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Objectives: This study aims to investigate the differences in plaque characteristics and fat attenuation index (FAI) between in patients who received revascularization versus those who did not receive revascularization and examine whether the machine learning (ML)-based model constructed by plaque characteristics and FAI can predict revascularization. Methods: This study was a post hoc analysis of a prospective single-centre registry of sequential patients undergoing coronary computed tomography angiography, referred from inpatient and emergency department settings (n = 261, 63 years ± 8; 188 men). The primary outcome was revascularization by percutaneous coronary revascularization. The computed tomography angiography (CTA) images were analysed by experienced radiologists using a dedicated workstation in a blinded fashion. The ML-based model was automatically computed. Results: The study cohort consisted of 261 subjects. Revascularization was performed in 105 subjects. Patients receiving revascularization had higher FAI value (67.35 ± 5.49 vs −80.10 ± 7.75 Hu, P < .001) as well as higher plaque length, calcified, lipid, and fibrous plaque burden and volume. When FAI was incorporated into an ML risk model based on plaque characteristics to predict revascularization, the area under the curve increased from 0.84 (95% CI, 0.68-0.99) to 0.95 (95% CI, 0.88-1.00). Conclusions: ML algorithms based on FAI and characteristics could help improve the prediction of future revascularization and identify patients likely to receive revascularization. Advances in knowledge: Pre-procedural FAI could help guide revascularization in symptomatic coronary artery disease patients. [ABSTRACT FROM AUTHOR]

Objectives: Residual dissection is a concern in endovascular treatment with a DCB, and there is limited knowledge of hemodynamics at a dissection lesion. Therefore, the objective of this study is to evaluate the mean pressure gradient (MPG) and fractional flow reserve (FFR) at a residual dissection after DCB angioplasty for the superficial femoral artery (SFA). Methods: A total of 59 cases with residual SFA dissection treated with DCB angioplasty at a single center were analyzed retrospectively. The dissection was classified into 6 types (A-F). The primary endpoints were MPG and FFR at a residual dissection lesion after DCB angioplasty, using evaluation with a pressure wire. Results: The median lesion length was 70 (40-130) mm with 24% popliteal involvement, and 11 cases (18%) had chronic total occlusion. A completion angiogram revealed dissection of types A (n = 33, 56%), B (n = 18, 31%), C (n = 7, 12%), and D (n = 1, 2%). The median MPGs in type A, B, and C cases were 0 (0-2), 0 (0-4), and 3 (0-6) mmHg, with a significant lower in type C cases than in type A cases (A vs C, P =.021). The median FFRs in type A, B, and C cases of 1.0 (.98-1.00), 1.0 (.96-1.00), and.98 (.95-1.00) did not differ significantly among dissection types (A vs B, P =.86; A vs C, P =.055; B vs C, P =.15). Conclusions: This is the first report of hemodynamics at a SFA dissection. The results suggest that low-grade dissection (types A or B) does not affect MPG and FFR at a SFA lesion. This indicates that a bailout stent may be unnecessary for patients with dissection of types A or B. A further investigation is needed to determine whether a scaffold is required for a SFA lesion with type C dissection. [ABSTRACT FROM AUTHOR]

The association of coronary computed tomography angiography (CTA) and left ventricular (LV) myocardium measurements with cancer therapy–related cardiac dysfunction (CTRCD) is limited. In this study, the authors sought to evaluate the changes in coronary arteries and LV myocardium in patients with left breast cancer (BC) receiving anthracycline with or without radiotherapy, with the use of coronary CTA. Participants with left BC receiving anthracycline with or without radiotherapy were prospectively included. All participants underwent coronary CTA before and after treatment, including nonenhanced calcium-scoring scan, computed tomography angiography, and dual-energy late enhancement scan. Computed tomographic fractional flow reserve (CT-FFR), pericoronary adipose tissue (PCAT) CT attenuation, and LV segments' extracellular volume (ECV) before and after treatment were compared. Logistic regression analysis was used to assess the association between baseline coronary CTA parameters and CTRCD. Eighty participants receiving anthracycline and 59 participants receiving anthracycline with radiotherapy were included. CT-FFR decreased and PCAT CT attenuation and LV global and segments' ECV increased after treatment (all P < 0.05). After chemoradiotherapy, CT-FFR was lower and PCAT CT attenuation and LV myocardial ECV were higher than after chemotherapy. Twenty-four participants developed CTRCD. After adjustment by Heart Failure Association–International Cardio-Oncology Society risk in multivariable logistic regression analysis, baseline stenosis of the left anterior descending artery (LAD) (OR: 1.987 [95% CI: 1.322-2.768]; P = 0.021), left circumflex artery (LCX) (OR: 1.895 [95% CI: 1.281-2.802]; P = 0.031), and right coronary artery (RCA) (OR: 1.920 [95% CI: 1.405-2.811]; P = 0.028), and baseline CT-FFR of the LAD (OR: 3.425 [95% CI: 1.621-9.434]; P < 0.001), LCX (OR: 2.058 [95% CI: 1.030-5.076]; P = 0.006), and RCA (OR: 2.469 [95% CI: 1.232-6.944]; P = 0.004) were associated with CTRCD. Multiparameter coronary CTA contributes to comprehensive assessment of the coronary arteries and myocardium in patients with left BC receiving anthracycline with or without radiotherapy. Baseline coronary artery stenosis and CT-FFR might be imaging markers for predicting CTRCD in these patients. [Display omitted] [ABSTRACT FROM AUTHOR]

On-site computed tomography-derived fractional flow reserve (CT-FFR) is a feasible method for examining lesion-specific ischemia, and plaque analysis of coronary CT angiography (CCTA) is useful for predicting future cardiac events. However, their utility and association on a per-vessel level remain unclear. We analyzed vessels showing 50–90 % stenosis on CCTA where planned revascularization was not performed after CCTA within 90 days. Relevant features, including CT-FFR and the plaque burden [necrotic core to the total plaque volume (% necrotic core), and non-calcified plaque (NCP) to vessel volume (% NCP)] using a novel algorithm for analyzing plaque to predict vessel-oriented composite outcomes (VOCO), including cardiac death, non-fatal myocardial infarction, and unplanned vessel-related revascularization, were assessed. In 256 patients (68.7 ± 9.4 years; 73.8 % male) with 354 vessels (10.5 % CT-FFR ≤ 0.80), VOCO occurred in 24 vessels (6.8 %) during a median follow-up of 3.6 years. Multivariable Cox analysis revealed CT-FFR ≤ 0.80 had the pronounced impact on VOCO, and moreover, higher % necrotic core and % NCP were independently associated with VOCO [adjusted hazard ratio 3.43 (95 % confidence interval 1.42–8.29) and 4.05 (1.19–13.71), respectively], especially for vessels with CT-FFR > 0.80. In vessels without planned revascularization, per-vessel CT-FFR ≤ 0.80 was the notable predictor of future cardiac events. Additionally, necrotic core volume and NCP were identified as independent predictors along with CT-FFR. [Display omitted] • Coronary computed tomography (CT) angiography evaluates both physiological and morphological aspects of coronary arteries. • CT-derived fractional flow reserve (FFR) was a significant predictor of future cardiac events on a per-vessel analysis. • Necrotic core characterized using the labeling method provided better prognostic value in addition to CT-FFR. [ABSTRACT FROM AUTHOR]

Fractional flow reserve (FFR) is regarded as the gold standard for assessing the functional significance of coronary artery lesions. However, its utilization in clinical practice remains limited. This study aims to determine whether FFR results can influence treatment decisions for coronary artery disease compared to visual assessments of angiographic images. We conducted a retrospective study involving 63 patients diagnosed with either chronic coronary syndrome (n = 39, 61.9%) or acute coronary syndrome (n = 24, 38.1%) who underwent an FFR assessment. Three experienced interventional cardiologists (>300 PCI procedures/year) reevaluated 105 ambiguous coronary lesions in these patients, blinded to the FFR results. The objective was to assess lesion significance and determine the treatment strategy based on a visual angiographic evaluation. The three operators reached concordant agreement (≥two operators) to perform PCI in 60 (57.1%) of the evaluated lesions based on the angiographic assessment. Of these, nine lesions (15%) were deemed functionally non-significant by FFR (FFR > 0.80). Conversely, they agreed to defer PCI in 45 (42.9%) lesions, but 4 lesions (8.9%) were found to be functionally significant (FFR ≤ 0.80) and required a re-evaluation for PCI. Visual-guided decision making by interventional cardiologists shows variability and does not always align with the functional significance of coronary lesions as determined by FFR. Incorporating FFR into routine decision making could enhance treatment accuracy and patient outcomes. [ABSTRACT FROM AUTHOR]

