Fractional Flow Reserve In Patients Research Articles

Correlation and consistency between resting full-cycle ratio and fractional flow reserve in assessing coronary artery function in a Chinese real-world cohort with non-ST-segment elevation acute coronary syndrome: a retrospective observational study

ObjectiveThe study aimed to investigate the correlation and consistency between resting full-cycle ratio (RFR) and fractional flow reserve (FFR) in functional assessment of coronary arteries in a Chinese real-world cohort...

Modelled impact of virtual fractional flow reserve in patients undergoing coronary angiography (VIRTU-4)

BackgroundThe practical application of ‘virtual’ (computed) fractional flow reserve (vFFR) based on invasive coronary angiogram (ICA) images is unknown. The objective of this cohort study was to investigate the potential...

Temporal changes in CT-derived fractional flow reserve in patients after heart transplantation.

Adding functional information by CT-derived fractional flow reserve (FFRct) to coronary CT angiography (CCTA) and assessing its temporal change may provide insight into the natural history and physiopathology of cardiac allograft vasculopathy (CAV) in heart transplantation (HTx) patients. We assessed FFRct changes as well as CAV progression over a 2-year period in HTx patients undergoing serial CT imaging. HTx patients from Erasmus MC and Mount Sinai Hospital, who had consecutive CCTAs 2 years apart were evaluated. FFRct analysis was performed for both scans. FFRct values at the most distal point in the left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) were measured after precisely matching the anatomical locations in both analyses. Also, the number of anatomical coronary stenoses of > 30% was scored. In total, 106 patients (median age 57 [interquartile range 47-67] years, 67% male) at 9 [6-13] years after HTx at the time of the baseline CCTA were included. Median distal FFRct values significantly decreased from baseline to follow-up for the LAD from 0.85 [0.79-0.90] to 0.84 [0.76-0.90] (p = 0.001), LCX from 0.92 [0.88-0.96] to 0.91 [0.85-0.95] (p = 0.009), and RCA from 0.92 [0.86-0.95] to 0.90 [0.86-0.94] (p = 0.004). The number of focal anatomical stenoses of > 30% increased from a median of 1 [0-2] at baseline to 2 [0-3] at follow-up (p = 0.009). The distal coronary FFRct values in post-HTX patients in each of the three major coronary arteries decreased, and the number of focal coronary stenoses increased over a 2-year period. Temporal FFRct change rate may become an additional parameter in the follow-up of HTx patients, but more research is needed to elucidate its role. CT-derived fractional flow reserve (FFRct) is important post-heart transplant because of additional information on coronary CT angiography for cardiac allograft vasculopathy (CAV) detection. The decrease and degree of reduction in distal FFRct value may indicate progression in anatomic CAV burden. CT-derived fractional flow reserve (FFRct) is important for monitoring cardiac allograft vasculopathy (CAV) in heart transplant patients. Over time, transplant patients showed a decrease in distal FFRct and an increase in coronary stenoses. Temporal changes in FFRct could be crucial for transplant follow-up, aiding in CAV detection.

Association of Coronary Computed Tomography-Defined Myocardial Bridge With Pre- and Post-Procedural Fractional Flow Reserve in Patients Undergoing Elective Percutaneous Coronary Intervention.

Myocardial bridge (MB) is a common coronary anomaly characterized by a tunneled course through the myocardium. Coronary computed tomography angiography (CCTA) can identify MB. The impact of MB detected by CCTA on coronary physiological parameters before and after percutaneous coronary intervention (PCI) is unknown.Methods and Results: We investigated 141 consecutive patients who underwent pre-PCI CCTA and fractional flow reserve (FFR)-guided elective PCI for de novo single proximal lesions in the left anterior descending artery (LAD). We compared clinical demographics and physiological parameters between patients with and without CCTA-defined MB. MB was identified in 46 (32.6%) patients using pre-PCI CCTA. The prevalence of diabetes was higher among patients with MB. Median post-PCI FFR values were significantly lower among patients with than without MB (0.82 [interquartile range 0.79-0.85] vs. 0.85 [interquartile range 0.82-0.89]; P=0.003), whereas pre-PCI FFR values were similar between the 2 groups. Multivariable linear regression analysis revealed that the presence of MB and greater left ventricular mass volume in the LAD territory were independently associated with lower post-PCI FFR values. Multivariable logistic regression analysis also revealed that the presence of MB and lower pre-PCI FFR values were independent predictors of post-PCI FFR values ≤0.80. CCTA-defined MB independently predicted both lower post-PCI FFR as a continuous variable and ischemic FFR as a categorical variable in patients undergoing elective PCI for LAD.

