Coronary Computed Tomography Angiography Research Articles

Coronary Artery Vasculitis and Encasement: Multimodality Imaging Findings and Mimics.

Coronary artery vasculitis (CAV) and coronary artery encasement are rarely diagnosed conditions that are important diagnostic considerations, particularly in patients with acute coronary syndrome without traditional cardiovascular risk factors or systemic illness. Vasculitis refers to inflammation of the blood vessel walls, which can be primary or secondary. This process should be distinguished from neoplastic involvement of the coronary arteries, termed coronary artery encasement. Prospective diagnosis of these diseases is challenging, often requiring multidisciplinary workup with careful attention to clinical presentation and multiorgan findings. While CAV and coronary artery encasement can be indistinguishable at coronary CT angiography, certain imaging features help order the differential diagnosis. CAV should be considered when there is smooth wall thickening that is circumferential and/or continuous. A diagnosis of coronary artery encasement is favored when there is irregular or nodular wall thickening that is eccentric to the vessel lumen. Epicardial fat stranding may also appear more extensive compared with CAV. Potential mimics of CAV include atherosclerosis, acute plaque rupture, coronary artery aneurysm, and spontaneous coronary artery dissection. Detection and diagnosis of CAV may help avoid complications related to accelerated atherosclerosis and infarction. Radiologists should be familiar with the range of pathologic conditions that can affect the coronary arteries beyond atherosclerosis as they may be the first to raise such diagnostic possibilities, guiding next steps in patient workup and management. ©RSNA, 2024 Supplemental material is available for this article.

Characterizing Nonculprit Lesions and Perivascular Adipose Tissue of Patients Following Acute Myocardial Infarction Using Coronary Computed Tomography Angiography: A Comparative Study.

The comparison of coronary computed tomography angiography plaques and perivascular adipose tissue (PVAT) between patients with acute myocardial infarction (AMI) posttreatment and patients with stable coronary artery disease is poorly understood. Our objective was to evaluate the differences in coronary computed tomography angiography-quantified plaque and PVAT characteristics in patients post-AMI and identify signs of residual inflammation. We analyzed 205 patients (age, 59.77±9.24 years; 92.20% men) with AMI ≤1 month and matched them with 205 patients with stable coronary artery disease (age, 60.52±10.04 years; 90.24% men) based on age, sex, and cardiovascular risk factors. Coronary computed tomography angiography scans were assessed for nonculprit plaque and vessel characteristics, plaque volumes by composition, high-risk plaques, and PVAT mean attenuation. Both patient groups exhibited similar noncalcified plaque volumes (383.35±313.23 versus 378.63±426.25 mm3, P=0.899). However, multivariable analysis revealed that patients post-AMI had a greater patient-wise noncalcified plaque volume ratio (estimate, 0.089 [95% CI, 0.053-0.125], P<0.001), largely attributed to a higher fibrofatty and necrotic core volume ratio, along with higher peri-lesion PVAT mean attenuation (estimate, 3.968 [95% CI, 2.556-5.379], P<0.001). When adjusted for vessel length, patients post-AMI had more high-risk plaques (estimate, 0.417 [95% CI, 0.298-0.536], P<0.001) per patient. Patients post-AMI displayed heightened noncalcified plaque components, largely due to fibrofatty and necrotic core content, more high-risk plaques, and increased PVAT mean attenuation on a per-patient level, highlighting the necessity for refined risk assessment in patients with AMI after treatment.

Coronary CTA and CT-FFR in trans-catheter aortic valve implantation candidates: a systematic review and meta-analysis

Abstract Objectives To perform a systematic review and meta-analysis on diagnostic accuracy and other outcomes of coronary computed tomography angiography (CCTA) and CT-derived fractional flow reserve (CT-FFR) in candidates for trans-catheter aortic valve implantation (TAVI). Background Screening for obstructive coronary artery disease (CAD) with CCTA during TAVI work-up could prevent unnecessary invasive coronary angiography (ICA). This becomes increasingly relevant as the TAVI-population grows. CT-FFR improves CCTA accuracy in chest pain patients, but its reliability is unknown in the TAVI-population. Methods Pubmed, Embase and Web of Science were searched for studies regarding CCTA and/or CT-FFR in TAVI-candidates. Primary endpoint was correct identification and rule-out of obstructive CAD. Results were pooled in a meta-analysis. Results Twenty-four of the 29 included articles were part of the meta-analysis, reporting results for CCTA and CT-FFR in 3.494 and 797 patients respectively. Reference standard was anatomical severity of CAD in most studies. At patient-level, pooled CCTA sensitivity was 94.3% and specificity 74.8%. CT-FFR sensitivity was 91.5% and specificity 60.3% with strong variation between studies. CCTA correctly ruled out CAD in 52% of all patients, but 42% of positive CCTAs were false positives. CT-FFR correctly ruled out CAD in 47% of all patients included in this meta-analysis, but showed better accuracy than CCTA in studies that compared both. In these studies, sensitivity of CCTA versus CT-FFR was 70.7% versus 79.0% and specificity was 64.4% versus 92.9%. Conclusions Negative CCTA effectively rules-out CAD in the TAVI-population. Adding CCTA to TAVI work-up could lead to significant reduction in pre-TAVI ICA procedures, but the proportion of false-positives remains high. In studies performing a direct comparison, CT-FFR performed better than CCTA. This is not reflected in the CT-FFR meta-analysis. Therefore, diagnostic accuracy of CT-FFR and added value over CCTA in the TAVI-population remains unclear. Further research regarding validation and reliability is warranted.Meta-analysis of CCTA and CT-FFR

Real world data after the implementation of coronary computed tomography angiography in Swedish primary care to rule out coronary artery disease, a cross-sectional study based on pre-test probability

