Atherosclerosis evaluation and cardiovascular risk estimation using coronary computed tomography angiography.

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.

Ultrahigh-Spatial-Resolution Photon-counting Detector CT Angiography of Coronary Artery Disease for Stenosis Assessment.

Background Coronary CT angiography is a first-line test in coronary artery disease but is limited by severe calcifications. Photon-counting-detector (PCD) CT improves spatial resolution. Purpose To investigate the effect of improved spatial resolution on coronary stenosis assessment and reclassification. Materials and Methods Coronary stenoses were evaluated prospectively in a vessel phantom (in vitro) containing two stenoses (25%, 50%), and retrospectively in patients (in vivo) who underwent ultrahigh-spatial-resolution cardiac PCD CT (from July 2022 to April 2023). Images were reconstructed at standard resolution (section thickness, 0.6 mm; increment, 0.4 mm; Bv44 kernel), high spatial resolution (section thickness, 0.4 mm; increment, 0.2 mm; Bv44 kernel), and ultrahigh spatial resolution (section thickness, 0.2; increment, 0.1 mm; Bv64 kernel). Percentages of diameter stenosis (DS) were compared between reconstructions. In vitro values were compared with the manufacturer specifications of the phantom and patient results were assessed regarding effects on Coronary Artery Disease Reporting and Data System (CAD-RADS) reclassification. Results The in vivo sample included 114 patients (mean age, 68 years ± 9 [SD]; 71 male patients). In vitro percentage DS measurements were more accurate with increasing spatial resolution for both 25% and 50% stenoses (mean bias for standard resolution, high spatial resolution, and ultrahigh spatial resolution, respectively: 10.1%, 8.0%, and 2.3%; P < .001). In vivo results confirmed decreasing median percentage DS with increasing spatial resolution for calcified stenoses (n = 161) (standard resolution, high spatial resolution, and ultrahigh spatial resolution, respectively: 41.5% [IQR, 27.3%-58.2%], 34.8% [IQR, 23.7%-55.1%], and 26.7% [IQR, 18.6%-44.3%]; P < .001), whereas noncalcified (n = 13) and mixed plaques (n = 19) did not show evidence of a difference (P ≥ .88). Ultrahigh-spatial-resolution reconstructions led to reclassification of 62 of 114 (54.4%) patients to lower CAD-RADS category than that assigned using standard resolution. Conclusion In vivo and in vitro coronary stenosis assessment improved for calcified stenoses by using ultrahigh-spatial-resolution PCD CT reconstructions, leading to lower percentage DS compared with standard resolution and clinically relevant rates of reclassification. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by McCollough in this issue.

Fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation (FLASH): Study protocol for a randomized controlled noninferiority trial.

BACKGROUND: Artificial intelligence-based quantitative coronary angiography (AI-QCA) has been developed to provide a more objective and reproducible data about the severity of coronary artery stenosis and the dimensions of the vessel for intervention in real-time, overcoming the limitations of significant inter- and intraobserver variability, and time-consuming nature of on-site QCA, without requiring extra time and effort. Compared with the subjective nature of visually estimated conventional CAG guidance, AI-QCA guidance provides a more practical and standardized angiography-based approach. Although the advantage of intravascular imaging-guided PCI is increasingly recognized, their broader adoption is limited by clinical and economic barriers in many catheterization laboratories. METHODS: The FLASH (fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation) trial is a randomized, investigator-initiated, multicenter, open-label, noninferiority trial comparing the AI-QCA-assisted PCI strategy with optical coherence tomography-guided PCI strategy in patients with significant coronary artery disease. All operators will utilize a novel, standardized AI-QCA software and PCI protocol in the AI-QCA-assisted group. A total of 400 patients will be randomized to either group at a 1:1 ratio. The primary endpoint is the minimal stent area (mm2), determined by the final OCT run after completion of PCI. Clinical follow-up and cost-effectiveness evaluations are planned at 1 month and 6 months for all patients enrolled in the study. RESULTS: Enrollment of a total of 400 patients from the 13 participating centers in South Korea will be completed in February 2024. Follow-up of the last enrolled patients will be completed in August 2024, and primary results will be available by late 2024. CONCLUSION: The FLASH is the first clinical trial to evaluate the feasibility of AI-QCA-assisted PCI, and will provide the clinical evidence on AI-QCA assistance in the field of coronary intervention. CLINICAL TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT05388357.

Relationship between TyG index and the degree of coronary artery lesions in patients with H-type hypertension.