Timing of fractional flow reserve-guided complete revascularization in patients with ST-segment elevation myocardial infarction with multivessel disease: Rationale and design of the OPTION-STEMI trial

Current guidelines recommend complete revascularization (CR) in hemodynamically stable patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease (MVD). With regard to the timing of percutaneous coronary intervention (PCI) for non-infarct-related artery (non-IRA), recent randomized clinical trials have revealed that immediate CR was non-inferior to staged CR. However, the optimal timing of CR remains uncertain. The OPTION-STEMI trial compared immediate CR and in-hospital staged CR guided by fractional flow reserve (FFR) for intermediate stenosis of the non-IRA. The OPTION-STEMI is a multicenter, investigator-initiated, prospective, open-label, non-inferiority randomized clinical trial. The study included patients with at least 1 non-IRA lesion with ≥50% stenosis by visual estimation. Patients fulfilling the inclusion criteria were randomized into 2 groups at a 1:1 ratio: immediate CR (i.e., PCI for the non-IRA performed during primary angioplasty) or in-hospital staged CR. In the in-hospital staged CR group, PCI for non-IRA lesions was performed on another day during the index hospitalization. Non-IRA lesions with 50%-69% stenosis by visual estimation were evaluated by FFR, whereas those with ≥70% stenosis was revascularized without FFR. The primary endpoint was the composite of all-cause death, non-fatal myocardial infarction, and all unplanned revascularization at 1 year after randomization. Enrolment began in December 2019 and was completed in January 2024. The follow-up for the primary endpoint will be completed in January 2025, and primary results will be available in the middle of 2025. The OPTION-STEMI is a multicenter, non-inferiority, randomized trial that evaluated the timing of in-hospital CR with the aid of FFR in patients with STEMI and MVD. URL: https://www. gov. Unique identifier: NCT04626882; and URL: https://cris.nih.go.kr. Unique identifier: KCT0004457.

Coronary Artery Disease Assessment via On-Site CT Fractional Flow Reserve in Patients Undergoing Transcatheter Aortic Valve Replacement.

Purpose To examine the clinical feasibility of workstation-based CT fractional flow reserve (CT-FFR) for coronary artery disease (CAD) evaluation during preprocedural planning in patients undergoing transcatheter aortic valve replacement (TAVR). Materials and Methods In this retrospective single-center study, 434 patients scheduled for TAVR between 2018 and 2020 were screened for study inclusion; a relevant proportion of patients (35.0% [152 of 434]) was not suitable for evaluation due to insufficient imaging properties. A total of 112 patients (mean age, 82.1 years ± 6.7 [SD]; 58 [52%] men) were included in the study. Invasive angiography findings, coronary CT angiography results, and Agatston score were acquired and compared with on-site CT-FFR computation for evaluation of CAD and prediction of major adverse cardiovascular events (MACE) within a 24-month follow-up. Results Hemodynamic relevant CAD, as suggested by CT-FFR of 0.80 or less, was found in 41 of 70 (59%) patients with stenosis of 50% or more. MACE occurred in 23 of 112 (20.5%) patients, from which 14 of 23 had stenoses with CT-FFR of 0.80 or less (hazard ratio [HR], 3.33; 95% CI: 1.56, 7.10; P = .002). CT-FFR remained a significant predictor of MACE after inclusion in a multivariable model with relevant covariables (HR, 2.89; 95% CI: 1.22, 6.86; P = .02). An Agatston score of 1000 Agatston units or more (HR, 2.25; 95% CI: 0.98, 5.21; P = .06) and stenoses of 50% or more determined via invasive angiography (HR, 0.94; 95% CI: 0.41, 2.17; P = .88) were not significant predictors of MACE. Conclusion Compared with conventional CAD markers, CT-FFR better predicted adverse outcomes after TAVR. A relevant portion of the screened cohort, however, was not suitable for CT-based CAD evaluation. Keywords: CT, Transcatheter Aortic Valve Implantation/Replacement (TAVI/TAVR), Cardiac, Coronary Arteries, Outcomes Analysis © RSNA, 2024 See also the commentary by Weir-McCall and Pugliese in this issue.