Fractional flow reserve (FFR) measurements are recommended for assessing hemodynamic coronary stenosis severity. Intracoronary ECG (icECG) is easily obtainable and highly sensitive in detecting myocardial ischemia due to its close vicinity to the myocardium. We hypothesized that the remission time of myocardial ischemia on icECG after a controlled coronary occlusion accurately detects hemodynamically relevant coronary stenosis. This retrospective, observational study included patients with chronic coronary syndrome undergoing hemodynamic coronary stenosis assessment immediately following a strictly 1-min proximal coronary artery balloon occlusion with simultaneous icECG recording. icECG was used for a beat-to-beat analysis of the ST-segment shift during reactive hyperemia immediately following balloon deflation. The time from coronary balloon deflation until the ST-segment shift reached 37% of its maximum level, i.e., icECG ST-segment shift remission time (τ-icECG in seconds), was obtained by an automatic algorithm. τ-icECG was tested against the simultaneously obtained reactive hyperemia FFR at a threshold of 0.80 as a reference parameter. From 120 patients, 139 icECGs (age, 68 ± 10 yr old) were analyzed. Receiver operating characteristic (ROC) analysis of τ-icECG for the detection of hemodynamically relevant coronary stenosis at an FFR of ≤0.80 was performed. The area under the ROC curve was equal to 0.621 (P = 0.0363) at an optimal τ-icECG threshold of 8 s (sensitivity, 61%; specificity, 67%). τ-icECG correlated inversely and linearly with FFR (P = 0.0327). This first proof-of-concept study demonstrates that τ-icECG, a measure of icECG ST segment-shift remission after a 1-min coronary artery balloon occlusion accurately detects hemodynamically relevant coronary artery stenosis according to FFR at a threshold of ≥8 s. NEW & NOTEWORTHY: Invasive hemodynamic measurements are recommended by the current cardiology guidelines to guide percutaneous coronary interventions in the setting of chronic coronary syndrome. However, those pressure-derived indices demonstrate several theoretical and practical limitations. Thus, this study demonstrates the accuracy of a novel, pathophysiology-driven approach using intracoronary ECG for the identification of hemodynamically relevant coronary lesions by quantitatively assessing myocardial ischemia remission. [ABSTRACT FROM AUTHOR]

In recent years, a new technique called computed tomography-derived fractional flow reserve (CT-FFR) has been developed. CT-FFR overcomes many limitations in the current gold-standard fractional flow reserve (FFR) techniques while maintaining a better concordance with FFR. This technique integrates static coronary CT angiography data with hydrodynamic models, employing algorithms rather than guidewire interventions to compute the FFR. In addition to diagnosing coronary heart disease, CT-FFR has been applied in the preoperative risk assessment of major adverse cardiovascular events (MACEs) in organ transplantation and transcatheter aortic valve replacement (TAVR). Continuous advancements in CT-FFR techniques and algorithms are expanding their applicability to other methodologies. Subsequently, with robust clinical trial validation, CT-FFR can potentially supersede FFR as the primary “gatekeeper” for interventions. [ABSTRACT FROM AUTHOR]

Background: Diagnosing myocardial ischemia in chronic kidney disease (CKD) patients is crucial since coronary artery disease (CAD) forms the predominant cause of mortality in these patients. Thus, this study aimed to assess the impact of kidney function on the results of coronary circulation physiological assessment. Methods: Data were collected from 279 consecutive patients admitted to the Clinical Department of Cardiology and Cardiovascular Interventions at the University Hospital in Krakow. A total of 417 vessels were assessed for fractional flow reserve (FFR) and non-hyperemic resting pressure ratios, such as instantaneous wave-free ratio (iFR) and resting full-cycle ratio (RFR). Patients were categorized into two groups: glomerular filtration rate (GFR)-L (estimated GFR (eGFR) <70 mL/min/1.73 m² ) and GFR-H (eGFR ≥70 mL/min/1.73 m²). Results: A total of 118 patients (42.3%) were included in the GFR-L group, while 161 patients (57.7%) were in the GFR-H group. The left anterior descending branch of the left coronary artery (LAD) was the assessed vessel in approximately 60% of procedures, the frequency of which was very similar in both study groups. Focusing solely on LAD assessments, both FFR metrics (continuous and binary) were comparable between the groups. In contrast, for non-LAD vessels, the GFR-H group revealed substantially reduced FFR values, with more vessels displaying significant constriction. Patients in the GFR-H group showed higher instances of FFR+ | iFR/RFR- discrepancies than their lower eGFR counterparts. An eGFR of 70 mL/min/1.73 m 2 was the optimal cut-off to differentiate patients concerning the mentioned discrepancies. Conclusions: Kidney function influenced the coronary circulation physiological assessment results. Patients with reduced eGFR tended to have negative hyperemic assessments, especially in non-LAD vessels. [ABSTRACT FROM AUTHOR]

AccuFFRct (ArteryFlow Technology) is a novel noninvasive method for calculating fractional flow reserve (FFR) from coronary computed tomography angiography (CCTA). The accuracy of AccuFFRct has not been adequately assessed. This study sought to evaluate the diagnostic performance of AccuFFRct in detecting lesion-specific ischemia. This prospective study enrolled 339 patients with 404 vessels. CCTA-derived FFR was calculated using an on-site computational fluid dynamics–based method and compared with invasive FFR. The performance of AccuFFRct was comprehensively analyzed in all lesions and subgroups, including "gray zone" lesions, various lesion classifications, clinical presentations, stenosis severities, and lesion locations. Using FFR ≤0.80 as a reference standard, the overall diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for AccuFFRct were 90.6% (95% CI: 87.3%-93.3%), 90.9% (95% CI: 85.1%-94.9%), 90.4% (95% CI: 86.1%-93.8%), 85.3% (95% CI: 79.8%-89.5%), and 94.2% (95% CI: 90.8%-96.4%), respectively. Good correlation and agreement were found between the computed AccuFFRct and measured FFR. AccuFFRct showed superior discrimination ability to CCTA (AUC: 0.93 [95% CI: 0.89-0.95] vs 0.77 [95% CI: 0.72-0.81]; P < 0.001) and quantitative coronary angiography (AUC: 0.93 [95% CI: 0.89-0.95] vs 0.89 [95% CI: 0.85-0.92]; P = 0.048) for identifying functionally significant stenosis. Notably, AccuFFRct maintained high diagnostic accuracy across the spectrum of lesion classifications, clinical presentations, stenosis severities, lesion locations, and in the "gray zone". Furthermore, in the cohort with ≥70% stenosis, AccuFFRct could significantly reduce the rate of un-necessary invasive tests (33.1% vs 6.6%; P < 0.001). The study confirms the potential of AccuFFRct as a noninvasive alternative to invasive FFR for detecting ischemia in coronary artery disease and to risk stratify patients. The results highlight AccuFFRct's robust diagnostic ability across a wide range of lesion classifications, clinical presentations, stenosis severities, lesion locations, and in the "gray zone". (Diagnostic Performance of Fractional Flow Reserve Derived From Coronary CT Angiography [ACCURATE-CT]; NCT04426396) [Display omitted] [ABSTRACT FROM AUTHOR]

BACKGROUND: Cardiovascular events still occur at intermediate stenosis with fractional flow reserve (FFR) ≥0.81, underscoring the additional measure to evaluate this residual risk. A reduction in distal coronary artery pressure/aortic pressure (Pd/ Pa) from baseline to hyperemia (ie, change in Pd/Pa) reflects lipidic burden within vessel walls. We hypothesized that this physiological measure might stratify the risk of future cardiac events at deferrable lesions. METHODS: Lesion- (899 intermediate lesions) and patient-based (899 deferred patients) analyses in those with FFR ≥0.81 were conducted to investigate the association between change in Pd/Pa and target lesion failure (TLF) and major adverse cardiac events at 7 years, respectively. RESULTS: The occurrence of TLF and major adverse cardiac events was 6.7% and 13.4%, respectively. The incidence of target lesion--related nonfatal myocardial infarction was 0.6%. Lesions with TLF had a greater change in Pd/Pa (0.11±0.03 versus 0.09±0.04; P=0.002), larger diameter stenosis (51.0±9.2% versus 46.4±12.4%; P=0.048), and smaller FFR (0.84 [0.82--0.87] versus 0.86 [0.83--0.90]; P=0.02). Change in Pd/Pa (per 0.01 increase) predicted TLF (odds ratio, 1.16 [95% CI, 1.05--1.28]; P=0.002) and major adverse cardiac event (odds ratio, 1.08 [95% CI, 1.01--1.16]; P=0.03). Lesions with change in Pd/Pa ≥0.10 had 2.94- and 1.85-fold greater likelihood of TLF (95% CI, 1.30--6.69; P=0.01) and major adverse cardiac event (95% CI, 1.08--3.17; P=0.03), respectively. Lesions with FFR ≤0.85 had a substantially higher likelihood of TLF when there is a change in Pd/Pa ≥0.10 (12.4% versus 2.9%; hazard ratio, 3.60 [95% CI, 1.01--12.80]; P=0.04). However, change in Pd/Pa did not affect TLF risk in lesions with FFR ≥0.86 (3.8% versus 3.7%; hazard ratio, 0.56 [95% CI, 0.06--5.62]; P=0.62). CONCLUSIONS: Despite deferrable FFR values, lesions and patients with a change in Pd/Pa ≥0.10 had higher cardiovascular risk. Change in Pd/Pa might help stratify lesion- and patient-level risks of future cardiac events in those with FFR ≥0.81. GRAPHIC ABSTRACT: A graphic abstract is available for this article. [ABSTRACT FROM AUTHOR]