BACKGROUND: The TyG index, a prominent metric for assessing insulin resistance, has gained traction as a prognostic tool for cardiovascular disease. Nevertheless, the understanding of the prognostic significance of the extent of coronary artery stenosis in individuals afflicted with H-type hypertension remains limited. METHODS: A retrospective study was conducted at Wuhan Third Hospital, including a cohort of 320 inpatients who were diagnosed with hypertension in combination with coronary artery disease. The study period spanned from January 1, 2021, to February 1, 2023. The study cohort was stratified based on the severity of stenosis into three distinct groups: low stenosis, medium stenosis, and high stenosis, as determined by the Gensini score derived from coronary angiography findings. The present study aimed to investigate the association between the severity of coronary stenosis and the number of lesion branches, utilizing the TyG index as a testing indicator. The predictive ability of TyG for coronary lesion severity was assessed using logistic regression analysis. RESULTS: The results of our study indicate a positive correlation between elevated levels of TyG and an increased susceptibility to severe stenosis in individuals diagnosed with H-type hypertension. Upon careful consideration of potential confounding variables, it has been observed that the TyG index exhibits a robust association with the likelihood of severe stenosis in individuals with H-type hypertension (odds ratio [OR] = 4000, 95% confidence interval CI 2.411-6.635, p = 0.0001), as well as the prevalence of multivessel disease (OR = 1.862, 95% CI 1.036-3.348, p < 0.0001). The TyG index demonstrated superior predictive ability for severe coronary stenosis in patients with H-type hypertension compared to those without H-type hypertension (area under the curve [AUC] = 0.888, 95% confidence interval CI 0.838-0.939, p < 0.0001, versus AUC = 0.615, 95% CI 0.494-0.737, p < 0.05). CONCLUSION: The TyG index is an independent risk factor for the degree of coronary stenosis and a better predictor in patients with H-type hypertension combined with coronary artery disease.

The additive effect of metabolic syndrome on left ventricular impairment in patients with obstructive coronary artery disease assessed by 3.0 T cardiac magnetic resonance feature tracking.

BACKGROUND: Metabolic syndrome (MetS) can increase the risk of morbidity and mortality of cardiovascular disease and obstructive coronary artery disease (OCAD), which usually have a poor prognosis. This study aimed to explore the impact of MetS on left ventricular (LV) deformation and function in OCAD patients and investigate the independent factors of impaired LV function and deformation. MATERIALS AND METHODS: A total of 121 patients with OCAD and 52 sex- and age-matched controls who underwent cardiac magnetic resonance scanning were enrolled in the study. All OCAD patients were divided into two groups: OCAD with MetS [OCAD(MetS+), n = 83] and OCAD without MetS [OCAD(MetS-), n = 38]. LV functional and global strain parameters were measured and compared among the three groups. Multivariable linear regression analyses were constructed to investigate the independent factors of LV impairment in OCAD patients. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed to test the prediction efficiency of MetS for LV impairment. RESULTS: From controls to the OCAD(MetS-) group to the OCAD(MetS+) group, LV mass (LVM) increased, and LV global function index (LVGFI) and LV global longitudinal peak strain (GLPS) decreased (all p < 0.05). Compared with the OCAD(MetS-) group, the LV GLPS declined significantly (p = 0.027), the LVM increased (p = 0.006), and the LVGFI decreased (p = 0.043) in the OCAD(MetS+) group. After adjustment for covariates in OCAD patients, MetS was an independent factor of decreased LV GLPS (ß = - 0.211, p = 0.002) and increased LVM (ß = 0.221, p = 0.003). The logistic multivariable regression analysis and ROC analysis showed that combined MetS improved the efficiency of predicting LV GLPS reduction (AUC = 0.88) and LVM (AUC = 0.89) increase. CONCLUSIONS: MetS aggravated the damage of LV deformation and function in OCAD patients and was independently associated with LV deformation and impaired LV strain. Additionally, MetS increased the prediction efficiency of increased LVM and decreased LV GLPS. Early detection and intervention of MetS in patients with OCAD is of great significance.

Diagnosis and treatment of ischemia-producing coronary stenoses improves 5-year survival of patients undergoing major vascular surgery.

OBJECTIVE: Patients undergoing vascular surgery procedures have poor long-term survival due to coexisting coronary artery disease (CAD), which is often asymptomatic, undiagnosed, and undertreated. We sought to determine whether preoperative diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with postoperative ischemia-targeted coronary revascularization can reduce adverse cardiac events and improve long-term survival following major vascular surgery METHODS: In this observational cohort study of 522 patients with no known CAD undergoing elective carotid, peripheral, or aneurysm surgery we compared two groups of patients. Group I included 288 patients enrolled in a prospective Institutional Review Board-approved study of preoperative coronary CT angiography (CTA) and FFRCT testing to detect silent coronary ischemia with selective postoperative coronary revascularization in addition to best medical therapy (BMT) (FFRCT guided), and Group II included 234 matched controls with standard preoperative cardiac evaluation and postoperative BMT alone with no elective coronary revascularization (Usual Care). In the FFRCT group, lesion-specific coronary ischemia was defined as FFRCT ≤0.80 distal to a coronary stenosis, with severe ischemia defined as FFRCT ≤0.75. Results were available for patient management decisions. Endpoints included all-cause death, cardiovascular death, myocardial infarction (MI), and major adverse cardiovascular events (MACE [death, MI, or stroke]) during 5-year follow-up. RESULTS: The two groups were similar in age, gender, and comorbidities. In FFRCT, 65% of patients had asymptomatic lesion-specific coronary ischemia, with severe ischemia in 52%, multivessel ischemia in 36% and left main ischemia in 8%. The status of coronary ischemia was unknown in Usual Care. Vascular surgery was performed as planned in both cohorts with no difference in 30-day mortality. In FFRCT, elective ischemia-targeted coronary revascularization was performed in 103 patients 1 to 3 months following surgery. Usual Care had no elective postoperative coronary revascularizations. At 5 years, compared with Usual Care, FFRCT guided had fewer all-cause deaths (16% vs 36%; hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.60; P < .001), fewer cardiovascular deaths (4% vs 21%; HR, 0.11; 95% CI, 0.04-0.33; P < .001), fewer MIs (4% vs 24%; HR, 0.13; 95% CI, 0.05-0.33; P < .001), and fewer MACE (20% vs 47%; HR, 0.36; 95% CI, 0.23-0.56; P < .001). Five-year survival was 84% in FFRCT compared with 64% in Usual Care (P < .001). CONCLUSIONS: Diagnosis of silent coronary ischemia with ischemia-targeted coronary revascularization in addition to BMT following major vascular surgery was associated with fewer adverse cardiovascular events and improved 5-year survival compared with patients treated with BMT alone as per current guidelines.