Advanced CT measures of coronary artery disease with intermediate stenosis in patients with severe aortic valve stenosis

BackgroundCoronary artery disease (CAD) and severe aortic valve stenosis (AS) frequently coexist. While pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) allows to rule out obstructive CAD, interpreting hemodynamic significance of intermediate stenoses is challenging. This study investigates the incremental value of CT-derived fractional flow reserve (CT-FFR), quantitative coronary plaque characteristics (e.g., stenosis degree, plaque volume, and composition), and peri-coronary adipose tissue (PCAT) density to detect hemodynamically significant lesions among those with AS and CAD.Materials and methodsWe included patients with severe AS and intermediate coronary lesions (20–80% diameter stenosis) who underwent pre-TAVR CTA and invasive coronary angiogram (ICA) with resting full-cycle ratio (RFR) assessment between 08/16 and 04/22. CTA image analysis included assessment of CT-FFR, quantitative coronary plaque analysis, and PCAT density. Coronary lesions with RFR ≤ 0.89 indicated hemodynamic significance as reference standard.ResultsOverall, 87 patients (age 77.9 ± 7.4 years, 38% female) with 95 intermediate coronary artery lesions were included. CT-FFR showed good discriminatory capacity (area under receiver operator curve (AUC) = 0.89, 95% confidence interval (CI) 0.81–0.96, p < 0.001) to identify hemodynamically significant lesions, superior to anatomical assessment, plaque morphology, and PCAT density. Plaque composition and PCAT density did not differ between lesions with and without hemodynamic significance. Univariable and multivariable analyses revealed CT-FFR as the only predictor for functionally significant lesions (odds ratio 1.28 (95% CI 1.17–1.43), p < 0.001). Overall, CT-FFR ≤ 0.80 showed diagnostic accuracy, sensitivity, and specificity of 88.4% (95%CI 80.2–94.1), 78.5% (95%CI 63.2–89.7), and 96.2% (95%CI 87.0–99.5), respectively.ConclusionCT-FFR was superior to CT anatomical, plaque morphology, and PCAT assessment to detect functionally significant stenoses in patients with severe AS.Clinical relevance statementCT-derived fractional flow reserve in patients with severe aortic valve stenosis may be a useful tool for non-invasive hemodynamic assessment of intermediate coronary lesions, while CT anatomical, plaque morphology, and peri-coronary adipose tissue assessment have no incremental or additional benefit. These findings might help to reduce pre-transcatheter aortic valve replacement invasive coronary angiogram.Key Points• Interpreting the hemodynamic significance of intermediate coronary stenoses is challenging in pre-transcatheter aortic valve replacement CT.• CT-derived fractional flow reserve (CT-FFR) has a good discriminatory capacity in the identification of hemodynamically significant coronary lesions.• CT-derived anatomical, plaque morphology, and peri-coronary adipose tissue assessment did not improve the diagnostic capability of CT-FFR in the hemodynamic assessment of intermediate coronary stenoses.

