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Background: Noninvasive stress testing is commonly used for detection of coronary ischemia but possesses variable accuracy and may result in excessive health care costs., Objectives: This study aimed to derive and validate an artificial intelligence-guided quantitative coronary computed tomography angiography (AI-QCT) model for the diagnosis of coronary ischemia that integrates atherosclerosis and vascular morphology measures (AI-QCT ISCHEMIA ) and to evaluate its prognostic utility for major adverse cardiovascular events (MACE)., Methods: A post hoc analysis of the CREDENCE (Computed Tomographic Evaluation of Atherosclerotic Determinants of Myocardial Ischemia) and PACIFIC-1 (Comparison of Coronary Computed Tomography Angiography, Single Photon Emission Computed Tomography [SPECT], Positron Emission Tomography [PET], and Hybrid Imaging for Diagnosis of Ischemic Heart Disease Determined by Fractional Flow Reserve) studies was performed. In both studies, symptomatic patients with suspected stable coronary artery disease had prospectively undergone coronary computed tomography angiography (CTA), myocardial perfusion imaging (MPI), SPECT, or PET, fractional flow reserve by CT (FFR CT ), and invasive coronary angiography in conjunction with invasive FFR measurements. The AI-QCT ISCHEMIA model was developed in the derivation cohort of the CREDENCE study, and its diagnostic performance for coronary ischemia (FFR ≤0.80) was evaluated in the CREDENCE validation cohort and PACIFIC-1. Its prognostic value was investigated in PACIFIC-1., Results: In CREDENCE validation (n = 305, age 64.4 ± 9.8 years, 210 [69%] male), the diagnostic performance by area under the receiver-operating characteristics curve (AUC) on per-patient level was 0.80 (95% CI: 0.75-0.85) for AI-QCT ISCHEMIA , 0.69 (95% CI: 0.63-0.74; P < 0.001) for FFR CT , and 0.65 (95% CI: 0.59-0.71; P < 0.001) for MPI. In PACIFIC-1 (n = 208, age 58.1 ± 8.7 years, 132 [63%] male), the AUCs were 0.85 (95% CI: 0.79-0.91) for AI-QCT ISCHEMIA , 0.78 (95% CI: 0.72-0.84; P = 0.037) for FFR CT , 0.89 (95% CI: 0.84-0.93; P = 0.262) for PET, and 0.72 (95% CI: 0.67-0.78; P < 0.001) for SPECT. Adjusted for clinical risk factors and coronary CTA-determined obstructive stenosis, a positive AI-QCT ISCHEMIA test was associated with aHR: 7.6 (95% CI: 1.2-47.0; P = 0.030) for MACE., Conclusions: This newly developed coronary CTA-based ischemia model using coronary atherosclerosis and vascular morphology characteristics accurately diagnoses coronary ischemia by invasive FFR and provides robust prognostic utility for MACE beyond presence of stenosis., Competing Interests: Funding Support and Author Disclosures This project has been supported by the Foundation “De Drie Lichten” in the Netherlands. Dr Nurmohamed has received grants from the Dutch Heart Foundation (Dekker 03-007-2023-0068) and grants from the European Atherosclerosis Society (2023); and is co-founder of Lipid Tools. Mr Wang, Dr Chan, Ms Crabtree, Ms Aquino, Dr Min, and Dr Earls are employees of Cleerly Inc. Dr Choi has received grant support from GW Heart and Vascular Institute; equity in Cleerly, Inc; and has received consulting fees from Siemens Healthineers. Dr Knaapen has received research grants from HeartFlow, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: We assessed whether combinations of cardiometabolic risk factors independently predict coronary plaque progression (PP) and major adverse cardiovascular events in patients with stable coronary artery disease., Methods: Patients with known or suspected stable coronary artery disease (60.9±9.3 years, 55.4% male) undergoing serial coronary computed tomography angiographies (≥2 years apart), with clinical characterization and follow-up (N=1200), were analyzed from the PARADIGM study (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging). Plaque volumes measured in coronary segments (≥2 mm in diameter) were summed to provide whole heart plaque volume (mm 3 ) and percent atheroma volume (plaque volume/vessel volume×100; %) per patient at baseline and follow-up. Rapid PP was defined as a percent atheroma volume increase of ≥1.0%/y. Major adverse cardiovascular events included nonfatal myocardial infarction, death, and unplanned coronary revascularization., Results: In an interscan period of 3.2 years (interquartile range, 1.9), rapid PP occurred in 341 patients (28%). At multivariable analysis, the combination of cardiometabolic risk factors defined as metabolic syndrome predicted rapid PP (odds ratio, 1.51 [95% CI, 1.12-2.03]; P =0.007) together with older age, smoking habits, and baseline percent atheroma volume. Among single cardiometabolic variables, high fasting plasma glucose (diabetes or fasting plasma glucose >100 mg/dL) and low HDL-C (high-density lipoprotein cholesterol; <40 mg/dL in males and <50 mg/dL in females) were independently associated with rapid PP, in particular when combined (odds ratio, 2.37 [95% CI, 1.56-3.61]; P <0.001). In a follow-up of 8.23 years (interquartile range, 5.92-9.53), major adverse cardiovascular events occurred in 201 patients (17%). At multivariable Cox analysis, the combination of high fasting plasma glucose with high systemic blood pressure (treated hypertension or systemic blood pressure >130/85 mm Hg) was an independent predictor of events (hazard ratio, 1.79 [95% CI, 1.10-2.90]; P =0.018) together with family history, baseline percent atheroma volume, and rapid PP., Conclusions: In patients with stable coronary artery disease, the combination of hyperglycemia with low HDL-C is associated with rapid PP independently of other risk factors, baseline plaque burden, and treatment. The combination of hyperglycemia with high systemic blood pressure independently predicts the worse outcome beyond PP., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02803411., Competing Interests: Dr Chang receives funding from the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT (grant No. 2012027176). Dr Min receives funding from GE Healthcare and serves on the scientific advisory board of Arineta and GE Healthcare. Dr Min also has an equity interest in and is an employee of Cleerly Inc. The other authors report no conflicts.

Background: Among patients with obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA), downstream positron emission tomography (PET) perfusion imaging can be performed to assess the presence of myocardial ischemia. A novel artificial-intelligence-guided quantitative computed tomography ischemia algorithm (AI-QCT ischemia ) aims to predict ischemia directly from coronary CTA images. We aimed to study the prognostic value of AI-QCT ischemia among patients with obstructive CAD on coronary CTA and normal or abnormal downstream PET perfusion., Methods: AI-QCT ischemia was calculated by blinded analysts among patients from the retrospective coronary CTA cohort at Turku University Hospital, Finland, with obstructive CAD on initial visual reading (diameter stenosis ≥50%) being referred for downstream 15 O-H 2 O-PET adenosine stress perfusion imaging. All coronary arteries with their side branches were assessed by AI-QCT ischemia . Absolute stress myocardial blood flow ≤2.3 ​ml/g/min in ≥2 adjacent segments was considered abnormal. The primary endpoint was death, myocardial infarction, or unstable angina pectoris. The median follow-up was 6.2 [IQR 4.4-8.3] years., Results: 662 of 768 (86%) patients had conclusive AI-QCT ischemia result. In patients with normal 15 O-H 2 O-PET perfusion, an abnormal AI-QCT ischemia result (n ​= ​147/331) vs. normal AI-QCT ischemia result (n ​= ​184/331) was associated with a significantly higher crude and adjusted rates of the primary endpoint (adjusted HR 2.47, 95% CI 1.17-5.21, p ​= ​0.018). This did not pertain to patients with abnormal 15 O-H 2 O-PET perfusion (abnormal AI-QCT ischemia result (n ​= ​269/331) vs. normal AI-QCT ischemia result (n ​= ​62/331); adjusted HR 1.09, 95% CI 0.58-2.02, p ​= ​0.794) (p-interaction ​= ​0.039)., Conclusion: Among patients with obstructive CAD on coronary CTA referred for downstream 15 O-H 2 O-PET perfusion imaging, AI-QCT ischemia showed incremental prognostic value among patients with preserved perfusion by 15 O-H 2 O-PET imaging, but not among those with reduced perfusion., Competing Interests: Declaration of competing interest Dr. Bär received research grants to the institution from Medis Medical Imaging Systems, Bangerter-Rhyner Stiftung (Basel, Switzerland) and Abbott, outside the submitted work. Dr. Saraste received consultancy fees from Astra Zeneca and Pfizer, and speaker fees from Abbott, Astra Zeneca, Janssen, Novartis and Pfizer. Dr. Bax received speaker fees from Abbott. Drs Earls and Min are employees of and hold equity in Cleerly Inc. Dr. Knuuti received consultancy fees from GE Healthcare and Synektik and speaker fees from Bayer, Lundbeck, Boehringer-Ingelheim, Pfizer and Siemens, outside of the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Clinical risk scores based on traditional risk factors of atherosclerosis correlate imprecisely to an individual's complex pathophysiological predisposition to atherosclerosis and provide limited accuracy for predicting major adverse cardiovascular events (MACE). Over the past two decades, computed tomography scanners and techniques for coronary computed tomography angiography (CCTA) analysis have substantially improved, enabling more precise atherosclerotic plaque quantification and characterization. The accuracy of CCTA for quantifying stenosis and atherosclerosis has been validated in numerous multicentre studies and has shown consistent incremental prognostic value for MACE over the clinical risk spectrum in different populations. Serial CCTA studies have advanced our understanding of vascular biology and atherosclerotic disease progression. The direct disease visualization of CCTA has the potential to be used synergistically with indirect markers of risk to significantly improve prevention of MACE, pending large-scale randomized evaluation., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Radiomics is expected to identify imaging features beyond the human eye. We investigated whether radiomics can identify coronary segments that will develop new atherosclerotic plaques on coronary computed tomography angiography (CCTA)., Methods: From a prospective multinational registry of patients with serial CCTA studies at ≥ 2-year intervals, segments without identifiable coronary plaque at baseline were selected and radiomic features were extracted. Cox models using clinical risk factors (Model 1), radiomic features (Model 2) and both clinical risk factors and radiomic features (Model 3) were constructed to predict the development of a coronary plaque, defined as total PV ​≥ ​1 ​mm 3 , at follow-up CCTA in each segment., Results: In total, 9583 normal coronary segments were identified from 1162 patients (60.3 ​± ​9.2 years, 55.7% male) and divided 8:2 into training and test sets. At follow-up CCTA, 9.8% of the segments developed new coronary plaque. The predictive power of Models 1 and 2 was not different in both the training and test sets (C-index [95% confidence interval (CI)] of Model 1 vs. Model 2: 0.701 [0.690-0.712] vs. 0.699 [0.0.688-0.710] and 0.696 [0.671-0.725] vs. 0.0.691 [0.667-0.715], respectively, all p ​> ​0.05). The addition of radiomic features to clinical risk factors improved the predictive power of the Cox model in both the training and test sets (C-index [95% CI] of Model 3: 0.772 [0.762-0.781] and 0.767 [0.751-0.787], respectively, all p ​< ​00.0001 compared to Models 1 and 2)., Conclusion: Radiomic features can improve the identification of segments that would develop new coronary atherosclerotic plaque., Clinical Trial Registration: ClinicalTrials.gov NCT0280341., Competing Interests: Declaration of competing interest Dr. Chang receives funding from the Leading Foreign Research Institute Recruitment Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT (MSIT) (Grant No. 2012027176). Dr. James K. Min receives funding from GE Healthcare and serves on the scientific advisory board of Arineta and GE Healthcare. Dr. Min also has an equity interest in and is an employee of Cleerly, Inc. The remaining authors have no relevant disclosures., (Copyright © 2024 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Aims: Coronary computed tomography angiography (CTA) imaging is used to diagnose patients with suspected coronary artery disease (CAD). A novel artificial intelligence-guided quantitative computed tomography ischaemia algorithm (AI-QCTischaemia) aims to identify myocardial ischaemia directly from CTA images and may be helpful to improve risk stratification. The aims were to investigate (i) the prognostic value of AI-QCTischaemia amongst symptomatic patients with suspected CAD entering diagnostic imaging with coronary CTA and (ii) the prognostic value of AI-QCTischaemia separately amongst patients with no/non-obstructive CAD (≤50% visual diameter stenosis) and obstructive CAD (>50% visual diameter stenosis)., Methods and Results: For this cohort study, AI-QCTischaemia was calculated by blinded analysts amongst patients with suspected CAD undergoing coronary CTA. The primary endpoint was the composite of death, myocardial infarction (MI), or unstable angina pectoris (uAP) (median follow-up 6.9 years). A total of 1880/2271 (83%) patients had conclusive AI-QCTischaemia result. Patients with an abnormal AI-QCTischaemia result (n = 509/1880) vs. patients with a normal AI-QCTischaemia result (n = 1371/1880) had significantly higher crude and adjusted rates of the primary endpoint [adjusted hazard ratio (HRadj) 1.96, 95% confidence interval (CI) 1.46-2.63, P < 0.001; covariates: age/sex/hypertension/diabetes/smoking/typical angina]. An abnormal AI-QCTischaemia result was associated with significantly higher crude and adjusted rates of the primary endpoint amongst patients with no/non-obstructive CAD (n = 1373/1847) (HRadj 1.81, 95% CI 1.09-3.00, P = 0.022), but not amongst those with obstructive CAD (n = 474/1847) (HRadj 1.26, 95% CI 0.75-2.12, P = 0.386) (P-interaction = 0.032)., Conclusion: Amongst patients with suspected CAD, an abnormal AI-QCTischaemia result was associated with a two-fold increased adjusted rate of long-term death, MI, or uAP. AI-QCTischaemia may be useful to improve risk stratification, especially amongst patients with no/non-obstructive CAD on coronary CTA., Competing Interests: Conflict of interest: S.B. reports research grants to the institution from Medis Medical Imaging Systems, Bangerter-Rhyner Stiftung (Basel, Switzerland), and Abbott, outside the submitted work. A.S. received consultancy fees from Astra Zeneca and Pfizer, and speaker fees from Abbott, Astra Zeneca, and Novartis. J.J.B. received speaker fees from Abbott. J.P.E. and J.K.M. are employees of and hold equity in Cleerly Inc. J.K. received consultancy fees from GE Healthcare and Synektik Pharma and speaker fees from Bayer, Lundbeck, Boehringer-Ingelheim, Pfizer, and Siemens, outside of the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