Abstract Background In primary care, most patients with of non-acute chest pain will neither receive a heart related diagnosis nor be referred to a cardiologist. Studies indicate a better cardiovascular prognosis in chest pain patients referred to Coronary Computed Tomography Angiography (CCTA) as compared to risk stratification solely based on risk prediction instruments(1). CCTA is recommended since 2019 for low to intermediate cardiovascular (CV) risk patients(2). In the study setting, the primary care has implemented CCTA as first line test for patients with suspected obstructive coronary artery disease (CAD) and a Pre-Test Probability (PTP) of &amp;lt;15% and any CV risk factor, with PTP mandatorily entered in the referral letters. Purpose To study the outcome of CCTA based on referred PTP values categorised into &amp;lt;5%, 5-15% and &amp;gt;15%. We hypothesized that the presence of significant stenosis would be on par with the mean PTP. Methods In this cross-sectional retrospective cohort study, all consecutive clinical referrals for a CCTA from primary health care centres with a catchment area of ~470 000 inhabitants in the country of Sweden between 1 June 2021 and 7 Dec. 2022, with PTP estimates and completed CCTA were included. CCTA findings were stratified as normal, atheromatosis, or significant stenosis (≥50% coronary lumen obstruction). Patient baseline characteristics routinely registered on the day of CCTA was retrieved from a nationwide quality registry, SWEDEHEART(3). Pearsons’s Chi2 and one-way ANOVA was used to test differences in group distributions. Results During the study period, 381 patients with a PTP had obtained CCTA, of which 75% (n=286) had PTP &amp;lt;15%. The mean age was 60 years (standard deviation [SD] 11), 70% were female, 30% were prescribed lipid-lowering medication and 47% anti-hypertensives (Table 1). In total, the mean PTP was 12.4% (SD 8.7) and in 18% a suspected significant stenosis was identified. (Figure 1). Among patients referred with PTP 5-15%, the presence of suspected significant stenosis was 12% and cardiology consultation was less frequently described than for PTP &amp;lt;5 or ≥15% (14% vs 33% vs 44%, p &amp;lt; 0.001). Conclusions This study indicates that PTP is an efficient means to select patients for CCTA in primary care. In total, about 1/5 had a suspected significant stenosis, which often requires further investigations, and about 4/5 could be reassured that symptoms were not due to coronary artery disease. In 31% atheromatosis was identified, potentially facilitating counselling on CV prevention. We conclude that CCTA is a clinically effective option for primary care physicians to rule out CAD in patients with low PTP.Figure 1Table 1

Assessment of surgical revascularization completeness with quantitative myocardial blood flow distribution derived from CCTA in severe coronary artery disease

Abstract Background Complete revascularization remained the "holy grail" in the treatment of patients with severe coronary artery disease (CAD). However, there is no universally accepted definition of complete revascularization after coronary bypass graft surgery (CABG). The current assessment methods are visual, categorical, and biased by the operator's intention. Moreover, no method to date provides an individualized quantification of residual ischemia burden. Purpose We aim to provide an individualized method to assess the completeness of surgical revascularization through quantitative myocardial blood flow distribution derived from coronary computed tomography angiography (CCTA) that could reflect the actual functional ischemia burden after CABG. Methods Patients with 3VD and/or left main CAD were enrolled in the first-in-human FAST TRACK CABG trial for surgical revascularization guided solely by CCTA and fractional flow reserve derived from CCTA (FFRCT). Following CABG, the study protocol mandated a 30-day follow-up CCTA, which provides graft patency and topographical adequacy of the bypass graft anastomoses. The pre- and post-CABG CCTA were analyzed. The FFRCT value and percent myocardial blood flow distribution (%MBF) were computed for all 16 SYNTAX score segments using the validated method of Keulards et al(1). On pre-CABG CCTA, the myocardium located distal to the site where the FFRCT value dropped below 0.80 on the vessel centerline was considered ischemic, and the %MBF of the subtended myocardium was summed into the total percent ischemic myocardium (Figure 1). Following CABG, the segment was considered adequately revascularized when a non-narrowed graft was anastomosed distally to the site of FFRCT≤0.8 on the pre-operative CCTA. The change in percent ischemic myocardium and the residual ischemic burden were calculated for each patient (Figure 2). Results CCTA, FFRCT, and %MBF were obtained pre- and post-CABG in 96 patients, and the percent ischemic myocardium was computed per patient. At baseline, the average percent ischemic myocardium was 72.0(19.1)%. Post-CABG, the residual percent ischemic myocardium was 13.6(15.1)%. Residual percent ischemic myocardium &amp;lt;10% was achieved in 44 patients (44.8%). The first diagonal branch(n=13), distal LCX(n=12), and the first obtuse marginal branch(n=10) were the most frequent segments not revascularized, which subtended an average MBF of 12.2(3.5)%, 16.7(8.4)%, and 11.3(7.3)%, respectively. The main reason for inadequate revascularization was surgical deferral, with graft occlusion accounting for only 13.6% of the residual ischemic segments. Conclusion Percent ischemic myocardium and the completeness of surgical revascularization can be assessed with CCTA-derived %MBF. This novel method allows clinicians to assess the individualized ischemia burden and the completeness of revascularization that could be incorporated into personalized CABG planning.Figure 1Figure 2

Association of sodium-glucose cotransporter-2 inhibitor with regression of coronary plaque burden

