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Competing Interests: The authors declare no conflicts of interest.

Aims: We compared diagnostic performance, costs, and association with major adverse cardiovascular events (MACE) of clinical coronary computed tomography angiography (CCTA) interpretation versus semiautomated approach that use artificial intelligence and machine learning for atherosclerosis imaging-quantitative computed tomography (AI-QCT) for patients being referred for nonemergent invasive coronary angiography (ICA)., Methods: CCTA data from individuals enrolled into the randomized controlled Computed Tomographic Angiography for Selective Cardiac Catheterization trial for an American College of Cardiology (ACC)/American Heart Association (AHA) guideline indication for ICA were analyzed. Site interpretation of CCTAs were compared to those analyzed by a cloud-based software (Cleerly, Inc.) that performs AI-QCT for stenosis determination, coronary vascular measurements and quantification and characterization of atherosclerotic plaque. CCTA interpretation and AI-QCT guided findings were related to MACE at 1-year follow-up., Results: Seven hundred forty-seven stable patients (60 ± 12.2 years, 49% women) were included. Using AI-QCT, 9% of patients had no CAD compared with 34% for clinical CCTA interpretation. Application of AI-QCT to identify obstructive coronary stenosis at the ≥50% and ≥70% threshold would have reduced ICA by 87% and 95%, respectively. Clinical outcomes for patients without AI-QCT-identified obstructive stenosis was excellent; for 78% of patients with maximum stenosis < 50%, no cardiovascular death or acute myocardial infarction occurred. When applying an AI-QCT referral management approach to avoid ICA in patients with <50% or <70% stenosis, overall costs were reduced by 26% and 34%, respectively., Conclusions: In stable patients referred for ACC/AHA guideline-indicated nonemergent ICA, application of artificial intelligence and machine learning for AI-QCT can significantly reduce ICA rates and costs with no change in 1-year MACE., (© 2023 The Authors. Clinical Cardiology published by Wiley Periodicals, LLC.)

Objectives: In this international, multicenter study, using third-generation dual-source computed tomography (CT), we investigated the diagnostic performance of dynamic stress CT myocardial perfusion imaging (CT-MPI) in addition to coronary CT angiography (CTA) compared to invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR)., Background: CT-MPI combined with coronary CTA integrates coronary artery anatomy with inducible myocardial ischemia, showing promising results for the diagnosis of hemodynamically significant coronary artery disease in single-center studies., Methods: At 9 centers in Europe, Japan, and the United States, 132 patients scheduled for ICA were enrolled; 114 patients successfully completed coronary CTA, adenosine-stress dynamic CT-MPI, and ICA. Invasive FFR was performed in vessels with 25% to 90% stenosis. Data were analyzed by independent core laboratories. For the primary analysis, for each coronary artery the presence of hemodynamically significant obstruction was interpreted by coronary CTA with CT-MPI compared to coronary CTA alone, using an FFR of ≤0.80 and angiographic severity as reference. Territorial absolute myocardial blood flow (MBF) and relative MBF were compared using C-statistics., Results: ICA and FFR identified hemodynamically significant stenoses in 74 of 289 coronary vessels (26%). Coronary CTA with ≥50% stenosis demonstrated a per-vessel sensitivity, specificity, and accuracy for the detection of hemodynamically significant stenosis of 96% (95% CI: 91%-100%), 72% (95% CI: 66%-78%), and 78% (95% CI: 73%-83%), respectively. Coronary CTA with CT-MPI showed a lower sensitivity (84%; 95% CI: 75%-92%) but higher specificity (89%; 95% CI: 85%-93%) and accuracy (88%; 95% CI: 84%-92%). The areas under the receiver-operating characteristic curve of absolute MBF and relative MBF were 0.79 (95% CI: 0.71-0.86) and 0.82 (95% CI: 0.74-0.88), respectively. The median dose-length product of CT-MPI and coronary CTA were 313 mGy·cm and 138 mGy·cm, respectively., Conclusions: Dynamic CT-MPI offers incremental diagnostic value over coronary CTA alone for the identification of hemodynamically significant coronary artery