BACKGROUND . Dose reduction strategies for coronary CTA (CCTA) have been underused in clinical practice given concern that the strategies may lower image quality. OBJECTIVE . The purpose of this study was to explore associations between dose reduction strategies and CCTA image quality in real-world clinical practice. METHODS . This subanalysis of the international Prospective Multicenter Registry on Radiation Dose Estimates of Cardiac CT Angiography in Daily Practice in 2017 (PROTECTION VI) study included 3725 patients (2109 men, 1616 women; median age, 59 years) who underwent CCTA for coronary artery evaluation performed at 55 sites in 32 countries. CCTA image sets were reviewed at a core laboratory. A range of patient and scan characteristics, including use of three dose reduction strategies (prospective ECG triggering, low tube potential, and iterative image reconstruction) and image dose, were recorded. A single core laboratory member reviewed all examinations for quantitative image quality measures, including signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and reviewed 50% of examinations to assign a qualitative CCTA image quality score and a semiquantitative coronary calcification measure. Multivariable logistic regression models were used to identify predictors of image quality. A second core laboratory member repeated quantitative measures for 100 examinations and the qualitative measure for 383 (approximately 20%) examinations to assess interreader agreement. RESULTS . Independent predictors ( p < .05) of SNR were female sex (effect size, 2.70), lower body mass index (0.38 per 1-unit decrease), stable sinus rhythm (1.71), and scanner manufacturer (variable effect across manufacturers). These factors were also the only independent predictors of CNR. Independent predictors ( p < .05) of CCTA image quality were heart rate (0.17 per 10 beats/min reduction) and coronary calcification (0.15 per coronary calcification grade). None of the three dose-saving strategies or dose-length product was an independent predictor of any image quality measure. Interreader agreement analysis showed intraclass correlation coefficients of 0.874 for SNR and 0.891 for CNR and a kappa value of 0.812 for the qualitative score. CONCLUSION . This large international multicenter study shows that three dose reduction strategies were not associated with decreased CCTA image quality. CLINICAL IMPACT . The dose reduction strategies should be routinely implemented in clinical CCTA.

Background Aortic valve calcification (AVC) is a key feature of aortic stenosis, and patients with aortic stenosis often have coronary -artery disease. Therefore, proving the association between the progression of AVC and coronary atherosclerosis could improve follow-up and treatment strategies. Purpose To explore the association between the progression of AVC and the progression of total and plaque volume composition from a large multicenter registry of serial coronary CT angiographic examinations. Materials and Methods A prospective multinational registry (PARADIGM) of consecutive participants who underwent serial coronary CT angiography at intervals of every 2 years or more was performed (January 2003-December 2015). AVC and the total and plaque volume composition at baseline and follow-up angiography were quantitatively analyzed. Plaque volumes were normalized by using the mean total analyzed vessel length of the study population. Multivariable linear mixed-effects models were constructed. Results Overall, 594 participants (mean age ± standard deviation, 62 years ± 10; 330 men) were included (mean interval between baseline and follow-up angiography, 3.9 years ± 1.5). At baseline, the AVC score was 31 Agatston units ± 117, and the normalized total plaque volume at baseline was 122 mm 3 ± 219. After adjustment for age, sex, clinical risk factors, and medication use, AVC was independently associated with total plaque volume (standardized β = 0.24; 95% CI: 0.16, 0.32; P < .001) and both calcified (β = 0.26; 95% CI: 0.18, 0.34; P < .001) and noncalcified (β = 0.17; 95% CI: 0.08, 0.25; P < .001) plaque volumes at baseline. The progression of AVC was associated with the progression of total plaque volume (β = 0.13; 95% CI: 0.03, 0.22; P = .01), driven solely by calcified plaque volume (β = 0.24; 95% CI: 0.14, 0.34; P < .001) but not noncalcified plaque volumes (β = -0.06; 95% CI: -0.14, 0.03; P = .17). Conclusion The overall burden of coronary atherosclerosis was associated with aortic valve calcification at baseline. However, the progression of aortic valve calcification was associated with only the progression of calcified plaque volume but not with the -progression of noncalcified plaque volume. Clinical trial registration no. NCT02803411 © RSNA, 2021 See also the editorial by Sinitsyn in this issue.

Coronary computed tomographic angiography (CCTA) provides a wealth of clinically meaningful information beyond anatomic stenosis alone, including the presence or absence of nonobstructive atherosclerosis and high-risk plaque features as precursors for incident coronary events. There is, however, no uniform agreement on how to identify and quantify these features or their use in evidence-based clinical decision-making. This statement from the Society of Cardiovascular Computed Tomography and North American Society of Cardiovascular Imaging addresses this gap and provides a comprehensive review of the available evidence on imaging of coronary atherosclerosis. In this statement, we provide standardized definitions for high-risk plaque (HRP) features and distill the evidence on the effectiveness of risk stratification into usable practice points. This statement outlines how this information should be communicated to referring physicians and patients by identifying critical elements to include in a structured CCTA report - the presence and severity of atherosclerotic plaque (descriptive statements, CAD-RADS™ categories), the segment involvement score, HRP features (e.g., low attenuation plaque, positive remodeling), and the coronary artery calcium score (when performed). Rigorous documentation of atherosclerosis on CCTA provides a vital opportunity to make recommendations for preventive care and to initiate and guide an effective care strategy for at-risk patients., (Copyright © 2020. Published by Elsevier Inc.)

