The role of coronary CT angiography in athletes.

The sudden death of a young or high-level athlete or adolescent during recreational sports is one of the events with the greatest impact on public opinion in modern society. Sudden cardiac death (SCD) is the principal medical cause of death in athletes and can be the first and last clinical presentation of underlying disease. To prevent such episodes, pre-participation screening has been introduced in many countries to guarantee cardiovascular safety during sports and has become a common target among medical sports/governing organizations. Different cardiac conditions may cause SCD, with incidence depending on definition, evaluation methods, and studied populations, and a prevalence and etiology changing according to the age of athletes, with CAD most frequent in master athletes, while coronary anomalies and non-ischemic causes prevalent in young. To detect silent underlying causes early would be of considerable clinical value. This review summarizes the pre-participation screening in athletes, the specialist agonistic suitability visit performed in Italy, the anatomical characteristics of malignant coronary anomalies, and finally, the role of coronary CT angiography in such arena. In particular, the anatomical conditions suggesting potential disqualification from sport, the post-treatment follow-up to reintegrate young athletes, the diagnostic workflow to rule-out CAD in master athletes, and their clinical management are analyzed.

Coronary Plaque in People With HIV vs Non-HIV Asymptomatic Community and Symptomatic Higher-Risk Populations.

Background: People with HIV (PWH) have a high burden of coronary plaques; however, the comparison to people without known HIV (PwoH) needs clarification. Objectives: The purpose of this study was to determine coronary plaque burden/phenotype in PWH vs PwoH. Methods: Nonstatin using participants from 3 contemporary populations without known coronary plaques with coronary CT were compared: the REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV) studying PWH without cardiovascular symptoms at low-to-moderate risk (n = 755); the SCAPIS (Swedish Cardiopulmonary Bioimage Study) of asymptomatic community PwoH at low-to-intermediate cardiovascular risk (n = 23,558); and the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) of stable chest pain PwoH (n = 2,291). The coronary plaque prevalence on coronary CT was compared, and comparisons were stratified by 10-year atherosclerotic cardiovascular disease (ASCVD) risk, age, and coronary artery calcium (CAC) presence. Results: Compared to SCAPIS and PROMISE PwoH, REPRIEVE PWH were younger (50.8 ± 5.8 vs 57.3 ± 4.3 and 60.0 ± 8.0 years; P < 0.001) and had lower ASCVD risk (5.0% ± 3.2% vs 6.0% ± 5.3% and 13.5% ± 11.0%; P < 0.001). More PWH had plaque compared to the asymptomatic cohort (48.5% vs 40.3%; P < 0.001). When stratified by ASCVD risk, PWH had more plaque compared to SCAPIS and a similar prevalence of plaque compared to PROMISE. CAC = 0 was more prevalent in PWH (REPRIEVE 65.2%; SCAPIS 61.6%; PROMISE 49.6%); among CAC = 0, plaque was more prevalent in PWH compared to the PwoH cohorts (REPRIEVE 20.8%; SCAPIS 5.4%; PROMISE 12.3%, P < 0.001). Conclusions: Asymptomatic PWH in REPRIEVE had more plaque than asymptomatic PwoH in SCAPIS but had similar prevalence to a higher-risk stable chest pain cohort in PROMISE. In PWH, CAC = 0 does not reliably exclude plaque.

A coronary CT angiography-derived myocardial radiomics model for predicting adverse outcomes in chronic myocardial infarction.