Coronary computed angiography (CCTA) with non-invasive fractional flow reserve (FFR) calculates lesion-specific ischemia when compared with invasive FFR and can be considered for patients with stable chest pain and intermediate-grade stenoses according to recent guidelines. The objective of this study was to compare a new CCTA-based artificial-intelligence deep-learning model for FFR prediction (FFRAI) to computational fluid dynamics CT-derived FFR (FFRCT) in patients with intermediate-grade coronary stenoses with FFR as reference standard. The FFRAI model was trained with curved multiplanar-reconstruction CCTA images of 500 stenotic vessels in 413 patients, using FFR measurements as the ground truth. We included 37 patients with 39 intermediate-grade stenoses on CCTA and invasive coronary angiography, and with FFRCT and FFR measurements in this retrospective proof of concept study. FFRAI was compared with FFRCT regarding the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for predicting FFR ≤ 0.80. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy of FFRAI in predicting FFR ≤ 0.80 were 91% (10/11), 82% (23/28), 67% (10/15), 96% (23/24), and 85% (33/39), respectively. Corresponding values for FFRCT were 82% (9/11), 75% (21/28), 56% (9/16), 91% (21/23), and 77% (30/39), respectively. Diagnostic accuracy did not differ significantly between FFRAI and FFRCT (p = 0.12). FFRAI performed similarly to FFRCT for predicting intermediate-grade coronary stenoses with FFR ≤ 0.80. These findings suggest FFRAI as a potential non-invasive imaging tool for guiding therapeutic management in these stenoses. [ABSTRACT FROM AUTHOR]

Background A sinus of Valsalva aneurysm involving a single cusp is a rare condition, and coronary computed tomography angiography with fractional flow reserve-computed tomography helps evaluate not only the anatomical aspects of the aneurysm and coronary artery but also the physiological details of coronary artery disease. Case summary A 71-year-old woman presented with exertional chest pain and dyspnoea. Enhanced computed tomography revealed an aneurysmal change in the right sinus of Valsalva, and coronary computed tomography angiography revealed diffuse narrowing of the proximal segment of right coronary artery due to mechanical stretching by the large Valsalva aneurysm. Fractional flow reserve-computed tomography revealed a significantly low fractional flow reserve (0.50 in the distal right coronary artery). A modified Bentall procedure was performed with a 21 mm bioprosthetic valve and a 24 mm Valsalva graft conduit for the aortic root aneurysm; mitral valve annuloplasty was performed for mitral valve regurgitation. Post-operative coronary computed tomography angiography revealed no significant stenosis in the proximal segment of the right coronary artery. Furthermore, fractional flow reserve-computed tomography revealed a normalized fractional flow reserve in the distal right coronary artery. The patient experienced relief from chest pain and was discharged 19 days after the surgery. Discussion A right coronary sinus of Valsalva aneurysm, which caused right coronary artery ischaemia, was successfully treated using a modified Bentall procedure. Coronary computed tomography angiography and fractional flow reserve-computed tomography revealed anatomical and functional improvements in the right coronary artery ischaemia post-operatively. [ABSTRACT FROM AUTHOR]

Purpose: Cerebral hemodynamics are important for the management of intracranial atherosclerotic stenosis (ICAS). The quantitative flow ratio (QFR) is a novel angiography-derived index for assessing the functional relevance of ICAS without pressure wires and adenosine. Good diagnostic yield with the hyperemic fractional flow reserve (FFR) have been reported, while data on the comparison of QFR to FFR are scarce. Methods: In this prospective study 56 patients with anterior circulation symptomatic ICAS who received endovascular treatment were included. The new method of computing QFR from a single angiographic view, i.e., the Murray law-based QFR (μQFR), was applied to the examined vessels. An artificial intelligence algorithm was developed to realize the automatic delineation of vascular contour. Pressure gradients were measured before and after treatment within the lesion vessel using a pressure guidewire and the FFR was calculated. Results: There was a good correlation between μQFR and FFR. Preoperative FFR predicted DWI watershed infarction (FFR optimal cut-off level: 0.755). Preoperative μQFR predicted DWI watershed infarction (μQFR optimal cut-off level: 0.51). Preoperative FFR predicted CTP hypoperfusion (FFR best predictive value: 0.62). Preoperative μQFR predicted CTP hypoperfusion (μQFR best predictive value: 0.375). Conclusion: The μQFR based on DSA images can be used as an indicator to assess the functional status of the lesion in patients with ICAS. [ABSTRACT FROM AUTHOR]

There is no definitive approach for assessing mesenteric ischemia and determining the optimal timing for endovascular intervention in the management of spontaneous isolated dissection of the superior mesenteric artery (SISMAD). A 56-year-old male with acute abdominal pain was diagnosed with SISMAD. After evaluating mesenteric ischemia through mesenteric fractional flow reserve (FFR), FFR was 0.72, and the patient was recommended conservative treatment for SISMAD, which involves fasting, total parenteral nutrition, and anticoagulation. The patient's syndrome was relieved after conservative treatment for 14 days without stent implantation. Over the next 5 years, no recurrence of abdominal pain or worsening of SISMAD was observed in the patient. Assessing the severity of mesenteric ischemia can be done through mesenteric FFR. Upon confirmation of the exclusion of risks related to dilatation or rupture of SISMAD aneurysm, an approach in favor of conservative management for SISMAD may indeed be considered pragmatic when the FFR exceeds 0.72. [ABSTRACT FROM AUTHOR]

Objectives: The guidelines recommend fractional flow reserve-guided coronary artery bypass grafting (CABG) during primary valve surgery without evidence. Quantitative flow ratio (QFR) is a novel coronary angiography (CAG)-based fractional flow reserve measurement. We aimed to compare the early clinical outcomes between QFR-guided and CAG-guided CABG in these patients. Methods: This observational study screened all 2081 patients admitted to our institution for elective primary mitral and/or aortic valve surgery from January 2017 to September 2020. Of them, all 188 patients with comorbid coronary artery lesions (visual estimated stenosis ≥50%) were included. Sixty-nine patients with QFR analysis received bypasses only for lesions with QFR ≤0.80 (QFR-guided group). The remaining 119 patients without QFR analysis received bypasses for all stenosis ≥50% (CAG-guided group). Propensity overlap weighting was used to neutralize the intergroup imbalance. The primary end point was major adverse cardiovascular events. Results: After propensity score weighting, the baseline characteristics were comparable. Concomitant coronary artery bypass grafting was performed 58.1% versus 100% in the QFR-guided and CAG-guided groups, respectively. The mean number of grafts was significantly lower in QFR-guided group than in the CAG-guided group (0.9 ± 0.7 vs 1.6 ± 0.5 [P

We discuss main challenges of much-debated endovascular treatment in patients with “false” bifurcation stenoses of the left main coronary artery. There are no convincing literature data on the rationale of planning complete bifurcation stenting using 2 stents and clear indications for this procedure. We highlight the importance of studying the effectiveness and safety of the complex routine use of various intravascular imaging during the left main coronary artery percutaneous coronary intervention. We analyzed observations in which a “false” bifurcation lesion can only be considered an ostial stenosis, which will affect the stenting strategy. We focus on the development of universal algorithms for performing endovascular interventions, including those using intravascular imaging which role at each stage of surgery should be additionally studied.

ABSTRACT Assessment of the functional significance of coronary artery stenoses to guide percutaneous coronary intervention is widely performed using pressure wire fractional flow reserve during adenosine- or adenosine triphosphate-induced hyperemia. However, the use of fractional flow reserve may be limited by the contraindications and adverse effects of this hyperemic stimulus, as well as the potential risk of vessel damage from the pressure wire. This review will discuss alternative evaluation methods, including various hyperemic agents, nonhyperemic pressure ratios, and angiography-based indices.

