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Background: Coronary computed tomography angiography (CCTA)-based transluminal attenuation gradient (TAG) was suggested to determine the functional significance of a stenosis. However, evidence that TAG acquired by wide-volume scanners can assess the hemodynamic significance of stenosis assessed by single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is lacking. Moreover, coronary cross-sectional area may influence TAG. Hence, we aimed at assessing the diagnostic value of TAG to predict ischemia in SPECT-MPI and the correlation between TAG and the transluminal cross-sectional area gradient (TCG)., Methods: Patients undergoing CCTA and SPECT-MPI for suspected coronary artery disease were included. TAG and TCG were calculated measuring the mean vessel attenuation and the cross-sectional area along major coronary vessels at 5-mm intervals., Results: A total of 255 coronary arteries of 87 patients were included. TAG and TCG did not discriminate between coronary arteries with or without ischemia as assessed by SPECT-MPI (p = .44 and p = .25, respectively). The area under the curve to predict ischemia was not increased by adding TAG (0.88, 95% CI 0.83-0.92) or TCG (0.87, 95% CI 0.81-0.90) to CCTA alone (0.85, 95% CI 0.80-0.89). There was a significant correlation between TAG and TCG (r = 0.43; p < .001)., Conclusions: CCTA-derived TAG and TCG do not offer any value in predicting ischemia assessed by SPECT-MPI. TAG is partly affected by differences in the coronary luminal area., (© 2020. American Society of Nuclear Cardiology.)

Coronary computed tomography angiography (CCTA) provides critical prognostic information on plaque burden and stenosis severity of coronary arteries. We aimed to investigate the long-term prognostic value of coronary artery volume per myocardial mass as a potential new imaging parameter. Consecutive patients with suspected coronary artery disease (CAD) were included. Coronary artery volume index (CAVi) was defined as volume over myocardial mass. Additionally, obstructive CAD (≥ 70% stenosis) and segment severity score (SSS: sum of all segments scored according to lesion severity with 0 = no lesion, 1 = narrowing < 50%, 2 = stenosis 50-69% and 3 = stenosis ≥ 70%) were evaluated. Major adverse cardiovascular events (MACE) were defined as cardiac death, non-fatal myocardial infarction or revascularization. The association of CAVi with MACE was evaluated using Cox regression hazards ratios (HR) and Kaplan Meier curves. In a total of 325 patients, 36 (11.1%) patients experienced MACE during the mean follow-up of 5.4 ± 1.7 years. Patients with low-CAVi (< 27.9 mm 3 /g) experienced more MACE than patients with high-CAVI (17.2% versus 4.5%, p < 0.001, Kaplan Meier curve p = 0.001). SSS, obstructive CAD and low-CAVi were all significant predictors of MACE in univariable analysis (HR 1.14, 95% CI 1.09-1.19, p < 0.001; HR 5.51, 95% CI 2.86-10.60, p < 0.001; and HR 3.79, 95% CI 1.66-8.65, p = 0.002, respectively). CAVi maintained significant association with MACE when adjusted to SSS (CAVi HR 2.43, 95% CI 1.02-5.75, p = 0.04) or obstructive CAD (CAVi HR 2.4, 95% CI 1.002-5.75, p = 0.049). CAVi could further risk stratify patients without obstructive CAD when stratifying patients according to obstructive CAD (Kaplan-Meier curve p = 0.049). CAVi is a novel CCTA-derived imaging parameter, yielding independent prognostic value over stenosis and plaque burden.