Diagnostic performance of noninvasive computed tomography-derived fractional flow reserve in patients with severe aortic stenosis

Abstract Background Noninvasive fractional flow reserve derived from coronary computed tomography angiography (FFRct) is developed as a decision-making tool in daily clinical practice. However, its diagnostic performance has not been sufficiently explored in patients with severe aortic stenosis (AS). Purpose To identify the diagnostic performance of FFRct in patients with severe AS using invasive fractional flow reserve (FFR) as the reference standard. Methods This study was a retrospective observational that included consecutive patients with severe AS undergoing TAVI who had concomitant intermediate coronary artery stenosis based on preoperative invasive coronary angiography. Preoperative invasive FFR and CT data preoperatively before TAVI were prospectively collected. Results We analyzed the data of patients with severe AS demonstrating intermediate coronary artery stenosis and compared the FFRct values with the invasive FFR values. Among 93 patients (100 vessels), the median FFR and FFRct (Q1, Q3) were 0.85 (0.78, 0.90) and 0.83 (0.72, 0.88), respectively. The FFRct values significantly correlated with the FFR values (r = 0.57; p &amp;lt; 0.0001). The vessel-based analysis of the accuracy of FFRct showed a sensitivity of 90.3%, specificity of 73.9%, positive predictive value of 60.9%, and negative predictive value of 94.4%. Conclusions FFRct demonstrated a significant correlation with invasive FFR and a high negative predictive value in patients with severe AS. These findings suggest that FFRct would be a clinically beneficial noninvasive tool for excluding functional coronary artery stenosis in patients with severe AS.

TCT-596 Sex Differences in Use of Fractional Flow Reserve in Patients Undergoing Coronary Angiography and Percutaneous Coronary Intervention

TCT-596 Sex Differences in Use of Fractional Flow Reserve in Patients Undergoing Coronary Angiography and Percutaneous Coronary Intervention

TCT-63 Cost-Effectiveness of Fractional Flow Reserve in Patients With Acute Myocardial Infarction and Multivessel Disease: Prespecified Analysis of FRAME-AMI Trial

TCT-63 Cost-Effectiveness of Fractional Flow Reserve in Patients With Acute Myocardial Infarction and Multivessel Disease: Prespecified Analysis of FRAME-AMI Trial

Coronary Computed Tomographic Angiography With Fractional Flow Reserve in Patients With Type 2 Myocardial Infarction

BackgroundType 2 myocardial infarction (T2MI) related to a supply/demand imbalance of coronary blood flow is common and associated with poor prognosis. Coronary artery disease (CAD) may predispose some individuals to T2MI and contribute to its high rate of recurrent cardiovascular events. Little is known about the presence and extent of CAD in this population. ObjectivesThe goal of this study was to evaluate the presence and characteristics of CAD among patients with T2MI. MethodsIn this prospective study, consecutive eligible individuals with Fourth Universal Definition of Myocardial Infarction criteria for T2MI were enrolled. Participants underwent coronary computed tomography angiography (CTA), fractional flow reserve derived with coronary CTA (FFRCT), and plaque volume analyses. ResultsAmong 50 participants, 25 (50%) were female, and the mean age was 68.0 ± 11.4 years. Atherosclerotic risk factors were common. Coronary CTA revealed coronary plaque in 46 participants (92%). A moderate or greater stenosis (≥50%) was identified in 42% of participants, and obstructive disease (≥50% left main stenosis or ≥70% stenosis in any other epicardial coronary artery) was present in 26%. Prevalence of obstructive CAD did not differ according to T2MI cause (P = 0.54). A hemodynamically significant focal stenosis identified by FFRCT was present in 13 participants (26%). Among participants with a stenosis ≥50% (n = 21), FFRCT excluded lesion-specific hemodynamically significant stenosis in 8 cases (38%). ConclusionsAmong individuals with adjudicated T2MI, CAD was prevalent, but the majority of patients had nonobstructive CAD. Mediators of ischemia are likely multifactorial in this population. (Defining the Prevalence and Characteristics of Coronary Artery Disease Among Patients with Type 2 Myocardial Infarction using CT-FFR [DEFINE TYPE 2 MI]; NCT04864119)