ABSTRACT Introduction and objectives: Functional assessment of coronary stenosis severity with the piezo-electric sensor pressure wire has shown a discrepancy of up to 20% between hyperemic and nonhyperemic indexes. No data are available with fiber-optic pressure wires. The aim of this study was to evaluate the incidence and factors related to the diagnostic discordance between these indexes with a fiber-optic pressure wire. Secondary aims were to assess diagnostic reproducibility in 2 consecutive measurements of fractional flow reserve (FFR) and diastolic pressure ratio (dPR) and evaluate the drift rate. Methods: We conducted a prospective, observational multicenter study in patients undergoing functional assessment with a fiber-optic pressure wire. We took 2 consecutive measurements of the dPR (cutoff point 0.89) and FFR (cut-off point 0.80) in each lesion analyzed. The diagnostic correlation between 2 measurements with the same technique and between the 2 techniques (dPR and FFR) was assessed. Clinical and angiographic factors associated with discordance (FFR−/dPR+ and FFR+/dPR−) between the 2 techniques were analyzed. Results: We included 428 cases of stenosis (361 patients). Diagnostic reproducibility was 95.8% for the dPR, with a correlation coefficient between the 2 measurements (dPR1 and dPR2) of 0.974 (P 60%. The drift rate was 5.7%. Conclusions: Although FFR and dPR measurements with a fiber-optic pressure wire have excellent reproducibility and a low drift rate, the discordance rate remains similar to those in previous studies with a piezo-electric pressure wire. FFR−/dPR+ discordance is associated with intracoronary adenosine and hypertension. FFR+/dPR− discordance is related to age < 75 years old and stenosis > 60%.

Seyedmohammadshahab Shivaie, Hadi Tohidi, Pragash Loganathan, Manish Kar, Habiba Hashemy, Mohammad A Shafiee Division of General Internal Medicine, Department of Medicine, Toronto General Hospital, Toronto, ON, M2G 2C4, CanadaCorrespondence: Mohammad A Shafiee, Toronto General Hospital, 200 Elizabeth Street, 14 EN-208, Toronto, ON, M5G 2C4, Canada, Tel +1 416-340-4800 6244, Fax +1 416-595-5826, Email Mohammad.Shafiee@uhn.caIntroduction: The reliability of interpretation of coronary angiography as a diagnostic tool was investigated. Furthermore, the impact of interobserver variability of coronary lesions on clinical decision-making was assessed. One of our motivations to do this research was the research gaps and our aim to have up-to-date information regarding interobserver variability among different cardiologists.Methods: Our objective was to quantify interobserver variability among cardiologists who have seen angiograms independently. Disagreement among cardiologists in the visual assessment of invasive coronary angiography of coronary artery stenosis is not uncommon in previous studies. Three cardiologists with extensive experience in coronary angiography, including the primary cardiologist of each patient, read the angiograms of 200 patients from Toronto General Hospital independently.Results: Our research showed the mean agreement among all participating observers was 77.4%; therefore, the interobserver variability of coronary angiography interpretation was 22.6%.Discussion: Coronary angiography is still the gold-standard technique for guidance regarding coronary lesions. Sometimes, coronary angiography results in underestimation or overestimation of a lesion’s functional severity. Interobserver variability should also be considered when interpreting the severity of coronary stenoses via invasive coronary angiography. This research shows that interobserver variability regarding coronary angiograms is still present (22.6%).Plain language summary:The gold-standard method for diagnosing coronary stenosis, invasive coronary angiography has some challenges too. One of these challenges has been the difference among various cardiologists regarding determination of severity of each coronary stenosis. In this study, we focused on differences in interobserver variability in coronary angiography interpretation. Three cardiologists who were experienced in coronary angiography read each patient’s coronary angiogram separately. Overall, 200 patients with a history of angiography at Toronto General Hospital were selected randomly. The research showed that overall agreement among all participating cardiologists with regard to the reading of coronary angiograms was 77.4%. In other words, interobserver variability of 22.6% was seen among the readers.Keywords: coronary angiography, ICA, PCI, fractional flow reserve, interobserver variability

Abstract Background The importance of a diagnostic strategy combining coronary computed tomography angiography (CCTA) with fractional flow reserve derived from CCTA (FFRCT) for detecting myocardial ischemia is increasing. However, sensitivity and specificity alone may be insufficient to understand the efficiency characteristics of a diagnostic strategy combining CCTA and FFRCT (DSCCF). Our study aimed to evaluate the overall efficiency of DSCCF in detecting myocardial ischemia and compare it with other diagnostic strategies to determine whether evaluation by DSCCF is currently appropriate. Results This simulation study included 1000 patients with stable chest pain and suspected myocardial ischemia. Using a decision tree analysis, assuming a diagnostic strategy of adding FFRCT to CCTA-positive patients, we calculated the following efficiency parameters of DSCCF: (1) true positive (TP), false positive (FP), net false negative (FN), and net true negative (TN) test results; (2) net sensitivity; (3) net specificity; (4) positive predictive value; (5) negative predictive value; (6) post-test probability; (7) diagnostic accuracy; (8) diagnostic odds ratio; and (9) number needed to diagnose. We also calculated the efficiency parameters of other diagnostic strategies and compared them with those of DSCCF. In the basic setting, regarding efficiency parameters (1), the number of TPs, FPs, net FNs, and net TNs were 254, 69, 46, and 631, respectively. Efficiency parameters (2)–(9) were 0.85 (95% confidence interval [CI], 0.80–0.89), 0.90 (95% CI 0.88–0.92), 0.79 (95% CI 0.74–0.83), 0.93 (95% CI 0.91–0.95), 0.07 (95% CI 0.05–0.09), 0.89 (95% CI 0.86–0.90), 50.50 (95% CI 33.83–75.37), and 1.34 (95% CI 1.24–1.48), respectively. Compared with other diagnostic strategies, DSCCF had good efficiency parameters. Moreover, the sensitivity analysis did not reveal any evidence to contradict the findings in the basic setting. Conclusions This study demonstrated the diagnostic ability characteristics of DSCCF by assessing various efficiency parameters. Compared with other diagnostic strategies, DSCCF had good efficiency. In terms of efficiency, evaluation using DSCCF for detecting myocardial ischemia appears to be appropriate.

[Display omitted] [ABSTRACT FROM AUTHOR]

Background: Negative CCTA can effectively exclude significant CAD, eliminating the need for further noninvasive or invasive testing. However, in the presence of severe CAD, the accuracy declines, thus necessitating additional testing. The aim of our study was to evaluate the diagnostic performance of noninvasive cFFR derived from CCTA, compared to ICA in detecting hemodynamically significant stenoses in participants with high CAC scores (>400). Methods: This study included 37 participants suspected of having CAD who underwent CCTA and ICA. CAC was calculated and cFFR analyses were performed using an on-site machine learning-based algorithm. Diagnostic accuracy parameters of CCTA and cFFR were calculated on a per-vessel level. Results: The median total CAC score was 870, with an IQR of 642–1370. Regarding CCTA, sensitivity and specificity for RCA were 60% and 67% with an AUC of 0.639; a LAD of 87% and 50% with an AUC of 0.688; an LCX of 33% and 90% with an AUC of 0.617, respectively. Regarding cFFR, sensitivity and specificity for RCA were 60% and 61% with an AUC of 0.606; a LAD of 75% and 54% with an AUC of 0.647; an LCX of 50% and 77% with an AUC of 0.647. No significant differences between AUCs of coronary CTA and cFFR for each vessel were found. Conclusions: Our results showed poor diagnostic accuracy of CCTA and cFFR in determining significant ischemia-related lesions in participants with high CAC scores when compared to ICA. Based on our results and study limitations we cannot exclude cFFR as a method for determining significant stenoses in people with high CAC. A key issue is accurate and detailed lumen segmentation based on good-quality CCTA images. [ABSTRACT FROM AUTHOR]

The article discusses the results of the FORZA trial, which compared the use of fractional flow reserve (FFR) and optical coherence tomography (OCT) for the management of angiographically intermediate coronary lesions (AICLs). The trial found that both FFR and OCT guidance provided similar rates of major adverse cardiac events (MACE) at the 5-year follow-up. The study suggests that OCT could be a valuable alternative to FFR for the management of patients with AICLs, but further investigation is needed to determine the optimal use of these tools. The article acknowledges the limitations of the study, including a small sample size and unreliable symptom assessment at long-term follow-up. [Extracted from the article]