Abstract Background Sodium-glucose cotransporter-2 inhibitor (SGLT2i), as a novel oral hypoglycemic therapy of type 2 diabetes mellitus (T2DM), has been proved to benefit cardiac function. However, it remains unknown whether SGLT2i has an impact on coronary plaque characteristics. Purpose The aim of this study was to investigate whether SGLT2i was able to improve coronary plaque composition, burden and inflammation [i.e., fat attenuation index (FAI)] using series coronary computed tomography angiography (CCTA) images among T2DM patients with angina pectoris. Methods T2DM patients presenting with angina pectoris admitted at our center were screened. Eligible patients were those underwent first CCTA within 3 months prior to initiating SGLT2i therapy, and repeated CCTA beyond 6 months after the first CCTA. Those patients not treated with SGLT2i underwent likewise longitudinal CCTA tests were propensity score matching in a 1:1 ratio using age, sex and CCTA time interval. Routine CCTA images were assessed for coronary plaque characteristics using dedicated softwares. Paired or unpaired Student’s t test or Mann–Whitney U test were used for comparing coronary plaque characteristics between series CCTA and patients with or without SGLT2i. The relationships between SGLT2i and changes of plaque characteristics was examined using logistic regression analysis. Results After propensity score matching, a total of 196 T2DM patients with angina pectoris were included (mean age, 60.4±9.2 years; male, 69.9%; SGLT2i treatment, 50%). Time interval between baseline and the last CCTA examinations was 400 (343,496) days. In the SGLT2i group, the non-calcified plaque burden [(39.86±14.30)% vs. (36.84±13.86)%, p=0.002)] and low attenuation non-calcified plaque burden (6.62 [4.11,10.13]% vs. 5.78 [3.40,9.28]%, p=0.042) were significantly decreased between two CCTA images. Whereas, in the non-SGLT2i group, there was no difference with regard to non-calcified and low attenuation non-calcified plaque burden between two CCTA images (all p&amp;gt;0.05). Moreover, changes of total plaque burden and non-calcified plaque burden were higher in the SGLT2i group than the non-SGLT2i group (all p&amp;lt;0.05). Importantly, SGLT2i was associated with total plaque volume (odd ratio=0.594, p=0.024) and non-calcified plaque volume regression (odd ratio=0.619, p=0.042) after adjusting for confounding factors. Conclusion SGLT2i significantly regresses coronary plaque burden, in particularly non-calcified plaque. These findings might explain the observed cardio-protective effect of SGLT2i in large trials.

Diagnostic performance of coronary computed tomography angiography for coronary in-stent re-stenosis

Abstract Background Through the development of CT equipment and proper preparation before CT scanning, the accuracy of Coronary computed tomography angiography (CCTA) diagnosis of ischemic heart disease (IHD) is improving, and the role of CCTA in treatment decision is gradually expanding. The latest guidelines recommend CCTA as Class IIa to evaluate stent patency and native vessels in patients with chronic coronary disease. However, diagnostic performance of CCTA to evaluate stent patency in patients who underwent coronary stent was not clarified, respectively the role of CCTA in the evaluation of IHD in native coronary artery was established.. Purpose In the present study, we evaluate the agreement between CCTA and CAG in assessing stent patency in patients with de novo ischemic chest pain who underwent percutaneous coronary intervention (PCI) and evaluated which factors contribute to the differences. Methods From January 1, 2010 to December 31, 2020, we analyzed 845 patients who underwent new CCTA and CAG sequentially for the evaluation of chest pain previously underwent PCI. In CAG and CCTA, ISR is equally defined as a stenosis greater than 50% of the vessel diameter of within the stented segment or its edge (5-mm segments adjacent to the stent). The degree of In-stent restenosis was analyzed by an independently by quantitative coronary angiography (QCA). Results A total of 208 stents were analyzed, the pooled sensitivity and specificity for CCTA on the diagnosis of ISR were 0.78 (0.65-0.89) and 0.93 (0.88-0.96), respectively. LR+ and LR- were 11.19 (6.22-20.15) and 0.23 (0.14-0.39). As a result of analyzing the ISR diagnostic agreement of CCTA by dividing into ACS and CCD group, the agreement of CCTA for ISR diagnosis was relatively low in the ACS group (Sensitivity 0.69 (0.48-0.86) vs. 0.88 (0.69-0.97), specificity 0.92 (0.84-0.97) vs. 0.94 (0.86-0.98), LR+ 9 (4-20.24) vs. 13.9 (5.88-32.88), LR- 0.33 (0.19-0.6) vs. 0.13 (0.04-0.37)) (Table 1). As a result of analyzing related factors in cases of discrepancy in ISR diagnosis, the degree of stenosis in both ACS and CCD groups was mostly intermediate stenosis, which often required additional clinical evaluation (Figure 1). Conclusion When new ischemic chest pain occurred in a patient who previously underwent PCI, the diagnostic accuracy of ISR by CCTA differed depending on the patient’s IHD category. In the CCD group, the diagnostic usefulness of CCTA was comparable both native vessels and ISR, but not in the ACS group. As majority of ISR diagnostic discrepancies were in intermediate lesions, even in the ACS group, CCTA may be considered as a diagnostic tool.

Coronary Computed Tomographic Angiography (CCTA) in non-ST elevation acute coronary syndromes

Abstract Background In patients presenting with an acute coronary syndrome (ACS), a diverse range of coronary artery disease is observed from structurally normal vessels to non-obstructive atherosclerosis and severe/obstructive coronary artery disease (CAD). In current clinical practice guidelines, the main diagnostic route for optimal management of patients with non-ST segment elevation acute coronary syndrome is invasive coronary angiography. However, in 30-40% of cases, no significant coronary lesions are evident. The purpose of this study is to describe the role of coronary computed tomographic angiography (CCTA) in non-ST elevation acute coronary syndromes in low and intermediate risk patients. Methods We describe the results of 504 patients evaluated with a protocol that includes the use of CCTA in patients with ACS. Patients over 18 years of age with a diagnosis of ACS without ST elevation who did not meet high-risk criteria (hemodynamic instability, dynamic changes in the ST segment or T wave, ventricular arrhythmia, GRACE score &amp;gt;140, refractory angina, heart failure or cardiorespiratory arrest) were included. They underwent CCTA as the initial coronary evaluation. Data collection was carried out between May 11, 2022 and February 20, 2024. Results 504 patients were included, with a mean age of 58 years, of which 44% were women and 56% men. Among the admission diagnoses, 26% were NSTEMI and 74% were unstable angina according to the 4th universal definition of acute myocardial infarction (AMI). The median high-sensitivity cardiac troponin T value was 7 nanograms per liter (interquartile range, 7 to 15) for the first troponin measurement. CCTA was performed in 93% of the patients. It was observed that 28% did not have any coronary lesions or plaques. 36% had non-obstructive coronary artery disease (plaques &amp;lt;50%). The rest had significant lesions in at least one vessel (27%), predominantly in the left anterior descending artery, or were nondiagnostic (9%). 31% had myocardial bridges, while in 13% of the patients a high-risk plaque was found. 38% of the patients included underwent invasive coronary angiography and 23% required revascularisation. Conclusion This study shows that the prevalence of ACS with coronary arteries without significant lesions by CCTA was 28%, which suggests CCTA could have a predominant role in the diagnostic algorithm of acute coronary syndromes without high-risk criteria, implying a decrease in the need of invasive studies in these patients. Only 38% required invasive coronary angiography, while revascularisation was performed in 23% of the patients. Furthermore, CCTA allowed a better detection of non-obstructive coronary artery disease (NOCAD) in 36% of the patients, and a more complete characterization of the atherosclerotic plaque, which could prompt to an initiation of preventive therapies or the optimization of medical treatment in these patients.Table 1CCTA findings