Prognostic value of plaque volume combined with CT fractional flow reserve in patients with suspected coronary artery disease

To investigate the prognostic value of quantitative plaque volume on coronary computed tomography (CT) angiography (CTA) combined with CT fractional flow reserve (CT-FFR) for major adverse cardiac events (MACE) in suspected coronary artery disease (CAD) patients. Patients who underwent coronary CTA with clinically suspected CAD were enrolled retrospectively in this study. Patients' baseline, Framingham Risk Score (FRS), coronary CTA plaque assessment, and CT-FFR were analysed retrospectively. Study outcomes included rehospitalisation and MACE (ST-segment elevation myocardial infarction, unstable angina, or non-ST-segment elevation myocardial infarction, revascularisation, and cardiac death). There were 251 patients in the study, with a follow-up period of 1-6.58 years. Mean age was 61.16±10.45 years and 146 (58%) patients were male. Higher CT-adapted Leaman score and quantitative plaque volume were found in patients with FRS >0.2 regardless of categorical or continuous variables. Coronary scores, quantitative plaque parameters, and CT-FFR were associated with MACE and rehospitalisation in univariate analysis. In model 1, CT-FFR was associated with MACE in multivariate Cox analysis when adjusted for FRS and CT-adapted Leaman score. Quantitative plaque parameters including calcified plaque volume, fibro-fatty plaque volume, low-attenuation plaque volume, non-calcified plaque volume, and total plaque volume were significantly associated with MACE and improved overall prognostic performance in a model adjusted for CT-FFR. Additional quantitative plaque volume and CT-FFR further improve the predictive incremental value based on risk factor scores for prognostic prediction in patients. Adding quantitative plaque volume combined with CT-FFR analysis to anatomical and clinical assessment will be further beneficial to predict patients' prognosis of MACE.

The diagnostic performance of quantitative flow ratio and perfusion imaging in patients with prior coronary artery disease.

In chronic coronary syndrome (CCS) patients with documented coronary artery disease (CAD), ischaemia detection by myocardial perfusion imaging (MPI) and an invasive approach are viable diagnostic strategies. We compared the diagnostic performance of quantitative flow ratio (QFR) with single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (CMR) in patients with prior CAD [previous percutaneous coronary intervention (PCI) and/or myocardial infarction (MI)]. This PACIFIC-2 sub-study evaluated 189 CCS patients with prior CAD for inclusion. Patients underwent SPECT, PET, and CMR followed by invasive coronary angiography with fractional flow reserve (FFR) measurements of all major coronary arteries (N = 567), except for vessels with a sub-total or chronic total occlusion. Quantitative flow ratio computation was attempted in 488 (86%) vessels with measured FFR available (FFR ≤0.80 defined haemodynamically significant CAD). Quantitative flow ratio analysis was successful in 334 (68%) vessels among 166 patients and demonstrated a higher accuracy (84%) and sensitivity (72%) compared with SPECT (66%, P < 0.001 and 46%, P = 0.001), PET (65%, P < 0.001 and 58%, P = 0.032), and CMR (72%, P < 0.001 and 33%, P < 0.001). The specificity of QFR (87%) was similar to that of CMR (83%, P = 0.123) but higher than that of SPECT (71%, P < 0.001) and PET (67%, P < 0.001). Lastly, QFR exhibited a higher area under the receiver operating characteristic curve (0.89) than SPECT (0.57, P < 0.001), PET (0.66, P < 0.001), and CMR (0.60, P < 0.001). QFR correlated better with FFR in patients with prior CAD than MPI, as reflected in the higher diagnostic performance measures for detecting FFR-defined, vessel-specific, significant CAD.