Background: To assess the functional relevance of a coronary artery stenosis, corrected coronary opacification (CCO) decrease derived from coronary computed tomography angiography (CCTA) has been proposed. The present study aims at validating CCO decrease with quantitative 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI)., Methods and Results: This retrospective study consists of 39 patients who underwent hybrid CCTA/PET-MPI. From CCTA, attenuation in the coronary lumen was measured before and after a stenosis and corrected to the aorta to calculate CCO and its decrease. Relative flow reserve (RFR) was calculated by dividing the stress myocardial blood flow (MBF) of a vessel territory subtended by a stenotic coronary by the stress MBF of the reference territories without stenoses. RFR was abnormal in 11 vessel territories (27%). CCO decrease yielded a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for prediction of an abnormal RFR of 73%, 70%, 88%, 47%, and 70%, respectively., Conclusions: CCTA-derived CCO decrease has moderate diagnostic accuracy to predict an abnormal RFR in PET-MPI. However, its high negative predictive value to rule out functional relevance of a given lesion may confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.

Aims: Left bundle branch block (LBBB) is considered an unfavourable prognostic marker in patients with underlying heart disease. Testing for coronary artery disease (CAD) is often prompted by incidental LBBB finding, but published studies disagree about a significant association between LBBB and CAD. We therefore assessed the association of LBBB with previously unknown CAD in patients undergoing coronary computed tomography angiography (CCTA)., Methods and Results: We enrolled 818 patients (mean age 57.2 ± 11.1 years, 106 patients with presumably new LBBB and 712 controls) without known CAD who underwent 64-slice CCTA. Image quality was assessed for each coronary segment. Comparison of obstructive CAD prevalence (defined as ≥50% stenosis) was performed using triple case-matching for pre-test probability (based on age, gender, and symptom typicality) in 101 LBBB patients and 303 matched controls with diagnostic quality in all segments. We found no difference in obstructive CAD prevalence between LBBB patients and matched controls (15 vs. 16%, P = 0.88). Similarly, there were no significant differences in cardiovascular risk factors (CVRF), stenosis severity, CAD extent, non-obstructive CAD, and vessel-based analysis between patient groups. Image quality was very high in LBBB patients and comparable to controls. On multivariate analysis, age, gender, typical angina, and CVRF, but not LBBB (P = 0.94), emerged as significant and independent predictors of obstructive CAD., Conclusion: CAD prevalence is similar in LBBB patients at low-to-moderate pre-test probability compared with controls with similar CVRF matched for age, gender, and symptom typicality. CCTA is a useful imaging modality in LBBB patients, providing comparable image quality to non-LBBB controls., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Background: In coronary CT angiography (CTA), stenosis evaluation is limited by artifacts such as blooming. Monochromatic reconstructions from single-source dual-energy coronary CTA have shown to reduce image noise and improve image quality., Objective: The aim of this study was to analyze the impact of monochromatic coronary CTA reconstructions on stenosis quantification using invasive coronary angiography (ICA) as standard of reference., Methods: Patients who were referred for clinically indicated assessment of coronary artery disease underwent coronary CTA and ICA within 4 months. In standard polychromatic coronary CTA images as well as 8 monochromatic series (50 keV-140 keV) luminal narrowing of coronary lesions was measured and compared to ICA with quantitative coronary angiography (QCA)., Results: In 37 patients with a mean age of 63.4 ± 8.2 years and a broad range of BMI (19.9-45.5 kg/m(2)), 124 lesions were studied. Throughout all the reconstructions, CT measurements showed a significant correlation with QCA (P < 0.001), except for reconstructions with 50 keV. Luminal narrowing of calcified and partly calcified lesions was generally overestimated, and underestimated in noncalcified plaques. After stepwise regression, reconstructions with 90 keV showed the best relation to QCA (P < 0.001, R2 = 0.9). Analysis by plaque composition suggested a superior performance of reconstructions at 90 keV for calcified and partly calcified plaques and at 140 keV for noncalcified plaques., Conclusion: The use of monochromatic reconstructions improves the overall accuracy of lesion assessment. Combining reconstructions at 90 keV for calcified and partly calcified lesions and at 140 keV for noncalcified lesions yielded optimal results. Thus monochromatic reconstruction bears the potential to improve accuracy of coronary CTA., (Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)