Background: Murray law-based quantitative flow ratio (μQFR) is a novel computational method that enables accurate estimation of fractional flow reserve (FFR) using a single angiographic projection. However, its diagnostic value in patients with severe aortic stenosis (AS) remains unclear. Method: We included 25 consecutive patients who underwent transcatheter aortic valve replacement (TAVR) for severe AS with intermediate or greater (30–90%) coronary artery disease (CAD). Pre- and post-TAVR μQFR, QFR, instantaneous flow reserve (iFR), and post-TAVR invasive FFR values were measured. We evaluated the diagnostic performance of pre-TAVR μQFR, QFR, and iFR using post-TAVR FFR ≤ 0.80 as a reference standard of ischemia. Result: Pre-TAVR μQFR was significantly correlated with post-TAVR FFR (r = 0.73, p < 0.0001). The area under the curve of pre-TAVR μQFR on post-TAVR FFR ≤ 0.8 was 0.91 (95% confidence interval [CI] 0.77–0.98), comparable to that of pre-TAVR iFR (0.86 [95% CI 0.71–0.98], p = 0.97). The accuracy, sensitivity, specificity, and positive and negative predictive values of pre-TAVR μQFR on post-TAVR FFR ≤ 0.8 were 84.2% (95% CI 68.7–93.4), 61.6% (95% CI 31.6–86.1), 96.0% (95% CI 79.6–99.9), 88.9% (95% CI 52.9–98.3), and 82.8% (95% CI 70.6–90.6), respectively. For pre-TAVR iFR, these values were 76.5% (95% CI 58.8–89.3), 90.9% (95% CI 58.7–99.8), 69.6% (95% CI 47.1–86.8), 58.8% (95% CI 42.8–73.1), and 94.1% (95% CI 70.8–99.1), respectively. Conclusion: μQFR could be useful for the physiological evaluation of patients with severe AS with concomitant CAD. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

Computer simulations of coronary fractional flow reserve (FFR) based on coronary imaging have emerged as an attractive alternative to invasive measurements. However, most methods are proprietary and employ non-physiological assumptions. Our aims were to develop and validate a physiologically realistic open-source simulation model for coronary flow, and to use this model to predict FFR based on intracoronary optical coherence tomography (OCT) data in individual patients. We included patients undergoing elective coronary angiography with angiographic borderline coronary stenosis. Invasive measurements of coronary hyperemic pressure and absolute flow and OCT imaging were performed. A computer model of coronary flow incorporating pulsatile flow and the effect of left ventricular contraction was developed and calibrated, and patient-specific flow simulation was performed. Forty-eight coronary arteries from 41 patients were included in the analysis. Average FFR was 0.79 ± 0.14, and 50% had FFR ≤ 0.80. Correlation between simulated and measured FFR was high (r = 0.83, p < 0.001). Average difference between simulated FFR and observed FFR in individual patients was − 0.009 ± 0.076. Overall diagnostic accuracy for simulated FFR ≤ 0.80 in predicting observed FFR ≤ 0.80 was 0.88 (0.75–0.95) with sensitivity 0.79 (0.58–0.93) and specificity 0.96 (0.79–1.00). The positive predictive value was 0.95 (0.75–1.00) and the negative predictive value was 0.82 (0.63–0.94). In conclusion, realistic simulations of whole-cycle coronary flow can be produced based on intracoronary OCT data with a new, computationally simple simulation model. Simulated FFR had moderate numerical agreement with observed FFR and a good diagnostic accuracy for predicting hemodynamic significance of coronary stenoses. [ABSTRACT FROM AUTHOR]

Cardiac electrical biomarker (CEB), an indicator of ischaemia-induced change in myocyte polarity, has been proposed for diagnosis of acute coronary syndrome. However, effect of coronary occlusion on CEB has not been demonstrated. CEB was acquired before (CEB0), during maximal adenosine hyperaemia (CEBhyp), balloon inflations (CEBmax) and 1 (CEB1h), 2 (CEB2h) and 3 (CEB3h) h after percutaneous coronary intervention along with pre- and post-procedural troponin-I. CEB of subjects with non-cardiac chest pain without risk factors was used as controls (CEBc). "Late recovery" (LR) of CEB was defined as CEB3h > median-CEB0. CEB was recorded in 75 patients undergoing stenting (group 1) including 8 with FFR < 0.8 (group 1a), 25 with FFR ≥ 0.8 (group 2) and 49 controls. In group 1, CEB0 (median, IQR) was higher than CEBc (48.0; 29.5–88.3 vs 30.0; 17.0–44.0; p < 0.001). CEBmax (185; 105.0–331.0) was higher than CEB0 (p < 0.0001). CEB1h (78.0; 31.5–143.8; p < 0.0001) and CEB2h (63.0; 31.5–114.3; p = 0.039) were higher than CEB0 while CEB3h (54.0; 24.3–94.8, p = 0.152) was similar. LR occurred in 50.7% patients. CEBmax predicted LR (OR 1.01, 95% CI 1.00–1.01, p < 0.001) (AUC 0.759, p < 0.001). CEB0 in group 1a and group 2 were similar (p = 0.524). CEBhyp was higher than CEB0 in group 1a (126.0, 109.5–266.0 vs 47.5, 20.5–73.5; p = 0.016) and group 2 (44.0, 27.8–104.8 vs 39.0, 24.0–90.3; p = 0.014). CEBhyp was higher in group 1a than 2 (p = 0.039). CEBhyp (AUC 0.75, p = 0.017) accurately predicted FFR < 0.8. Coronary arterial occlusion increases CEB that retains a "memory" of the ischaemic event. CEBhyp was higher only when FFR was ischaemic and accurately identified FFR < 0.8. [ABSTRACT FROM AUTHOR]

Background and Objectives: Atherosclerotic disease is a major contributor to heart failure, stroke, and myocardial infarction, significantly lowering the quality of life and life expectancy and placing a significant burden on healthcare. Not all lesions deemed non-significant are benign, and conversely, not all significant lesions are causative of ischemia. Fractional flow reserve (FFR) provides a functional assessment of coronary lesions, while optical coherence tomography (OCT) offers detailed imaging of plaque morphology, aiding in therapeutic decision-making. The objective of this study was to evaluate the utility of OCT and FFR as adjunctive tools in the catheterization laboratory for guiding therapeutic decisions in patients with multivessel disease for non-culprit vessels. Specifically, we aimed to assess how OCT and FFR influence therapeutic decision-making in patients with multivessel coronary artery disease. Materials and Methods: A total of 36 patients with acute coronary syndrome (ACS) and multivessel disease were randomized 1:1 into two groups: one guided by FFR alone and the other by a combination of FFR and OCT. For the FFR group, revascularization decisions for non-culprit lesions were based solely on FFR measurements. If the FFR was >0.8, the procedure was concluded, and the patient received maximal medical treatment. If the FFR was ≤0.8, a stent was placed. For the FFR + OCT group, if the FFR was >0.8, the revascularization decision was based on OCT findings. If there were no vulnerable plaques (VP), the procedure was concluded, and the patient received maximal medical treatment. If OCT imaging indicated VP, then the patient underwent revascularization. If the FFR was ≤0.8, the patient underwent revascularization regardless of OCT findings. Results: OCT imaging altered the therapeutic decision in 11 cases where FFR measurements were above 0.8, but the lesions were characterized as VP. Analyzing the total change in the decision to stent, 4 cases in the FFR group and 15 cases in the FFR and OCT groups (4 based on FFR and 11 on OCT) revealed a statistically significant difference (p = 0.0006; Relative Risk = 0.2556; 95% CI: 0.1013 to 0.5603). When analyzing the change in the total decision both to stent and not to stent, we observed a statistically significant difference, with Group 1 having 7 cases and Group 2 having 15 cases (p = 0.0153; Relative Risk = 0.4050; 95% CI: 0.2004 to 0.7698. Conclusions: Based on the findings of this study, OCT significantly increases the percentage of stenting procedures by identifying vulnerable lesions. The use of intracoronary imaging facilitates the timely identification and treatment of these vulnerable lesions. This underscores the crucial role of OCT in enhancing the precision of coronary interventions by ensuring timely intervention for vulnerable lesions, thereby potentially improving patient outcomes. [ABSTRACT FROM AUTHOR]