Economic evaluation and analysis of the budget effect of the measuring of fractional flow reserve in Bulgaria

Introduction: Fractional fl ow reserve (FFR) implies the ratio of the maximal hyperemic myocardial blood fl ow in the case of a pathologically changed coronary artery to the maximal hyperemic myocardial blood fl ow in the case of a healthy coronary artery. Aims: The aim of the current study is to perform an economic evaluation and budget impact analysis of measuring FFR as a medical activity in Bulgaria. Material and Methods: For the purpose of the current analysis, two models using Microsoft Excel and TreeAge Pro were developed to evaluate the cost-effectiveness of the FFR-guided percutaneous coronary intervention (PCI) compared to the classic angiography-guided PCI in patients with ischemic heart disease (IHD) with one-vessel coronary artery disease (CAD) or multivessel CAD. The analysis will focus on the health perspective and the payer perspective - National Health Insurance Fund (NHIF). Results: The medico-diagnostic activity related to measuring FFR in patients with multi-vessel coronary artery disease is shown to be a cost-effective therapeutic approach in Bulgaria compared to the angiography-guided PCI (ICER = 50 456 BGN/QALY) with a cost-effectiveness threshold of 51 510 BGN/QALY. FFR- guided PCI strategy in one-vessel coronary artery disease patients is a cost-saving approach (-853 BGN) when compared to the angiography-guided PCI (4 150 BGN). Conclusion: Budget impact analysis revealed that the FFR-guided PCI strategy is a cost-saving alternative approach to the angiographyguided PCI. The savings of the NHIF during the fi rst year of reimbursement of FFR would be -1,1 million BGN and could reach -1,6 million BGN in the third year.

Temporal Change In CT-Derived Fractional Flow Reserve In Patients After Heart Transplantation

Temporal Change In CT-Derived Fractional Flow Reserve In Patients After Heart Transplantation

Incremental value of computed tomography angiographic derived fractional flow reserve in patients with stable chest pain and anatomical obstructive coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Coronary computed tomography angiography (CCTA)-derived fractional flow reserve (FFRCT) is endorsed by guidelines for the evaluation of obstructive coronary artery disease (OCAD) (1). However, real-world impact of selective use of FFRCT in patients with suspected OCAD by CCTA on subsequent invasive coronary angiography (ICA) and revascularization remains unclear. Purpose To assess the impact and diagnostic accuracy of FFRCT interpretation in patients with suspected OCAD by CCTA on downstream ICA and revascularization. Methods All consecutive patients who underwent coronary CCTA for the evaluation of stable chest pain between 01/10/2013 and 28/05/2021 in our tertiary university hospital were included in a registry. From a total population of 7541 patients, 1601 with reported anatomical obstructive OCAD on CCTA, were included in our study. OCAD was defined as the presence of a stenosis ≥ 50% in at least one of the three main vessels. CCTA were selectively send to FFRCT analysis according to radiologist's decision. A numerical interpretation of FFRCT was firstly performed by defining a lowest distal value≤ 0.8 as a possible need for revascularization and secondly, a comprehensive interpretation of FFRCT was completed by an experienced interventional cardiologist and radiologist. In brief, this interpretation takes into account not only the lowest distal FFRCT value, but also the post-stenotic FFR, the trans-lesional gradient and anatomical distribution of FFRCT changes. Results From a registry of 7541 patients, suspected OCAD derived from CCTA was reported in 1601 cases, including 808 (50.5%) patients evaluated by FFRCT. ICA was performed in 1160 (72.5%) and revascularization in 559 (34.9%) patients. Overall proportion of ICA decreased from 77.2 to 67.8% with FFRCT use (chi² p&amp;lt;0.01) (Figure 1). After propensity score weighting, FFRCT use was independently associated with decreased ICA (OR: 0.66; 95% CI 0.53–0.83, p&amp;lt; 0.001) and with a decreased rate of myocardial revascularization (OR: 0.71; 95% CI 0.58 –0.88, p&amp;lt; 0.01). Compared to a numerical interpretation, a comprehensive assessment of FFRCT increased the ratio of revascularization per ICA (61.8 vs 50.2 %, p&amp;lt; 0.01) and was more accurate to rule-in OCAD patient requiring a myocardial revascularization (Figure 2). After propensity score adjustment, numerically abnormal FFRCT and pathological coronary disease distribution on comprehensive assessment similar were still independently associated with an increased the rate of ICA use (OR:3.03 95% CI 2.18–4.23, p&amp;lt; 0.001 and OR: 3.45; 95% CI 2.47–4.82, p&amp;lt; 0.001, respectively) and myocardial revascularization (OR:5.13; 95% CI 3.23–8.15, p&amp;lt; 0.001 and OR:6.48; 95% CI 4.55–9.22, p&amp;lt; 0.001, respectively). Conclusion We observed in a large single-center real-world registry that implementing FFRCT downstream ICA and that a comprehensive assessment of FFRCT ensures an improved selection of patients requiring myocardial revascularization.