Artificial intelligence evaluation of coronary computed tomography angiography for coronary stenosis classification and diagnosis.

BACKGROUND: Ruling out obstructive coronary artery disease (CAD) using coronary computed tomography angiography (CCTA) is time-consuming and challenging. This study developed a deep learning (DL) model to assist in detecting obstructive CAD on CCTA to streamline workflows. METHODS: In total, 2929 DICOM files and 7945 labels were extracted from curved planar reformatted CCTA images. A modified Inception V3 model was adopted. To validate the artificial intelligence (AI) model, two cardiologists labelled and adjudicated the classification of coronary stenosis on CCTA. The model was trained to differentiate the coronary artery into binary stenosis classifications <50% and ≥50% stenosis. Using the quantitative coronary angiography (QCA) consensus results as a reference standard, the performance of the AI model and CCTA radiology readers was compared by calculating Cohen's kappa coefficients at patient and vessel levels. The net reclassification index was used to evaluate the net benefit of the DL model. RESULTS: The diagnostic accuracy of the AI model was 92.3% and 88.4% at the patient and vessel levels, respectively. Compared with CCTA radiology readers, the AI model had a better agreement for binary stenosis classification at both patient and vessel levels (Cohen kappa coefficient: .79 vs. .39 and .77 vs. .40, p < .0001). The AI model also exhibited significantly improved model discrimination and reclassification (Net reclassification index = .350; Z = 4.194; p < .001). CONCLUSIONS: The developed AI model identified obstructive CAD, and the model results correlated well with QCA results. Incorporating the model into the reporting system of CCTA may improve workflows.

Preprocedural assessment of coronary artery disease in patients undergoing transcatheter aortic valve implantation: Rationale and design of the EASE-IT CT registry.

BACKGROUND: Invasive coronary angiography (ICA) is the standard for pre-procedural assessment of coronary artery disease (CAD) in patients undergoing transcatheter aortic valve implantation (TAVI). However, it requires hospitalization and can be associated with complications. Computed tomography angiography (CTA) may be a viable alternative to rule out prognostically relevant CAD. METHODS: The EASE-IT CT Registry is an investigator-initiated, prospective, observational, multicentre pilot registry involving patients aged ≥75 years with severe aortic stenosis (AS) intended to implant a transcatheter heart valve (THV) of the SAPIEN family. A total of 150 patients will be recruited from four sites in Germany and Austria. The registry will consist of two prospective cohorts: the investigational CTA-only cohort and the CTA + ICA control cohort. The CTA-only cohort will enrol 100 patients in whom significant (≥50%) left main (LM) and/or proximal left anterior descending artery (LAD) stenosis are ruled out on CTA. The CTA + ICA control cohort will enrol 50 patients who have undergone both CTA and ICA before TAVI and in whom ≥50% LM/proximal LAD stenosis has been ruled out by CTA. Three composite endpoints will be assessed at 3 months post-TAVI: CAD-specific endpoints, VARC-3-defined device success and early safety. CONCLUSION: The EASE-IT CT Registry evaluates whether TAVI can be carried out safely without performing ICA if prognostically relevant CAD of the LM/proximal LAD is ruled out with CTA. If so, the omission of ICA would help streamline the pre-procedural workup of TAVI patients.

Increased prevalence of high-risk coronary plaques in metabolic dysfunction associated steatotic liver disease patients: A meta-analysis.