Background: CT coronary angiography (CTA) with Fractional Flow Reserve as determined by CT (FFR CT ) is a safe alternative to invasive coronary angiography. A negative FFR CT has been shown to have low cardiac event rates compared to those with a positive FFR CT . However, the clinical utility of FFR CT according to age is not known., Methods: Patients' in the ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) registry, were stratified into those ≥65 or <65 years of age. The impact of FFR CT on clinical decision-making, as assessed by patient age, was determined by evaluating patient management using CTA results alone, followed by site investigators submitting a report on the treatment plan based upon the newly provided FFR CT data. Outcomes at 1-year post CTA were assessed, including major adverse cardiovascular events (myocardial infarction, all-cause mortality or unplanned hospitalization for ACS leading to revascularisation) and total revascularisation. Positive FFR CT was deemed to be ​≤ ​0.8., Results: FFR CT was calculated in 1849 (40.6%) subjects aged <65 and 2704 (59.4%) ​≥ ​65 years of age. Subjects ≥65 years were more likely to have anatomic obstructive disease on CTA (≥50% stenosis), compared to those aged <65 (69.7% and 73.2% respectively, p ​= ​0.008). There was a similar graded increase in recommended and actual revascularisation with either CABG or PCI, with declining FFR CT strata for subjects above and below the age of 65. MACE and revascularisation rates were not significantly different for those ​≥ ​or <65, regardless of FFR CT positivity or stenosis severity <50% or ≥50%. With a negative FFR CT result, and anatomical stenosis ≥50%, those ​≥ ​and <65 years of age, had similar rates of MACE (0.2% for both, p ​= ​0.1) and revascularisation (8.7% and 10.4% respectively p ​= ​0.4). Logistic regression analysis, with age as a continuous variable, and adjustment for Diamond Forrester Risk, baseline FFR CT and treatment (CABG, PCI, medical therapy), indicated a statistically significant, but small increase in the odds of a MACE event with increasing age (OR 1.04, 95% CI 1.006-1.08, p ​= ​0.02). Amongst patients with a FFR CT > 0.80, there was no effect of age on the odds of revascularisation., Conclusion: The findings of this study point to a low risk of MACE events or need for revascularisation in those aged ​≥ ​or <65 with a FFR CT >0.80, despite the higher incidence of anatomic obstructive CAD in those ≥65 years. The findings show the clinical usefulness and outcomes of FFR CT are largely constant regardless of age., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background: The ADVANCE registry is a large prospective study of outcomes and resource utilization in patients undergoing coronary computed tomography angiography (CCTA) and CT-based fractional flow reserve (FFR CT ). As experience with new technologies and practices develops over time, we investigated temporal changes in the use of FFR CT within the ADVANCE registry., Methods: 5083 patients with coronary artery disease (CAD) on CCTA were prospectively enrolled in the ADVANCE registry and were divided into 3 equally sized cohorts based on the temporal order of enrollment per site. Demographics, CCTA and FFR CT findings, and clinical outcomes through 1-year follow-up, were recorded and compared between tertiles., Results: The number of patients with a ≥70% stenosis on CCTA was similar over time (33.6%, 30.9%, and 33.8% for cohort 1-3). The rate of positive FFR CT ≤0.80 was higher for cohorts 2 (67.3%) and 3 (74.6%) than for cohort 1 (57.1%, p < 0.001). Invasive FFR rates decreased from 25.8% to 22.4% between cohort 1 and 3 (p = 0.023). Moreover, patients with a FFR CT ≤0.80 were less frequently referred for invasive coronary angiography (ICA) (from 62.9% to 52.9%, p < 0.001), and underwent fewer revascularizations between cohort 1 and 3 (from 41.9% to 32.0%, p < 0.001). The prevalence of major events was low (1.2%) and similar between cohorts., Conclusions: Growing experience with FFR CT improved the likelihood of identifying hemodynamically significant CAD and safely reduced the need for ICA and revascularization in patients with anatomically significant disease even in the instance of an abnormal FFR CT., Competing Interests: Declaration of competing interest Dr. Nous has received travel sponsorship from HeartFlow. Dr. Fairbairn has served on the Speakers Bureau for HeartFlow. Dr. Nørgaard has received unrestricted institutional research grants from Siemens and HeartFlow. Dr. Berman has received unrestricted research support from HeartFlow. Dr. Hurwitz-Koweek has received research support and fee as speaker from HeartFlow and Siemens. Dr. Pontone has received research grant and/or fee as speaker from GE Healthcare, Bracco, and HeartFlow. Dr. Budde has institutional research support from HeartFlow and Siemens Healthineers. Dr. Sonck has received research grant support from the Cardiopath PhD program. Dr. Rabbat has served as a consultant for HeartFlow. Dr. Mullen is an employee of and owns equity in HeartFlow. Dr. De Bruyne has received consulting fees from Abbott, Opsens, and Boston Scientific; and is a shareholder for Siemens, GE Healthcare, Bayer, Philips, HeartFlow, Edwards Lifesciences, and Sanofi. Dr. Rogers is employee of and owns equity in HeartFlow. Dr. Leipsic has served as a consultant for and owns stock options in Circle CVI and HeartFlow. Dr. Patel has received research grants from HeartFlow, Bayer, Janssen, and the National Heart, Lung, and Blood Institute; and has served on the advisory board for HeartFlow, Bayer, and Janssen. Dr. Nieman has received institutional research support from Siemens Healthineers, HeartFlow, GE Healthcare, and Bayer Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Importance: Stress imaging has been the standard for diagnosing functionally significant coronary artery disease. It is unknown whether novel, atherosclerotic plaque measures improve accuracy beyond coronary stenosis for diagnosing invasive fractional flow reserve (FFR) measurement., Objective: To compare the diagnostic accuracy of comprehensive anatomic (obstructive and nonobstructive atherosclerotic plaque) vs functional imaging measures for estimating vessel-specific FFR., Design, Setting, and Participants: Controlled clinical trial of diagnostic accuracy with a multicenter derivation-validation cohort of patients referred for nonemergent invasive coronary angiography. A total of 612 patients (64 [10] years; 30% women) with signs and symptoms suggestive of myocardial ischemia from 23 sites were included. Patients were recruited from 2014 to 2017. Data analysis began in August 2018., Interventions: Patients underwent invasive coronary angiography with measurement of invasive FFR, coronary computed tomographic angiography (CCTA) quantification of atherosclerotic plaque and FFR by CT (FFR-CT), and semiquantitative scoring of rest/stress myocardial perfusion imaging (by magnetic resonance, positron emission tomography, or single photon emission CT). Multivariable generalized linear mixed models were derived and validated calculating the area under the receiver operating characteristics curve., Main Outcomes and Measures: The primary end point was invasive FFR of 0.80 or less., Results: Of the 612 patients, the mean (SD) age was 64 (10) years, and 426 (69.9%) were men. An invasive FFR of 0.80 or less was measured in 26.5% of 1727 vessels. In the derivation cohort, CCTA vessel-specific factors associated with FFR 0.80 or less were stenosis severity, percentage of noncalcified atheroma volume, lumen volume, the number of lesions with high-risk plaque (≥2 of low attenuation plaque, positive remodeling, napkin ring sign, or spotty calcification), and the number of lesions with stenosis greater than 30%. Fractional flow reserve-CT was not additive to this model including stenosis and atherosclerotic plaque. Significant myocardial perfusion imaging predictors were the summed rest and difference scores. In the validation cohort, the areas under the receiver operating characteristic curve were 0.81 for CCTA vs 0.67 for myocardial perfusion imaging (P < .001)., Conclusions and Relevance: A comprehensive anatomic interpretation with CCTA, including quantification of obstructive and nonobstructive atherosclerotic plaque, was superior to functional imaging in the diagnosis of invasive FFR. Comprehensive CCTA measures improve prediction of vessel-specific coronary physiology more so than stress-induced alterations in myocardial perfusion., Trial Registration: ClinicalTrials.gov Identifier: NCT02173275.

To determine whether the assessment of individual plaques is superior in predicting the progression to obstructive coronary artery disease (CAD) on serial coronary computed tomography angiography (CCTA) than per-patient assessment. From a multinational registry of 2252 patients who underwent serial CCTA at a ≥ 2-year inter-scan interval, patients with only non-obstructive lesions at baseline were enrolled. CCTA was quantitatively analyzed at both the per-patient and per-lesion level. Models predicting the development of an obstructive lesion at follow up using either the per-patient or per-lesion level CCTA measures were constructed and compared. From 1297 patients (mean age 60 ± 9 years, 43% men) enrolled, a total of 3218 non-obstructive lesions were identified at baseline. At follow-up (inter-scan interval: 3.8 ± 1.6 years), 76 lesions (2.4%, 60 patients) became obstructive, defined as > 50% diameter stenosis. The C-statistics of Model 1, adjusted only by clinical risk factors, was 0.684. The addition of per-patient level total plaque volume (PV) and the presence of high-risk plaque (HRP) features to Model 1 improved the C-statistics to 0.825 [95% confidence interval (CI) 0.823-0.827]. When per-lesion level PV and the presence of HRP were added to Model 1, the predictive value of the model improved the C-statistics to 0.895 [95% CI 0.893-0.897]. The model utilizing per-lesion level CCTA measures was superior to the model utilizing per-patient level CCTA measures in predicting the development of an obstructive lesion (p < 0.001). Lesion-level analysis of coronary atherosclerotic plaques with CCTA yielded better predictive power for the development of obstructive CAD than the simple quantification of total coronary atherosclerotic burden at a per-patient level.Clinical Trial Registration: ClinicalTrials.gov NCT0280341.

Multidetector computed tomography (MDCT) is currently the imaging technique of choice for the assessment of tricuspid valve (TV) annulus geometry and relationship with the right coronary artery (RCA). However, standardized protocols with a full 3D analysis are still lacking to plan percutaneous procedures for functional tricuspid regurgitation (FTR). A novel customized 4-dimensional tool based on MDCT data was developed and provided accurate information on TV annulus morphology (3D-perimeter, 2D-Area, maximum and minimum diameters, eccentricity index), function and distance to the RCA, crucial for patient selection of percutaneous TV procedures., (Copyright © 2020 [The Author/The Authors]. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Different methodologies to report whole-heart atherosclerotic plaque on coronary computed tomography angiography (CCTA) have been utilized. We examined which of the three commonly used plaque burden definitions was least affected by differences in body surface area (BSA) and sex., Methods: The PARADIGM study includes symptomatic patients with suspected coronary atherosclerosis who underwent serial CCTA >2 years apart. Coronary lumen, vessel, and plaque were quantified from the coronary tree on a 0.5 mm cross-sectional basis by a core-lab, and summed to per-patient. Three quantitative methods of plaque burden were employed: (1) total plaque volume (PV) in mm 3 , (2) percent atheroma volume (PAV) in % [which equaled: PV/vessel volume * 100%], and (3) normalized total atheroma volume (TAV norm ) in mm 3 [which equaled: PV/vessel length * mean population vessel length]. Only data from the baseline CCTA were used. PV, PAV, and TAV norm were compared between patients in the top quartile of BSA vs the remaining, and between sexes. Associations between vessel volume, BSA, and the three plaque burden methodologies were assessed., Results: The study population comprised 1479 patients (age 60.7 ± 9.3 years, 58.4% male) who underwent CCTA. A total of 17,649 coronary artery segments were evaluated with a median of 12 (IQR 11-13) segments per-patient (from a 16-segment coronary tree). Patients with a large BSA (top quartile), compared with the remaining patients, had a larger PV and TAV norm , but similar PAV. The relation between larger BSA and larger absolute plaque volume (PV and TAV norm ) was mediated by the coronary vessel volume. Independent from the atherosclerotic cardiovascular disease risk (ASCVD) score, vessel volume correlated with PV (P < 0.001), and TAV norm (P = 0.003), but not with PAV (P = 0.201). The three plaque burden methods were equally affected by sex., Conclusions: PAV was less affected by patient's body surface area then PV and TAV norm and may be the preferred method to report coronary atherosclerotic burden., Competing Interests: Declaration of competing interest Dr. James K. Min receives funding from the Dalio Foundation, National Institutes of Health, and GE Healthcare. Dr. Min serves on the scientific advisory board of Arineta and GE Healthcare, and has an equity interest in Cleerly. Dr. Habib Samady serves on the scientific advisory board of Philips, has equity interest in Covanos Inc., and has a research grant from Medtronic. Dr. Kavitha Chinnaiyan is a non-compensated medical advisory board member of Heartflow Inc. The remaining authors have no relevant disclosures., (Copyright © 2020. Published by Elsevier Inc.)