Prognostic value of coronary CT angiography derived fractional flow reserve in patients with myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: None. Introduction We sought to analyze whether invasive fractional flow reserve (FFRi) values of non-infarction related (non-IRA) lesions change over time in ST Elevation Myocardial Infarction (STEMI) patients and to evaluate the diagnostic performance of coronary CT angiography derived FFR (FFRCT) close to the index event for defining follow-up FFRi. Methods We prospectively enrolled 38 multi-vessel STEMI patients (mean age 61.6±9 years, mean body mass index 28.8±4.8 kg/m2, 23.1 % female) who underwent non-IRA baseline and follow-up FFRi measurement and during the 10-day period after the index event FFRCT measurement. Follow-up FFRi was performed in 45–60 days after the index event and staged percutaneous coronary intervention (PCI) was carried out if FFRi was ≤0.8 at follow-up. Results Mean FFRi values showed significant difference between baseline and follow-up (0.83±0.11 vs. 0.80±0.13 p = 0.04, respectively). Mean FFR-CT was 0.79±0.14. Stronger correlation and smaller mean bias was found between FFR-CT and follow-up FFRi (ρ=0.86, p&amp;lt;0.001, bias: 0.01) as compared with baseline FFRi (ρ=0.68, p&amp;lt;0.001, bias: 0.04). The overall accuracy was 94.7% with 100.0% sensitivity and 90.0% specificity for identifying lesions ≤0.8 on follow-up FFRi. Accuracy, sensitivity and specificity were 81.5%, 93.3% 73.9%, respectively for identifying lesions on baseline FFRi using FFR-CT. Conclusion Non-invasive assessment of FFR at hospital discharge after the acute event lead to a better diagnostic performance for the identification of hemodynamically relevant non-IRA lesions as compared with baseline FFRi. FFRCT might improve decision making by selecting the patients for staged PCI in patients with multi-vessel STEMI.

Identification of ischemia-causing lesions using coronary plaque quantification and changes in fractional flow reserve derived from computed tomography across the lesion.

This study sought to evaluate the association between coronary plaque characteristics, changes in the fractional flow reserve (FFR) derived from computed tomography across the lesion (ΔFFRCT), and lesion-specific ischemia using the FFR in patients with suspected or known coronary artery disease. The study assessed coronary computed tomography (CT) angiography stenosis, plaque characteristics, ΔFFRCT, and FFR in 164 vessels of 144 patients. Obstructive stenosis was defined as stenosis ≥50%. An area under the receiver -operating characteristics curve (AUC) analysis was conducted to define the optimal thresholds for ΔFFRCT and the plaque variables. Ischemia was defined as a FFR of ≤0.80. The optimal cut-off value of ΔFFRCT was 0.14. Low-attenuation plaque (LAP) ≥76.23 mm3 and a percentage aggregate plaque volume (%APV) ≥28.91% can be used to predict ischemia independent of other plaque characteristics. The addition of LAP ≥76.23 mm3 and %APV ≥28.91% improved the discrimination (AUC, 0.742 vs. 0.649, P=0.001) and reclassification abilities [category-free net reclassification index (NRI), 0.339, P=0.027; relative integrated discrimination improvement (IDI) index, 0.093, P<0.001] of the assessments compared to the stenosis evaluation alone, and the addition of information about ΔFFRCT ≥0.14 further increased the discrimination (AUC, 0.828 vs. 0.742, P=0.004) and reclassification abilities (NRI, 1.029, P<0.001; relative IDI, 0.140, P<0.001) of the assessments. The addition of the plaque assessment and ΔFFRCT to the stenosis assessments improved the identification of ischemia compared to the stenosis assessment alone.