Fractional flow reserve (FFR) determined invasively has been globally accepted as the gold standard for determining the functional significance of coronary artery stenoses. However, despite its great importance, the invasive method has certain disadvantages, including the risk of vascular injuries, the need for vasodilation, and significant medical costs. That is why great attention was paid to the development of non-invasive methods that would enable reliable diagnosis without exposing patients to the risk of unwanted consequences. This paper aimed to create and verify an alternative, less resource- and time-demanding, non-invasive solution. The determination of FFR is based on the application of the fundamental laws of fluid dynamics. All energy losses in the coronary artery with stenosis were identified and analyzed in detail. A three-dimensional model of a coronary artery was generated using the corresponding angiographic images. Finally, the pressure due to stenosis was calculated and the FFR was determined. The results obtained using the proposed analytical method were compared with available experimental data for 40 patients who experienced the invasive coronary angiography. The coefficient of determination, mean difference and standard deviation values are determined to be 0.726, -0.017 and 0.056, respectively. These values were slightly higher for FFR values above 0.80. The FFR calculated by the proposed analytical method has a relatively good correlation with clinical data, which leads to the conclusion that it can provide a reliable assessment of the functional significance of coronary stenosis. [ABSTRACT FROM AUTHOR]

Background of the study: Fractional flow reserve (FFR) is an invasive index that state the functional significance of severity of coronary stenosis which can be applied for simple as well as complex lesion assessment along with coronary angiography. This FFRICO study was designed to evaluate the utility of FFR for intermediate coronary lesions (50-70% diameter stenosis) in patients with coronary artery disease (CAD) and their clinical outcome in Indian patients. It also compares the clinical outcomes among patients who underwent revascularization versus those kept under medical follow-up based on FFR assessment. Methods: FFRICO study was a single-center, retrospective study which included 100 patients who underwent coronary angiography followed by FFR for intermediate coronary lesions during the period, January 2016 to January 2018. Study populations were divided into three groups:i) Group-1--FFR>0.8 with medical follow-up;ii) Group-2--FFR ≤0.8 and under went revascularization; and iii) Group-3--FFR≤0.8 and did not undergo revascularization. FFR was measured in lesions with intermediate coronary stenosis. The endpoint was major adverse cardiac events (MACE), defined as composite of cardiac death, non-fatal acute coronary syndrome, and any repeat revascularization. Results: The mean age of 100 patients was 59.79 years. About62% patients had multi-vessel disease. Majority 60 (82.2%) of the patients had unstable angina ingroup-1,while12(52.3%) in group-2 and all the 4 (100%) in group-3 had unstable angina. Mean FFR was0.87 in group- 1,0.76 in group-2 and group-3. MACE was reported in 3(4.1%) patients in group-1, 1(4.3%) in group-2 and 2(50%)in group-3.MACE rate was significantly high in group-3 compared to group-1 and group-2 (p<0.001). Conclusion: This study helps in reassuring the utility of FFR-based clinical decisions in patients with CAD in Indian patients. [ABSTRACT FROM AUTHOR]

Despite guideline-based recommendation of the interchangeable use of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) to guide revascularization decision-making, iFR/FFR could demonstrate different physiological or clinical outcomes in some specific patient or lesion subsets. Therefore, we sought to investigate the impact of difference between iFR and FFR-guided revascularization decision-making on clinical outcomes in patients with left main disease (LMD). In this international multicenter registry of LMD with physiological interrogation, we identified 275 patients in whom physiological assessment was performed with both iFR/FFR. Major adverse cardiovascular event (MACE) was defined as a composite of death, non-fatal myocardial infarction, and ischemia-driven target lesion revascularization. The receiver-operating characteristic analysis was performed for both iFR/FFR to predict MACE in respective patients in whom revascularization was deferred and performed. In 153 patients of revascularization deferral, MACE occurred in 17.0% patients. The optimal cut-off values of iFR and FFR to predict MACE were 0.88 (specificity:0.74; sensitivity:0.65) and 0.76 (specificity:0.81; sensitivity:0.46), respectively. The area under the curve (AUC) was significantly higher for iFR than FFR (0.74; 95%CI 0.62–0.85 vs. 0.62; 95%CI 0.48–0.75; p = 0.012). In 122 patients of coronary revascularization, MACE occurred in 13.1% patients. The optimal cut-off values of iFR and FFR were 0.92 (specificity:0.93; sensitivity:0.25) and 0.81 (specificity:0.047; sensitivity:1.00), respectively. The AUCs were not significantly different between iFR and FFR (0.57; 95%CI 0.40–0.73 vs. 0.46; 95%CI 0.31–0.61; p = 0.43). While neither baseline iFR nor FFR was predictive of MACE in patients in whom revascularization was performed, iFR-guided deferral seemed to be safer than FFR-guided deferral. Impact of Physiological Assessment with iFR and FFR on Clinical Outcomes of Patients with LMD. In the present study, physiological assessment, both with iFR and FFR, provided a high predictability of adverse cardiovascular event in LMD patients with revascularization deferral. Furthermore, the iFR-guided deferral strategy was safer as compared to FFR. Conversely, in patients in whom revascularization was performed for LMD, neither iFR nor FFR was predictive of cardiovascular event. AUC: area under the curve; FFR: fractional flow reserve; iFR: instantaneous wave-free ratio; LMD: left main coronary artery disease. [ABSTRACT FROM AUTHOR]

Background: This study investigated factors influencing discrepancies between fractional flow reserve (FFR) and resting full-cycle ratio (RFR) in the functional assessment of coronary artery stenosis in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Methods: We included 320 diseased vessels from 253 consecutive patients with NSTE-ACS. Vessels were categorized into four groups based on FFR ≤0.80 and RFR ≤0.89 thresholds: group 1 concordant negative (RFR–/FFR–), group 2 positive RFR and negative FFR (RFR+/FFR–), group 3 negative RFR and positive FFR (RFR–/FFR+), and group 4 concordant positive (RFR+/FFR+). Univariate and multivariate logistic regression analyses were conducted to identify predictors of diagnostic discrepancy between FFR and RFR. Results: Of the 320 diseased vessels, 182 (56.9%) were in group 1 (RFR–/FFR–), 33 (10.3%) in group 2 (RFR+/FFR–), 31 (9.7%) in group 3 (RFR–/FFR+), and 74 (23.1%) in group 4 (RFR+/FFR+). The concordance between FFR and RFR was 80.0%. Notably, left anterior descending artery (LAD) lesions exhibited significantly lower consistency compared to non-LAD lesions (p = 0.001), with distinct differences in FFR and RFR values between these groups (p < 0.001). The presence of a LAD lesion emerged as an independent predictor of diagnostic inconsistency between positive RFR and negative FFR measurements (p = 0.001). Conclusions: LAD involvement independently predicts diagnostic discrepancies between FFR and RFR in evaluating functional coronary artery stenosis in NSTE-ACS patients. [ABSTRACT FROM AUTHOR]

Background: Age-related remodelling has the potential to affect the microvascular response to hyperemic stimuli. However, its precise effects on the vasodilatory response to adenosine and contrast medium, as well as its influence on fractional flow reserve (FFR) and contrast fractional flow reserve (cFFR), have not been previously investigated. We investigate the impact of age on these indices. Methods: We extrapolated data from the post-revascularization optimization and physiological evaluation of intermediate lesions using fractional flow reserve (PROPHET-FFR) and The Multi-center Evaluation of the Accuracy of the Contrast Medium Induced Pd/Pa RaTiO in Predicting (MEMENTO) studies. Only lesions with a relevant vasodilatory response to adenosine and contrast medium were considered of interest. A total of 2080 patients, accounting for 2294 pressure recordings were available for analysis. The cohort was stratified into three age terciles. Age-dependent correlations with FFR, cFFR, distal pressure/aortic pressure (Pd/Pa) and instantaneous wave-free ratio (iFR) were calculated. The vasodilatory response was calculated in 1619 lesions (with both FFR and cFFR) as the difference between resting and hyperaemic pressure ratios and correlated with aging. The prevalence of FFR-cFFR discordance was assessed. Results: Age correlated positively to FFR (r = 0.062, p = 0.006), but not with cFFR (r = 0.024, p = 0.298), Pd/Pa (r = –0.015, p = 0.481) and iFR (r = –0.026, p = 0.648). The hyperemic response to adenosine (r = –0.102, p ≤ 0.0001) and to contrast medium (r = –0.076, p = 0.0023) showed a negative correlation with age. When adjusted for potential confounders, adenosine induced hyperaemia was negatively associated with age (p = 0.04 vs p = 0.08 for cFFR). Discordance decreased across age terciles (14.64% vs 12.72% vs 10.12%, p = 0.032). Conclusions: As compared to adenosine, contrast induced hyperaemia appeared to be less affected by age. cFFR may be considered a more stable and reproducible tool to assess epicardial stenosis in elderly patients. Clinical Trial Registration: PROPHET-FFR STUDY, Clinicaltrials.gov (NCT05056662). [ABSTRACT FROM AUTHOR]