Background: The association between triglyceride glucose (TyG) index and coronary atherosclerotic change remains unclear. We aimed to evaluate the association between TyG index and coronary plaque progression (PP) using serial coronary computed tomography angiography (CCTA)., Methods: A total of 1143 subjects (aged 60.7 ± 9.3 years, 54.6% male) who underwent serial CCTA with available data on TyG index and diabetic status were analyzed from The Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry. PP was defined as plaque volume (PV) (mm 3 ) at follow-up minus PV at index > 0. Annual change of PV (mm 3 /year) was defined as PV change divided by inter-scan period. Rapid PP was defined as the progression of percent atheroma volume (PV divided by vessel volume multiplied by 100) ≥ 1.0%/year., Results: The median inter-scan period was 3.2 (range 2.6-4.4) years. All participants were stratified into three groups based on TyG index tertiles. The overall incidence of PP was 77.3%. Baseline total PV (group I [lowest]: 30.8 (0.0-117.7), group II: 47.2 (6.2-160.4), and group III [highest]: 57.5 (8.4-154.3); P < 0.001) and the annual change of total PV (group I: 5.7 (0.0-20.2), group II: 7.6 (0.5-23.5), and group III: 9.4 (1.4-27.7); P = 0.010) were different among all groups. The risk of PP (odds ratio [OR] 1.648; 95% confidence interval [CI] 1.167-2.327; P = 0.005) and rapid PP (OR 1.777; 95% CI 1.288-2.451; P < 0.001) was increased in group III compared to that in group I. TyG index had a positive and significant association with an increased risk of PP and rapid PP after adjusting for confounding factors., Conclusion: TyG index is an independent predictive marker for the progression of coronary atherosclerosis. Clinical registration ClinicalTrials.gov NCT02803411.

Objectives: This study explored whether the pattern of nonobstructive lesion progression into obstructive lesions would differ according to the presence of high-risk plaque (HRP)., Background: It is still debatable whether HRP simply represents a certain phase during the natural history of coronary atherosclerotic plaques or if disease progression would differ according to the presence of HRP., Methods: Patients with nonobstructive coronary artery disease, defined as percent diameter stenosis (%DS) <50%, were enrolled from a prospective, multinational registry of consecutive patients who underwent serial coronary computed tomography angiography at an interscan interval of ≥2 years. HRP was defined as lesions with ≥2 features of positive remodeling, spotty calcification, or low-attenuation plaque. Quantitative total and compositional percent atheroma volume (PAV) at baseline and annualized PAV change were compared between non-HRP and HRP lesions., Results: A total of 3,049 nonobstructive lesions were identified from 1,297 patients (mean age 60.3 ± 9.3 years; 56.8% men). There were 2,624 non-HRP and 425 HRP lesions. HRP lesions had a greater total PAV and all noncalcified components of PAV and %DS at baseline compared with non-HRP lesions. However, the annualized total PAV changes were greater in non-HRP lesions than in HRP lesions. On multivariate analysis adjusted for clinical risk factors, drug use, change in lipid level, total PAV, %DS, and HRP, only the baseline total PAV and %DS independently predicted the development of obstructive lesions (hazard ratio [HR]: 1.04; 95% confidence interval [CI]: 1.02 to 1.07, and HR: 1.07; 95% CI: 1.04 to 1.10, respectively, all p < 0.05), whereas the presence of HRP did not (p > 0.05)., Conclusions: The pattern of individual coronary atherosclerotic plaque progression differed according to the presence of HRP. Baseline PAV, not the presence of HRP features, was the most important predictor of lesions developing into obstructive lesions. (Progression of Atherosclerotic Plaque Determined By Computed Tomographic Angiography Imaging [PARADIGM]; NCT02803411)., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: We aimed to compare semiquantitative coronary computed tomography angiography (CCTA) risk scores - which score presence, extent, composition, stenosis and/or location of coronary artery disease (CAD) - and their prognostic value between patients with and without diabetes mellitus (DM). Risk scores derived from general chest-pain populations are often challenging to apply in DM patients, because of numerous confounders., Methods: Out of a combined cohort from the Leiden University Medical Center and the CONFIRM registry with 5-year follow-up data, we performed a secondary analysis in diabetic patients with suspected CAD who were clinically referred for CCTA. A total of 732 DM patients was 1:1 propensity-matched with 732 non-DM patients by age, sex and cardiovascular risk factors. A subset of 7 semiquantitative CCTA risk scores was compared between groups: 1) any stenosis ≥50%, 2) any stenosis ≥70%, 3) stenosis-severity component of the coronary artery disease-reporting and data system (CAD-RADS), 4) segment involvement score (SIS), 5) segment stenosis score (SSS), 6) CT-adapted Leaman score (CT-LeSc), and 7) Leiden CCTA risk score. Cox-regression analysis was performed to assess the association between the scores and the primary endpoint of all-cause death and non-fatal myocardial infarction. Also, area under the receiver-operating characteristics curves were compared to evaluate discriminatory ability., Results: A total of 1,464 DM and non-DM patients (mean age 58 ± 12 years, 40% women) underwent CCTA and 155 (11%) events were documented after median follow-up of 5.1 years. In DM patients, the 7 semiquantitative CCTA risk scores were significantly more prevalent or higher as compared to non-DM patients (p ≤ 0.022). All scores were independently associated with the primary endpoint in both patients with and without DM (p ≤ 0.020), with non-significant interaction between the scores and diabetes (interaction p ≥ 0.109). Discriminatory ability of the Leiden CCTA risk score in DM patients was significantly better than any stenosis ≥50% and ≥70% (p = 0.003 and p = 0.007, respectively), but comparable to the CAD-RADS, SIS, SSS and CT-LeSc that also focus on the extent of CAD (p ≥ 0.265)., Conclusion: Coronary atherosclerosis scoring with semiquantitative CCTA risk scores incorporating the total extent of CAD discriminate major adverse cardiac events well, and might be useful for risk stratification of patients with DM beyond the binary evaluation of obstructive stenosis alone., Competing Interests: Declaration of competing interest Dr. James K. Min receives funding from the Dalio Foundation, National Institutes of Health, and GE Healthcare. Dr. Min serves on the scientific advisory board of Arineta and GE Healthcare, and has an equity interest in Cleerly. The Department of Cardiology of the Leiden University Medical Center received research grants from Biotronik, Medtronic, Boston Scientific and Edwards Lifesciences. Arthur J.H.A. Scholte received consulting fees from GE Healthcare and Canon., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background Rapid coronary plaque progression (RPP) is associated with incident cardiovascular events. To date, no method exists for the identification of individuals at risk of RPP at a single point in time. This study integrated coronary computed tomography angiography-determined qualitative and quantitative plaque features within a machine learning (ML) framework to determine its performance for predicting RPP. Methods and Results Qualitative and quantitative coronary computed tomography angiography plaque characterization was performed in 1083 patients who underwent serial coronary computed tomography angiography from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) registry. RPP was defined as an annual progression of percentage atheroma volume ≥1.0%. We employed the following ML models: model 1, clinical variables; model 2, model 1 plus qualitative plaque features; model 3, model 2 plus quantitative plaque features. ML models were compared with the atherosclerotic cardiovascular disease risk score, Duke coronary artery disease score, and a logistic regression statistical model. 224 patients (21%) were identified as RPP. Feature selection in ML identifies that quantitative computed tomography variables were higher-ranking features, followed by qualitative computed tomography variables and clinical/laboratory variables. ML model 3 exhibited the highest discriminatory performance to identify individuals who would experience RPP when compared with atherosclerotic cardiovascular disease risk score, the other ML models, and the statistical model (area under the receiver operating characteristic curve in ML model 3, 0.83 [95% CI 0.78-0.89], versus atherosclerotic cardiovascular disease risk score, 0.60 [0.52-0.67]; Duke coronary artery disease score, 0.74 [0.68-0.79]; ML model 1, 0.62 [0.55-0.69]; ML model 2, 0.73 [0.67-0.80]; all P <0.001; statistical model, 0.81 [0.75-0.87], P =0.128). Conclusions Based on a ML framework, quantitative atherosclerosis characterization has been shown to be the most important feature when compared with clinical, laboratory, and qualitative measures in identifying patients at risk of RPP.