disease. Generalized results from this multicenter study encourage broader consideration of dynamic CT-MPI in clinical practice. (Dynamic Stress Perfusion CT for Detection of Inducible Myocardial Ischemia [SPECIFIC]; NCT02810795)., Competing Interests: Funding Support and Author Disclosures This study was supported by unrestricted grants from Siemens Healthineers and Bayer Healthcare. Dr Nguyen’s research is supported by the National Institutes of Health (R01HL134830-01). Koen Nieman’s research is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health (R01HL141712; R01HL146754). Dr Geisler has received research grants from Medtronic and Edwards Lifesciences. Dr Kitagawa has received an endowed chair position supported by Siemens Healthineers. Dr Vliegenthart has received an institutional research grant from Siemens Healthineers. Dr Hausleiter has received receiving speaker honoraria and research support from Abbott Vascular and Edwards Lifesciences; and has served as a consultant for Edwards Lifesciences. Dr Pugliese has received research support from Siemens Healthineers. Dr Budde has received institutional research support to the Erasmus MC from Siemens Healthineers. Dr Nikolauo has received research grants from Siemens Healthineers, GE Healthcare, and Bayer Healthcare; and has served as a consultant for Siemens Healthineers; and Bayer Healthcare. Dr Sakuma has received departmental research grants from FUJIFILM Toyama Chemical Co, Ltd, and Guerbet Japan KK. Dr Klotz is a retired employee of and serves as a consultant for Siemens Healthineers. Dr Bamberg has received research grants from Siemens Healthineers and Bayer Healthcare; and has served as a consultant for Siemens Healthineers, Bayer Healthcare, and Bracco. Dr Nieman has received unrestricted institutional research support from Siemens Healthineers and HeartFlow Inc; has served as a consultant for Siemens Medical Systems USA; and holds equity in Lumen Therapeutics. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Compared with invasive fractional flow reserve (FFR), coronary CT angiography (cCTA) is limited in detecting hemodynamically relevant lesions. cCTA-based FFR (CT-FFR) is an approach to overcome this insufficiency by use of computational fluid dynamics. Applying recent innovations in computer science, a machine learning (ML) method for CT-FFR derivation was introduced and showed improved diagnostic performance compared to cCTA alone. We sought to investigate the influence of stenosis location in the coronary artery system on the performance of ML-CT-FFR in a large, multicenter cohort., Methods: Three hundred and thirty patients (75.2% male, median age 63 years) with 502 coronary artery stenoses were included in this substudy of the MACHINE (Machine Learning Based CT Angiography Derived FFR: A Multi-Center Registry) registry. Correlation of ML-CT-FFR with the invasive reference standard FFR was assessed and pooled diagnostic performance of ML-CT-FFR and cCTA was determined separately for the following stenosis locations: RCA, LAD, LCX, proximal, middle, and distal vessel segments., Results: ML-CT-FFR correlated well with invasive FFR across the different stenosis locations. Per-lesion analysis revealed improved diagnostic accuracy of ML-CT-FFR compared with conventional cCTA for stenoses in the RCA (71.8% [95% confidence interval, 63.0%-79.5%] vs. 54.8% [45.7%-63.8%]), LAD (79.3 [73.9-84.0] vs. 59.6 [53.5-65.6]), LCX (84.1 [76.0-90.3] vs. 63.7 [54.1-72.6]), proximal (81.5 [74.6-87.1] vs. 63.8 [55.9-71.2]), middle (81.2 [75.7-85.9] vs. 59.4 [53.0-65.6]) and distal stenosis location (67.4 [57.0-76.6] vs. 51.6 [41.1-62.0])., Conclusion: In a multicenter cohort with high disease prevalence, ML-CT-FFR offered improved diagnostic performance over cCTA for detecting hemodynamically relevant stenoses regardless of their location., Competing Interests: Declaration of competing interest Dr. Renker has received speaker fees from Abbott. Dr. Baumann has received consulting fees from Phillips Volcano. Dr. Tesche has received research support and honoraria for speaking from Siemens. Dr. Kim received proctor/speaker fees from Abbott, Boston Scientific, Edwards Lifesciences, Medtronic, Meril. Dr. Nieman reports unrestricted institutional support from Siemens Healthineers, Bayer, GE, and Heartflow Inc., and consultancy honoraria