Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm3, 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features

Automatic centerline extraction of coronary arteries in coronary computed tomographic angiography

Coronary computed tomographic angiography (CCTA) is a non-invasive imaging modality for the visualization of the heart and coronary arteries. To fully exploit the potential of the CCTA datasets and apply it in clinical practice, an automated coronary artery extraction approach is needed. The purpose of this paper is to present and validate a fully automatic centerline extraction algorithm for coronary arteries in CCTA images. The algorithm is based on an improved version of Frangi’s vesselness filter which removes unwanted step-edge responses at the boundaries of the cardiac chambers. Building upon this new vesselness filter, the coronary artery extraction pipeline extracts the centerlines of main branches as well as side-branches automatically. This algorithm was first evaluated with a standardized evaluation framework named Rotterdam Coronary Artery Algorithm Evaluation Framework used in the MICCAI Coronary Artery Tracking challenge 2008 (CAT08). It includes 128 reference centerlines which were manually delineated. The average overlap and accuracy measures of our method were 93.7% and 0.30 mm, respectively, which ranked at the 1st and 3rd place compared to five other automatic methods presented in the CAT08. Secondly, in 50 clinical datasets, a total of 100 reference centerlines were generated from lumen contours in the transversal planes which were manually corrected by an expert from the cardiology department. In this evaluation, the average overlap and accuracy were 96.1% and 0.33 mm, respectively. The entire processing time for one dataset is less than 2 min on a standard desktop computer. In conclusion, our newly developed automatic approach can extract coronary arteries in CCTA images with excellent performances in extraction ability and accuracy

Foreword

Extraction of the aorto-femoral vessel trajectory is important to utilize computed tomography angiography (CTA) in an integrated workflow of the image-guided work-up prior to trans-catheter aortic valve replacement (TAVR). The aim of this study was to develop a new, fully-automated technique for the extraction of the entire arterial access route from the femoral artery to the aortic root. An automatic vessel tracking algorithm was first used to find the centerline that connected the femoral accessing points and the aortic root. Subsequently, a deformable 3D-model fitting method was used to delineate the lumen boundary of the vascular trajectory in the whole-body CTA

Vessel and sex differences in pericoronary adipose tissue attenuation obtained with coronary CT in individuals without coronary atherosclerosis

Pericoronary adipose tissue (PCAT) attenuation, derived from coronary computed tomography angiography (CCTA), is associated with coronary artery inflammation. Values for PCAT attenuation in men and women without atherosclerosis on CCTA are lacking. The aim of the current study was to assess the mean PCAT attenuation in individuals without coronary artery atherosclerosis on CCTA. Data on PCAT attenuation in men and women without coronary artery atherosclerosis on CCTA were included in this retrospective analysis. The PCAT attenuation was analyzed from the proximal part of the right coronary artery (RCA), the left anterior descending artery (LAD), and the left circumflex artery (LCx). For patient level analyses the mean PCAT attenuation was defined as the mean of the three coronary arteries. In 109 individuals (mean age 45 +/- 13 years; 44% men), 320 coronary arteries were analyzed. The mean PCAT attenuation of the overall population was - 64.4 +/- 8.0 HU. The mean PCAT attenuation was significantly lower in the LAD compared with the LCx and RCA (- 67.8 +/- 7.8 HU vs - 62.6 +/- 6.8 HU vs - 63.6 +/- 7.9 HU, respectively, p </p

Plaque progression assessed by a novel semi-automated quantitative plaque software on coronary computed tomography angiography between diabetes and non-diabetes patients: A propensity-score matching study