BACKGROUND: Metabolic dysfunction associated steatotic liver disease (MASLD) is associated with an increased risk of coronary artery disease. Computed Tomography Coronary Angiography (CTCA) can assess both the extent and the features of coronary plaques. We aimed to gather evidence about the prevalence and features of coronary plaques among MASLD patients. METHODS: PubMed, Scopus, and Google Scholar databases were searched for randomized controlled trials and adjusted observational studies assessing the prevalence and features of coronary plaques by means of CTCA in MASLD patients as compared with a control group. The prevalence of coronary stenosis (defined as >30% and >50% diameter of stenosis), of increasing coronary artery calcium (CAC) score and of high-risk features (namely low-attenuation plaques, napkin ring sign, spotty calcification and positive remodelling) in MASLD patients were the endpoints of interest. RESULTS: Twenty-four observational studies were included. MASLD was associated with an increased prevalence of critical coronary stenosis compared with controls (odds ratio [OR] 1.54, 95%CI 1.23-1.93). Increased values of CAC score were observed in MASLD patients (OR 1.35, 95%CI 1.02-1.78 and OR 2.26, 95%CI 1.57-3.23 for CAC score 0-100 and >100, respectively). An increased risk of 'high-risk' coronary plaques was observed in MASLD patients (OR 2.13, 95%CI 1.42-3.19). As high-risk features plaques, a higher prevalence of positive remodelling and spotty calcification characterize MASLD patients (OR 2.92, 95%CI 1.79-4.77 and OR 2.96, 95%CI 1.22-7.20). CONCLUSIONS: Patients with MASLD are at increased risk of developing critical coronary stenosis and coronary plaques characterized by high-risk features as detected by CTCA.

Use of biliary stents for large coronary arteries.

Dedicated coronary artery drug-eluting stents may be inadequate in coronary arteries >6 mm in diameter, due to the risk of stent undersizing if the stent is not fully expanded or to loss of radial strength or damage to the drug coating if the stent is expanded >6 mm. We present two patients with large coronary arteries who were successfully treated with biliary balloon expandable stents.

Kidney disease, diabetes, and diameter stenosis predict Rotablation bailout in modified balloon application for severely calcified coronary lesions.

BACKGROUND: Modified balloon (MB) treatment in severely calcified coronary artery lesions is an established technique. However, some lesions require Rotablation (RA) as bailout strategy. AIMS: This study aimed to assess predictors of switch from MB to RA and its impact on procedural and midterm outcomes. METHODS: Four hundred and eighty-three consecutive patients were included undergoing MB treatment (n = 204) with a scoring or cutting balloon, or upfront RA treatment (n = 279) serving as control cohort. Strategy switch from MB to RA was performed in 19 of 204 patients. Procedural success was defined as successful stent implantation and TIMI III flow. RESULTS: In the MB cohort, median age was 72 [63-78] years, 75.5% were male and 42.1% had acute coronary syndrome. Procedure success was achieved in 89.4% of the switch group versus 98.4% of the MB only group (p < 0.001) and in 96.4% of the RA cohort. In the switch group, periprocedural complications (31.6% vs. 8.1% vs. 11.8%, p = 0.007), radiation dose (149 [126-252] vs. 59 [30-97] vs. 102 [59-156] Gcm2; p < 0.001) and contrast volume (250 [190-250] vs. 190 [150-250] vs. 195 [190--250] mL; p < 0.001) were significantly higher. Diabetes (OR 3.8, 95% CI 1.1-13.9, p = 0.042), chronic kidney disease stage 4 or 5 (OR 19.0, 95% CI 3.3-108.6, p < 0.001) and pronounced calcification resulting in higher angiographic diameter stenosis (OR 1.13, 95% CI 1.1-1.2, p = 0.001) independently predicted strategy switch. Midterm results were not affected by strategy switch regarding 1-year target lesion revascularization rates (86% vs. 89% vs. 89%; log-rank p = 0.95). CONCLUSION: Primary RA strategy might be considered in patients with severely calcified coronary artery lesions with high angiographic diameter stenosis, diabetes or impaired renal function due to increased periprocedural complication rates, radiation dose, and contrast volume following strategy switch.

Efficacy of intravascular lithotripsy (IVL) in coronary stenosis with severe calcification: A multicenter systematic review and meta-analysis.

BACKGROUND: With heavily calcified coronary and peripheral artery lesions, lesion preparation is crucial before stent placement to avoid underexpansion, associated with stent thrombosis or restenosis and patency failure in the long-term. Intravascular lithotripsy (IVL) technology disrupts superficial and deep calcium by using localized pulsative sonic pressure waves, making it to a promising tool for patients with severe calcification in coronary bed. AIMS: The aim of the study is to systematically review and summarize available data regarding the safety and efficacy of IVL for lesion preparation in severely calcified coronary arteries before stenting. METHODS: This study was conducted according to the PRISMA guidelines. We systematically searched PubMed, SCOPUS, and Cochrane databases from their inception to February 23, 2023, for studies assessing the characteristics and outcomes of patients undergoing IVL before stent implantation. The diameter of the vessel lumen before and after IVL, as well as stent implantation, were analyzed. The occurrence of major adverse cardiovascular events (MACE) was assessed using a random-effects model. RESULTS: This meta-analysis comprised 38 studies including 2977 patients with heavily calcified coronary lesions. The mean age was 72.2 ± 9.1 years, with an overall IVL clinical success of 93% (95% confidence interval [CI]: 91%-95%, I2 = 0%) and procedural success rate of 97% (95% CI: 95%-98%, I2 = 73.7%), while the in-hospital and 30-days incidence of MACE, myocardial infarction (MI), and death were 8% (95% CI: 6%-11%, I2 = 84.5%), 5% (95% CI: 2%-8%, I2 = 85.6%), and 2% (95% CI: 1%-3%, I2 = 69.3%), respectively. There was a significant increase in the vessel diameter (standardized mean difference [SMD]: 2.47, 95% CI: 1.77-3.17, I2 = 96%) and a decrease in diameter stenosis (SMD: -3.44, 95% CI: -4.36 to -2.52, I2 = 97.5%) immediately after IVL application, while it was observed further reduction in diameter stenosis (SMD: -6.57, 95% CI: -7.43 to -5.72, I2 = 95.8%) and increase in the vessel diameter (SMD: 4.37, 95% CI: 3.63-5.12, I2 = 96.7%) and the calculated lumen area (SMD: 3.23, 95% CI: 2.10-4.37, I2 = 98%), after stent implantation. The mean acute luminal gain following IVL and stent implantation was estimated to be 1.27 ± 0.6 and 1.94 ± 1.1 mm, respectively. Periprocedural complications were rare, with just a few cases of perforations, dissection, or no-reflow phenomena recorded. CONCLUSIONS: IVL seems to be a safe and effective strategy for lesion preparation in severely calcified lesions before stent implantation in coronary arteries. Future prospective studies are now warranted to compare IVL to other lesion preparation strategies.

