetes was associated with more calcified plaques on MSCT (52% vs 24%). Relatively more fibrocalcific plaques in diabetic patients (29% versus 9%) were observed on VH IVUS. Moreover, these plaques contained more necrotic core (10.8 +/- 5.9% vs 8.6 +/- 5.2%, P = .01). CONCLUSION: A higher plaque extent and more calcified lesions were observed in diabetic patients on MSCT. The findings were confirmed on gray-scale and VH IVUS. Thus, MSCT may potentially be used to explore patterns of coronary atherosclerosis in diabetic patients.

The value of multi-slice-computed tomography coronary angiography for risk stratification.

Multi-slice-computed tomography coronary angiography (CTA) provides direct non-invasive anatomic assessment of the coronary arteries allowing for early identification of coronary artery disease (CAD). This information is useful for diagnosis of CAD, particularly the rule out of CAD. In addition, early identification of CAD with CTA may also be useful for risk stratification. The purpose of this review is to provide an overview of the current literature on the prognostic value of CTA and to discuss how the prognostic information obtained with CTA can be used to further integrate the technique into clinical practice. Non-invasive anatomic assessment of plaque burden, location, composition, and remodeling using CTA may provide prognostically relevant information. This information has been shown to be incremental to the Framingham risk score, coronary artery calcium scoring, and myocardial perfusion imaging. Characterization of atherosclerosis non-invasively has the potential to provide important prognostic information enabling a more patient-tailored approach to disease management.Future studies assessing outcome after CTA-based risk adjustments are needed to further understand the value of detailed non-invasive anatomic imaging.

Prevalence of coronary artery disease across the Framingham risk categories: coronary artery calcium scoring and MSCT coronary angiography.

BACKGROUND: Non-invasive assessment of subclinical atherosclerosis by means of coronary artery calcium scoring (CACS) and multi-slice computed tomography (MSCT) coronary angiography could improve patients' risk stratification. However, data relating observations on CACS and MSCT coronary angiography to traditional risk assessment are scarce. METHODS AND RESULTS: In 314 consecutive outpatients (54 +/- 13 years, 56% males) without known CAD, CACS and 64-slice MSCT coronary angiography were performed. According to the Framingham risk score (FRS), 51% of patients were at low, 24% at intermediate and 25% at high risk, respectively. MSCT angiograms showing atherosclerosis were classified as showing obstructive (> or =50% luminal narrowing) CAD or not. Both CACS and MSCT coronary angiography showed a high prevalence of normal coronary arteries in low FRS patients (70% and 61%, respectively). An increase in the prevalence of CACS >400 (4% low vs 19% intermediate vs 36% high), CAD (39% low vs 79% intermediate vs 91% high), and obstructive CAD (15% low vs 43% intermediate vs 58% high) was observed across the FRS categories (P < .0001 for all comparisons). CONCLUSIONS: A strong positive relationship exists between FRS and the prevalence and extent of atherosclerosis. Especially in intermediate FRS patients, CACS and MSCT coronary angiography provide useful information on the presence of subclinical atherosclerosis.

Multi-slice computed tomography coronary angiography for ruling out suspected coronary artery disease: what is the prevalence of a normal study in a general clinical population?

AIMS: To assess the prevalence of a normal multi-slice computed tomography (MSCT) in patients with suspected coronary artery disease (CAD) and to relate these observations to clinical presentation and pre-test likelihood of CAD. METHODS AND RESULTS: In total, 340 consecutive patients (182 men, 55 +/- 12 years) without a history of CAD who were referred for MSCT angiography were included in the study. Based on patient characteristics and the referral reason for MSCT angiography, patients were classified as having a low, intermediate, or high pre-test likelihood of CAD. Patients were evaluated for the presence of coronary artery calcium as well as the presence of atherosclerosis. Overall, 157 (46%) patients did not have coronary artery calcium and 133 (40%) patients had a completely normal MSCT angiogram. In 58% of the patients with low pre-test likelihood, no coronary atherosclerosis was observed when compared with 33 and 17% of the patients with intermediate and high pre-test likelihood, respectively. CONCLUSION: MSCT ruled out coronary atherosclerosis in 40-46% of patients without known CAD who were referred for MSCT. Accordingly, in patients with low-to-intermediate pre-test likelihood, MSCT may be an attractive modality to exclude coronary atherosclerosis and may prevent unnecessary additional functional testing or invasive angiography.

