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Objectives To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations. Design Retrospective pooled analysis of individual patient data. Setting 18 hospitals in Europe and the United States. Participants Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively). Main outcome measures Obstructive coronary artery disease (>= 50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model facto Results We included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended Conclusions Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates.

Aims The aim was to validate, update, and extend the Diamond-Forrester model for estimating the probability of obstructive coronary artery disease (CAD) in a contemporary cohort. Methods and results Prospectively collected data from 14 hospitals on patients with chest pain without a history of CAD and referred for conventional coronary angiography (CCA) were used. Primary outcome was obstructive CAD, defined as ≥50% stenosis in one or more vessels on CCA. The validity of the Diamond-Forrester model was assessed using calibration plots, calibration-in-the-large, and recalibration in logistic regression. The model was subsequently updated and extended by revising the predictive value of age, sex, and type of chest pain. Diagnostic performance was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) and reclassification was determined. We included 2260 patients, of whom 1319 had obstructive CAD on CCA. Validation demonstrated an overestimation of the CAD probability, especially in women. The updated and extended models demonstrated a c-statistic of 0.79 (95% CI 0.77-0.81) and 0.82 (95% CI 0.80-0.84), respectively. Sixteen per cent of men and 64% of women were correctly reclassified. The predicted probability of obstructive CAD ranged from 10% for 50-year-old females with non-specific chest pain to 91% for 80-year-old males with typical chest pain. Predictions varied across hospitals due to differences in disease prevalence. Conclusion Our results suggest that the Diamond-Forrester model overestimates the probability of CAD especially in women. We updated the predictive effects of age, sex, type of chest pain, and hospital setting which improved model performance and we extended it to include patients of 70 years and older.

OBJECTIVE: To assess the effect of systolic data acquisition for electrocardiography (ECG)-triggered high-pitch computed tomography (CT) on motion artefacts of coronary arteries in patients with high heart rates (HRs). METHODS: Eighty consecutive patients (15 women, age 67 +/- 14 years) with HR >/=70 bpm underwent CT angiography of the thoracic aorta (CTA) on 128-slice dual-source CT in ECG-triggered high-pitch acquisition mode (pitch = 3.2) set at 60% (group A, n = 40) or 30% (group B, n = 40) of the RR interval. Two blinded readers graded coronary artery image quality on a three-point scale. Radiation doses were calculated. RESULTS: Inter-observer agreement in grading image quality of the 1,154 coronary segments was good (kappa = 0.62). HRs were similar in groups A and B (85 +/- 13 bpm vs 85 +/- 14 bpm, p not significant). Significantly fewer coronary segments with non-diagnostic image quality occurred (i.e. score 3) in group B than in group A [2.8% (16/579) vs 8.3% (48/575), p < 0.001]. Seventeen patients (42.5%) of group A and 12 patients (30.0%) of group B had at least one non-diagnostic segment. Effective radiation doses were 2.3 +/- 0.3 mSv for chest CTA. CONCLUSION: A systolic acquisition window for high-pitch dual-source CTA in patients with high HRs (>/=70 bpm) significantly improves coronary artery image quality at a low radiation dose.

Contains fulltext : 81282.pdf (publisher's version ) (Open Access), To determine in patients with abdominal aortic aneurysm (AAA) the coronary calcium burden and prevalence of coronary artery disease (CAD) in relation to cardiovascular risk factors, and to assess the left ventricular (LV) function using cardiac computed tomography (CT). Sixty consecutive patients (six females; 72.2+/-9.0 years) with AAA underwent dual-source CT calcium scoring and coronary angiography prior to AAA repair. In the 60 patients, the Framingham risk score (FRS) ranged from 5-43%. Twenty patients (33%) were at low, 16 (27%) at intermediate, and 24 (40%) at high risk for cardiovascular disease. The median Agatston score (AS) was 393 (0-3538). No significant correlation was found between AS and FRS (P=0.76). 846/851 coronary segments (99%) in 57/60 patients (95%) were depicted with a diagnostic image quality. Significant stenoses were found in 132/846 segments (16%) in 33/60 patients (55%). Five patients (8%) with significant coronary artery stenosis showed reduced LV function [ejection fraction (EF)<50%]. The extent of CAD was significantly correlated with AS (r=0.43, P<0.01), whereas no correlation was found for FRS (P=0.55). Cardiac CT is feasible in patients with AAA and allows for the assessment of coronary calcium, coronary stenoses, and LV function. The calcium burden and coronary stenoses assessment with cardiac CT provides incremental information beyond traditional cardiovascular risk factors alone.