Combination of computed tomography angiography with coronary artery calcium score for improved diagnosis of coronary artery disease: a collaborative meta-analysis of stable chest pain patients referred for invasive coronary angiography.

OBJECTIVES: Coronary computed tomography angiography (CCTA) has higher diagnostic accuracy than coronary artery calcium (CAC) score for detecting obstructive coronary artery disease (CAD) in patients with stable chest pain, while the added diagnostic value of combining CCTA with CAC is unknown. We investigated whether combining coronary CCTA with CAC score can improve the diagnosis of obstructive CAD compared with CCTA alone. METHODS: A total of 2315 patients (858 women, 37%) aged 61.1 ± 10.2 from 29 original studies were included to build two CAD prediction models based on either CCTA alone or CCTA combined with the CAC score. CAD was defined as at least 50% coronary diameter stenosis on invasive coronary angiography. Models were built by using generalized linear mixed-effects models with a random intercept set for the original study. The two CAD prediction models were compared by the likelihood ratio test, while their diagnostic performance was compared using the area under the receiver-operating-characteristic curve (AUC). Net benefit (benefit of true positive versus harm of false positive) was assessed by decision curve analysis. RESULTS: CAD prevalence was 43.5% (1007/2315). Combining CCTA with CAC improved CAD diagnosis compared with CCTA alone (AUC: 87% [95% CI: 86 to 89%] vs. 80% [95% CI: 78 to 82%]; p < 0.001), likelihood ratio test 236.3, df: 1, p < 0.001, showing a higher net benefit across almost all threshold probabilities. CONCLUSION: Adding the CAC score to CCTA findings in patients with stable chest pain improves the diagnostic performance in detecting CAD and the net benefit compared with CCTA alone. CLINICAL RELEVANCE STATEMENT: CAC scoring CT performed before coronary CTA and included in the diagnostic model can improve obstructive CAD diagnosis, especially when CCTA is non-diagnostic. KEY POINTS: • The combination of coronary artery calcium with coronary computed tomography angiography showed significantly higher AUC (87%, 95% confidence interval [CI]: 86 to 89%) for diagnosis of coronary artery disease compared to coronary computed tomography angiography alone (80%, 95% CI: 78 to 82%, p < 0.001). • Diagnostic improvement was mostly seen in patients with non-diagnostic C. • The improvement in diagnostic performance and the net benefit was consistent across age groups, chest pain types, and genders.

Comparison of machine learning-based CT fractional flow reserve with cardiac MR perfusion mapping for ischemia diagnosis in stable coronary artery disease.