Superior Risk Stratification With Coronary Computed Tomography Angiography Using a Comprehensive Atherosclerotic Risk Score.

OBJECTIVES: This study was designed to assess the prognostic value of a new comprehensive coronary computed tomography angiography (CTA) score compared with the stenosis severity component of the Coronary Artery Disease-Reporting and Data System (CAD-RADS). BACKGROUND: Current risk assessment with coronary CTA is mainly focused on maximal stenosis severity. Integration of plaque extent, location, and composition in a comprehensive model may improve risk stratification. METHODS: A total of 2,134 patients with suspected but without known CAD were included. The predictive value of the comprehensive CTA score (ranging from 0 to 42 and divided into 3 groups: 0 to 5, 6 to 20, and >20) was compared with the CAD-RADS combined into 3 groups (0% to 30%, 30% to 70% and ≥70% stenosis). Its predictive performance was internally and externally validated (using the 5-year follow-up dataset of the CONFIRM [Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry], n = 1,971). RESULTS: The mean age of patients was 55 ± 13 years, mean follow-up 3.6 ± 2.8 years, and 130 events (myocardial infarction or death) occurred. The new, comprehensive CTA score showed strong and independent predictive value using the Cox proportional hazard analysis. A model including clinical variables plus comprehensive CTA score showed better discrimination of events compared with a model consisting of clinical variables plus CAD-RADS (0.768 vs. 0.742, p = 0.001). Also, the comprehensive CTA score correctly reclassified a significant proportion of patients compared with the CAD-RADS (net reclassification improvement 12.4%, p < 0.001). Good predictive accuracy was reproduced in the external validation cohort. CONCLUSIONS: The new comprehensive CTA score provides better discrimination and reclassification of events compared with the CAD-RADS score based on stenosis severity only. The score retained similar prognostic accuracy when externally validated. Anatomic risk scores can be improved with the addition of extent, location, and compositional measures of atherosclerotic plaque. (Comprehensive CTA risk score calculator is available at: http://18.224.14.19/calcApp/).

Anatomic correlates of a normal perfusion scan using 64-slice computed tomographic coronary angiography.

Both myocardial perfusion imaging (MPI) and multislice computed tomography (MSCT) are currently used to detect coronary artery disease (CAD). However, MSCT permits early detection of atherosclerosis while myocardial perfusion is still normal. In addition, MPI results can be normal despite the presence of high-risk CAD (left main and balanced 3-vessel CAD). In this study, the range of anatomic findings using MSCT in patients with normal MPI results was evaluated. In 180 patients presenting with chest pain, MPI (with gated single-photon emission computed tomography) and 64-slice MSCT were performed. In patients with normal MPI results, prevalences of completely normal coronary arteries, nonobstructive CAD, and obstructive CAD were determined using MSCT. The occurrence of high-risk CAD, including left main and 3-vessel disease, was also evaluated. Normal MPI and adequate MSCT findings were obtained in 97 patients (54%; 50% women; average age 58 +/- 12 years; 5% with known CAD). A total of 38 patients (39%) showed normal coronary anatomy, whereas nonsignificant and significant CAD were observed in 37 (38%) and 18 patients (19%), respectively. Importantly, only 4 patients (4%) presented with high-risk CAD using 64-slice MSCT, 2 with left main and 2 with 3-vessel disease. In conclusion, a normal MPI result can be associated with a wide range of anatomic observations and cannot exclude the presence of both nonobstructive and obstructive CAD. However, importantly, the prevalence of high-risk CAD was rare.

Safety of contrast-enhanced echocardiography within 24 h after acute myocardial infarction.