Background: The importance of a diagnostic strategy combining coronary computed tomography angiography (CCTA) with fractional flow reserve derived from CCTA (FFRCT) for detecting myocardial ischemia is increasing. However, sensitivity and specificity alone may be insufficient to understand the efficiency characteristics of a diagnostic strategy combining CCTA and FFRCT (DSCCF). Our study aimed to evaluate the overall efficiency of DSCCF in detecting myocardial ischemia and compare it with other diagnostic strategies to determine whether evaluation by DSCCF is currently appropriate. Results: This simulation study included 1000 patients with stable chest pain and suspected myocardial ischemia. Using a decision tree analysis, assuming a diagnostic strategy of adding FFRCT to CCTA-positive patients, we calculated the following efficiency parameters of DSCCF: (1) true positive (TP), false positive (FP), net false negative (FN), and net true negative (TN) test results; (2) net sensitivity; (3) net specificity; (4) positive predictive value; (5) negative predictive value; (6) post-test probability; (7) diagnostic accuracy; (8) diagnostic odds ratio; and (9) number needed to diagnose. We also calculated the efficiency parameters of other diagnostic strategies and compared them with those of DSCCF. In the basic setting, regarding efficiency parameters (1), the number of TPs, FPs, net FNs, and net TNs were 254, 69, 46, and 631, respectively. Efficiency parameters (2)–(9) were 0.85 (95% confidence interval [CI], 0.80–0.89), 0.90 (95% CI 0.88–0.92), 0.79 (95% CI 0.74–0.83), 0.93 (95% CI 0.91–0.95), 0.07 (95% CI 0.05–0.09), 0.89 (95% CI 0.86–0.90), 50.50 (95% CI 33.83–75.37), and 1.34 (95% CI 1.24–1.48), respectively. Compared with other diagnostic strategies, DSCCF had good efficiency parameters. Moreover, the sensitivity analysis did not reveal any evidence to contradict the findings in the basic setting. Conclusions: This study demonstrated the diagnostic ability characteristics of DSCCF by assessing various efficiency parameters. Compared with other diagnostic strategies, DSCCF had good efficiency. In terms of efficiency, evaluation using DSCCF for detecting myocardial ischemia appears to be appropriate. [ABSTRACT FROM AUTHOR]

We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography Angiography FFRCT. A total of 14 patient‐specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra ±6% and inter‐operator ±15% variations on the segmentation threshold. FFRCT was evaluated in each case by 3D‐OD CFD simulations. The findings suggest that the sensitivity of FFRCT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if the FFRCT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluating FFRCT results. [ABSTRACT FROM AUTHOR]

Aim To explore the feasibility of using machine learning algorithms combined with coronary computed tomography (CT) derived perivascular fat attenuation index (FAI) and plaque information to evaluate myocardial ischemia in stable coronary heart disease patients. Methods A retrospective analysis was conducted on the clinical and imaging data of patients who underwent preoperative coronary CT angiography (CCTA), invasive coronary angiography (ICA), and flow reserve fraction (FFR) measurements at Zhongshan Hospital Affiliated to Fudan University from April 2019 to October 2021. 206 patients with stable coronary heart disease were selected. The semi-automatic plaque analysis software was used for quantification of plaque and lumen parameters and perivascular FAI measurement, with manual delineation of a 40 mm segment of the coronary artery starting 10 mm from the ostium for perivascular FAI measurement. Differences in plaque characteristics, perivascular FAI, and coronary perivascular FAI between stable coronary heart disease patients with FFR≤0. 8 and FFR>0. 8 were compared. The diagnostic performance of combining perivascular FAI, coronary perivascular FAI, and plaque features using machine learning algorithms for myocardial ischemia in stable coronary heart disease patients was evaluated through ROC curves. Results 206 stable coronary heart disease patients were divided into FFR≤0. 8 group (50 cases) and FFR>0. 8 group (156 cases). The mean periplaque FAI of patients with FFR≤0. 8 was -69. 28±5. 65 HU, significantly higher than that of patients with FFR>0. 8 at -80. 10±7. 75 HU (P<0. 001). Further analysis was conducted using machine learning models, including XGBoost, random forest, and Logistic regression models, all of which had an accuracy rate of over 0. 8 in diagnosing myocardial ischemia. Among them, the XGBoost model performed the best with an accuracy of 0. 903, an F1 value of 0. 774, and an AUC of 0. 931, indicating its high effectiveness in diagnosing myocardial ischemia. Conclusion The combination of FAI and machine learning algorithm XGBoost model is a new method for diagnosing myocardial ischemia, which has better diagnostic value in evaluating myocardial ischemia in stable coronary heart disease patients. [ABSTRACT FROM AUTHOR]

To investigate the diagnostic value of fractional flow reserve (FFR) of coronary CT angiography (CCTA) in coronary heart disease (CHD) in high altitude environment of plateau. 54 patients who underwent CCTA examination and guidewire measurement of FFR in Qinghai Provincial Cardiovascular and Cerebrovascular Disease Specialized Hospital from January 2022 to May 2023 were selected as the research objects. The data were collected by Flash dual-source spiral CT, CCTA-based FFR (CT-FFR) was simulated calculation by fluid mechanics principle based on CCTA images. FFR as the gold standard, positive predictive value, negative predictive value, sensitivity, accuracy and specificity of CT-FFR in the diagnosis of coronary heart disease and coronary artery lesions were analyzed, the diagnostic efficacy of CT-FFR in coronary heart disease and coronary artery lesions were analyzed by receiver operating characteristic (ROC) curve. The consistency between CT-FFR and FFR were analyzed by Bland-Altman plot. The positive predictive value of CT-FFR in the diagnosis of coronary heart disease was 73.08%, negative predictive value was 89.29%, sensitivity was 86.36%, accuracy was 81.48%, sensitivity was 78.13%. The area under the curve (AUC) of CT-FFR in the diagnosis of coronary heart disease was 0.854, and 95%CI was 0.747~0.962. The positive predictive value of CT-FFR in the diagnosis of coronary artery lesions was 71.05%, negative predictive value was 91.84%, sensitivity was 87.10%, accuracy was 82.76%, sensitivity was 80.36%. The AUC of CT-FFR in the diagnosis of coronary artery lesions was 0.921, and 95%CI was 0.865~0.978. Whether the diagnosis of coronary heart disease or diagnosis of coronary artery lesions, CT-FFR and FFR had good consistency. CT-FFR has high accuracy and sensitivity in the diagnosis of coronary heart disease in high altitude environment, and the detection efficiency is ideal, which has good consistency with FFR. [ABSTRACT FROM AUTHOR]

The role of fractional flow reserve (FFR) in coronary intermediate lesions is widely recommended by guidelines. The effect of uric acid (UA) on cardiovascular events is also well known. However, the relationship between UA and long-term cardiovascular outcomes in patients who received FFR with intermediate lesions remains unknown. We retrospectively included 428 patients who underwent both coronary angiography (CAG) and FFR. Participants were stratified into two groups based on the median UA. The primary endpoint was the composite of major adverse cardiovascular and cerebrovascular events (MACCEs), including repeat revascularization, nonfatal stroke, nonfatal myocardial infarction, and all-cause death. A Cox proportional hazards model was utilized to analyze the association between UA and the prevalence of MACCEs. During a median follow-up of 5.8 years, a higher MACCEs rate occurred in the high UA group compared to the low UA group (16.8% vs. 5.1%, p log-rank<0.01). Elevated UA was independently linked to a higher incidence of MACCEs, whether UA was treated as a categorical or continuous variable (hazard ratio [HR] 2.76, 95% confidence interval [CI] 1.27–6.03 or HR 1.01, 95% CI 1.01–1.02). The restricted cubic spline (RCS) analysis illustrated that the HR for MACCEs increased with increasing UA. The present study demonstrates that UA is associated with MACCEs risk and suggests that UA is a reliable predictor of long-term cardiovascular events in coronary intermediate stenosis patients. • We explored the long-term prognostic value of UA in patients with coronary intermediate stenosis for the first time. • Patients with a high level of UA suffered an increased incidence of cardiac events compared to those with a low level. • High UA levels were independently linked to a higher risk of MACCEs, regardless of whether UA was treated as a categorical or continuous variable. • The detrimental effects of UA will be significant in patients with coronary intermediate stenosis, when UA exceeds 407 μmol/L. [ABSTRACT FROM AUTHOR]