from Siemens Medical Solutions USA. Dr. Persson reports on institutional support from Siemens Healthineers. Dr. Schoepf has received grants and/or personal fees from Bayer, Bracco, Elucid BioImaging, GE, Guerbet, HeartFlow Inc., Keya Medical, and Siemens. All other authors declare that they have no financial disclosures., (Copyright © 2021 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Purpose: The quantitative RESOLVE (Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion) score derived from coronary computed tomography angiography (coronary CTA) was developed as a noninvasive and accurate prediction tool for side branch (SB) occlusion in coronary bifurcation intervention. We aimed to determine the ability of a visually estimated CTA-derived RESOLVE score (V-RESOLVE score) to predict SB occlusion in coronary bifurcation intervention., Materials and Methods: The present study included 363 patients with 400 bifurcation lesions. CTA-derived V-RESOLVE score was derived and compared with the quantitative CTA-derived RESOLVE score. The scoring systems were divided into quartiles, and classified as the high-risk and non-high-risk groups. SB occlusion was defined as any decrease in thrombolysis in myocardial infarction flow grade after main vessel stenting., Results: In total, 28 SB occlusions (7%) occurred. The concordance between visual and quantitative CTA analysis showed poor to excellent agreement (weighted κ range: 0.099 to 0.867). The area under the receiver operating curve for the prediction of SB occlusion was significantly higher for the CTA-derived V-RESOLVE score than for quantitative CTA-derived RESOLVE score (0.792 vs. 0.709, P=0.049). The total net reclassification index was 42.7% (P=0.006), and CTA-derived V-RESOLVE score showed similar capability to discriminate between high-risk group (18.6% vs. 13.8%, P=0.384) and non-high-risk group (3.8% vs. 4.9%, P=0.510) as compared with quantitative CTA-derived RESOLVE score., Conclusions: Visually estimated CTA-derived V-RESOLVE score is an accurate and easy-to-use prediction tool for the stratification of SB occlusion in coronary bifurcation intervention., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To test the accuracy of clinical pre-test probability (PTP) for prediction of obstructive coronary artery disease (CAD) in a pan-European setting., Methods: Patients with suspected CAD and stable chest pain who were clinically referred for invasive coronary angiography (ICA) or computed tomography (CT) were included by clinical sites participating in the pilot study of the European multi-centre DISCHARGE trial. PTP of CAD was determined using the Diamond-Forrester (D+F) prediction model initially introduced in 1979 and the updated D+F model from 2011. Obstructive coronary artery disease (CAD) was defined by one at least 50% diameter coronary stenosis by both CT and ICA., Results: In total, 1440 patients (654 female, 786 male) were included at 25 clinical sites from May 2014 until July 2017. Of these patients, 725 underwent CT, while 715 underwent ICA. Both prediction models overestimated the prevalence of obstructive CAD (31.7%, 456 of 1440 patients, PTP: initial D+F 58.9% (28.1-90.6%), updated D+F 47.3% (34.2-59.9%), both p < 0.001), but overestimation of disease prevalence was higher for the initial D+F (p < 0.001). The discriminative ability was higher for the updated D+F 2011 (AUC of 0.73 95% confidence interval [CI] 0.70-0.76 versus AUC of 0.70 CI 0.67-0.73 for the initial D+F; p < 0.001; odds ratio (or) 1.55 CI 1.29-1.86, net reclassification index 0.11 CI 0.05-0.16, p < 0.001)., Conclusions: Clinical PTP calculation using the initial and updated D+F prediction models relevantly overestimates the actual prevalence of obstructive CAD in patients with stable chest pain clinically referred for ICA and CT suggesting that further refinements to improve clinical decision-making are needed., Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT02400229 KEY POINTS: • Clinical pre-test probability calculation using the initial and updated D+F model overestimates the prevalence of obstructive CAD identified by ICA and CT. • Overestimation of disease prevalence is higher for the initial D+F compared with the updated D+F. • Diagnostic accuracy of PTP assessment varies strongly between different clinical sites throughout Europe.