BACKGROUND: The prognostic efficacy of a coronary computed tomography angiography (CCTA)-derived myocardial radiomics model in patients with chronic myocardial infarction (MI) is unclear. METHODS: In this retrospective study, a cohort of 236 patients with chronic MI who underwent both CCTA and cardiac magnetic resonance (CMR) examinations within 30 days were enrolled and randomly divided into training and testing datasets at a ratio of 7:3. The clinical endpoints were major adverse cardiovascular events (MACE), defined as all-cause death, myocardial reinfarction and heart failure hospitalization. The entire three-dimensional left ventricular myocardium on CCTA images was segmented as the volume of interest for the extraction of radiomics features. Five models, namely the clinical model, CMR model, clinical+CMR model, CCTA-radiomics model, and clinical+CCTA-radiomics model, were constructed using multivariate Cox regression. The prognostic performances of these models were evaluated through receiver operating characteristic curve analysis and the index of concordance (C-index). RESULTS: Fifty-one (20.16%) patients experienced MACE during a median follow-up of 1439.5 days. The predictive performance of the CCTA-radiomics model surpassed that of the clinical model, CMR model, and clinical+CMR model in both the training (area under the curve (AUC) of 0.904 vs. 0.691, 0.764, 0.785; C-index of 0.88 vs. 0.71, 0.75, 0.76, all p values <0.001) and testing (AUC of 0.893 vs. 0.704, 0.851, 0.888; C-index of 0.86 vs. 0.73, 0.85, 0.85, all p values <0.05) datasets. CONCLUSIONS: The CCTA-based myocardial radiomics model is a valuable tool for predicting adverse outcomes in chronic MI, providing incremental value to conventional clinical and CMR parameters.

Improved stent sharpness evaluation with super-resolution deep learning reconstruction in coronary CT angiography.

OBJECTIVES: This study aimed to assess the impact of super-resolution deep learning reconstruction (SR-DLR) on coronary CT angiography (CCTA) image quality and blooming artifacts from coronary artery stents in comparison to conventional methods, including hybrid iterative reconstruction (HIR) and deep learning-based reconstruction (DLR). METHODS: A retrospective analysis included 66 CCTA patients from July to November 2022. Major coronary arteries were evaluated for image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Stent sharpness was quantified using 10%-90% edge rise slope (ERS) and 10%-90% edge rise distance (ERD). Qualitative analysis employed a 5-point scoring system to assess overall image quality, image noise, vessel wall, and stent structure. RESULTS: SR-DLR demonstrated significantly lower image noise compared to HIR and DLR. SNR and CNR were notably higher in SR-DLR. Stent ERS was significantly improved in SR-DLR, with mean ERD values of 0.70 ± 0.20 mm for SR-DLR, 1.13 ± 0.28 mm for HIR, and 0.85 ± 0.26 mm for DLR. Qualitatively, SR-DLR scored higher in all categories. CONCLUSIONS: SR-DLR produces images with lower image noise, leading to improved overall image quality, compared with HIR and DLR. SR-DLR is a valuable image reconstruction algorithm for enhancing the spatial resolution and sharpness of coronary artery stents without being constrained by hardware limitations. ADVANCES IN KNOWLEDGE: The overall image quality was significantly higher in SR-DLR, resulting in sharper coronary artery stents compared to HIR and DLR.

Coronary CTA-based Vascular Radiomics Predicts Atherosclerosis Development Proximal to LAD Myocardial Bridging.

BACKGROUND: Cardiac cycle morphological changes can accelerate plaque growth proximal to myocardial bridging (MB) in the left anterior descending artery (LAD). OBJECTIVE: To assess coronary CT angiography (CCTA)-based vascular radiomics for predicting proximal plaque development in LAD MB. METHODS: Patients with repeated CCTA scans showing LAD MB without proximal plaque in index CCTA were included from Jinling Hospital as development set. They were divided into training and internal testing in an 8:2 ratio. Patients from 4 other tertiary hospitals were set as external validation set. The endpoint was proximal plaque development of LAD MB in follow-up CCTA. Four vascular radiomics models were built: MB centerline (MB CL), proximal MB CL (pMB CL), MB cross section (MB CS), and proximal MB CS (pMB CS), whose performances were evaluated using area under the curve (AUC), integrated discrimination improvement (IDI) and net reclassification improvement (NRI). RESULTS: 295 patients were included in the development (n=192; median age, 54±11 years; 137 men) and external validation sets (n=103; median age, 57±9 years; 57 men). The pMB CS vascular radiomics model exhibited higher AUCs in training, internal test, and external sets (AUC=0.78, 0.75, 0.75) than the clinical and anatomical model (all p<0.05). Integration of the pMB CS vascular radiomics model significantly raised the AUC of the clinical and anatomical model from 0.56 to 0.75 (p=0.002), along with enhanced NRI (0.76 [0.37-1.14], p<0.001) and IDI (0.17 [0.07-0.26], p<0.001) in the external validation set. CONCLUSION: The CCTA-based pMB CS vascular radiomics model can predict plaque development in LAD MB.