CCTA and CTP imaging for detecting clinically suspected in-stent restenosis: a meta-analysis

Abstract Background The evaluation of coronary artery stents via Coronary Computed Tomography Angiography (CCTA) can be compromised by artefacts, potentially undermining its diagnostic accuracy. The integration of CT Perfusion (CTP) with CCTA (CCTA+CTP) has been proposed to enhance the diagnostic yield in detecting in-stent restenosis (ISR). Purpose This meta-analysis aims to assess the diagnostic performance of CCTA and combined CCTA+CTP in detecting ISR. Methods A comprehensive literature search of studies from 2005 to 2022 identified 13,747 articles. Inclusion criteria comprised the utilization of multidetector CT scanners with ≥64 slices and invasive coronary angiography as the reference standard. Studies that systematically evaluated stent patency in asymptomatic patients as part of their protocol were excluded. Results After removing duplicates, screening titles and abstracts, and conducting full-text reviews, 20 studies met the inclusion criteria (17 CCTA, 3 CCTA+CTP). Data on 2,674 CCTA-assessed stents and 752 CCTA+CTP-assessed stents were analyzed. The meta-analysis revealed that CCTA alone achieved a sensitivity of 90% (95% CI; 84-94%) and a specificity of 89% (95% CI; 86-92%)(Figure 1). CCTA+CTP exhibited comparable diagnostic performance, with a per-stent sensitivity of 88% (95% CI; 80-94%) and a specificity of 88% (95% CI; 84-93%) (Figure 2). The summary Receiver Operating Characteristic (sROC) Area Under the Curve (AUC) was 0.96 (95% CI; 0.94-0.97) for CCTA and 0.96 (95% CI; 0.89-1.00) for CCTA+CTP, indicating a high overall performance for both diagnostic modalities. Conclusion Utilizing contemporary imaging hardware, both CCTA and CCTA+CTP demonstrate high diagnostic performance in evaluating ISR. The findings suggest that the presence of coronary artery stents should not preclude the use of these non-invasive diagnostic tests in clinical practice.Figure 1Figure 2

Impact of coronary CT angiography on the hospital outcome among patients admitted with AMI undergoing revascularization procedures in theUS

Abstract Background Coronary CT angiography (CCTA) is gaining popularity as a diagnostic modality for risk stratification among patients hospitalized with acute myocardial infarction (AMI). However, its impact on the hospital outcomes among this population of patients remains to be determined. Methods Using national inpatient sample database, admission cases with a diagnosis of AMI who underwent revascularization procedures were identified from 2016-2020. The prevalence of CCTA was determined among the patient population and stratified based on the type of AMI (STEMI vs. NSTEMI) and revascularization procedure (PCI vs. CABG). Hospital outcomes were compared among the study strata. Results A total of 862,064 admission cases for STEMI and 3,586,944 admission cases for NSTEMI were identified out of which 661,958 cases underwent revascularization procedures. The utilization of CCTA was roughly 10 times higher among AMI cases undergoing PCI than those undergoing CABG (0.5% vs. 0.06%, p&amp;lt;0.0001). Prior CCTA increased the odds of receiving PCI by 79.3 times and the odds of undergoing CABG by 2.8 times. Among STEMI patients undergoing PCI, prior CCTA was associated with a lower mortality rate and non-home disposition (13.8% vs. 21.2%, p&amp;lt;0.0001) compared to no CCTA (3% vs. 5.5%, p=0.01). For NSTEMI patients undergoing PCI, CCTA was associated with a lower non-home disposition (16.5% vs. 20.6%, p=0.003) but not a significantly lower mortality rate. CCTA did not demonstrate any statistically significant differences for AMI patients undergoing CABG. On the other hand, CCTA increased the cost of hospitalization by $15,130.7 for STEMI patients undergoing PCI, length of stay (9 days) and hospital cost for STEMI patients undergoing CABG ($302,802), and total hospital cost for NSTEMI patients undergoing PCI by $8,705. Conclusions Using CCTA helps in risk stratifying AMI patients for revascularization procedures, allocating PCI to those admitted with STEMI and CABG to those with NSTEMI. Although CCTA reduces the risk of death and non-home disposition among STEMI patients undergoing PCI, it also increases hospital charges for patients receiving revascularization procedures.