Background: The purpose of this study was to assess the feasibility of low-dose dynamic regadenoson computed tomography perfusion (CTP) protocol, and to determine which parameters provide the best diagnostic yield for the presence and burden of ischemia in reference to the magnetic resonance myocardial perfusion imaging (MR MPI)., Methods: Fifty six patients with ≥1 intermediate (50-90%) coronary artery stenosis on CTA underwent dynamic stress CTP and MR MPI. The distribution of contrast agent in CTP was represented for each myocardial segment as either absolute or indexed: myocardial blood flow (MBF), myocardial blood volume (MBV), perfused capillary blood volume (PCBV), peak value (PV), time to peak (TTP), respectively., Results: Of 56 patients (25 females, 63.5 ± 8.5y), 15 (27%) were diagnosed with reversible ischemia and 3 (5%) with fixed ischemia on the MR MPI. The median radiation dose for dynamic CTP scan was 352.00 [276.4-496.6] mGy*cm. The optimal cut-off point for the prediction of reversible ischemia on MR MPI for the absolute parameters were: MBF ≤156.49 (AUC=0.899), MBV ≤15.06 (AUC=0.901), PCBV ≤7.90 (AUC=0.880), PV ≤ 88.30 (AUC=0.766), TTP ≥22.58 (AUC=0.595); and for the indexed: indexed MBF ≤0.78 (AUC=0.926), indexed MBV ≤0.81 (AUC=0.924), indexed PCBV ≤0.70 (AUC=0.894); indexed PV ≤ 0.79 (AUC=0.869), indexed TTP ≤0.87 (AUC=0.685). The best parameters for ischemia detection were indexed MBF and indexed MBV, with sensitivities 91% and 89%, specificities 97% and 96%, NPV 99% and 99%, PPV 76% and 69%, and accuracies 96% and 95%, respectively. In per patient analysis, indexed MBF correlated significantly better with the ischemia burden than any of the absolute parameters (p < 0.01 for all comparisons)., Conclusions: Regadenoson dynamic CTP using low-dose protocol is feasible while maintaining high diagnostic accuracy. The best diagnostic value may be provided by indexed parameters, of which indexed MBF and indexed MBV may provide best incremental value in identification of the presence and burden of ischemia., Competing Interests: Declaration of competing interest This work forms part of the translational research portfolio of the Biomedical Research Centre at Barts which is supported and funded by the NIHR. Dr F. Pugliese has received research funding by Siemens Healthineers. Other authors do not have conflict of interest do disclose., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

The Medina classification is used to determine the presence of significant stenosis (≥50%) within each of the 3 arterial segments of coronary bifurcation in invasive coronary angiography (ICA). The utility of coronary computed tomography angiography (coronary CTA) for assessment of Medina classification is unknown. We aimed to compare the agreement and reproducibility of Medina classification between ICA and coronary CTA, and evaluate its ability to predict side branch (SB) occlusion following percutaneous coronary intervention (PCI). In total 363 patients with 400 bifurcations were included, and 28 (7%) SB occlusions among 26 patients were noted. Total agreement between CTA and ICA for assessment of Medina class was poor (kappa = 0.189), and discordance between both modalities was noted in 253 (63.3%) lesions. Larger diameter ratio between main vessel and SB in CTA, and larger bifurcation angle in ICA were independently associated with discordant Medina assessment. Whereas the interobserver agreement on Medina classification in CTA was moderate (kappa = 0.557), only fair agreement (kappa = 0.346) was observed for ICA. Finally, Medina class with any proximal involvement of main vessel and SB (1.X.1) on CTA or ICA was the most predictive of SB occlusion following PCI with no significant differences between both modalities (area under the curve 0.686 vs 0.663, p = 0.693, respectively). In conclusion, Medina classification was significantly affected by the imaging modality, and coronary CTA improved reproducibility of Medina classification compared with ICA. Both CTA and ICA-derived Medina class with any involvement of the proximal main vessel and SB was predictive of SB occlusion following PCI., (Copyright © 2020. Published by Elsevier Inc.)