AIMS: Contrast-enhanced echocardiography is widely used to enhance left ventricular (LV) endocardial border delineation in stable patients with known or suspected coronary artery disease. In patients with acute myocardial infarction, accurate assessment of LV function and size is important, but data on the safety of contrast-enhanced echocardiography in the early stage of myocardial infarction (within 24 h) are lacking. In the current study, the experience on the safety of contrast-enhanced echocardiography within 24 h of acute myocardial infarction is reported. METHODS AND RESULTS: A total of 115 consecutive patients (58 +/- 11 years; 77% male) admitted to the coronary care unit for ST-elevation acute myocardial infarction underwent clinically indicated contrast-enhanced echocardiography within 24 h of hospital admission to assess LV size and function. Perflutren (Luminity, Bristol-Myers Squibb Pharma, Bruxelles, Belgium) was used as contrast agent. Safety was determined evaluating vital signs, physical examination, ECG, and adverse events. On contrast-enhanced echocardiography, the mean LV ejection fraction was 44 +/- 11%, and 56% of patients had an LV ejection fraction

Non-invasive computed tomography coronary angiography as a gatekeeper for invasive coronary angiography.

To determine the rate of subsequent invasive coronary angiography (ICA) and revascularization in relation to computed tomography coronary angiography (CTA) results. In addition, independent determinants of subsequent ICA and revascularization were evaluated. CTA studies were performed using a 64-row (n = 413) or 320-row (n = 224) multidetector scanner. The presence and severity of CAD were determined on CTA. Following CTA, patients were followed up for 1 year for the occurrence of ICA and revascularization. A total of 637 patients (296 male, 56 ± 12 years) were enrolled and 578 CTA investigations were available for analysis. In patients with significant CAD on CTA, subsequent ICA rate was 76%. Among patients with non-significant CAD on CTA, subsequent ICA rate was 20% and among patients with normal CTA results, subsequent ICA rate was 5.7% (p < 0.001). Of patients with significant CAD on CTA, revascularization rate was 47%, as compared to a revascularization rate of 0.6% in patients with non-significant CAD on CTA and no revascularizations in patients with a normal CTA results (p < 0.001). Significant CAD on CTA and significant three-vessel or left main disease on CTA were identified as the strongest independent predictors of ICA and revascularization. CTA results are strong and independent determinants of subsequent ICA and revascularization. Consequently, CTA has the potential to serve as a gatekeeper for ICA to identify patients who are most likely to benefit from revascularization and exclude patients who can safely avoid ICA.

Age- and gender-specific differences in the prognostic value of CT coronary angiography.

OBJECTIVE: To evaluate the potential age- and gender-specific differences in the incidence and prognostic value of coronary artery disease (CAD) in patients undergoing CT coronary angiography (CTA). DESIGN AND PATIENTS: In this multicentre prospective registry study, 2432 patients (mean age 57 ± 12, 56% male) underwent CTA for suspected CAD. Patients were stratified into four groups according to age <60 or ≥60 years and, male or female gender. MAIN OUTCOME MEASURES: A composite end point of cardiac death and non-fatal myocardial infarction. RESULTS: CTA results were normal in 991 (41%) patients, showed non-significant CAD in 761 (31%) patients and significant CAD in the remaining 680 (28%) patients. During follow-up (median 819 days, 25-75th centile 482-1142) a cardiovascular event occurred in 59 (2.4%) patients. The annualised event rate was 1.1% in the total population (men=1.3% and women=0.9%). In patients aged <60 years, the annualised event rate of male and female patients was 0.6% and 0.5%, respectively. Among patients aged ≥60 years the annualised event rate was 1.9% in male and 1.1% in female patients. Observations on CTA predicted events in male patients, both age <60 and ≥60 years and in female patients age ≥60 years (log-rank test in all groups, p<0.01). However, CTA provided limited prognostic value in female patients aged <60 years (log-rank test, p=0.45). CONCLUSIONS: After age and gender stratification, CTA findings were shown to be of limited predictive value in female patients aged <60 years as compared with male patients at any age and female patients aged ≥60 years.

Coronary artery calcium scoring in cardiovascular risk assessment.