Computed tomography for prediction of stent underexpansion after percutaneous recanalization of calcified coronary chronic total occlusions

Abstract Background Coronary calcifications are the leading cause of stent underexpansion after percutaneous coronary intervention (PCI) and are commonly encountered in chronic total occlusions (CTO). Coronary computed tomography angiography (CCTA) is uniquely suited for pre-procedural assessment of coronary calcifications. Recently quantitative CCTA, providing exact volumes of each plaque component, has shown additional value in future risk assessment compared with conventional qualitative CCTA. Purpose The aim of this study was to evaluate whether CCTA predicts intravascular ultrasound (IVUS)-defined suboptimal stent expansion following percutaneous recanalization of calcified CTO lesions. Methods We retrospectively identified consecutive patients with a CCTA performed within 6-months prior to successful PCI of a calcified CTO (defined as calcification within the target lesion on CCTA). All patients had final IVUS of implanted stents (Figure 1). Patients requiring atherectomy were excluded. The primary outcome was IVUS-derived stent expansion index (SEI), defined as stent area divided by vessel area (both measured at the site of maximum calcium). SEI&amp;lt;0.4 indicated suboptimal stent expansion. The site of maximum calcium was a cross-section with greatest calcium arc on pre-stent IVUS within the target lesion. CCTA calcium analysis was performed by a researcher blinded to the IVUS and angiography results. Measurements included total-, vessel-, and lesion-specific calcium score (CAC), total calcium length, maximum calcium thickness and maximum CT calcium attenuation at the target lesion defined as occlusion site and adjacent severely diseased segments. Calcium quantification was performed using a semi-automated software to obtain volumes and burdens of calcified and non-calcified plaque components within the target lesion. Results The cohort included 43 patients (age 64.9±10.0 years, 88% males) with 43 CTO lesions. Mean final stent area at maximum calcium by IVUS was 8.2±2.1mm². Mean SEI was 0.47±0.1, and suboptimal SEI of &amp;lt;0.4 was found in 10 (23.3%) lesions. Lesions with suboptimal stent expansion (SEI&amp;lt;0.4) were characterized by numerically higher total-, vessel- and lesion-specific CAC, higher maximum calcium attenuation, greater calcium length and remodeling index compared with patients with optimal stent expansion (Table 1). However, only calcified plaque volume (105 [IQR 27-271] vs. 29 [4-96]mm³, P=0.02) and calcified plaque burden (16 [7-24] vs. 6 [1-10]%, P=0.03) were significantly greater in lesions with suboptimal stent expansion compared with lesions with optimal stent expansion, respectively. Calcified plaque volume ≥51 mm³ within the target lesion predicted suboptimal stent expansion with 70% sensitivity and 62.5% specificity (AUC 0.74). Conclusion CCTA-derived calcium volume identifies CTO lesions at greater risk of stent underexpansion. Such lesions require more aggressive plaque modification prior to stent implantation.

Predictive value of plaque characteristics assessed by coronary computed tomography angiography and optical coherence tomography for identification of lesions causing ischemia

Abstract Background In patients with intermediate coronary stenosis, the functional assessment with fractional flow reserve (FFR) and the anatomical assessment with optical coherence tomography (OCT) have been widely used in clinical practice. Additionally, coronary computed tomography angiography (CTA) is commonly used non-invasive imaging technique for evaluating suspected coronary artery disease before being referred for angiography. Objectives This study sought to investigate the association between FFR and plaque characteristics assessed by coronary CTA and OCT in intermediate coronary stenosis. Methods Based on the prospective multicentre registry, a total of 159 patients including 339 coronary lesions with intermediate stenosis were included. All patients underwent coronary CTA before being referred for coronary angiography and both FFR measurement and OCT examination were performed during angiography. The stenotic lesion with FFR ≤0.80 was considered diagnostic of lesion causing ischemia. The predictive value of plaque characteristics assessed by coronary CTA and OCT for identifying lesions causing ischemia was analyzed. Results Stenosis severity and plaque characteristics on coronary CTA and OCT were different between the lesions causing ischemia versus not causing ischemia. On multivariate analysis, low attenuation plaque on coronary CTA (odds ratio [OR]= 2.78; P=0.038) and thrombus (OR=5.13; 0.042), plaque rupture (OR=3.25; P=0.017), and intimal vasculature on OCT (OR=2.57; P=0.012) were independent predictors for the lesions causing ischemia. Increasing number of these plaque characteristics offered incremental improvement in predicting the lesions causing ischemia. Conclusions Comprehensive anatomical evaluation of coronary stenosis may be able to provide additional supportive information for predicting the lesions causing ischemia.

Role of pericoronary adipose tissue inflammation at CCTA after heart transplantation as non-invasive diagnostic tool of cardiac rejection and predictor of major adverse cardiovascular events

Abstract Background Long-term survival of heart transplanted (HT) patients is challenged by cardiac rejection and cardiac allograft vasculopathy (CAV). Until now, there are no established biomarkers for graft dysfunction, and the conventional approach for cardiac rejection surveillance is through the endomyocardial biopsy (EMB), an invasive and costly procedure. Purpose This study investigates the prognostic value of the pericoronary Fat Attenuation Index (FAI) and its role as a marker of inflammation and rejection in HT recipients. Methods A double-center observational retrospective study was conducted on a cohort of HT patients who underwent coronary computed tomography angiography (CCTA) between January 2016 and December 2022. FAI was measured with dedicated software and using the cut-off described in literature, we considered each coronary as "inflamed" if FAI was ≥ - 70,1 HU and "not inflamed" if FAI was &amp;lt; - 70,1 HU. Then, based on the number of inflamed coronary arteries for each patient, we divided the population into two comparison groups: high inflammatory (high INF) phenotype (alle three coronary arteries inflamed) and low inflammatory (low INF) phenotype (at least one coronary artery not inflamed). The primary endpoint was a composite of all-cause mortality, acute myocardial infarction, urgent revascularization and heart failure hospitalization. Furthermore, we investigated the correlation between FAI and cardiac rejection by looking for T cell-mediated rejection (TCMR) and antibody-mediated rejection (AMR) through EMB performed no more than six months before or after CCTA. Results A total of 101 HT patients were included; of this group 58 patients underwent EMBs within six months after or before the CCTA. The median duration of follow-up was 28 months. The composite endpoint occurred in 17 patients (16.8%). We documented 26 significative cardiac rejection episodes, 14 TCMR ≥ 2R and 12 AMR. The composite endpoint was achieved in 37.9% of patients with high INF phenotype compared to 8.3% with low INF phenotype (p &amp;lt; 0.001). In the multivariate analysis, the high INF phenotype remained an independent predictor of the composite endpoint in our population (HR: 10.5; 95% CI: 1.88-58.71; p = 0.007). Patients with TCMR and AMR had significantly higher FAI values. High INF phenotype correlated with the presence of ACR ≥ 2R (55.0% vs 7.9%, p &amp;lt; 0.001) and AMR (55.0% vs 2.6%, p &amp;lt; 0.001). Conclusion In HT patients, FAI is an independent predictor of major cardiovascular events. It is also associated with TCMR and AMR within six months from CCTA. FAI, therefore, may offer a non-invasive approach to stratify the prognosis of HT patients and serve as a valuable inflammatory biomarker for early diagnosis of cardiac rejection, supporting the use of CCTA in this setting of patients.Correlation FAI and MACECorrelation FAI and cardiac rejection