Purpose: This study investigated the impact of gender differences on the diagnostic performance of machine-learning based coronary CT angiography (cCTA)-derived fractional flow reserve (CT-FFR ML ) for the detection of lesion-specific ischemia., Method: Five centers enrolled 351 patients (73.5% male) with 525 vessels in the MACHINE (Machine leArning Based CT angiograpHy derIved FFR: a Multi-ceNtEr) registry. CT-FFR ML and invasive FFR ≤ 0.80 were considered hemodynamically significant, whereas cCTA luminal stenosis ≥50% was considered obstructive. The diagnostic performance to assess lesion-specific ischemia in both men and women was assessed on a per-vessel basis., Results: In total, 398 vessels in men and 127 vessels in women were included. Compared to invasive FFR, CT-FFR ML reached a sensitivity, specificity, positive predictive value, and negative predictive value of 78% (95%CI 72-84), 79% (95%CI 73-84), 75% (95%CI 69-79), and 82% (95%CI: 76-86) in men vs. 75% (95%CI 58-88), 81 (95%CI 72-89), 61% (95%CI 50-72) and 89% (95%CI 82-94) in women, respectively. CT-FFR ML showed no statistically significant difference in the area under the receiver-operating characteristic curve (AUC) in men vs. women (AUC: 0.83 [95%CI 0.79-0.87] vs. 0.83 [95%CI 0.75-0.89], p = 0.89). CT-FFR ML was not superior to cCTA alone [AUC: 0.83 (95%CI: 0.75-0.89) vs. 0.74 (95%CI: 0.65-0.81), p = 0.12] in women, but showed a statistically significant improvement in men [0.83 (95%CI: 0.79-0.87) vs. 0.76 (95%CI: 0.71-0.80), p = 0.007]., Conclusions: Machine-learning based CT-FFR performs equally in men and women with superior diagnostic performance over cCTA alone for the detection of lesion-specific ischemia., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Coronary computed tomographic angiography (CTA) is a reliable modality to detect coronary artery disease. However, CTA generally overestimates stenosis severity compared with invasive angiography, and angiographic stenosis does not necessarily imply hemodynamic relevance when fractional flow reserve (FFR) is used as reference. CTA-based FFR (CT-FFR), using computational fluid dynamics (CFD), improves the correlation with invasive FFR results but is computationally demanding. More recently, a new machine-learning (ML) CT-FFR algorithm has been developed based on a deep learning model, which can be performed on a regular workstation. In this large multicenter cohort, the diagnostic performance ML-based CT-FFR was compared with CTA and CFD-based CT-FFR for detection of functionally obstructive coronary artery disease., Methods and Results: At 5 centers in Europe, Asia, and the United States, 351 patients, including 525 vessels with invasive FFR comparison, were included. ML-based and CFD-based CT-FFR were performed on the CTA data, and diagnostic performance was evaluated using invasive FFR as reference. Correlation between ML-based and CFD-based CT-FFR was excellent ( R =0.997). ML-based (area under curve, 0.84) and CFD-based CT-FFR (0.84) outperformed visual CTA (0.69; P <0.0001). On a per-vessel basis, diagnostic accuracy improved from 58% (95% confidence interval, 54%-63%) by CTA to 78% (75%-82%) by ML-based CT-FFR. The per-patient accuracy improved from 71% (66%-76%) by CTA to 85% (81%-89%) by adding ML-based CT-FFR as 62 of 85 (73%) false-positive CTA results could be correctly reclassified by adding ML-based CT-FFR., Conclusions: On-site CT-FFR based on ML improves the performance of CTA by correctly reclassifying hemodynamically nonsignificant stenosis and performs equally well as CFD-based CT-FFR., (© 2018 American Heart Association, Inc.)