Background: This study assesses the accuracy of the new dual-source computed tomography (DSCT) for detection of coronary artery disease (CAD) compared with invasive coronary angiography (ICA) with a specifically designed data presentation protocol for cardiac surgeons. Methods: Forty patients (30 males/10 females) underwent ICA and DSCT. Best-quality images were prepared by radiologists. Evaluation of 12 segments of significant coronary stenosis was done by two cardiac surgeons with a data presentation protocol including different coronary views in two-/three-dimensional (2D/3D) images. No beta-blockers were administered prior to DSCT. Results: ICA revealed CAD in 21 patients and valvular disease but no CAD in 19 patients. In DSCT, 20/21 patients were diagnosed with CAD (at least one significant stenosis per patient). In 11/21 patients, all 12 segments were assessed correctly; in 7/21 patients one segment and in 3/21 patients two segments were evaluated incorrectly. Of all 21 patients with CAD, 239/252 segments (95%) were correctly evaluated. In 18/19 patients without CAD, DSCT correctly ruled-out the ICA results in 226/228 segments (99%). In total, 465/480 segments were correctly assessed (97%). Of 480 segments, only six were considered not assessable. DSCT assessments of the segments showed a sensitivity of 91%, specificity of 99%, a positive predictive value of 92% and a negative predictive value of 99%. Conclusions: The accuracy of DSCT coronary angiography especially for exclusion of CAD is promising. The introduced data presentation protocol allows for the independent evaluation by cardiac surgeons after pre-arrangement from the radiologists.

The aim of the study was to determine the impact of vessel attenuation on quantitative 64-slice computed tomography coronary angiography (CTCA). CTCA and invasive quantitative coronary angiography (QCA) were performed in 100 consecutive patients (42 women, 58 men; mean age 64.4+/-9.4 years; age range 39-87 years). In QCA, stenoses were quantified with dedicated software, whereas in CTCA, stenosis severity was assessed with an electronic caliper tool: stenoses were graded in 10% steps and assigned as either a calcified or non-calcified lesion. Vessel attenuation in the left main (LMA) and the proximal right coronary artery (RCA) were measured and correlated with differences in quantifications of stenosis grade between QCA and CTCA. A total of 113 coronary stenoses were detected by both methods (94 significant and 19 non-significant); 52 stenoses were rated as non-calcified and 61 as calcified lesions. The mean difference between QCA and quantitative CTCA grading was 5.1+/-16.9% (range -27 to 46%) overall; 1.9+/-14.2% (range -27 to 38%) for non-calcified lesions and 7.8+/-18.6% (range -23 to 46%) for calcified lesions. Mean vessel attenuation was 362+/-76 HU (range 191 to 584 HU) in the LMA and 333+/-81 HU (range 162 to 564 HU) in the RCA. Attenuation did not significantly correlate with differences in QCA and CTCA gradings; neither overall, nor for calcified or non-calcified lesions. When 64-slice CTCA is used, coronary vessel attenuation had no impact on the quantitative grading of stenoses.

Triage decisions in patients suffering from acute chest pain remain a challenge. The patient's history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated.

To determine in patients with abdominal aortic aneurysm (AAA) the coronary calcium burden and prevalence of coronary artery disease (CAD) in relation to cardiovascular risk factors, and to assess the left ventricular (LV) function using cardiac computed tomography (CT). Sixty consecutive patients (six females; 72.2+/-9.0 years) with AAA underwent dual-source CT calcium scoring and coronary angiography prior to AAA repair. In the 60 patients, the Framingham risk score (FRS) ranged from 5-43%. Twenty patients (33%) were at low, 16 (27%) at intermediate, and 24 (40%) at high risk for cardiovascular disease. The median Agatston score (AS) was 393 (0-3538). No significant correlation was found between AS and FRS (P=0.76). 846/851 coronary segments (99%) in 57/60 patients (95%) were depicted with a diagnostic image quality. Significant stenoses were found in 132/846 segments (16%) in 33/60 patients (55%). Five patients (8%) with significant coronary artery stenosis showed reduced LV function [ejection fraction (EF)<50%]. The extent of CAD was significantly correlated with AS (r=0.43, P<0.01), whereas no correlation was found for FRS (P=0.55). Cardiac CT is feasible in patients with AAA and allows for the assessment of coronary calcium, coronary stenoses, and LV function. The calcium burden and coronary stenoses assessment with cardiac CT provides incremental information beyond traditional cardiovascular risk factors alone. Keywords: Coronary artery disease; Computed tomography; Coronary angiography; Aortic aneurysm.

The detection of calcified plaques is an essential step in the assessment of coronary heart diseases. However, manual plaque segmentation is subjected to intra- and inter-observer variability. We present a novel framework for the automatic detection of calcified coronary plaques in Computed Tomography images. In contrast to the state-of-the-art, both the native and the angio data sets are included to gain additional information about each plaque for its detection and subsequent assessment. The framework was successfully tested on 127 patients where 85.5% of the calcified and 96% of the obstructive plaques have been detected.