Quantitative myocardial blood flow distribution derived from CCTA and determination of myocardium at risk in the FAST TRACK CABG trial

Abstract Background In the anatomic SYNTAX score derived from invasive coronary angiography, the ischemic impact of each stenotic coronary segment is weighed with a fixed score based on the severity of luminal diameter narrowing and the theoretical amount of blood flow supplied to the myocardium(1). This method neither accounts for individual variation nor reflects the true extent of myocardium ischemia. Purpose We aim to provide a quantitative CT SYNTAX score derived from coronary computed tomography angiography (CCTA) with customized percent blood flow distribution to the myocardium supplied by each stenotic coronary segment to determine the myocardium at risk of ischemia. Methods Patients with 3VD and/or left main coronary artery disease (CAD) were included in the first-in-human FAST TRACK CABG trial and received surgical revascularization guided solely by CCTA and fractional flow reserve derived from CCTA (FFRCT). The recently reported anatomic CT-SYNTAX score was calculated for all cases. The FFRCT value and percent myocardial blood flow distribution(%MBF) were computed for all 16 SYNTAX score segments using the validated method of Keulards et al(2). On the pre-CABG CCTA, the segments located distal to the site where the FFRCT value dropped below 0.80 were considered at risk of ischemia, and the individual weight point per segment was calculated as 6×%MBF for each segment. The SYNTAX score derived from %MBF is compared to the anatomic and functional CT-SYNTAX score. Results Out of 114 patients enrolled, FFRCT and %MBF were analyzable in 106 patients. After excluding vessels with total occlusion, the coronary flow distribution between the right and left coronary systems was 20.5% vs 79.5%, respectively, similar to the 1:5 ratio in the anatomic SYNTAX score. The anatomic and functional CT-SYNTAX scores were 43.6 and 41.1, respectively. The average total %MBF per patient was 72.0(19.1)%, and the average SYNTAX score derived from %MBF was 38.0. There is a strong correlation between functional SYNTAX score and SYNTAX score derived from %MBF (Peason’s R=0.93). Passing-Bablock regression trends showed that the functional SYNTAX score slightly overestimated the SYNTAX score derived from %MBF (Figure 1). The coronary segment weight varied significantly per individual, especially in the presence of total occlusion. Overall, the fixed weight of the anatomic SYNTAX score is a good surrogate for the individualized weighing based on %MBF (Figure 2). Conclusion CCTA-derived %MBF enabled clinicians to quantify the individualized myocardium at risk of ischemia or injury in patients with severe CAD. Retrospectively, the fixed weight score used in the anatomical SYNTAX score appeared to be a robust surrogate for myocardial blood flow distribution.Figure 1Figure 2

Symptomatic patients without coronary artery disease do not have excess cardiovascular risk compared to the general population

Abstract Background Patients with stable angina with no coronary atherosclerosis by coronary computed tomography angiography (CCTA) have a lower cardiovascular risk compared to CCTA patients with greater atherosclerotic burden. However, it remains unknown whether these symptomatic patients have excess cardiovascular risk when compared to the general population and if any excess risk is sex or age dependent. Purpose To examine the 10-year cardiovascular risk and mortality in patients with no coronary atherosclerosis by CCTA compared to a matched general population comparison cohort. Methods We included every symptomatic CCTA patient with no coronary artery disease (CAD), defined as no coronary plaques and Agatston calcium score of 0, in Western Denmark from 2008-2021. Each patient was matched by age and sex with 5 individuals with no previous history of ischemic heart disease from the Western Danish general population. Maximum follow-up was 10 years. Outcomes were myocardial infarction, ischemic stroke, and all-cause death. We estimated 10-year risk difference (RD) and incidence rate ratios (IRR) using a conditional Poisson regression, comparing patients with no CAD to the general population cohort. Additionally, we performed age- (&amp;lt;45 year, 45-65 years, and ≥65 years) and sex stratified analyses. Results We included 39,223 patients with no CAD who were matched with 196,115 individuals from the general population. Median age was 54 and 60% were women. Baseline use of anti-thrombotic agents, statins, and anti-hypertensive drugs was higher in patients with no CAD than the general population. Median follow-up was 6.1 years. CCTA patients with no CAD had lower risk of myocardial infarction [RD -0.2%, IRR 0.75 (95% CI 0.65-0.85)] and death [RD -3.3%, IRR 0.51 (95% CI 0.48-0.55)], but similar risk of ischemic stroke [RD 0.0%, IRR 0.93 (95% CI 0.84-1.02)] compared to the general population (Figure 1). However, patients &amp;lt;45 years had higher 10-year risk of both myocardial infarction and ischemic stroke despite absence of CAD by CCTA compared the general population (Figure 2). Conclusions Symptomatic patients without CAD by CCTA do not have excess cardiovascular risk when compared to a general population cohort without known ischemic heart disease. Future cardiovascular risk management of these patients should therefore follow primary prevention guidelines. However, patients &amp;lt;45 years did exhibit higher risk of ischemic outcomes and may require intensified preventative treatment.Figure 1Figure 2

Low density lipoprotein cholesterol and cardiovascular disease risk in patients with absence of coronary artery calcification: a multicenter cohort study