Purpose: The aim of this study was to evaluate the utility of automated plaque analysis in differentiating chronic total occlusion (CTO) from subtotal occlusion (SO) in patients with ambiguous coronary lesions on coronary computed tomography angiography (CTA)., Materials and Methods: A total of 63 patients with 63 ambiguous coronary lesions on CTA were included. The lesion length (LL), diameter stenosis, plaque volume and composition, remodeling index, and contrast density difference (CDD) (reflecting intraluminal contrast kinetics over the lesion) were assessed using an automatic software tool. All patients underwent invasive coronary angiography., Results: Coronary angiography confirmed 28 CTOs and 35 SOs. CTOs showed significantly longer LL (6.4±12.3 vs. 1.0±2.2 mm, P=0.03) and higher CDD (74%±31% vs. 55%±32%, P=0.02) compared with SO. The optimal thresholds for prediction of CTO for CDD and LL were ≥43% and ≥1 mm, respectively (max. sensitivity: 82% for CDD, max. specificity: 77% for LL). The guidewire manipulation time correlated with LL (r=0.529, P=0.004) and CDD (r=0.435, P=0.021) in lesions attempted by percutaneous coronary intervention., Conclusions: Automated computed tomography plaque analysis may be applied as a noninvasive tool to differentiate CTO from SO.

Objectives: This study aimed to evaluate the diagnostic accuracy of coronary computed tomography angiography (CTA) for detecting coronary artery stenoses in patients with valvular heart disease undergoing valve surgery., Background: Coronary CTA is currently not routinely recommended for detecting coronary artery stenoses before cardiac valve surgery. However, recent improvements in computed tomography technology may enable the identification of the most appropriate candidates for coronary CTA before valve surgery., Methods: A systematic review was performed of PubMed, EMBASE, and the Cochrane databases for all studies that used ≥16-detector row computed tomography scanning to perform coronary CTA in patients with valvular heart disease scheduled for valve surgery and validated the results against invasive angiography. Summary diagnostic accuracies were calculated by using a bivariate random effects model, and a generalized linear mixed model was applied for heterogeneity analysis., Results: Seventeen studies analyzing 1,107 patients and 12,851 coronary segments were included. Patient-based analysis revealed a pooled sensitivity of 93% (95% confidence interval [CI]: 86 to 97), specificity of 89% (95% CI: 86 to 91), a negative likelihood ratio (LR) of 0.07 (95% CI: 0.04 to 0.16), and a positive LR of 8.44 (95% CI: 6.49 to 10.99) for coronary CTA to identify individuals with stenosis ≥50%. Specificity and positive LR were higher in patients without aortic stenosis (AS) versus those with AS (96% vs. 87% and 21.2 vs. 7.4, respectively), as well as with ≥64 detectors versus <64 detectors (90% vs. 86% and 9.5 vs. 6.9). Heterogeneity analysis revealed a significant impact of AS and the number of detectors on specificity of CTA., Conclusions: Coronary CTA using currently available technology is a reliable imaging alternative to invasive angiography with excellent sensitivity and negative LR for the detection of significant coronary stenoses in patients undergoing cardiac valve surgery. The specificity of coronary CTA may be decreased against the background of AS (Computed Tomography Angiography for the Detection of Coronary Artery Disease in Patients Referred for Cardiac Valve Surgery: A Meta-Analysis; CRD42015016213)., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: The widespread clinical application of coronary computed tomography angiography (CCTA) has resulted in increased referral patterns of patients with intermediate coronary stenoses to invasive coronary angiography. We evaluated the application of advanced quantitative coronary angiography (A-QCA) for predicting fractional flow reserve (FFR) in intermediate coronary lesions detected on CCTA., Materials and Methods: Fifty-six patients with 66 single intermediate coronary lesions (≥ 50% to 80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. A-QCA including calculation of the Poiseuille-based index defined as the ratio of lesion length to the fourth power of the minimal lumen diameter (MLD) was performed. Significant stenosis was defined as FFR ≤ 0.80., Results: The mean FFR was 0.86 ± 0.09, and 18 lesions (27%) were functionally significant. FFR correlated with lesion length (R=-0.303, P=0.013), MLD (R=0.527, P<0.001), diameter stenosis (R=-0.404, P=0.001), minimum lumen area (MLA) (R=0.530, P<0.001), lumen stenosis (R=-0.400, P=0.001), and Poiseuille-based index (R=-0.602, P<0.001). The optimal cutoff values for MLD, MLA, diameter stenosis, and lumen stenosis were ≤ 1.3 mm, ≤ 1.5 mm, >44%, and >69%, respectively (maximum negative predictive value of 94% for MLA, maximum positive predictive value of 58% for diameter stenosis). The Poiseuille-based index was the most accurate (C statistic 0.86, sensitivity 100%, specificity 71%, positive predictive value 56%, and negative predictive value 100%) predictor of FFR ≤ 0.80, but showed the lowest interobserver agreement (intraclass correlation coefficient 0.37)., Conclusions: A-QCA might be used to rule out significant ischemia in intermediate stenoses detected by CCTA. The diagnostic application of the Poiseuille-based angiographic index is precluded by its high interobserver variability.