Objectives: The aim of this study was to assess the use of low tube potentials for coronary computed tomography angiography (CCTA) in worldwide clinical practice and its influence on radiation exposure, contrast agent volume, and image quality., Background: CCTA is frequently used in clinical practice. Lowering of tube potential is a potent method to reduce radiation exposure and to economize contrast agent volume., Methods: CCTAs of 4,006 patients from 61 international study sites were analyzed regarding very-low (≤80 kVp), low (90 to 100 kVp), conventional (110 to 120 kVp), and high (≥130 kVp) tube potentials. The impact on dose-length product (DLP) and contrast agent volume was analyzed. Image quality was determined by evaluation of the diagnostic applicability and assessment of the objective image parameters signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR)., Results: When compared with conventional tube potentials, low tube potentials were used in 56% of CCTAs (≤80 kVp: 9%; 90 to 100 kVp: 47%), which varied among sites from 0% to 100%. Tube potential reduction was associated with low-cardiovascular risk profile, low body mass index (BMI), and new-generation scanners. Median radiation exposure was lowered by 68% or 50% and median contrast agent volume by 25% or 13% for tube potential protocols of ≤80 kVp or 90 to 100 kVp when compared with conventional tube potentials, respectively (all p < 0.001). With the use of lower tube potentials, the frequency of diagnostic scans was maintained (p = 0.41), whereas SNR and CNR significantly improved (both p < 0.001). Considering BMI eligibility criteria, 58% (n = 946) of conventionally scanned patients would have been suitable for low tube potential protocols, and 44% (n = 831) of patients scanned with 90 to 100 kVp would have been eligible for very-low tube potential CCTA imaging of ≤80 kVp., Conclusions: This large international registry confirms the feasibility of tube potential reduction in clinical practice leading to lower radiation exposure and lower contrast volumes. The current registry also demonstrates that this strategy is still underused in daily practice. (PROspective multicenter registry on radiaTion dose Estimates of cardiac CT angIOgraphy iN daily practice in 2017 [PROTECTION-VI]; NCT02996903)., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Symptom-based pretest probability scores that estimate the likelihood of obstructive coronary artery disease (CAD) in stable chest pain have moderate accuracy. We sought to develop a machine learning (ML) model, utilizing clinical factors and the coronary artery calcium score (CACS), to predict the presence of obstructive CAD on coronary computed tomography angiography (CCTA)., Methods and Results: The study screened 35 281 participants enrolled in the CONFIRM registry, who underwent ≥64 detector row CCTA evaluation because of either suspected or previously established CAD. A boosted ensemble algorithm (XGBoost) was used, with data split into a training set (80%) on which 10-fold cross-validation was done and a test set (20%). Performance was assessed of the (1) ML model (using 25 clinical and demographic features), (2) ML + CACS, (3) CAD consortium clinical score, (4) CAD consortium clinical score + CACS, and (5) updated Diamond-Forrester (UDF) score. The study population comprised of 13 054 patients, of whom 2380 (18.2%) had obstructive CAD (≥50% stenosis). Machine learning with CACS produced the best performance [area under the curve (AUC) of 0.881] compared with ML alone (AUC of 0.773), CAD consortium clinical score (AUC of 0.734), and with CACS (AUC of 0.866) and UDF (AUC of 0.682), P < 0.05 for all comparisons. CACS, age, and gender were the highest ranking features., Conclusion: A ML model incorporating clinical features in addition to CACS can accurately estimate the pretest likelihood of obstructive CAD on CCTA. In clinical practice, the utilization of such an approach could improve risk stratification and help guide downstream management., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Objectives: The 1-year data from the international ADVANCE (Assessing Diagnostic Value of Non-invasive FFR CT in Coronary Care) Registry of patients undergoing coronary computed tomography angiography (CTA) was used to evaluate the relationship of fractional flow reserve derived from coronary CTA (FFR CT ) with downstream care and clinical outcomes., Background: Guidelines for management of chest pain using noninvasive imaging pathways are based on short- to intermediate-term outcomes., Methods: Patients (N = 5,083) evaluated for clinically suspected coronary artery disease and in whom atherosclerosis was identified by coronary CTA were prospectively enrolled at 38 international sites from July 15, 2015, to October 20, 2017. Demographics, symptom status, coronary CTA and FFR CT findings and resultant site-based treatment plans, and clinical outcomes through 1 year were recorded and adjudicated by a blinded core laboratory. Major adverse cardiac events (MACE), death, myocardial infarction (MI), and acute coronary syndrome leading to urgent revascularization were captured., Results: At 1 year, 449 patients did not have follow-up data. Revascularization occurred in 1,208 (38.40%) patients with an FFR CT  ≤0.80 and in 89 (5.60%) with an FFR CT >0.80 (relative risk [RR]: 6.87; 95% confidence interval [CI]: 5.59 to 8.45; p < 0.001). MACE occurred in 55 patients, 43 events occurred in patients with an FFR CT  ≤0.80 and 12 occurred in those with an FFR CT >0.80 (RR: 1.81; 95% CI: 0.96 to 3.43; p = 0.06). Time to first event (all-cause death or MI) occurred in 38 (1.20%) patients with an FFR CT  ≤0.80 compared with 10 (0.60%) patients with an FFR CT >0.80 (RR: 1.92; 95% CI: 0.96 to 3.85; p = 0.06). Time to first event (cardiovascular death or MI) occurred cardiovascular death or MI occurred more in patients with an FFR CT  ≤0.80 compared with patients with an FFR CT >0.80 (25 [0.80%] vs. 3 [0.20%]; RR: 4.22; 95% CI: 1.28 to 13.95; p = 0.01)., Conclusions: The 1-year outcomes from the ADVANCE FFR CT Registry show low rates of events in all patients, with less revascularization and a trend toward lower MACE and significantly lower cardiovascular death or MI in patients with a negative FFR CT compared with patients with abnormal FFR CT values. (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Wave [ADVANCE]; NCT02499679)., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: The long-term prognostic value of coronary computed tomography angiography (CCTA)-identified coronary artery disease (CAD) has not been evaluated in elderly patients (≥70 years). We compared the ability of coronary CCTA to predict 5-year mortality in older vs. younger populations., Methods and Results: From the prospective CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry, we analysed CCTA results according to age <70 years (n = 7198) vs. ≥70 years (n = 1786). The severity of CAD was classified according to: (i) maximal stenosis degree per vessel: none, non-obstructive (1-49%), or obstructive (>50%); (ii) segment involvement score (SIS): number of segments with plaque. Cox-proportional hazard models assessed the relationship between CCTA findings and time to mortality. At a mean 5.6 ± 1.1 year follow-up, CCTA-identified CAD predicted increased mortality compared with patients with a normal CCTA in both <70 years [non-obstructive hazard ratio (HR) confidence interval (CI): 1.70 (1.19-2.41); one-vessel: 1.65 (1.03-2.67); two-vessel: 2.24 (1.21-4.15); three-vessel/left main: 4.12 (2.27-7.46), P < 0.001] and ≥70 years [non-obstructive: 1.84 (1.15-2.95); one-vessel: HR (CI): 2.28 (1.37-3.81); two-vessel: 2.36 (1.33-4.19); three-vessel/left main: 2.41 (1.33-4.36), P = 0.014]. Similarly, SIS was predictive of mortality in both <70 years [SIS 1-3: 1.57 (1.10-2.24); SIS ≥4: 2.42 (1.65-3.57), P < 0.001] and ≥70 years [SIS 1-3: 1.73 (1.07-2.79); SIS ≥4: 2.45 (1.52-3.93), P < 0.001]. CCTA findings similarly predicted long-term major adverse cardiovascular outcomes (MACE) (all-cause mortality, myocardial infarction, and late revascularization) in both groups compared with patients with no CAD., Conclusion: The presence and extent of CAD is a meaningful stratifier of long-term mortality and MACE in patients aged <70 years and ≥70 years old. The presence of obstructive and non-obstructive disease and the burden of atherosclerosis determined by SIS remain important predictors of prognosis in older populations., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

The 2018 American College of Cardiology (ACC)/American Heart Association (AHA) cholesterol management guideline recommends risk enhancers in the borderline-risk and statin recommended/intermediate-risk groups. We determined the risk reclassification by the presence and severity of coronary computed tomography angiography (CCTA)-visualized coronary artery disease (CAD) according to statin eligibility groups. Of 35,281 individuals who underwent CCTA, 1,303 asymptomatic patients (age 59, 65% male) were identified. Patients were categorized as low risk, borderline risk, statin recommended/intermediate risk or statin recommended/high risk according to the guideline. CCTA-visualized CAD was categorized as no CAD, nonobstructive, or obstructive. Major adverse cardiovascular events (MACE) were defined as a composite outcome of all-cause mortality, nonfatal myocardial infarction, and late coronary revascularization (>90 days). We tested a reclassification wherein no CAD reclassifies downward, and the presence of any CAD reclassifies upward. During a median follow-up of 2.9 years, 93 MACE events (7.1%) were observed. Among the borderline-risk and statin-recommended/intermediate-risk groups eligible for risk enhancers, the presence or absence of any CCTA-visualized CAD led to a net increase of 2.3% of cases and 22.4% of controls correctly classified (net reclassification index [NRI] 0.27, 95% CI 0.13 to 0.41, p = 0.0002). The NRI was not significant among low- or statin-recommended/high-risk patients (all p >0.05). The presence or absence of CCTA-visualized CAD, including both obstructive and nonobstructive CAD, significantly improves reclassification in patients eligible for risk enhancers in 2018 ACC/AHA guidelines. Patients in low- and high-risk groups derive no significant improvement in risk reclassification from CCTA., (Copyright © 2019. Published by Elsevier Inc.)

Aims: Coronary artery calcium score (CACS) is a strong predictor of major adverse cardiac events (MACE). Conversely, statins, which markedly reduce MACE risk, increase CACS. We explored whether CACS progression represents compositional plaque volume (PV) progression differently according to statin use., Methods and Results: From a prospective multinational registry of consecutive patients (n = 2252) who underwent serial coronary computed tomography angiography (CCTA) at a ≥ 2-year interval, 654 patients (61 ± 10 years, 56% men, inter-scan interval 3.9 ± 1.5 years) with information regarding the use of statins and having a serial CACS were included. Patients were divided into non-statin (n = 246) and statin-taking (n = 408) groups. Coronary PVs (total, calcified, and non-calcified; sum of fibrous, fibro-fatty, and lipid-rich) were quantitatively analysed, and CACS was measured from both CCTAs. Multivariate linear regression models were constructed for both statin-taking and non-statin group to assess the association between compositional PV change and change in CACS. In multivariate linear regression analysis, in the non-statin group, CACS increase was positively associated with both non-calcified (β = 0.369, P = 0.004) and calcified PV increase (β = 1.579, P < 0.001). However, in the statin-taking group, CACS increase was positively associated with calcified PV change (β = 0.756, P < 0.001) but was negatively associated with non-calcified PV change (β = -0.194, P = 0.026)., Conclusion: In the non-statin group, CACS progression indicates the progression of both non-calcified and calcified PV progression. However, under the effect of statins, CACS progression indicates only calcified PV progression, but not non-calcified PV progression. Thus, the result of serial CACS should be differently interpreted according to the use of statins., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

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/)., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Cardiovascular computed tomography (CCT) has undergone rapid maturation over the last decade and is now of proven clinical utility in the diagnosis and management of coronary artery disease, in guiding structural heart disease intervention, and in the diagnosis and treatment of congenital heart disease. The next decade will undoubtedly witness further advances in hardware and advanced analytics that will potentially see an increasingly core role for CCT at the center of clinical cardiovascular practice. In coronary artery disease assessment this may be via improved hemodynamic adjudication, and shear stress analysis using computational flow dynamics, more accurate and robust plaque characterization with spectral or photon-counting CT, or advanced quantification of CT data via artificial intelligence, machine learning, and radiomics. In structural heart disease, CCT is already pivotal to procedural planning with adjudication of gradients before and following intervention, whereas in congenital heart disease CCT is already used to support clinical decision making from neonates to adults, often with minimal radiation dose. In both these areas the role of computational flow dynamics, advanced tissue printing, and image modelling has the potential to revolutionize the way these complex conditions are managed, and CCT is likely to become an increasingly critical enabler across the whole advancing field of cardiovascular medicine., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Quantitative flow ratio (QFR) is a novel technique to calculate fractional flow reserve (FFR), without hyperemia induction or a pressure wire, and has not yet been validated in patients with diabetes mellitus (DM), who are at increased risk of coronary microvascular dysfunction. The purpose of our study was to compare the diagnostic performance of QFR in diabetic and nondiabetic patients. Patients who underwent invasive coronary angiography and subsequent invasive FFR measurement within 6 months were included. QFR was determined in all coronary arteries in which invasive FFR was performed, using a dedicated software package. Diagnostic accuracy and the area under the receiver-operating characteristic curve (AUC) were determined for QFR, using an invasive FFR cut-off value of ≤0.80 as the reference standard. In total, 320 coronary arteries from 66 (25%) diabetic and 193 (75%) nondiabetic patients were analyzed. On a vessel-based analysis, diagnostic accuracy, sensitivity, and specificity showed no significant difference between diabetic and nondiabetic patients: 88% versus 85% (p = 0.47), 71% versus 69% (p = 0.72), and 95% versus 91% (p = 0.24). Moreover, the AUC was not significantly different between patients with and without DM, 0.91 versus 0.93 (p = 0.74). The per-vessel AUC was significantly higher for QFR compared with percent diameter stenosis in both diabetic and nondiabetic patients, 0.91 versus 0.76 (p <0.05) and 0.93 versus 0.77 (p <0.001), respectively. In conclusion, we showed a good diagnostic performance of QFR which was independent of the presence of DM., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