Artificial Intelligence-Enabled Quantitative Coronary Plaque and Hemodynamic Analysis for Predicting Acute Coronary Syndrome.

BACKGROUND: A lesion-level risk prediction for acute coronary syndrome (ACS) needs better characterization. OBJECTIVES: This study sought to investigate the additive value of artificial intelligence-enabled quantitative coronary plaque and hemodynamic analysis (AI-QCPHA). METHODS: Among ACS patients who underwent coronary computed tomography angiography (CTA) from 1 month to 3 years before the ACS event, culprit and nonculprit lesions on coronary CTA were adjudicated based on invasive coronary angiography. The primary endpoint was the predictability of the risk models for ACS culprit lesions. The reference model included the Coronary Artery Disease Reporting and Data System, a standardized classification for stenosis severity, and high-risk plaque, defined as lesions with ≥2 adverse plaque characteristics. The new prediction model was the reference model plus AI-QCPHA features, selected by hierarchical clustering and information gain in the derivation cohort. The model performance was assessed in the validation cohort. RESULTS: Among 351 patients (age: 65.9 ± 11.7 years) with 2,088 nonculprit and 363 culprit lesions, the median interval from coronary CTA to ACS event was 375 days (Q1-Q3: 95-645 days), and 223 patients (63.5%) presented with myocardial infarction. In the derivation cohort (n = 243), the best AI-QCPHA features were fractional flow reserve across the lesion, plaque burden, total plaque volume, low-attenuation plaque volume, and averaged percent total myocardial blood flow. The addition of AI-QCPHA features showed higher predictability than the reference model in the validation cohort (n = 108) (AUC: 0.84 vs 0.78; P < 0.001). The additive value of AI-QCPHA features was consistent across different timepoints from coronary CTA. CONCLUSIONS: AI-enabled plaque and hemodynamic quantification enhanced the predictability for ACS culprit lesions over the conventional coronary CTA analysis. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary Computed Tomography Angiography and Computational Fluid Dynamics II [EMERALD-II]; NCT03591328).

Use of coronary artery calcium score and coronary CT angiography to guide cardiovascular prevention and treatment.

Currently, cardiovascular risk stratification to guide preventive therapy relies on clinical scores based on cardiovascular risk factors. However, the discriminative power of these scores is relatively modest. The use of coronary artery calcium score (CACS) and coronary CT angiography (CCTA) has surfaced as methods for enhancing the estimation of risk and potentially providing insights for personalized treatment in individual patients. CACS improves overall cardiovascular risk prediction and may be used to improve the yield of statin therapy in primary prevention, and possibly identify patients with a favorable risk/benefit relationship for antiplatelet therapies. CCTA holds promise to guide anti-atherosclerotic therapies and to monitor individual response to these treatments by assessing individual plaque features, quantifying total plaque volume and composition, and assessing peri-coronary adipose tissue. In this review, we aim to summarize current evidence regarding the use of CACS and CCTA for guiding lipid-lowering and antiplatelet therapy and discuss the possibility of using plaque burden and plaque phenotyping to monitor response to anti-atherosclerotic therapies.

Virtual calcium removal in calcified coronary arteries with photon-counting detector CT-first in-vivo experience.