Abstract Background Low-density lipoprotein cholesterol (LDL-C) plays a central role in the development of coronary heart disease (CHD). Absence of coronary artery calcification (CAC 0), as assessed by coronary computed tomography angiography (CCTA), is associated with a favorable outcome as it indicates a low burden of atherosclerosis. However, questions remain regarding the risk of non-calcified plaque and CHD in younger patients with CAC zero, as atherosclerosis tends to be non-calcified in earlier stages. Purpose To assess if LDL-C is associated with presence of non-calcified plaque and future cardiovascular events in patients with CAC zero across the age spectrum. Methods This observational multicenter cohort study included patients aged 18 years or more who underwent CCTA between January 2008 and May 2021 with CAC zero. LDL-C was measured prior to CCTA. Patients were followed from date of CCTA to occurrence of cardiovascular event, death, or 1st of October 2022. No patients were lost to follow-up. We assessed the association between LDL-C and presence of non-calcified plaque on CCTA as adjusted odds ratios, and risk for myocardial infarction and CHD (myocardial infarction or coronary revascularization) as adjusted hazard ratios using Cox regression analyses, across different age groups. Results A total of 23,776 patients with CAC zero were included in the study. Median age was 54 years (IQR 47-61) and 14,605 (61%) were women. During median follow-up of 5.5 years, 165 (0.7%) and 427 (1.8%) experienced myocardial infarction and CHD, respectively. Overall, the prevalence of non-calcified plaque was 11.1% (n=2,650). Higher LDL-C was associated with presence of non-calcified plaque with an odds ratio of 1.21 (95% CI 1.16-1.27) per 1 mmol/L higher LDL-C. Individuals aged ≤45 years had a higher odds ratio for non-calcified plaque per 1 mmol/L higher LDL-C compared to individuals aged 46-60 and &amp;gt;60 years; 1.36 (95% CI 1.22-1.52), 1.22 (95% CI 1.15-1.30) and 1.13 (95% CI 1.04-1.22), respectively, p value for interaction between the youngest and oldest age group was &amp;lt;0.05. Overall, LDL-C was associated with higher risk for myocardial infarction and CHD with hazard ratios of 1.29 (95% CI 1.10-1.52) and 1.26 (95% CI 1.14-1.39) per 1 mmol/L higher LDL-C, despite CAC zero. Conclusions Particularly in younger patients with absence of CAC, elevated LDL-C is associated with presence of non-calcified plaque and increased risk for future cardiovascular events. These data are important for clinical practice, as they demonstrate the importance of managing LDL-C in younger individuals over the long-time horizon despite CAC zero.

Coronary bypass surgery guided by multislice computed tomography angiography in a low surgical risk population

Abstract Background In patients with three-vessel disease and/or left main disease, selecting revascularization strategies based on coronary computed tomography angiography (CCTA) has a high level of virtual agreement with treatment decisions based on invasive coronary angiography(ICA).(1) Purpose The FASTTRACK CABG trial aims to assess the feasibility and safety of using CCTA and FFRCT as guidance for planning and performing CABG in patients with 3VD and/or LMCAD. Methods In this multicentre study, coronary artery bypass grafts (CABG) were planned and performed based on CCTA without knowledge of ICA. CABG strategy was recommended by a central Core laboratory assessing the anatomy and functionality of the coronary circulation. The primary feasibility endpoint was the percentage of operations performed without access to the ICA. The primary safety endpoint was graft patency on 30-day follow-up CCTA. Secondary endpoints included topographical adequacy of grafting, major adverse cardiac and cerebrovascular events (MACCE), and major bleeding events at 30 days. The study was considered positive if the lower boundary of confidence intervals(CI) for feasibility ≥75%.(2) Results The study enrolled 114 patients with a mean (standard deviation) anatomical SYNTAX Score and Society of Thoracic Surgery score of 43.6 (15.3) and 0.81 (0.63), respectively. Three patients did not undergo CABG due to the patient’s preference for percutaneous treatment (n=1) or lack of graft material. Unblinding ICA was required in one case, yielding a feasibility of 99.1% (95%CI: 95.2%-100%). The concordance and agreement in revascularization planning between the ICA- and CCTA-Heart Team was 82.9% with a moderate kappa of 0.58 (95%CI:0.50-0.66). The concordance and agreement in revascularization planning between the CCTA-Heart Team and actual treatment was 83.7% with a substantial kappa of 0.61 (95%CI:0.53-0.68). The 30-day follow-up CCTA was performed in 102 (91.9%) of the 111 operated patients, which showed an anastomosis patency rate of 92.6%. At 30 days, the incidence of MACCE was 7.2% whereas major bleeding was 2.7%. Conclusions CABG guided by CCTA is feasible and has an acceptable safety profile in a selected population of complex coronary artery disease.

NICE guidance in the rapid access chest pain clinic: does it work?

Abstract Background Rapid Access Chest Pain Clinics (RACPC) were developed following the publication of the National Service Framework for Coronary Heart Disease in 2000(1). The National Institute for Health and Care Excellence (NICE) produces guidelines for the management of patients with recent onset chest pain of suspected cardiac origin(2). In 2016 the guidance was updated and recommended the use of CT coronary angiography (CTCA) as the initial investigation for patients with chest pain which was typical or atypical of angina. Adherence to the guideline may be dependent upon factors such as local availability of CT scanners and clinician preference. The RACPC in this tertiary centre is nurse-run with no medical involvement. There is good engagement with the CT department and in July 2017 the NICE guidance was adopted in the clinic. Purpose To evaluate the use of CTCA as the first line investigation for patients with typical or atypical chest pain. Methods Data from all patients reviewed in the clinic between 01/07/2017 and 31/12/2023 were prospectively collected, entered into a database, and then retrospectively analysed. The data were organised into 3 groups: patients with typical chest pain; atypical pain and those with non-cardiac sounding chest pain. The number of patients in each group who underwent a CTCA, and the outcome of the scan were evaluated. The CT scans were categorised as showing significant coronary artery disease (CAD), non-obstructive CAD, no CAD, or as inconclusive. The outcome of patients who had a positive CTCA was also recorded. Results 2986 patients were reviewed in the RACPC in the above period. 14.2% of patients presented with typical pain, 47.4% with atypical pain, and 30.6% had non-cardiac pain. The remaining patients presented with other symptoms such as breathlessness. CTCA was used as the first investigation in the majority of patients with typical or atypical pain, unless alternative investigations or management were deemed to be more clinically appropriate. In 59.5% of typical and 78.5% of atypical presentations, the CT scan showed no CAD, or non-significant CAD. There was a low incidence of positive scans in both groups, however patients with typical pain were more likely to have significant CAD (Table). All patients who had a CTCA indicating significant CAD, were referred for invasive angiography. 88.0% of typical presentations, and 64.0% of those with atypical pain, underwent revascularisation. No patient who underwent invasive angiography was found to have normal coronary arteries. Conclusion Atypical pain is the most frequent presentation in the RACPC, however the majority of these patients, and most of those with typical pain, do not have significant CAD. Careful assessment and the use of CTCA as the initial investigation, enable the identification of those patients who need invasive angiography. This is a cost-effective strategy which also reduces risk and radiation exposure for patients.