AIMS: To prospectively investigate the diagnostic accuracy of dual-source computed tomography coronary angiography (CTCA) to diagnose coronary stenoses in relation to body mass index (BMI), Agatston score (AS), and heart rate (HR) as compared with catheter coronary angiography (CCA). METHODS AND RESULTS: Hundred and fifty consecutive patients (47 female, mean age 62.9 +/- 12.1 years) underwent dual-source CTCA without HR control. Patients were divided into subgroups depending on the median of their BMI (26.0 kg/m2), AS (194), and HR (66 b.p.m.). CCA was considered the standard of reference. Mean BMI was 26.5 +/- 4.2 kg/m2 (range 18.3-39.1 kg/m2), mean AS was 309 +/- 408 (range 0-4387), and HR was 68.5 +/- 12.6 b.p.m. (range 35-102 b.p.m.). Diagnostic image quality was found in 98.1% of all segments (2020/2059). Considering not-evaluative segments at CTCA as false-positive, overall per-patient sensitivity, specificity, positive, and negative predictive value were 96.6%, 86.8%, 82.6%, and 97.5%, respectively. High HR did not deteriorate diagnostic accuracy of CTCA. High BMI and AS were associated with a decrease in per-patient specificity to 84.1% and 77.8%, respectively, while sensitivity and negative predictive value remained high. CONCLUSION: Dual-source CTCA provides high diagnostic accuracy irrespective of the HR and serves as a modality to rule-out coronary artery stenoses even in patients with high BMI and AS.

RATIONALE AND OBJECTIVES: The aim of this study was to compare the diagnostic accuracy of 64-slice computed tomographic coronary angiography (CTCA) in groups of patients with low, intermediate, and high risk for coronary artery disease (CAD) events. MATERIALS AND METHODS: The institutional review board approved this study; written informed consent was obtained from all patients. Eighty-eight consecutive patients with suspected CAD (40 women; mean age, 64.3 +/- 9.4 years; range, 39-82) underwent CTCA, calcium scoring, and invasive coronary angiography and were grouped according to their Framingham 10-year risk for hard coronary events into low (<10%), intermediate (10%-20%), and high (>20%) risk categories. Significant stenoses (luminal diameter narrowing > or =50%) were assessed on an intention-to-diagnose-basis; no coronary segment was excluded and nonevaluative segments were rated false positive. To determine differences between groups, Kruskal-Wallis tests were performed for individually determined values of diagnostic performance. RESULTS: Per-patient sensitivity, specificity, negative predictive, and positive predictive values were 90.0%, 79.2%, 95.0%, and 64.3%, respectively, with low (n = 34), 87.5%, 92.3%, 85.7%, and 93.3%, respectively, with intermediate (n = 29), and 100%, 75.0%, 100%, and 89.5%, respectively, with high risk (n = 25), with a trend toward higher positive predictive value (P = .07). Per-segment negative predictive value was lower with high pretest probability (P < .01). Mean calcium-score units were 90, 220, and 312 (P = .23), and the prevalence of CAD was 29.4%, 55.2%, and 68.0% (P < .01) with low, intermediate, and high risk. CONCLUSION: Sensitivity and specificity of CTCA are not influenced by the prevalence of CAD, whereas the negative predictive value is lower and the positive predictive value tends to be higher in patients with a high prevalence of CAD.

The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1+/-16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1+/-6 HU comparing right and left coronary artery and 56+/-9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291+/-65 HU in the ascending aorta, 334+/-93 HU in the pulmonary trunk, and 285+/-66 HU and 268+/-67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain.

The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control. Thirty patients (24 male, 6 female, mean age 63.1+/-11.3 years) with a high pre-test probability of CAD underwent DSCT coronary angiography and invasive coronary angiography (ICA) within 14+/-9 days. No beta-blockers were administered prior to the scan. Two readers independently assessed image quality of all coronary segments with a diameter > or =1.5 mm using a four-point score (1: excellent to 4: not assessable) and qualitatively assessed significant stenoses as narrowing of the luminal diameter >50%. Causes of false-positive (FP) and false-negative (FN) ratings were assigned to calcifications or motion artifacts. ICA was considered the standard of reference. Mean body mass index was 28.3+/-3.9 kg/m2 (range 22.4-36.3 kg/m2), mean heart rate during CT was 70.3+/-14.2 bpm (range 47-102 bpm), and mean Agatston score was 821+/-904 (range 0-3,110). Image quality was diagnostic (scores 1-3) in 98.6% (414/420) of segments (mean image quality score 1.68+/-0.75); six segments in three patients were considered not assessable (1.4%). DSCT correctly identified 54 of 56 significant coronary stenoses. Severe calcifications accounted for false ratings in nine segments (eight FP/one FN) and motion artifacts in two segments (one FP/one FN). Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively. First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control.