Identification of patients at risk of future coronary artery disease (CAD) events traditionally relies on scoring tools that take demographic and clinical characteristics into account (e.g., the Framingham risk score in the United States and the Heart Score in Europe). Although these scoring tools have been shown to have a good predictive value, they may still fail to recognize a proportion of patients with coronary atherosclerosis at risk for future CAD events. In order to improve risk stratification, direct visualization of subclinical atherosclerosis has been advocated. Electron-beam computed tomography and multislice computed tomography provide a direct estimation of coronary calcium, a marker of coronary atherosclerosis. A large amount of data is available supporting the clinical value of the noninvasive assessment of coronary artery calcium score (CACS) with these techniques and its incremental prognostic information over traditional risk stratification. Aim of this review is to provide an overview of the literature regarding the prognostic value of CACS assessment. In addition, potential other applications of CACS assessment as well as the limitations of the technique are discussed.

Feasibility of diastolic function assessment with cardiac CT: feasibility study in comparison with tissue Doppler imaging.

OBJECTIVES: This study aimed to demonstrate the feasibility of multidetector row computed tomography (CT) for assessment of diastolic function in comparison with 2-dimensional (2D) echocardiography using tissue Doppler imaging (TDI). BACKGROUND: Diastolic left ventricular (LV) function plays an important role in patients with cardiovascular disease. 2D echocardiography using TDI has been used most commonly to evaluate diastolic LV function. Although the role of cardiac CT imaging for evaluation of coronary atherosclerosis has been explored extensively, its feasibility to evaluate diastolic function has not been studied. METHODS: Patients who had undergone 64-multidetector row CT and 2D echocardiography with TDI were enrolled. Diastolic function was evaluated using early (E) and late (A) transmitral peak velocity (cm/s) and peak mitral septal tissue velocity (Ea; cm/s). Peak transmitral velocity (cm/s) was calculated by dividing peak diastolic transmitral flow (ml/s) by the corresponding mitral valve area (cm(2)). Mitral septal tissue velocity was calculated from changes in LV length per cardiac phase. Subsequently, the estimation of LV filling pressures (E/Ea) was determined. RESULTS: Seventy patients (46 men; mean age 55 ± 11 years) who had undergone cardiac CT and 2D echocardiography with TDI were included. Good correlations were observed between cardiac CT and 2D echocardiography for assessment of E (r = 0.73; p < 0.01), E/A (r = 0.87; p < 0.01), Ea (r = 0.82; p < 0.01), and E/Ea (r = 0.81; p < 0.01). Moreover, a good diagnostic accuracy (79%) was found for detection of diastolic dysfunction using cardiac CT. Finally, the study showed a low intraobserver and interobserver variability for assessment of diastolic function on cardiac CT. CONCLUSIONS: Cardiac CT imaging showed good correlations for transmitral velocity, mitral septal tissue velocity, and estimation of LV filling pressures when compared with 2D echocardiography. Additionally, cardiac CT and 2D echocardiography were comparable for assessment of diastolic dysfunction. Accordingly, cardiac CT may provide information on diastolic dysfunction.

Relationship between obstructive coronary artery disease and abnormal stress testing in patients with paroxysmal or persistent atrial fibrillation.

Atrial fibrillation (AF) has been linked to the presence of underlying coronary artery disease (CAD). However, whether the higher burden of CAD observed in AF patients translates into higher burden of myocardial ischemia is unknown. In 87 patients (71% male, mean age 61 ± 10 years) with paroxysmal or persistent AF and without history of CAD, MSCT coronary angiography and stress testing (exercise ECG test or myocardial perfusion imaging) were performed. CAD was classified as obstructive (≥50% luminal narrowing) or not. Stress tests were classified as normal or abnormal. A population of 122 patients without history of AF, similar to the AF group as to age, gender, symptomatic status and pre-test likelihood, served as a control group. Based on MSCT, 17% of AF patients were classified as having no CAD, whereas 43% showed non-obstructive CAD and the remaining 40% had obstructive CAD. A positive stress test was observed in 49% of AF patients with obstructive CAD. Among non-AF patients, 34% were classified as having no CAD, while 41% showed non-obstructive CAD and 25% had obstructive CAD (P = 0.013 compared to AF patients). A positive stress test was observed in 48% of non-AF patients with obstructive CAD. In conclusion, the higher burden of CAD observed in AF patients is not associated to higher burden of myocardial ischemia.