The Influence of Microcirculatory Dysfunction on the Resting Full Cycle Ratio Compared to Fractional Flow Reserve

BackgroundThe relation between the resting full cycle ratio (RFR) and fractional flow reserve (FFR) is not fully understood. This study aims to investigate the influence of coronary microvascular dysfunction, assessed by the index of microvascular resistance (IMR), on RFR compared to FFR in patients undergoing functional assessment for coronary stenosis. Materials and methodsTwo-hundred patients with borderline stenosis underwent functional assessment of RFR, FFR, coronary flow reserve (CFR) and IMR. Retriever operator curve analysis was performed to assess the diagnostic value of RFR in patients with (IMR ≥ 24) and (IMR < 24). ResultsMedian RFR did not differ significantly in patients with IMR ≥ 24 compared to patients with IMR < 24: 0.89 (interquartile range (IQR) 0.84, 0.95) vs. 0.90 (IQR 0.84, 0.92), p = 0.29). FFR was significantly higher in patients with IMR ≥ 24 compared to patients with IMR < 24: median FFR 0.85 (IQR (0.76, 0.92)) vs. 0.82 (IQR 0.73, 0.86), p = 0.009, and median CFR was significantly lower 1.80 (IQR 1.40, 2.55) vs. 2.70 (IQR 1.80, 3.95), p < 0.001. The diagnostic value of RFR was high (Area under the curve (AUC) 0.89 95 % Confidence Interval: [0.85, 0.93]) and AUC did not differ between patients with IMR ≥ 24 compared to patients with IMR < 24: 0.89 vs. 0.90, p = 0.89. An overall optimal cut off of 0.88 was identified. The cut off did not differ significantly between patients with IMR ≥ 24 compared to patients with IMR < 24: 0.88 vs. 0.90, p = 0.397. ConclusionIn patients with coronary borderline stenosis, the coronary microvascular function did not influence on the cut off values or AUC of RFR compared to FFR.

Benefits of the selective invasive strategy guided by CTA andCTA-derived fractional flow reserve in patients with coronary artery disease.

Coronary computed tomography angiography (CTA) has high diagnostic accuracy in ruling out significant stenosis of coronary arteries. The additional use of CTA- derived fractional flow reserve (FFR) further enhances diagnostic utility of coronary CTA. Some patients interrogated non-invasively have diseased coronary arteries and undergo further diagnostic testing, including invasive coronary angiography (ICA). Patients with one-vessel disease may benefit from invasive interrogation limited to the diseased vessel only. We analyzed the impact of a "diseased-vessel-only" selective invasive diagnostic approach in 100 patients undergoing ICA following coronary CTA (and CT-FFR) as compared to the traditional "full ICA" approach. We aimed to compare contrast volume and radiation dose used during ICA in both scenarios, seeking potential benefits for the patient in reducing those values by the "dis-eased-vessel-only" approach. Sensitivity, specificity, positive predictive value, and negative predictive value of CTA in prediction of subsequent revascularization were 96%, 75%, 51%, and 99%, respectively, and for CT-FFR 90%, 90%, 69%, and 97%, respectively. Using CTA as a method to guide ICA would reduce contrast volume and estimated radiation dose (ED) by 35% and 42.0%, respectively (P <0.0001 for both). Taking into consideration CT-FFR results, contrast volume would be reduced by 57% and ED by 69% (P <0.0001 for both). These real-world data support the concept that vessels with <50% diameter stenosis on quantitative computed tomography and with hemodynamically insignificant CTA-derived FFR result may be omitted during ICA. Such an approach would result in substantial reductions in con-trast media volume used, as well as patients' exposure to radiation during ICA, while not leading to misdiagnoses.