Purpose: To evaluate the feasibility and accuracy of quantification of calcified coronary stenoses using virtual non-calcium (VNCa) images in coronary CT angiography (CCTA) with photon-counting detector (PCD) CT compared with quantitative coronary angiography (QCA). Materials and methods: This retrospective, institutional-review board approved study included consecutive patients with calcified coronary artery plaques undergoing CCTA with PCD-CT and invasive coronary angiography between July and December 2022. Virtual monoenergetic images (VMI) and VNCa images were reconstructed. Diameter stenoses were quantified on VMI and VNCa images by two readers. 3D-QCA served as the standard of reference. Measurements were compared using Bland-Altman analyses, Wilcoxon tests, and intraclass correlation coefficients (ICC). Results: Thirty patients [mean age, 64 years ± 8 (standard deviation); 26 men] with 81 coronary stenoses from calcified plaques were included. Ten of the 81 stenoses (12%) had to be excluded because of erroneous plaque subtraction on VNCa images. Median diameter stenosis determined on 3D-QCA was 22% (interquartile range, 11%-35%; total range, 4%-88%). As compared with 3D-QCA, VMI overestimated diameter stenoses (mean differences -10%, p < .001, ICC: .87 and -7%, p < .001, ICC: .84 for reader 1 and 2, respectively), whereas VNCa images showed similar diameter stenoses (mean differences 0%, p = .68, ICC: .94 and 1%, p = .07, ICC: .93 for reader 1 and 2, respectively). Conclusion: First experience in mainly minimal to moderate stenoses suggests that virtual calcium removal in CCTA with PCD-CT, when feasible, has the potential to improve the quantification of calcified stenoses.

A novel hybrid machine learning model for auxiliary diagnosing myocardial ischemia.

Introduction: Accurate identification of the myocardial texture features of fat around the coronary artery on coronary computed tomography angiography (CCTA) images are crucial to improve clinical diagnostic efficiency of myocardial ischemia (MI). However, current coronary CT examination is difficult to recognize and segment the MI characteristics accurately during earlier period of inflammation. Materials and methods: We proposed a random forest model to automatically segment myocardium and extract peripheral fat features. This hybrid machine learning (HML) model is integrated by CCTA images and clinical data. A total of 1,316 radiomics features were extracted from CCTA images. To further obtain the features that contribute the most to the diagnostic model, dimensionality reduction was applied to filter features to three: LNS, GFE, and WLGM. Moreover, statistical hypothesis tests were applied to improve the ability of discriminating and screening clinical features between the ischemic and non-ischemic groups. Results: By comparing the accuracy, recall, specificity and AUC of the three models, it can be found that HML had the best performance, with the value of 0.848, 0.762, 0.704 and 0.729. Conclusion: In sum, this study demonstrates that ML-based radiomics model showed good predictive value in MI, and offer an enhanced tool for predicting prognosis with greater accuracy.

Polygenic Scores and Preclinical Cardiovascular Disease in Individuals With HIV: Insights From the REPRIEVE Trial.

BACKGROUND: Coronary artery disease (CAD) is a leading cause of death among the 38.4 million people with HIV globally. The extent to which cardiovascular polygenic risk scores (PRSs) derived in non-HIV populations generalize to people with HIV is not well understood. METHODS AND RESULTS: PRSs for CAD (GPSMult) and lipid traits were calculated in a global cohort of people with HIV treated with antiretroviral therapy with low-to-moderate atherosclerotic cardiovascular disease risk enrolled in REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV). The PRSs were associated with baseline lipid traits in 4495 genotyped participants, and with subclinical CAD in a subset of 662 who underwent coronary computed tomography angiography. Among participants who underwent coronary computed tomography angiography (mean age, 50.9 [SD, 5.8] years; 16.1% women; 41.8% African, 57.3% European, 1.1% Asian), GPSMult was associated with plaque presence with odds ratio (OR) per SD in GPSMult of 1.42 (95% CI, 1.20-1.68; P=3.8×10-5), stenosis >50% (OR, 2.39 [95% CI, 1.48-3.85]; P=3.4×10-4), and noncalcified/vulnerable plaque (OR, 1.45 [95% CI, 1.23-1.72]; P=9.6×10-6). Effects were consistent in subgroups of age, sex, 10-year atherosclerotic cardiovascular disease risk, ancestry, and CD4 count. Adding GPSMult to established risk factors increased the C-statistic for predicting plaque presence from 0.718 to 0.734 (P=0.02). Furthermore, a PRS for low-density lipoprotein cholesterol was associated with plaque presence with OR of 1.21 (95% CI, 1.01-1.44; P=0.04), and partially calcified plaque with OR of 1.21 (95% CI, 1.01-1.45; P=0.04) per SD. CONCLUSIONS: Among people with HIV treated with antiretroviral therapy without documented atherosclerotic cardiovascular disease and at low-to-moderate calculated risk in REPRIEVE, an externally developed CAD PRS was predictive of subclinical atherosclerosis. PRS for low-density lipoprotein cholesterol was also associated with subclinical atherosclerosis, supporting a role for low-density lipoprotein cholesterol in HIV-associated CAD. REGISTRATION: URL: https://www.reprievetrial.org; Unique identifier: NCT02344290.