Background: The coronary artery disease‐reporting and data system (CAD‐RADS) 2.0 is used to standardize the reporting of coronary computed tomography angiography (CCTA) results. Artificial intelligence software can quantify the plaque composition, fat attenuation index, and fractional flow reserve. Objective: To analyze plaque features of varying severity in patients with a combination of CAD‐RADS stenosis and plaque burden categorization and establish a random forest classification model. Methods: The data of 100 patients treated between April 2021 and February 2022 were retrospectively collected. The most severe plaque observed in each patient was the target lesion. Patients were categorized into three groups according to CAD‐RADS: CAD‐RADS 1−2 + P0−2, CAD‐RADS 3−4B + P0−2, and CAD‐RADS 3−4B + P3−4. Differences and correlations between variables were assessed between groups. AUC, accuracy, precision, recall, and F1 score were used to evaluate the diagnostic performance. Results: A total of 100 patients and 178 arteries were included. The differences of computed tomography fractional flow reserve (CT‐FFR) (H = 23.921, p < 0.001), the volume of lipid component (H = 12.996, p = 0.002), the volume of fibro‐lipid component (H = 8.692, p = 0.013), the proportion of lipid component volume (H = 22.038, p < 0.001), the proportion of fibro‐lipid component volume (H = 11.731, p = 0.003), the proportion of calcification component volume (H = 11.049, p = 0.004), and plaque type (χ2 = 18.110, p = 0.001) was statistically significant. Conclusion: CT‐FFR, volume and proportion of lipid and fibro‐lipid components of plaques, the proportion of calcified components, and plaque type were valuable for CAD‐RADS stenosis + plaque burden classification, especially CT‐FFR, volume, and proportion of lipid and fibro‐lipid components. The model built using the random forest was better than the clinical model (AUC: 0.874 vs. 0.647). [ABSTRACT FROM AUTHOR]

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Coronary artery disease (CAD) is one of the main causes of death in the world. Functional indices such as fractional flow reserve (FFR), coronary flow reserve (CFR) and instantaneous wave-free ratio (iFR) are used to estimate the severity of CAD. Approximately 30–50% of patients have residual myocardial ischaemia even after formally successful percutaneous coronary intervention (PCI). Myocardial perfusion impairment is one of the main factors responsible for recurrence. We propose a novel 1D model of coronary hemodynamics that takes into account myocardial contraction, stenoses and impaired microcirculation. It uses non-invasively acquired data. The model is able to simulate FFR and iFR with a mean relative error of 3% and a standard mean deviation of 0.04. We find that healthy FFR and iFR values in the short and long term do not always correspond to healthy CFR values and recovery of coronary blood flow. We also show that PCI of stenosis also improves hemodynamic indices in adjacent stenosed vessels, with a more pronounced effect in the long term. [ABSTRACT FROM AUTHOR]

We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography Angiography FFRCT. A total of 14 patient‐specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra ±6% and inter‐operator ±15% variations on the segmentation threshold. FFRCT was evaluated in each case by 3D‐OD CFD simulations. The findings suggest that the sensitivity of FFRCT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if the FFRCT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluating FFRCT results. [ABSTRACT FROM AUTHOR]

AimsIcosapent ethyl (IPE) significantly reduced ischaemic events in statin-treated patients with atherosclerosis or diabetes and elevated triglycerides in REDUCE-IT, including large reductions in myocardial infarction and elective, urgent, and emergent coronary revascularization. However, the mechanisms driving this clinical benefit are not fully known. The EVAPORATE trial demonstrated that IPE significantly reduced plaque burden. No study to date has assessed the impact of IPE on coronary physiology. Fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) data sets (FFRCT) applies computational fluid dynamics to calculate FFR values in epicardial coronary arteries. Our objective was to assess the impact of IPE on coronary physiology assessed by FFRCT using imaging data from EVAPORATE.Methods and resultsA total of 47 patients and of 507 coronary lesions at baseline, 9 months, and 18 months with coronary CTA and FFRCT were studied in a blinded core lab. The pre-specified primary endpoint was the FFRCT value in the distal coronary segment from baseline to follow-up in the most diseased vessel per patient using IPE compared with placebo. The pre-specified secondary endpoint was the change in translesional FFRCT (ΔFFRCT) across the most severe (minimum 30% diameter stenosis) coronary lesion per vessel. Baseline FFRCT was similar for IPE compared with placebo (0.83 ± 0.08 vs. 0.84 ± 0.08, P = 0.55). There was significant improvement in the primary endpoint, as IPE improved mean distal segment FFRCT at 9- and 18-month follow-up compared with placebo (0.01 ± 0.05 vs. -0.05 ± 0.09, P = 0.02, and -0.01 ± 0.09 vs. -0.09 ± 0.12, P = 0.03, respectively). ΔFFRCT in 140 coronary lesions was improved, although not statistically significant, with IPE compared with placebo (-0.06 ± 0.08 vs. -0.09 ± 0.1, P = 0.054).ConclusionIcosapent ethyl demonstrated significant benefits in coronary physiology compared with placebo. This early and sustained improvement in FFRCT at 9- and 18-month follow-up provides mechanistic insight into the clinical benefit observed in the REDUCE-IT trial. Furthermore, this is the first assessment of FFRCT to determine drug effect.

Background The applicability of quantitative flow ratio (QFR), a nonhyperemic, invasive coronary angiography‐derived computation of fractional flow reserve (FFR), has not been studied in coronary artery bypass grafts. We sought to explore the correlation and diagnostic agreement between QFR and FFR in saphenous vein grafts (SVGs). Methods and Results A total of 129 prospectively included patients (mean age 73±8 years, 84% male) with prior coronary artery bypass grafting underwent invasive coronary angiography and pressure‐derived functional assessment in 150 nonoccluded SVGs. QFR dedicated angiography images of the SVGs were acquired and used for offline QFR computation. The diagnostic performance of QFR was compared with 2‐dimensional quantitative coronary angiography, using FFR as a reference. A threshold of ≤0.80 was used to define functional significance. QFR was successfully computed in 140 (93%) SVGs. We found a significant correlation between QFR and FFR (r=0.72, P

Background: Chronic total occlusion (CTO) is the most challenging subset in percutaneous coronary intervention (PCI), but the optimal selection of patients and indication for such procedures remain a subject of debate. We sought to investigate the role of physiological function in treatment decisions of CTO PCI by measuring fractional flow reserve (FFR) and Dynamic SPECT imaging in this study. Methods: All the FFR of CTO vessel were measured before and immediately after CTO revascularization, and Dynamic SPECT imaging were detected before PCI in patients with an identified CTO. Results: A total of 53 patients with single-vessel CTO lesions were included in this cohort study. The mean FFR value was 0.34 ± 0.09 at baseline. Immediately after successful CTO PCI, the FFR value significantly increased to 0.79 ± 0.11. The regional coronary flow reserve (CFR) of CTO vessels was 1.62 ± 0.64, which was significantly and positively correlated with the baseline FFR value (r = 0.607, p = 0.005). The area under the ROC curve of the baseline FFR for the detection of ischemia was 0.923 (p

Coronary computed tomographic angiography (CCTA) is becoming the first-line investigation for establishing the presence of coronary artery disease and, with fractional flow reserve (FFRCT), its haemodynamic significance. In patients without significant epicardial obstruction, its role is either to rule out atherosclerosis or to detect subclinical plaque that should be monitored for plaque progression/regression following prevention therapy and provide risk classification. Ischaemic non-obstructive coronary arteries are also expected to be assessed by non-invasive imaging, including CCTA. In patients with significant epicardial obstruction, CCTA can assist in planning revascularisation by determining the disease complexity, vessel size, lesion length and tissue composition of the atherosclerotic plaque, as well as the best fluoroscopic viewing angle; it may also help in selecting adjunctive percutaneous devices (e.g., rotational atherectomy) and in determining the best landing zone for stents or bypass grafts.

BackgroundWe sought to determine whether management of LDL-C following invasive angiography and assessment by fractional flow reserve (FFR) differs between those with obstructive vs non-obstructive CAD.MethodsRetrospective study of 721 patients undergoing coronary angiography involving assessment by FFR between 2013 and 2020 at a single academic center. Groups with obstructive vs non-obstructive CAD by index angiographic and FFR findings were compared over 1 year of follow-up.ResultsBased on index angiographic and FFR findings, 421 (58%) patients had obstructive CAD vs 300 (42%) with non-obstructive CAD, mean (±SD) age 66±11 years, 217 (30%) women, and 594 (82%) white. There was no difference in baseline LDL-C. At 3-months follow-up, LDL-C was lower than baseline in both groups, with no between group difference. In contrast, at 6-months, median (Q1, Q3) LDL-C was significantly higher in non-obstructive vs obstructive CAD (LDL-C 73 (60, 93) vs 63 (48, 77) mg/dL, respectively (p = 0.003), (p = 0.001 in multivariable linear regression)). At 12-months, LDL-C remained higher in non-obstructive vs obstructive CAD (LDL-C 73 (49, 86) vs 64 (48, 79) mg/dL, respectively, although not statistically significant (p = 0.104)). The rate of high-intensity statin use was lower among those with non-obstructive CAD vs obstructive CAD at all time points (p