Background and aimsWe aimed at investigating whether diabetes is associated with progression in coronary plaque components.MethodsWe identified 142 study subjects undergoing serial coronary computed tomography angiography. The resulting propensity score was applied 1:1 to match diabetic patients to non-diabetic patients for clinical risk factors, prior coronary stenting, coronary artery calcium (CAC) score and the serial scan interval, resulting in the 71 diabetes and 71 non-diabetes patients. Coronary plaque (total, calcified, non-calcified including fibrous, fibrous-fatty and low attenuation plaque [LAP]) volume normalized by total coronary artery length was measured using semi-automated plaque software and its change overtime between diabetic and non-diabetic patients was evaluated.ResultsThe matching was successful without significant differences between the two groups in all matched variables. The baseline volumes in each plaque also did not differ. During a mean scan interval of 3.4 ± 1.8 years, diabetic patients showed a 2-fold greater progression in normalized total plaque volume (TPV) than non-diabetes patients (52.8 mm3vs. 118.3 mm3, p = 0.005). Multivariable linear regression model revealed that diabetes was associated with normalized TPV progression (β 72.3, 95%CI 24.3-120.3). A similar trend was observed for the non-calcified components, but not calcified plaque (β 3.8, 95%CI -27.0-34.7). Higher baseline CAC score was found to be associated with total, non-calcified and calcified plaque progression. However, baseline non-calcified volume but not CAC score was associated with LAP progression.ConclusionsThe current study among matched patients indicates diabetes is associated with a greater plaque progression. Our results show the need for strict adherence of diabetic patients to the current preventive guidelines

Abnormal Diastolic Hemodynamic Forces: A Link Between Right Ventricular Wall Motion, Intracardiac Flow, and Pulmonary Regurgitation in Repaired Tetralogy of Fallot

Background and Objective: The effect of chronic pulmonary regurgitation (PR) on right ventricular (RV) dysfunction in repaired Tetralogy of Fallot (RTOF) patients is well recognized by cardiac magnetic resonance (CMR). However, the link between RV wall motion, intracardiac flow and PR has not been established. Hemodynamic force (HDF) represents the global force exchanged between intracardiac blood volume and endocardium, measurable by 4D flow or by a novel mathematical model of wall motion. In our study, we used this novel methodology to derive HDF in a cohort of RTOF patients, exclusively using routine CMR imaging. Methods: RTOF patients and controls with CMR imaging were retrospectively included. Three-dimensional (3D) models of RV were segmented, including RV outflow tract (RVOT). Feature-tracking software (QStrain 2.0, Medis Medical Imaging Systems, Leiden, Netherlands) captured endocardial contours from long/short-axis cine and used to reconstruct RV wall motion. A global HDF vector was computed from the moving surface, then decomposed into amplitude/impulse of three directional components based on reference (Apical-to-Basal, Septal-to-Free Wall and Diaphragm-to-RVOT direction). HDF were compared and correlated against CMR and exercise stress test parameters. A subset of RTOF patients had 4D flow that was used to derive vorticity (for correlation) and HDF (for comparison against cine method). Results: 68 RTOF patients and 20 controls were included. RTOF patients had increased diastolic HDF amplitude in all three directions (\u3c0.05). PR% correlated with Diaphragm-RVOT HDF amplitude/impulse ( = 0.578, \u3c0.0001, = 0.508, \u3c 0.0001, respectively). RV ejection fraction modestly correlated with global HDF amplitude ( = 0.2916, = 0.031). VO correlated with Septal-to-Free Wall HDF impulse ( = 0.536, = 0.007). Diaphragm-to-RVOT HDF correlated with RVOT vorticity ( = 0.4997, = 0.001). There was no significant measurement bias between Cine-derived HDF and 4D flow-derived HDF by Bland-Altman analysis. Conclusion: RTOF patients have abnormal diastolic HDF that is correlated to PR, RV function, exercise capacity and vorticity. HDF can be derived from conventional cine, and is a potential link between RV wall motion and intracardiac flow from PR in RTOF patients

Diagnostic performance of transluminal attenuation gradient and fractional flow reserve by coronary computed tomographic angiography (FFR(CT)) compared to invasive FFR: a sub-group analysis from the DISCOVER-FLOW and DeFACTO studies.