The 2016 National Institute of Health and Care Excellence clinical guideline for the assessment and diagnosis of chest pain positions coronary computed tomography angiography as the first test for all stable chest pain patients without confirmed coronary artery disease and discards the previous emphasis on calculation of pre-test likelihood recommended in their 2012 edition of the guidelines. On the other hand, the American College of Cardiology Foundation/American Heart Association and the European Society of Cardiology guidelines continue to present the stress testing functional modalities as the tests of choice. The aim of this review is to present, in the form of a debate, the pros and cons of these paradigm changing recommendations, with an emphasis on literature review and projection of future needs, with conclusions to be drawn by the reader., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

The prognostic performance of coronary artery calcium score (CACS) for predicting adverse outcomes in patients with decreased renal function remains unclear. We aimed to examine whether CACS improves risk stratification by demonstrating incremental value beyond a traditional risk score according to renal function status. 9,563 individuals without known coronary artery disease were enrolled. Estimated glomerular filtration rate (eGFR, ml/min/1.73 m 2 ) was ascertained using the modified Modification of Diet in Renal Disease formula, and was categorized as: ≥90, 60 to 89, and <60. CACS was categorized as 0, 1 to 100, 101 to 400, and >400. Multivariable Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (95% CI) for major adverse cardiac events (MACE), comprising all-cause mortality, myocardial infarction, and late revascularization (>90 days). Mean age was 55.8 ± 11.5 years (52.8% male). In total, 261 (2.7%) patients experienced MACE over a median follow-up of 24.5 months (interquartile range: 16.9 to 41.1). Incident MACE increased with higher CACS across each eGFR category, with the highest rate observed among patients with CACS >400 and eGFR <60 (95.1 per 1,000 person-years). A CACS >400 increased MACE risk with HR 4.46 (95% CI 1.68 to 11.85), 6.63 (95% CI 4.03 to 10.92), and 6.14 (95% CI 2.85 to 13.21) for eGFR ≥90, 60 to 89, and <60, respectively, as compared with CACS 0. Further, CACS improved discrimination and reclassification beyond Framingham 10-year risk score (FRS) (AUC: 0.70 vs 0.64; category free-NRI: 0.51, all p <0.001) for predicting MACE in patients with impaired renal function (eGFR < 90). In conclusion, CACS improved risk stratification and provided incremental value beyond FRS for predicting MACE, irrespective of eGFR status., (Published by Elsevier Inc.)

Introduction: Non-statin therapy (NST) is used as second-line treatment when statin monotherapy is inadequate or poorly tolerated., Objective: To determine the association of NST with plaque composition, alone or in combination with statins, in patients undergoing coronary computed tomography angiography (coronary CTA)., Methods: From the multicenter CONFIRM registry, we analyzed individuals who underwent coronary CTA with known lipid-lowering therapy status and without prior coronary artery disease at baseline. We created a propensity score for being on NST, followed by stepwise multivariate linear regression, adjusting for the propensity score as well as risk factors, to determine the association between NST and the number of coronary artery segments with each plaque type (non-calcified (NCP), partially calcified (PCP) or calcified (CP)) and segment stenosis score (SSS)., Results: Of the 27,125 subjects in CONFIRM, 4,945 met the inclusion criteria; 371 (7.5%) took NST. At baseline, patients on NST had more prevalent risk factors and were more likely to be on concomitant cardiac medications. After multivariate and propensity score adjustment, NST was not associated with plaque composition: NCP (0.07 increase, 95% CI: -0.05, 0.20; p = 0.26), PCP (0.10 increase, 95% CI: -0.10, 0.31; p = 0.33), CP (0.18 increase, 95% CI: -0.10, 0.46; p = 0.21) or SSS (0.45 increase, 95% CI: -0.02,0.93; p = 0.06). The absence of an effect of NST on plaque type was not modified by statin use (p for interaction > 0.05 for all)., Conclusion: In this cross-sectional study, non-statin therapy was not associated with differences in plaque composition as assessed by coronary CTA., (Copyright © 2019. Published by Elsevier Inc.)

Background: Data on the impact of glycemic status on coronary plaque progression have been limited. This study evaluated the association between glycemic status and coronary plaque volume change (PVC) using coronary computed tomography angiography (CCTA)., Methods: A total of 1296 subjects (61 ± 9, 56.9% male) who underwent serial CCTA with available glycemic status were enrolled and analyzed from the Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry. The median inter-scan period was 3.2 (2.6-4.4) years. Quantitative assessment of coronary plaques was performed at both scans. All participants were categorized into the following groups according to glycemic status: normal, pre-diabetes (pre-DM), and diabetes mellitus (DM)., Results: During the follow-up, significant differences in PVC (normal: 51.3 ± 83.3 mm 3 vs. pre-DM: 51.0 ± 84.3 mm 3 vs. DM: 72.6 ± 95.0 mm 3 ; p < 0.001) and annualized PVC (normal: 14.9 ± 24.9 mm 3 vs. pre-DM: 15.7 ± 23.8 mm 3 vs. DM: 21.0 ± 27.7 mm 3 ; p = 0.001) were observed among the 3 groups. Compared with normal individuals, individuals with pre-DM showed no significant differences in the adjusted odds ratio (OR) for plaque progression (PP) (1.338, 95% confidence interval [CI] 0.967-1.853; p = 0.079). However, the adjusted OR for PP was higher in DM individuals than in normal individuals (1.635, 95% CI 1.126-2.375; p = 0.010)., Conclusion: DM had an incremental impact on coronary PP, but pre-DM appeared to have no significant association with an increased risk of coronary PP after adjusting for confounding factors., Clinical Trial Registration: ClinicalTrials.govNCT02803411., (Copyright © 2018. Published by Elsevier Inc.)

Objective: Data describing clinical relevance of chronic total occlusion (CTO) identified by coronary CT angiography (CCTA) have not been reported to date. We investigated the prognosis of CTO on CCTA., Methods: We identified 22 828 patients without prior known coronary artery disease (CAD), who were followed for a median of 26 months. Based on CCTA, coronary lesions were graded as normal (no atherosclerosis), non-obstructive (1%-49%), moderate-to-severe (50%-99%) or totally occluded (100%). All-cause mortality, and major adverse cardiac events defined as mortality, non-fatal myocardial infarction and late coronary revascularisation (≥90 days after CCTA) were assessed., Results: The distribution of patients with normal coronaries, non-obstructive CAD, moderate-to-severe CAD and CTO was 10 034 (44%), 7965 (34.9%), 4598 (20.1%) and 231 (1%), respectively. The mortality rate per 1000 person-years of CTO patients was non-significantly different from patients with moderate-to-severe CAD (22.95; 95% CI 12.71 to 41.45 vs 14.46; 95% CI 12.34 to 16.94; p=0.163), and significantly higher than of those with normal coronaries and non-obstructive CAD (p<0.001 for both). Among 14 382 individuals with follow-up for the composite end point, patients with CTO had a higher rate of events than those with moderate-to-severe CAD (106.56; 95% CI 76.51 to 148.42 vs 65.45; 95% CI 58.01 to 73.84, p=0.009). This difference was primarily driven by an increase in late revascularisations in CTO patients (27 of 35 events). After multivariable adjustment, compared with individuals with normal coronaries, the presence of CTO conferred the highest risk for adverse cardiac events (14.54; 95% CI 9.11 to 23.20, p<0.001)., Conclusions: The detection of CTO on non-invasive CCTA is associated with increased rate of late revascularisation but similar 2-year mortality as compared with moderate-to-severe CAD., Trial Registration Number: NCT01443637., Competing Interests: Competing interests: Dr JKM receives funding from the Dalio Foundation, National Institutes of Health and GE Healthcare. Dr JKM serves on the scientific advisory board of Arineta and GE Healthcare, and has an equity interest in Cleerly. All other coauthors have no relevant disclosures., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: Advances of cardiac computed tomography angiography (CTA) have been developed for dose reduction, but their efficacy in clinical practice is largely unknown. This study was designed to evaluate radiation dose exposure and utilization of dose-saving strategies for contrast-enhanced cardiac CTA in daily practice., Methods and Results: Sixty one hospitals from 32 countries prospectively enrolled 4502 patients undergoing cardiac CTA during one calendar month in 2017. Computed tomography angiography scan data and images were analysed in a central core lab and compared with a similar dose survey performed in 2007. Linear regression analysis was performed to identify independent predictors associated with dose. The most frequent indication for cardiac CTA was the evaluation of coronary artery disease in 89% of patients. The median dose-length product (DLP) of coronary CTA was 195 mGy*cm (interquartile range 110-338 mGy*cm). When compared with 2007, the DLP was reduced by 78% (P < 0.001) without an increase in non-diagnostic coronary CTAs (1.7% in 2007 vs. 1.9% in 2017 surveys, P = 0.55). A 37-fold variability in median DLP was observed between the hospitals with lowest and highest DLP (range of median DLP 57-2090 mGy*cm). Independent predictors for radiation dose of coronary CTA were: body weight, heart rate, sinus rhythm, tube voltage, iterative image reconstruction, and the selection of scan protocols., Conclusion: This large international radiation dose survey demonstrates considerable reduction of radiation exposure in coronary CTA during the last decade. However, the large inter-site variability in radiation exposure underlines the need for further site-specific training and adaptation of contemporary cardiac scan protocols.