OBJECTIVES: To compare the diagnostic performance of machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) and cardiac magnetic resonance (MR) perfusion mapping for functional assessment of coronary stenosis. METHODS: Between October 2020 and March 2022, consecutive participants with stable coronary artery disease (CAD) were prospectively enrolled and underwent coronary CTA, cardiac MR, and invasive fractional flow reserve (FFR) within 2 weeks. Cardiac MR perfusion analysis was quantified by stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Hemodynamically significant stenosis was defined as FFR ≤ 0.8 or > 90% stenosis on invasive coronary angiography (ICA). The diagnostic performance of CT-FFR, MBF, and MPR was compared, using invasive FFR as a reference. RESULTS: The study protocol was completed in 110 participants (mean age, 62 years ± 8; 73 men), and hemodynamically significant stenosis was detected in 36 (33%). Among the quantitative perfusion indices, MPR had the largest area under receiver operating characteristic curve (AUC) (0.90) for identifying hemodynamically significant stenosis, which is in comparison with ML-based CT-FFR on the vessel level (AUC 0.89, p = 0.71), with comparable sensitivity (89% vs 79%, p = 0.20), specificity (87% vs 84%, p = 0.48), and accuracy (88% vs 83%, p = 0.24). However, MPR outperformed ML-based CT-FFR on the patient level (AUC 0.96 vs 0.86, p = 0.03), with improved specificity (95% vs 82%, p = 0.01) and accuracy (95% vs 81%, p < 0.01). CONCLUSION: ML-based CT-FFR and quantitative cardiac MR showed comparable diagnostic performance in detecting vessel-specific hemodynamically significant stenosis, whereas quantitative perfusion mapping had a favorable performance in per-patient analysis. CLINICAL RELEVANCE STATEMENT: ML-based CT-FFR and MPR derived from cardiac MR performed well in diagnosing vessel-specific hemodynamically significant stenosis, both of which showed no statistical discrepancy with each other. KEY POINTS: • Both machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) and quantitative perfusion cardiac MR performed well in the detection of hemodynamically significant stenosis. • Compared with stress myocardial blood flow (MBF) from quantitative perfusion cardiac MR, myocardial perfusion reserve (MPR) provided higher diagnostic performance for detecting hemodynamically significant coronary artery stenosis. • ML-based CT-FFR and MPR from quantitative cardiac MR perfusion yielded similar diagnostic performance in assessing vessel-specific hemodynamically significant stenosis, whereas MPR had a favorable performance in per-patient analysis.

Prognostic implications of pre-transcatheter aortic valve replacement computed tomography-derived coronary plaque characteristics and stenosis severity.

OBJECTIVES: The study aimed to investigate the prognostic value of pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) in assessing physiological stenosis severity (CTA-derived fractional flow reserve (CT-FFR)) and high-risk plaque characteristics (HRPC). MATERIALS AND METHODS: Among TAVR patients who underwent pre-procedure CTA, the presence and number of HRPCs (minimum lumen area of < 4 mm2, plaque burden ≥ 70%, low-attenuating plaques, positive remodeling, napkin-ring sign, or spotty calcification) as well as CT-FFR were assessed. The risk of vessel-oriented composite outcome (VOCO, a composite of vessel-related ischemia-driven revascularization, vessel-related myocardial infarction, or cardiac death) was compared according to the number of HRPC and CT-FFR categories. RESULTS: Four hundred and twenty-seven patients (68.4% were male) with 1072 vessels were included. Their mean age was 70.6 ± 10.6 years. Vessels with low CT-FFR (≤ 0.80) (41.7% vs. 15.8%, adjusted hazard ratio (HRadj) 1.96; 95% confidence interval (CI): 1.28-2.96; p = 0.001) or lesions with ≥ 3 HRPC (38.7% vs. 16.0%, HRadj 1.81; 95%CI 1.20-2.71; p = 0.005) demonstrated higher VOCO risk. In the CT-FFR (> 0.80) group, lesions with ≥ 3 HRPC showed a significantly higher risk of VOCO than those with < 3 HRPC (34.7% vs. 13.0%; HRadj 2.04; 95%CI 1.18-3.52; p = 0.011). However, this relative increase in risk was not observed in vessels with positive CT-FFR (≤ 0.80). CONCLUSIONS: In TAVR candidates, both CT-FFR and the presence of ≥ 3 HRPC were associated with an increased risk of adverse clinical events. However, the value of HRPC differed with the CT-FFR category, with more incremental predictability among vessels with negative CT-FFR but not among vessels with positive CT-FFR. CLINICAL RELEVANCE STATEMENT: In transcatheter aortic valve replacement (TAVR) candidates, pre-TAVR CTA provided the opportunity to assess coronary physiological stenosis severity and high-risk plaque characteristics, both of which are associated with worse clinical outcomes. KEY POINTS: • The current study investigated the prognostic value of coronary physiology significance and plaque characteristics in transcatheter aortic valve replacement patients. • The combination of coronary plaque vulnerability and physiological significance showed improved accuracy in predicting clinical outcomes in transcatheter aortic valve replacement patients. • Pre-transcatheter aortic valve replacement CT can be a one-stop-shop tool for coronary assessments in clinical practice.

Intra-arterial Fractional Flow Reserve Measurements Provide an Objective Assessment of the Functional Significance of Peripheral Arterial Stenoses.