Artificial intelligence-based automated plaque quantification from CCTA to predict acute coronary syndrome on top of obstructive or ischemic coronary artery disease

Abstract Background Artificial intelligence (AI)-based quantitative computed tomography (AI-QCT) is a novel tool for automated plaque characterization and quantification from coronary computed tomography angiography (CCTA). The prognostic value of various AI-QCT plaque types on top of the presence of obstructive or ischemic coronary artery disease (CAD) is unknown. Purpose To investigate the added prognostic value for acute coronary syndrome (ACS) of AI-QCT total plaque burden (percent atheroma volume (PAV) %), and its subcomponents non-calcified plaque burden (NCPB), low-attenuation plaque burden (LAP), and calcified plaque burden (CPB) (%) on top of obstructive or ischemic CAD. Methods A cohort of 2007 symptomatic patients having undergone CCTA and selective downstream PET perfusion for suspected CAD was analyzed. Patients with prior or early elective revascularization within 6 months from CCTA were excluded. Obstructive CAD was defined as ≥1 vessel with &amp;gt;50% visual stenosis, and ischemic CAD as absolute hyperemic myocardial blood flow ≤2.3 ml/g/min in ≥2 adjacent segments on 15O-H2O PET. Multivariable Cox regressions adjusted for clinical confounders (age, sex hypertension, typical angina) including each plaque type separately (per 1.0%) on top of obstructive or ischemic CAD, respectively, were performed. The amount of LAP was &amp;lt;1% and therefore pooled together with NCPB. Results Throughout a median follow-up of 7 years, 72/2007 patients experienced ACS (50 myocardial infarction, 22 unstable angina). On top of obstructive CAD, all plaque types were independent predictors of ACS (Figure 1A), however according to the C-indexes (p-value vs. obstructive CAD), only PAV (C-index=0.814, p=0.010) and NCPB+LAP (C-index=0.818, p=0.014), but not CPB (C-index=0.800, p=0.066) significantly improved the prediction of ACS on top of obstructive CAD (C-index=0.790) (Figure 2A). On top of ischemic CAD (1967 patients, 66 events), all plaque types were also independent predictors of ACS (Figure 1B). But, similarly, according to the C-indexes (p-value vs. ischemic CAD), only PAV (C-index=0.818, p=0.003), and NCPB+LAP (C-index=0.818, p=0.005), but not CPB (C-index=0.798, p=0.054) significantly improved the prediction of ACS on top of ischemic CAD (C-index=0.776) (Figure 2B). NCPB+LAP alone performed similarly as PAV on top of obstructive (p=0.554) and ischemic CAD (p=0.991) (Figure 2). Conclusions Among patients with native coronary arteries treated medically, AI-based plaque quantification significantly improved the prediction of ACS on top of obstructive or ischemic CAD. The risk of ACS was largely related to NCPB+LAP, whereas CPB did not significantly improve risk stratification.Adjusted HR for ACS per plaque typeC-indexes for ACS

Assessing the need for coronary angiography in high-risk acute coronary syndrome patients using artificial intelligence and computed tomography

Abstract Background/Introduction The use of coronary computed tomography angiography (CCTA) in managing high-risk acute coronary syndrome (ACS) patients is increasingly common. Yet, its role remains unvalidated in this context, posing challenges to traditional clinical decision-making algorithms. Physicians, accustomed to a hierarchical and structured approach involving symptom assessment, electrocardiograms, and biomarkers for deciding on the necessity of invasive coronary angiography (ICA), now face dilemmas when CCTA results challenge established diagnostic pathways and contradict clinical decisions based on usual criteria. Meanwhile, the potential of artificial intelligence (AI) which processes information in a way fundamentally different from human clinical reasoning, has been shown to aid decision-making in cardiovascular medicine. Yet, it has not been tested in this acute setting. Purpose This study aimed to evaluate the efficacy of the Chat Generative Pre-trained Transformer (ChatGPT) in guiding the need for ICA in high-risk ACS patients based on both standard clinical data and CCTA findings. Methods This investigation is a sub-study of a larger research project where high-risk ACS patients (all having a theoretical guideline-based indication for ICA) underwent CCTA prior to ICA. ChatGPT analyzed clinical vignettes containing patient data, electrocardiograms, troponin levels, and CCTA results to determine the necessity of ICA. The AI's recommendations were then compared to actual ICA findings to assess its decision-making accuracy. Results Among 86 patients with a clear indication for ICA, ChatGPT recommended against it for 19 patients, 16 of whom indeed had no significant findings at ICA (Figure). For 67 patients, ChatGPT advised proceeding with ICA, and a significant lesion was confirmed in 58 of them. Consequently, ChatGPT's overall accuracy stood at 86%, with a sensitivity of 95% and a specificity of 64%. The model's negative predictive value was 84%, and its positive predictive value was 87%. Conclusion These preliminary data suggest that ChatGPT can effectively assist in guiding the need for ICA among high-risk ACS patients, potentially reducing unnecessary procedures but further clinical studies to refine AI's role in clinical decision-making are required.ChatGPT's decision as per ICA's results