Aims: Non-invasive assessment of stable chest pain patients is a critical determinant of resource utilization and clinical outcomes. Increasingly coronary computed tomography angiography (CCTA) with selective CCTA-derived fractional flow reserve (FFRCT) is being used. The ADVANCE Registry, is a large prospective examination of using a CCTA and FFRCT diagnostic pathway in real-world settings, with the aim of determining the impact of this pathway on decision-making, downstream invasive coronary angiography (ICA), revascularization, and major adverse cardiovascular events (MACE)., Methods and Results: A total of 5083 patients with symptoms concerning for coronary artery disease (CAD) and atherosclerosis on CCTA were enrolled at 38 international sites from 15 July 2015 to 20 October 2017. Demographics, symptom status, CCTA and FFRCT findings, treatment plans, and 90 days outcomes were recorded. The primary endpoint of reclassification between core lab CCTA alone and CCTA plus FFRCT-based management plans occurred in 66.9% [confidence interval (CI): 64.8-67.6] of patients. Non-obstructive coronary disease was significantly lower in ICA patients with FFRCT ≤0.80 (14.4%) compared to patients with FFRCT >0.80 (43.8%, odds ratio 0.19, CI: 0.15-0.25, P < 0.001). In total, 72.3% of subjects undergoing ICA with FFRCT ≤0.80 were revascularized. No death/myocardial infarction (MI) occurred within 90 days in patients with FFRCT >0.80 (n = 1529), whereas 19 (0.6%) MACE [hazard ratio (HR) 19.75, CI: 1.19-326, P = 0.0008] and 14 (0.3%) death/MI (HR 14.68, CI 0.88-246, P = 0.039) occurred in subjects with an FFRCT ≤0.80., Conclusions: In a large international multicentre population, FFRCT modified treatment recommendation in two-thirds of subjects as compared to CCTA alone, was associated with less negative ICA, predicted revascularization, and identified subjects at low risk of adverse events through 90 days.

Objectives: This study aimed to determine the rate and extent of plaque progression (PP), changes in plaque features, and clinical predictors of PP in patients with diabetes mellitus (DM)., Background: The natural history of coronary PP in patients with DM is not well established., Methods: A total of 1,602 patients (age 61.3 ± 9.0 years; 60.3% men; median scan interval 3.8 years) who underwent serial coronary computed tomography angiography over a period of at least 24 months were enrolled and analyzed from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) trial. Study endpoints were changes in plaque features in diabetics with PP and risk factors for PP by serial coronary computed tomography angiography between patients with and without DM. PP was defined if plaque volume at follow-up minus plaque volume at baseline was >0., Results: DM was an independent risk factor for PP (84.6%; 276 of 326 patients with PP) in multivariate analysis (odds ratio [OR]: 1.526; 95% confidence interval [CI]: 1.100 to 2.118; p = 0.011). Independent risk factors for PP in patients with DM were male sex (OR: 1.485; 95% CI: 1.003 to 2.199; p = 0.048) and mean plaque burden at baseline ≥75% (OR: 3.121; 95% CI: 1.701 to 5.725; p ≤0.001). After propensity matching, percent changes in overall plaque volume (30.3 ± 36.9% in patients without DM and 36.0 ± 29.7% in those with DM; p = 0.032) and necrotic core volume (-7.0 ± 35.8% in patients without DM and 21.5 ± 90.5% in those with DM; p = 0.007) were significantly greater in those with DM. The frequency of spotty calcification, positive remodeling, and burden of low-attenuation plaque were significantly greater in patients with DM., Conclusions: People with DM experience greater PP, particularly significantly greater progression in adverse plaque, than those without DM. Male sex and mean plaque burden >75% at baseline were identified as independent risk factors for PP., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Diagnosis of coronary artery disease and management strategies have relied solely on the presence of diameter stenosis ≥50%. We assessed whether direct quantification of plaque burden (PB) and plaque characteristics assessed by coronary computed tomography angiography could provide additional value in terms of predicting rapid plaque progression., Methods and Results: From a 13-center, 7-country prospective observational registry, 1345 patients (60.4±9.4 years old; 57.1% male) who underwent repeated coronary computed tomography angiography >2 years apart were enrolled. For conventional angiographic analysis, the presence of stenosis ≥50%, number of vessel involved, segment involvement score, and the presence of high-risk plaque feature were determined. For quantitative analyses, PB and annual change in PB (△PB/y) in the entire coronary tree were assessed. Clinical outcomes (cardiac death, nonfatal myocardial infarction, and coronary revascularization) were recorded. Rapid progressors, defined as a patient with ≥median value of △PB/y (0.33%/y), were older, more frequently male, and had more clinical risk factors than nonrapid progressors (all P <0.05). After risk adjustment, addition of baseline PB improved prediction of rapid progression to each angiographic assessment of coronary artery disease, and the presence of high-risk plaque further improved the predictive performance (all P <0.001). For prediction of adverse outcomes, adding both baseline PB and △PB/y showed best predictive performance (C statistics, 0.763; P <0.001)., Conclusions: Direct quantification of atherosclerotic PB in addition to conventional angiographic assessment of coronary artery disease might be beneficial for improving risk stratification of coronary artery disease., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02803411., (© 2018 American Heart Association, Inc.)

Introduction: Machine learning (ML) is a field in computer science that demonstrated to effectively integrate clinical and imaging data for the creation of prognostic scores. The current study investigated whether a ML score, incorporating only the 16 segment coronary tree information derived from coronary computed tomography angiography (CCTA), provides enhanced risk stratification compared with current CCTA based risk scores., Methods: From the multi-center CONFIRM registry, patients were included with complete CCTA risk score information and ≥3 year follow-up for myocardial infarction and death (primary endpoint). Patients with prior coronary artery disease were excluded. Conventional CCTA risk scores (conventional CCTA approach, segment involvement score, duke prognostic index, segment stenosis score, and the Leaman risk score) and a score created using ML were compared for the area under the receiver operating characteristic curve (AUC). Only 16 segment based coronary stenosis (0%, 1-24%, 25-49%, 50-69%, 70-99% and 100%) and composition (calcified, mixed and non-calcified plaque) were provided to the ML model. A boosted ensemble algorithm (extreme gradient boosting; XGBoost) was used and the entire data was randomly split into a training set (80%) and testing set (20%). First, tuned hyperparameters were used to generate a trained model from the training data set (80% of data). Second, the performance of this trained model was independently tested on the unseen test set (20% of data)., Results: In total, 8844 patients (mean age 58.0 ± 11.5 years, 57.7% male) were included. During a mean follow-up time of 4.6 ± 1.5 years, 609 events occurred (6.9%). No CAD was observed in 48.7% (3.5% event), non-obstructive CAD in 31.8% (6.8% event), and obstructive CAD in 19.5% (15.6% event). Discrimination of events as expressed by AUC was significantly better for the ML based approach (0.771) vs the other scores (ranging from 0.685 to 0.701), P < 0.001. Net reclassification improvement analysis showed that the improved risk stratification was the result of down-classification of risk among patients that did not experience events (non-events)., Conclusion: A risk score created by a ML based algorithm, that utilizes standard 16 coronary segment stenosis and composition information derived from detailed CCTA reading, has greater prognostic accuracy than current CCTA integrated risk scores. These findings indicate that a ML based algorithm can improve the integration of CCTA derived plaque information to improve risk stratification., (Published by Elsevier Inc.)

Background: The aim of the study is examine the impact of non-obstructive (<50%stenosis) left main (LM) disease on the natural history of coronary artery disease using serial coronary computed tomography angiography (CTA)., Methods: CTAs from the PARADIGM (Progression of atherosclerotic plaque determined by computed tomographic angiography imaging) study, a prospective multinational registry of patients who underwent serial CTA at a ≥2 year interval were analyzed. Those without evidence of CAD on their baseline scan were excluded, as were those with obstructive left main disease. Coronary artery vessels and their branches underwent quantification of: plaque volume and composition; diameter stenosis; presence of high-risk plaque., Results: Of 944 (62 ± 9 years, 60% male) who had evidence of CAD at baseline, 444 (47%) had LM disease. Those with LM disease had a higher baseline plaque volume (194.8 ± 221mm3 versus 72.9 ± 84.3mm3, p < 0.001) and a higher prevalence of high-risk plaque (17.5% versus 13%, p < 0.001) than those without LM disease. On multivariable general linear model, patients with LM disease had greater annual rates of progression of total (26.5 ± 31.4mm3/yr versus 14.9 ± 20.1mm3/yr, p < 0.001) and calcified plaque volume (17 ± 24mm3/yr versus 7 ± 11mm3/yr, p < 0.001), with no difference in fibrous, fibrofatty or necrotic core plaque components., Conclusion: The presence of non-obstructive LM disease is associated with greater rates of plaque progression and a higher prevalence of high-risk plaque throughout the entire coronary artery tree compared to CAD without LM involvement. Our data suggests that non-obstructive LM disease may be a marker for an aggressive phenotype of CAD that may benefit from more intensive treatment strategies., (Copyright © 2018. Published by Elsevier Inc.)