OBJECTIVE: Peripheral arterial stenoses (PAS) are commonly investigated with duplex ultrasound (DUS) and angiography, but these are not functional tests. Fractional flow reserve (FFR), a pressure based index, functionally assesses the ischaemic potential of coronary stenoses, but its utility in PAS is unknown. FFR in the peripheral vasculature in patients with limb ischaemia was investigated. METHODS: Patients scheduled for angioplasty and or stenting of isolated iliac and superficial femoral artery stenoses were recruited. Resting trans-lesional pressure gradient (Pd/Pa) and FFR were measured after adenosine provoked hyperaemia using an intra-arterial 0.014 inch flow and pressure sensing wire (ComboWire XT, Philips). Prior to revascularisation, exercise ABPI (eABPI) and DUS derived peak systolic velocity ratio (PSVR) of the index lesion were determined. Calf muscle oxygenation was measured using blood oxygenation level dependent cardiovascular magnetic resonance prior to and after revascularisation. RESULTS: Forty-one patients (32, 78%, male, mean age 65 ± 11 years) with 61 stenoses (iliac 32; femoral 29) were studied. For lesions < 80% stenosis, resting Pd/Pa was not influenced by the degree of stenosis (p = .074); however, FFR was discriminatory, decreasing as the severity of stenosis increased (p = .019). An FFR of < 0.60 was associated with critical limb threatening ischaemia (area under the curve [AUC] 0.87; 95% CI 0.75 - 0.95), in this study performing better than angiographic % stenosis (0.79; 0.63 - 0.89), eABPI (0.72; 0.57 - 0.83), and PSVR (0.65; 0.51 - 0.78). FFR correlated strongly with calf oxygenation (rho, 0.76; p < .001). A greater increase in FFR signalled resolution of symptoms and signs (ΔFFR 0.25 ± 0.15 vs. 0.13 ± 0.09; p = .009) and a post-angioplasty and stenting FFR of > 0.74 predicted successful revascularisation (combined sensitivity and specificity of 95%; AUC 0.98; 0.91 - 1.00). CONCLUSION: This pilot study demonstrates that FFR can objectively measure the functional significance of PAS that compares favourably with visual and DUS based assessments. Its role as a quality control adjunct that confirms optimal vessel patency after angioplasty and or stenting also merits further investigation.

[15O]H2O myocardial perfusion positron emission tomography: Added value of relative stress perfusion deficit in the prediction of significant coronary artery stenosis in a mixedpopulation.

BACKGROUND: It remains unknown whether estimation of the relative stress perfusion deficit offers added value in the prediction of significant coronary artery stenosis in myocardial perfusion imaging with [15O]H2O positron emission tomography (PET) in a population with high prevalence of established cardiac disease. METHODS: During eight months, we consecutively included all patients undergoing [15O]H2O PET and subsequent invasive coronary angiography (ICA). Significant stenosis was defined from ICA as fractional flow reserve ≤.8 or coronary artery narrowing of ≥70%. We calculated absolute and relative total perfusion deficits (aTPD and rTPD, respectively) as semiquantitative measures of the extent and severity of reduced stress perfusion. A multivariate logistic regression analysis was performed to test the adjusted associations (odds ratio (OR) with 95% CI) with significant coronary artery stenosis. RESULTS: Of 800 patients undergoing [15O]H2O PET, 144 underwent ICA, where 142 patients had aTPD of ≥3% and 79 (55%) of these had at least one significant stenosis. In an adjusted analysis, rTPD (OR10% increase = 2.12 (1.44-3.12), P < .001), previous coronary artery bypass grafting (CABG) (OR = .11 (.03-.36), P < .001) and reduced left ventricular ejection fraction (LVEF) (OR = .25 (.08-.84), P = .02) were independently associated with significant stenosis, whereas the association with aTPD (OR10% increase = 1.14 (.98-1.32), P = .08) was modest. CONCLUSIONS: In the presence of an absolute perfusion deficit (aTPD of ≥3%), rTPD may improve the prediction of significant stenosis in a heterogeneous population of patients examined with [15O]H2O PET. Furthermore, previous CABG and reduced LVEF are associated with nonstenotic perfusion deficiencies, suggesting caution when interpreting myocardial perfusion imaging in such patients.

Photon-Counting Detector CT Virtual Monoenergetic Images for Coronary Artery Stenosis Quantification: Phantom and In Vivo Evaluation.

BACKGROUND. Calcium blooming causes stenosis overestimation on coronary CTA. OBJECTIVE. The purpose of this article was to evaluate the impact of virtual monoenergetic imaging (VMI) reconstruction level on coronary artery stenosis quantification using photon-counting detector (PCD) CT. METHODS. A phantom containing two custom-made vessels (representing 25% and 50% stenosis) underwent PCD CT acquisitions without and with simulated cardiac motion. A retrospective analysis was performed of 33 patients (seven women, 26 men; mean age, 71.3 ± 9.0 [SD] years; 64 coronary artery stenoses) who underwent coronary CTA by PCD CT followed by invasive coronary angiography (ICA). Scans were reconstructed at nine VMI energy levels (40-140 keV). Percentage diameter stenosis (PDS) was measured, and bias was determined from the ground-truth stenosis percentage in the phantom and ICA-derived quantitative coronary angiography measurements in patients. Extent of blooming artifact was measured in the phantom and in calcified and mixed plaques in patients. RESULTS. In the phantom, PDS decreased for 25% stenosis from 59.9% (40 keV) to 13.4% (140 keV) and for 50% stenosis from 81.6% (40 keV) to 42.3% (140 keV). PDS showed lowest bias for 25% stenosis at 90 keV (bias, 1.4%) and for 50% stenosis at 100 keV (bias, -0.4%). Blooming artifacts decreased for 25% stenosis from 61.5% (40 keV) to 35.4% (140 keV) and for 50% stenosis from 82.7% (40 keV) to 52.1% (140 keV). In patients, PDS for calcified plaque decreased from 70.8% (40 keV) to 57.3% (140 keV), for mixed plaque decreased from 69.8% (40 keV) to 56.3% (140 keV), and for noncalcified plaque was 46.6% at 40 keV and 54.6% at 140 keV. PDS showed lowest bias for calcified plaque at 100 keV (bias, 17.2%), for mixed plaque at 140 keV (bias, 5.0%), and for noncalcified plaque at 40 keV (bias, -0.5%). Blooming artifacts decreased for calcified plaque from 78.4% (40 keV) to 48.6% (140 keV) and for mixed plaque from 73.1% (40 keV) to 44.7% (140 keV). CONCLUSION. For calcified and mixed plaque, stenosis severity measurements and blooming artifacts decreased at increasing VMI reconstruction levels. CLINICAL IMPACT. PCD CT with VMI reconstruction helps overcome current limitations in stenosis quantification on coronary CTA.