2024 Consensus Statement on Coronary Stenosis and Plaque Evaluation in CT Angiography From the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT).

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.

Coronary Artery Disease: Role of Computed Tomography and Recent Advances.

In this review, the authors summarize the role of coronary computed tomography angiography and coronary artery calcium scoring in different clinical presentations of chest pain and preventative care and discuss future directions and new technologies such as pericoronary fat inflammation and the growing footprint of artificial intelligence in cardiovascular medicine.

[Validation of Optimal Imaging Conditions for Coronary Computed Tomography Angiography Using High-definition Mode and Deep Learning Image Reconstruction Algorithm].

PURPOSE: To verify the optimal imaging conditions for coronary computed tomography angiography (CCTA) examinations when using high-definition (HD) mode and deep learning image reconstruction (DLIR) in combination. METHOD: A chest phantom and an in-house phantom using 3D printer were scanned with a 256-row detector CT scanner. The scan parameters were as follows - acquisition mode: ON (HD mode) and OFF (normal resolution [NR] mode), rotation time: 0.28 s/rotation, beam coverage width: 160 mm, and the radiation dose was adjusted based on CT-AEC. Image reconstruction was performed using ASiR-V (Hybrid-IR), TrueFidelity Image (DLIR), and HD-Standard (HD mode) and Standard (NR mode) reconstruction kernels. The task-based transfer function (TTF) and noise power spectrum (NPS) were measured for image evaluation, and the detectability index (d') was calculated. Visual evaluation was also performed on an in-house coronary phantom. RESULT: The in-plane TTF was better for the HD mode than for the NR mode, while the z-axis TTF was lower for DLIR than for Hybrid-IR. The NPS values in the high-frequency region were higher for the HD mode compared to those for the NR mode, and the NPS was lower for DLIR than for Hybrid-IR. The combination of HD mode and DLIR showed the best value for in-plane d', whereas the combination of NR mode and DLIR showed the best value for z-axis d'. In the visual evaluation, the combination of NR mode and DLIR showed the best values from a noise index of 45 HU. CONCLUSION: The optimal combination of HD mode and DLIR depends on the image noise level, and the combination of NR mode and DLIR was the best imaging condition under noisy conditions.

Implantación de un protocolo de angio-TC coronaria basado en el índice de masa corporal: reducción de dosis, calidad de imagen y rendimiento diagnóstico / Implementing a coronary CT angiography protocol based on the body mass index: radiation dose reduction, image quality, and diagnostic performance