Background: To date, the clinical utility of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFRCT) has been limited to trials and single center experiences. We herein report the incidence of abnormal FFRCT (≤0.80) and the relationship of lesion-specific ischemia to subject demographics, symptoms, and degree of stenosis in the multicenter, prospective ADVANCE registry., Methods: One thousand patients with suspected angina having documented coronary artery disease on coronary CTA and clinically referred for FFR CT were prospectively enrolled in the registry. Patient demographics, symptom status, coronary CTA and FFR CT findings were recorded. Univariate and multivariate analyses were performed to investigate the predictors related to abnormal FFR CT ., Results: FFR CT data were analyzed in 952 patients (95.2%). Overall, 51.1% patients had a positive FFR CT value (≤0.80). Patients with ≥3 risk factors had a significantly higher rate of abnormal FFR CT than those with <3 risk factors (60.2% vs. 43.9%, p = 0.0001). On multivariate analysis, baseline diabetes (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.04-2.21, p = 0.030) and hypertension (OR 1.56, 95%CI 1.14-2.14, p = 0.005) were both predictive of abnormal FFR CT . In addition, >70% stenosis was significantly associated with low FFR CT (OR 31.16, 95%CI 12.25-79.22, p < 0.0001) vs. <30% stenosis. Notably, stenosis 30-49% vs. <30% had an increased likelihood of ischemia (OR 3.74, 95%CI 1.52-9.17, p < 0.0001)., Conclusions: In this real-world registry, CT angiographic stenosis severity in addition to baseline cardiovascular risk factors conferred an increased likelihood of an abnormal FFR CT . Importantly, however, mild CT angiographic stenoses were noted to have an increased hazard for ischemia and the converse holding true for more severe stenoses as well., (Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of the present study was to evaluate, in low-to-intermediate pre-test probability patients who were referred for coronary computed tomography angiography (CTA) and did not show obstructive coronary artery disease (CAD), whether an intramural course of a coronary artery is associated with worse outcome compared with patients without an intramural course of the coronary arteries., Background: The prognostic value of an intramural course of the coronary arteries on coronary CTA in patients without obstructive CAD is not well-known., Methods: The study population consisted of 947 patients with a low-to-intermediate pre-test probability who were referred for coronary CTA and who did not have obstructive CAD. During follow-up, the occurrence of unstable angina pectoris that required hospitalization, nonfatal myocardial infarction, and all-cause mortality was evaluated., Results: On coronary CTA, 210 patients (22%) had an intramural course of a coronary artery. The median depth of the intramural course was 1.9 mm (interquartile range: 1.4 to 2.6 mm). In 84 patients (40%), the depth of the intramural course was considered deep (>2 mm surrounded by myocardium). During a median follow-up of 4.9 years (interquartile range: 3.2 to 6.9 years), a total of 43 events occurred: hospitalization due to unstable angina pectoris in 13 patients (1.4%); 7 patients (0.7%) had a nonfatal myocardial infarction; and 23 patients died (2.4%). The 6-year cumulative event rate of unstable angina pectoris requiring hospitalization (0.0% vs. 1.1%), nonfatal myocardial infarction (0.5% vs. 0.4%), all-cause mortality (1.9% vs. 2.2%) as well as the combined endpoint of all 3 events (2.4% vs. 3.7%) was similar in patients with and without an intramural course of a coronary artery., Conclusions: In patients without obstructive CAD on coronary CTA, the presence of an intramural course of a coronary artery was not associated with worse outcome., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Introduction: A standardised approach to the interpretation of FFRCT data is currently lacking. We evaluated the rate of reclassification of FFRCT positivity using the FFRCT value distal to an anatomical stenoses compared to the lowest FFRCT value., Method: Patients who underwent coronary CTA and FFRCT analysis were eligible. FFRCT value of ≤ 0.80 was considered positive. Positive FFRCT distal to stenosis was defined as those with a stenoses of ≥ 25% with an associated FFRCT value of ≤ 0.80 within 2cm distal to the lesion. Outcome data on subsequent invasive coronary angiography (ICA) and coronary revascularisation were collected with a minimum follow-up of 60 days to account for delay between referral for invasive testing and/or revascularisation and receiving the procedure., Result: 192 patients (mean age 60.7 ± 10.6 years, 67.5% men) were included. FFRCT was positive for lowest FFRCT value in 55.7% of patients. Positive FFRCT value distal to stenosis was found in 31.3%. The overall reclassification rate of those positive for lowest FFRCT value to negative for FFRCT value distal to stenosis was 43.9% (p < 0.01). The reclassification rates were most pronounced for those with intermediate stenoses - 67% for those with < 50% stenoses, p < 0.01; 49% for 50-69% stenoses, p < 0.01. Amongst those who underwent ICA, the rate of revascularization was significant higher for those with positive FFRCT distal to stenosis compared to those positive for lowest FFRCT value (revascularization/ICA = 0.53 vs 0.44, p < 0.01)., Conclusion: Using FFRCT values distal to a anatomical stenoses, 44% of patients positive for lowest FFRCT value were reclassified as negative for FFRCT value distal to stenosis. Those who underwent ICA, the rate of revascularisation was higher amongst those with positive FFRCT distal to stenosis compared to those positive for lowest FFRCT value., (Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background: Microvascular angina (MVA) is an incompletely understood clinical entity. Computational analysis of coronary Computed Tomography Angiography (CTA) has shown an association between low coronary lumen volume to myocardial mass (V/M) ratio and lower Fractional Flow Reserve values, independent of plaque measures. We hypothesized that low V/M ratio may be present in patients with MVA., Methods: A retrospective case-control analysis was performed using patients fulfilling guideline criteria for MVA with controls matched for age, gender, coronary risk factors and atherosclerotic plaque burden. V/M was extracted off site (Heartflow Inc; Redwood City, CA) employing allometric scaling laws that allow the definition of the coronary circulation beyond the epicardium. FFR CT values were calculated in the major epicardial coronary arteries for each group., Results: A total of 30 patients with MVA and 32 matched controls were included in the study. Mean total coronary lumen volume (2302 mm 3  ± 109 vs 2978 mm 3  ± 134, p < 0.001) and mean myocardial mass (90.4 g ± 13.7 vs 100.4 g ± 20.1, p = 0.029) were lower in MVA patients compared to controls. Mean V/M ratio was significantly lower in MVA compared to controls (25.6 mm 3 /g ± 5.9 vs 30.0 mm 3 /g ± 6.5, p = 0.007; c-statistic 0.69). V/M ratio did not differ significantly between subclasses of angina severity (p = 0.747). No difference in mean nadir FFR CT values was found between MVA and control groups in the LAD (0.86 ± 0.07 vs 0.83 ± 0.07, p = 0.154), LCX (0.90 ± 0.05 vs 0.90 ± 0.06, p = 0.240) and RCA (0.90 ± 0.04 vs 0.90 ± 0.03, p = 0.773) vessels., Conclusion: Patients with microvascular angina demonstrate a significantly lower coronary CTA-derived coronary volume/myocardial mass ratio than asymptomatic controls., (Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to evaluate the prognostic value of sequential hybrid imaging strategy in which positron emission tomography (PET) perfusion imaging is performed selectively in patients with suspected obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA)., Background: Coronary CTA is an accurate diagnostic test for excluding obstructive CAD. However, the positive predictive value is suboptimal., Methods: We investigated 864 consecutive symptomatic patients with intermediate probability of CAD who adhered to the sequential imaging approach. PET myocardial perfusion imaging using 15 O-labeled water during adenosine stress was performed when suspected obstructive stenosis was present on coronary CTA. The major adverse events (AEs) including all-cause mortality, myocardial infarction (MI), and unstable angina pectoris (UAP) were recorded., Results: During a median follow-up of 3.6 years, 16 deaths, 10 MIs, and 5 UAPs occurred. Obstructive CAD was excluded by coronary CTA in 462 (53%) patients who had significantly lower annual AE rate than did patients with suspected obstructive stenosis on coronary CTA (0.4% vs. 1.5%; p = 0.003). The latter underwent PET study, on which 195 (49%) had normal and 207 had abnormal perfusion. The annual rate of AEs was 5 times higher in those with abnormal perfusion than with normal perfusion (2.5% vs. 0.5%; p = 0.004). Patients with normal perfusion had AE rate comparable to patients without obstructive CAD on coronary CTA (p = 0.77)., Conclusions: In patients with suspected CAD obstructive disease can be excluded in 53% of patients by coronary CTA, and these patients have good outcome. About one-half (49%) of the remaining patients have normal perfusion and event rate comparable to patients without obstructive CAD on coronary CTA while patients with ischemia have clearly worse outcome. Sequential approach utilizing anatomical imaging by coronary CTA followed by selective functional perfusion imaging is a feasible strategy to diagnose and risk-stratify patients with suspected CAD., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Coronary microvascular dysfunction (CMD) can cause angina in the absence of obstructive coronary artery disease (CAD). We studied the frequency and angiographic characteristics of CMD in symptomatic patients with suspected stable CAD and identified CMD as diffusely abnormal coronary vasodilator capacity by positron emission tomography (PET) perfusion imaging., Methods and Results: We recruited prospectively 189 patients with intermediate pre-test probability of CAD who underwent coronary computed tomography angiography and quantitative 15O-water PET perfusion imaging followed by invasive coronary angiography, and assessment of fractional flow reserve when feasible. Prevalence of obstructive epicardial CAD was 37%. Absolute myocardial blood flow was diffusely reduced (<2.4 mL/g/min) within the left ventricle during adenosine stress in 32 (17%) patients. In 15 (8%) patients, this was explained by three-vessel obstructive CAD, whereas the remaining 17 (9%) were diagnosed with CMD. Of these, 2 (1% of all patients) had no coronary atherosclerosis, 5 (3% of all patients) had non-obstructive atherosclerosis, and in 10 (5% of all patients) CMD co-existed with obstructive CAD. Atypical angina or non-anginal chest pain (53%) was the most common presentation. Older age and male sex were associated with CMD, but other risk factors of CAD were equally common in patients with or without CMD., Conclusion: Coronary microvascular dysfunction exists in 9% of symptomatic stable patients with suspected CAD. However, the prevalence of microvascular dysfunction without any coronary atherosclerosis is low (1%) in this population., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)

Background and Purpose: Patients who received chest irradiation for treatment of a malignancy are at increased risk for the development of coronary artery atherosclerosis. Little is known about the anatomical coronary artery plaque characteristics of irradiation induced coronary artery disease (CAD). This study aimed to evaluate potential differences in the presence, extent, severity, composition and location of CAD in patients treated with mediastinal irradiation compared with non-irradiated controls matched on age, gender and cardiovascular risk factors., Material and Methods: Seventy-nine asymptomatic Hodgkin and non-Hodgkin lymphoma survivors, all treated with mediastinal irradiation with or without chemotherapy, who underwent coronary computed tomography angiography (CTA) to exclude or detect CAD were included. Patients were 1:3 matched with non-irradiated controls (n=237) for age, gender, diabetes, hypertension, hypercholesterolemia, family history of CAD and currently smoking. Mean age at cancer diagnosis was 26±9years and age at the time of coronary CTA was 45±11years., Results: More patients had an abnormal CTA (defined as any coronary artery atherosclerosis): 59% vs. 36% (P<0.001) and significantly more patients had two vessel CAD: 10% vs. 6% and three vessel/left main CAD: 24% vs. 9% compared with controls (overall P<0.001). The maximum stenosis severity among patients was less often <30% (53% vs. 68%) and more often >70% (7% vs. 0%) (overall P=0.001). Patients had more coronary artery plaques in proximal coronary artery segments: left main (17% vs. 6%, P=0.004), proximal left anterior descending artery (30% vs. 16%, P=0.004), proximal right coronary artery (25% vs 10%, P<0.001) and proximal left circumflex artery (14% vs 6%, P=0.022), whereas the number of plaques in non-proximal segments did not differ between groups., Conclusions: Hodgkin and non-Hodgkin lymphoma survivors treated with mediastinal irradiation with or without chemotherapy showed a higher presence, greater severity, larger extent and more proximally located CAD compared with age, gender and risk factor matched non-irradiated controls. These findings represent features of higher risk CAD and may explain the worse cardiovascular outcome after chest irradiation., (Copyright © 2017 Elsevier B.V. All rights reserved.)