Objective: To determine the application of advanced coronary computed tomography angiography (CCTA) plaque analysis for predicting invasive fractional flow reserve (FFR) in intermediate coronary lesions., Methods: Sixty-one patients with 71 single intermediate coronary lesions (≥ 50-80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. Advanced anatomical and morphometric plaque analysis was performed based on CCTA data set to determine optimal criteria for significant flow impairment. A significant stenosis was defined as FFR ≤ 0.80., Results: FFR averaged 0.85 ± 0.09, and 19 lesions (27%) were functionally significant. FFR correlated with minimum lumen area (MLA) (r=0.456, p<0.001), minimum lumen diameter (MLD) (r=0.326, p=0.006), reference lumen diameter (RLD) (r=0.245, p=0.039), plaque burden (r=-0.313, p=0.008), lumen area stenosis (r=-0.305, p=0.01), lesion length (r=-0.692, p<0.001), and plaque volume (r=-0.668, p<0.001). There was no relationship between FFR and CCTA morphometric plaque parameters. By multivariate analysis the independent predictors of FFR were lesion length (beta=-0.581, p<0.001), MLA (beta=0.360, p=0.041), and RLD (beta=-0.255, p=0.036). The optimal cutoffs for lesion length, MLA, MLD, RLD, and lumen area stenosis were >18.5mm, ≤ 3.0mm(2), ≤ 2.1mm, ≤ 3.2mm, and >69%, respectively (max. sensitivity: 100% for MLA, max. specificity: 79% for lumen area stenosis)., Conclusions: CCTA predictors for FFR support the mathematical relationship between stenosis pressure drop and coronary flow. CCTA could prove to be a useful rule-out test for significant hemodynamic effects of intermediate coronary stenoses., (Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: Effectiveness evaluation and search for the factors determining long-term results of beta intracoronary brachytherapy (ICBT) are of a special importance in an upcoming era of drug-eluting stents usage for a wide range of clinical indications: de novo and in-stent restenosis lesions., Methods: One hundred forty eight consecutive patients (59.6+/-9.6 years, 72% men) treated with beta ICBT for in-stent restenosis (ISR) or de novo lesions were studied. There were 135 ISR in 121 patients and 31 de novo lesions in 27 patients. Follow-up coronary angiography was performed in all patients after a mean of 8.9+/-4.5 months. Detailed qualitative and quantitative angiographic analysis of pre-, peri- and postprocedural as well as follow-up angiograms was performed., Results: Forty five percent of patients treated for de novo lesions were diabetic. Thirty five percent of all targets were located in vessels with a reference vessel diameter <2.5 mm. Furthermore, 77% of ISR lesions were in Class 1 according to the Mehran classification. The mean length of an irradiated segment was 37.6 mm. The overall recurrent restenosis rate was 28.3%. Multivariate analysis revealed that the reference vessel diameter and the presence of edge injury within the proximal 32P source dose-fall off were the only independent predictors of recurrent restenosis after ICBT (OR 0.46; 95%CI 0.24-0.89; p=0.021 and OR 2.55; 95%CI 1.23-5.25; p=0.011, respectively)., Conclusions: Recurrent restenosis after beta intracoronary brachytherapy treatment is negatively associated with the target vessel size. Presence of edge injury within the proximal 32P source dose-fall increases the frequency of recurrent renarrowing after ICBT. Our results indicate that target vessel size should be taken into account in optimising interventional strategy for ISR treatment: drug eluting stents versus intracoronary brachytherapy. Avoidance of edge injury within the proximal 32P source dose fall-off is strongly recommended while ICBT application.