Objetivos: Valorar la relación entre el score de calcio coronario y la elección posterior del kilovoltaje según el criterio del radiólogo en un protocolo estándar (PE) de angio-TC coronaria (aTCC) para descartar enfermedad coronaria. Cuantificar la reducción de la radiación ionizante después de vincular el kilovoltaje al índice de masa corporal en un protocolo de baja dosis (PBD) con reconstrucción iterativa de modelado. Valorar la calidad de imagen y el rendimiento diagnóstico del PBD. Material y método: Las características antropométricas, el score de calcio, los niveles de kilovoltaje y los valores de dosis estimada específica para el tamaño (SSDE) y del producto dosis-longitud fueron comparados entre un grupo de 50 pacientes con PBD reclutados prospectivamente y una cohorte histórica adquirida con el PE. Estos parámetros, el número de segmentos coronarios no valorables sin y con tolerancia de fase, la atenuación y la relación señal-ruido en la aorta ascendente en el PBD fueron correlacionados con una calidad de imagen de nivel excelente según una escala semicuantitativa. El rendimiento diagnóstico por paciente fue calculado usando la revaloración clínica a los 24 meses como el método diagnóstico de referencia, incluyendo las pruebas derivadas. Resultados: En el PE existía una relación entre la presencia de calcio coronario y la elección de kilovoltajes altos (p=0,02), que desaparecía en el PBD (p=0,47). Los valores de SSDE y de DLP en el PBD fueron significativamente inferiores y presentaron menor dispersión que en el PE (9,22 mGy [RIQ 7,84-12,1 mGy] y 97 mGy*cm [RIQ 78-134 mGy*cm] contra 26,5 mGy [RIQ 21,3-36,3 mGy] y 253 mGy*cm [RIQ 216-404 mGy*cm]; p <0,001 para las comparaciones de las medianas y de las dispersiones entre ambos grupos)...(AU)

Objectives: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists’ criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients’ body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. Material and methods: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. Results: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (P=0.02); this correlation was not found in the low-dose protocol (P=0.47). Median values of SSDE and DLP were significantly (P<0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97mGy*cm (IQR 78-134mGy*cm) vs. 253mGy*cm (IQR 216-404mGy*cm) in the standard protocol], respectively...(AU)

Implementing a coronary CT angiography protocol based on the body mass index: Radiation dose reduction, image quality, and diagnostic performance.

OBJECTIVES: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists' criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients' body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. MATERIAL AND METHODS: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. RESULTS: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (p = 0.02); this correlation was not found in the low-dose protocol (p = 0.47). Median values of SSDE and DLP were significantly (p < 0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97 mGy cm (IQR 78-134 mGy cm) vs. 253 mGy cm (IQR 216-404 mGy cm) in the standard protocol], respectively. The overall quality of the images obtained with the low-dose protocol was considered good or excellent in 96% of the studies. The parameters associated with image quality in a multivariable model (C statistic = 0.792) were heart rate (estimated coefficient, -0,12 [95% confidence interval: -0.2, -0.04]; p < 0.01) and the SSDE (estimated coefficient, -0,26 [95% confidence interval: -0.51, -0.01]; p < 0.05). The CAD-RADS modifier for a not fully evaluable or diagnostic study was used on two occasions (4%); the final measures for the diagnosis of coronary disease were sensitivity 100%, specificity 94%, and efficacy 94%. CONCLUSIONS: In the standard protocol, the radiologist selects higher kilovoltage for CT angiography studies for patients whose previous calcium score indicates the presence of coronary calcium. In the low-dose protocol, linking kilovoltage with body mass index enables the dose of radiation to be reduced by 65% while obtaining excellent or good image quality in 96% of studies and excellent diagnostic performance.

The role of epicardial fat radiomic profiles for atrial fibrillation identification and recurrence risk with coronary CT angiography.

OBJECTIVES: Fat radiomic profile (FRP) was a promising imaging biomarker for identifying increased cardiac risk. We hypothesize FRP can be extended to fat regions around pulmonary veins (PV), left atrium (LA), and left atrial appendage (LAA) to investigate their usefulness in identifying atrial fibrillation (AF) and the risk of AF recurrence. METHODS: We analysed 300 individuals and grouped patients according to the occurrence and types of AF. We used receiver operating characteristic and survival curves analyses to evaluate the value of imaging biomarkers, including fat attenuation index (FAI) and FRP, in distinguishing AF from sinus rhythm and predicting post-ablation recurrence. RESULTS: FRPs from AF-relevant fat regions showed significant performance in distinguishing AF and non-AF with higher AUC values than FAI (peri-PV: FRP = 0.961 vs FAI = 0.579, peri-LA: FRP = 0.923 vs FAI = 0.575, peri-LAA: FRP = 0.900 vs FAI = 0.665). FRPs from peri-PV, peri-LA, and peri-LAA were able to differentiate persistent and paroxysmal AF with AUC values of 0.804, 0.819, and 0.694. FRP from these regions improved AF recurrence prediction with an AUC of 0.929, 0.732, and 0.794. Patients with FRP cut-off values of ≥0.16, 0.38, and 0.26 had a 7.22-, 5.15-, and 4.25-fold higher risk of post-procedure recurrence, respectively. CONCLUSIONS: FRP demonstrated potential in identifying AF, distinguishing AF types, and predicting AF recurrence risk after ablation. FRP from peri-PV fat depot exhibited a strong correlation with AF. Therefore, evaluating epicardial fat using FRP was a promising approach to enhance AF clinical management. ADVANCES IN KNOWLEDGE: The role of epicardial adipose tissue (EAT) in AF had been confirmed, we focussed on the relationship between EAT around pulmonary arteries and LAA in AF which was still unknown. Meanwhile, we used the FRP to excavate more information of EAT in AF.