Association between Troponin Elevation and Decreased Myocardial Blood Flow Reserve in Patients without Obstructive Coronary Artery Disease.

INTRODUCTION: To study the prognostic factors of patients with chest pain and without obstructive coronary artery disease is of great significance for the management of such patients. We assessed whether a high-sensitivity troponin I (hs-TnI) is associated with prognosis in patients with chest pain and without obstructive coronary artery disease. METHODS: From 2011 to 2017, 489 consecutively hospitalized patients with chest pain and without significant coronary artery stenosis (<50%) were tested for hs-TnI and underwent stress myocardial contrast echocardiography (MCE). Myocardial blood flow reserve (MBFR) was measured by stress MCE. Patients were followed (median, 41 months) for composite endpoints, including cardiovascular death and non-fatal myocardial infarction. Cox proportional hazards models were performed to determine associations between hs-TnI and the composite endpoints. RESULTS: Among 489 patients with chest pain and without significant coronary artery stenosis, 257 patients (52.6%) had elevated hs-TnI. Compared to patients with normal hs-TnI, patients with elevated hs-TnI were older (p = 0.013) and had a higher prevalence of atrial fibrillation (p = 0.003), higher left ventricular mass index (p = 0.002) and E/e' septal (p < 0.001), and a lower MBFR (p < 0.001). After adjustment, there was still a significant association between hs-TnI and MBFR (odds ratio = 1.145; 95% confidence interval [CI], 1.079-1.214; p < 0.001). Compared with patients with normal hs-TnI, patients with elevated hs-TnI had a greater cumulative event rate (log-rank p = 0.002). Males (hazard ratio [HR], 4.770; 95% CI, 1.175-19.363; p = 0.029) and reduced MBFR (HR, 2.496; 95% CI, 1.446-4.311; p = 0.001) were risk factors associated with composite endpoints in patients with elevated hs-TnI. CONCLUSIONS: In patients with chest pain and without obstructive coronary artery disease, elevated hs-TnI is associated with decreased myocardial perfusion by contrast echocardiography as well as a higher incidence of cardiovascular events.

Association of systemic inflammatory response index with ST segment elevation myocardial infarction and degree of coronary stenosis: a cross-sectional study.

BACKGROUND: Systemic Inflammatory Response Index (SIRI), a composite inflammatory marker encompassing neutrophils, monocytes, and lymphocytes, has been recognized as a reliable marker of systemic inflammation. This article undertakes an analysis of clinical data from ST-segment Elevation Myocardial Infarction (STEMI) patients, aiming to comprehensively assess the relationship between SIRI, STEMI, and the degree of coronary stenosis. METHODS: The study involved 1809 patients diagnosed with STEMI between the years 2020 and 2023. Univariate and multivariate logistic regression analyses were conducted to evaluate the risk factors for STEMI. Receiver operating characteristic (ROC) curves were generated to determine the predictive power of SIRI and neutrophil-to-lymphocyte ratio (NLR). Spearman correlation analysis was performed to assess the correlation between SIRI, NLR, and the Gensini score (GS). RESULTS: Multivariate logistic regression analysis showed that the SIRI was the independent risk factor for STEMI (adjusted odds ratio (OR) in the highest quartile = 24.96, 95% confidence interval (CI) = 15.32-40.66, P < 0.001). In addition, there is a high correlation between SIRI and GS (ß:28.54, 95% CI: 24.63-32.46, P < 0.001). The ROC curve analysis was performed to evaluate the predictive ability of SIRI and NLR for STEMI patients. The area under the curve (AUC) for SIRI was 0.789. The AUC for NLR was 0.754. Regarding the prediction of STEMI in different gender groups, the AUC for SIRI in the male group was 0.771. The AUC for SIRI in the female group was 0.807. Spearman correlation analysis showed that SIRI exhibited a stronger correlation with GS, while NLR was lower (SIRI: r = 0.350, P < 0.001) (NLR: r = 0.313, P < 0.001). CONCLUSION: The study reveals a strong correlation between the SIRI and STEMI as well as the degree of coronary artery stenosis. In comparison to NLR, SIRI shows potential in predicting acute myocardial infarction and the severity of coronary artery stenosis. Additionally, SIRI exhibits a stronger predictive capability for female STEMI patients compared to males.