Although coronary computed tomographic angiography (CCTA) has been a robust diagnostic tool to identify anatomical significance of coronary artery disease (CAD), the utility of CCTA to assess hemodynamic significance of CAD remains unclear. We investigated the diagnostic performance of transluminal attenuation gradient (TAG) and fractional flow reserve derived from CCTA (FFRCT) to predict lesion-specific ischemia by invasive FFR. We identified 103 patients with suspected or known CAD enrolled from the DISCOVER-FLOW and DeFACTO studies who underwent invasive coronary angiography with FFR and high quality ≥64-slice CCTA. Diagnostic performance for predicting abnormal invasive FFR (≤0.80) was assessed for TAG [≤-1.1 HU/mm by the area under the curve (AUC) by receiver-operating characteristic curve analysis (ROC)], FFR(CT) (≤0.80), and CCTA stenosis (≥50%). On a per-vessel analysis (n = 146), 52 vessels (35.6%) had ischemia by invasive FFR. The sensitivity, specificity, positive predictive value and negative predictive value were 53.8, 45.7, 35.4, 64.2% for TAG, 82.7, 74.5, 64.2, 88.6% for FFR(CT), 84.6, 39.4, 43.6, 82.2% for CCTA stenosis, respectively. The AUC by ROC curve analysis for FFR(CT) (0.79) demonstrated greater discrimination of hemodynamic ischemia compared to TAG (0.50, p &lt; 0.0001 vs. FFR(CT)), CCTA stenosis (0.62, p = 0.0004 vs. FFR(CT)) and the combination of the two (0.63, p = 0.004 vs. FFR(CT)). These results remained consistent regardless of the number of CCTA slices. FFR(CT) allows identification of lesion-specific ischemia using invasive FFR as a reference standard with greater diagnostic accuracy than TAG, CCTA stenosis, or the combination of the two

Automated determination of optimal angiographic viewing angles for coronary artery bifurcations from CTA data

For optimal diagnosis and treatment of lesions at coronary artery bifurcations using x-ray angiography, it is of utmost importance to determine proper angiographic viewing angles. Due to the increasing use of CTA as a first line diagnostic tool, 3D CTA data is more frequently available before x-ray angiographic procedures take place. Motivated by this, we propose to use available CTA data for the determination of patient specific optimal x-ray viewing angles. A semi-automatic iterative region growing scheme is developed for the segmentation of the coronary arterial tree. From the segmented arterial tree, a complete hierarchical surface and centerline representation, including bifurcation points, is automatically obtained. The optimal viewing angle for a selected bifurcation is determined as the view rendering the least amount of foreshortening and vessel overlap. For 83 bifurcation areas, viewing angles were automatically determined. The sensitivity of the method to patient positioning in the x-ray system was also studied. Next, the automatically determined angels were both quantitatively and qualitatively compared with angles determined by two experts. The method was found not to be sensitive to the positioning of the patient in the angiographic x-ray system. In 95% of the cases our method produced a clinically usable view (mean score of 8.4 out of 10) as compared to 98% for the experts (mean score of 8.7). Our method produced angiographic views with significantly less foreshortening (mean difference of 10 percentage points) than the angiographic views set by the experts

Plaque progression assessed by a novel semi-automated quantitative plaque software on coronary computed tomography angiography between diabetes and non-diabetes patients: A propensity-score matching study.

Background and aimsWe aimed at investigating whether diabetes is associated with progression in coronary plaque components.MethodsWe identified 142 study subjects undergoing serial coronary computed tomography angiography. The resulting propensity score was applied 1:1 to match diabetic patients to non-diabetic patients for clinical risk factors, prior coronary stenting, coronary artery calcium (CAC) score and the serial scan interval, resulting in the 71 diabetes and 71 non-diabetes patients. Coronary plaque (total, calcified, non-calcified including fibrous, fibrous-fatty and low attenuation plaque [LAP]) volume normalized by total coronary artery length was measured using semi-automated plaque software and its change overtime between diabetic and non-diabetic patients was evaluated.ResultsThe matching was successful without significant differences between the two groups in all matched variables. The baseline volumes in each plaque also did not differ. During a mean scan interval of 3.4 ± 1.8 years, diabetic patients showed a 2-fold greater progression in normalized total plaque volume (TPV) than non-diabetes patients (52.8 mm3vs. 118.3 mm3, p = 0.005). Multivariable linear regression model revealed that diabetes was associated with normalized TPV progression (β 72.3, 95%CI 24.3-120.3). A similar trend was observed for the non-calcified components, but not calcified plaque (β 3.8, 95%CI -27.0-34.7). Higher baseline CAC score was found to be associated with total, non-calcified and calcified plaque progression. However, baseline non-calcified volume but not CAC score was associated with LAP progression.ConclusionsThe current study among matched patients indicates diabetes is associated with a greater plaque progression. Our results show the need for strict adherence of diabetic patients to the current preventive guidelines