Long-term prognostic implications of CT angiography-derived fractional flow reserve: Results from the DISCOVER-FLOW study.

BACKGROUND & OBJECTIVES: The long-term prognostic implications of CT angiography-derived fractional flow reserve (FFRCT) remains unclear. We aimed to explore the long-term outcomes of FFRCT in the first-in-human study of it. MATERIALS & METHODS: A total of 156 vessels from 102 patients with stable coronary artery disease, who underwent coronary CT angiography (CCTA) and invasive FFR measurement, were followed. The primary endpoint was target vessel failure (TVF), including cardiovascular death, target vessel myocardial infarction, and target vessel revascularization. Outcome analysis with FFRCT was performed on a per-vessel basis using a marginal Cox proportional hazard model. RESULTS: During median 9.9 years of follow-up, TVF occurred in 20 (12.8%) vessels. FFRCT â€‹≤0.80 discriminated TVF (hazard ratio [HR] 2.61, 95% confidence interval [CI] 1.06, 6.45). Among 94 vessels with deferral of percutaneous coronary intervention (PCI), TVF risk was inversely correlated with FFRCT â€‹(HR 0.62 per 0.1 increase, 95% CI 0.44, 0.86), with the cumulative incidence of TVF being 2.6%, 15.2%, and 28.6% for vessels with FFRCT â€‹>0.90, 0.81-0.90, and ≤0.80, respectively (p-for-trend 0.005). Predictive value for clinical outcomes of FFRCT was similar to that of invasive FFR (c-index 0.79 vs 0.71, P â€‹= â€‹0.28). The estimated TVF risk was higher in the deferral of PCI group than the PCI group for vessels with FFRCT ≤0.81. CONCLUSION: FFRCT showed improved long-term risk stratification and displayed a risk continuum similar to invasive FFR. CLINICAL TRIAL REGISTRATION: NCT01189331.

The Role of CCTA-derived Cardiac Structure and Function Analysis in the Prediction of Readmission in Nonischemic Heart Failure.

Cardiac function and structure significantly impact nonischemic heart failure (HF) patient outcomes. This study investigated 236 patients (107 nonischemic heart failure, 129 healthy) to assess the relationship between coronary computed tomography angiography (CCTA)-derived parameters and clinical outcomes. Among the nonischemic heart failure patients, 37.3% experienced readmissions. In this group, specific CCTA measurements were identified as significant predictors of readmission: epicardial adipose tissue (CTEAT) at 54.49 cm3 (HR: 1.05; 95% CI: 1.03-1.07; P < 0.001), cardiac muscle mass to lumen volume (CTV/M) at 20% (HR: 0.59; 95% CI: 0.48-0.72; P < 0.001), peri-coronary adipose (CTPCAT) at -64.68 HU (HR: 1.1; 95% CI: 1.03-1.16; P = 0.002) for the right coronary artery, -81.07 HU (HR: 1.3; 95% CI: 1.1-1.53; P = 0.002) for the left anterior descending artery, and -73.42 HU (HR: 1.33; 95% CI: 1.18-1.51; P < 0.001) for the circumflex branch of the left coronary artery. In patients with nonischemic heart failure, increased CTEAT, CTPCAT, and CTV/M independently predicted rehospitalization.