Assessment Of Coronary Stenosis Severity Research Articles

Prospective Deep Learning-based Quantitative Assessment of Coronary Plaque by CT Angiography Compared with Intravascular Ultrasound.

Coronary computed tomography angiography provides noninvasive assessment of coronary stenosis severity and flow impairment. Automated artificial intelligence analysis may assist in precise quantification and characterization of coronary atherosclerosis, enabling patient-specific risk determination and management strategies. This multicenter international study compared an automated deep-learning-based method for segmenting coronary atherosclerosis in coronary computed tomography angiography (CCTA) against the reference standard of intravascular ultrasound (IVUS). The study included clinically stable patients with known coronary artery disease from 15 centers in the U.S. and Japan. An artificial intelligence (AI)-enabled plaque analysis service was utilized to quantify and characterize total plaque (TPV), vessel, lumen, calcified plaque (CP), non-calcified plaque (NCP), and low attenuation plaque (LAP) volumes derived from CCTA and compared with IVUS measurements in a blinded, core laboratory-adjudicated fashion. In 237 patients, 432 lesions were assessed; mean lesion length was 24.5 mm. Mean IVUS-TPV was 186.0 mm3. AI-enabled plaque analysis on CCTA showed strong correlation and high accuracy when compared with IVUS; correlation coefficient, slope, and Y intercept for TPV were 0.91, 0.99, and 1.87, respectively; for CP volume 0.91, 1.05, and 5.32, respectively; and for NCP volume 0.87, 0.98, and 15.24, respectively. Bland-Altman analysis demonstrated strong agreement with little bias for these measurements. Artificial intelligence enabled CCTA quantification and characterization of atherosclerosis demonstrated strong agreement with IVUS reference standard measurements. This tool may prove effective for accurate evaluation of coronary atherosclerotic burden and cardiovascular risk assessment.[ClinicalTrails.gov identifier: NCT05138289].

Segmentation of X-ray coronary angiography with an artificial intelligence deep learning model: Impact in operator visual assessment of coronary stenosis severity.

Visual assessment of the percentage diameter stenosis (%DSVE ) of lesions is essential in coronary angiography (CAG) interpretation. We have previously developed an artificial intelligence (AI) model capable of accurate CAG segmentation. We aim to compare operators' %DSVE in angiography versus AI-segmented images. Quantitative coronary analysis (QCA) %DS (%DSQCA ) was previously performed in our published validation dataset. Operators were asked to estimate %DSVE of lesions in angiography versus AI-segmented images in separate sessions and differences were assessed using angiography %DSQCA as reference. A total of 123 lesions were included. %DSVE was significantly higher in both the angiography (77% ± 20% vs. 56% ± 13%, p < 0.001) and segmentation groups (59% ± 20% vs. 56% ± 13%, p < 0.001), with a much smaller absolute %DS difference in the latter. For lesions with %DSQCA of 50%-70% (60% ± 5%), an even higher discrepancy was found (angiography: 83% ± 13% vs. 60% ± 5%, p < 0.001; segmentation: 63% ± 15% vs. 60% ± 5%, p < 0.001). Similar, less pronounced, findings were observed for %DSQCA < 50% lesions, but not %DSQCA > 70% lesions. Agreement between %DSQCA /%DSVE across %DSQCA strata (<50%, 50%-70%, >70%) was approximately twice in the segmentation group (60.4% vs. 30.1%; p < 0.001). %DSVE inter-operator differences were smaller with segmentation. %DSVE was much less discrepant with segmentation versus angiography. Overestimation of %DSQCA < 70% lesions with angiography was especially common. Segmentation may reduce %DSVE overestimation and thus unwarranted revascularization.

Challenges in Diagnosis and Functional Assessment of Coronary Artery Disease in Patients With Severe Aortic Stenosis.

More than half of patients with severe aortic stenosis (AS) over 70 years old have coronary artery disease (CAD). Exertional angina is often present in AS-patients, even in the absence of significant CAD, as a result of oxygen supply/demand mismatch and exercise-induced myocardial ischemia. Moreover, persistent myocardial ischemia leads to extensive myocardial fibrosis and subsequent coronary microvascular dysfunction (CMD) which is defined as reduced coronary vasodilatory capacity below ischemic threshold. Therefore, angina, as well as noninvasive stress tests, have a low specificity and positive predictive value (PPV) for the assessment of epicardial coronary stenosis severity in AS-patients. Moreover, in symptomatic patients with severe AS exercise testing is even contraindicated. Given the limitations of noninvasive stress tests, coronary angiography remains the standard examination for determining the presence and severity of CAD in AS-patients, although angiography alone has poor accuracy in the evaluation of its functional severity. To overcome this limitation, the well-established invasive indices for the assessment of coronary stenosis severity, such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), are now in focus, especially in the contemporary era with the rapid increment of transcatheter aortic valve replacement (TAVR) for the treatment of AS-patients. TAVR induces an immediate decrease in hyperemic microcirculatory resistance and a concomitant increase in hyperemic flow velocity, whereas resting coronary hemodynamics remain unaltered. These findings suggest that FFR may underestimate coronary stenosis severity in AS-patients, whereas iFR as the non-hyperemic index is independent of the AS severity. However, because resting coronary hemodynamics do not improve immediately after TAVR, the coronary vasodilatory capacity in AS-patients treated by TAVR remain impaired, and thus the iFR may overestimate coronary stenosis severity in these patients. The optimal method for evaluating myocardial ischemia in patients with AS and co-existing CAD has not yet been fully established, and this important issue is under further investigation. This review is focused on challenges, limitations, and future perspectives in the functional assessment of coronary stenosis severity in these patients, bearing in mind the complexity of coronary physiology in the presence of this valvular heart disease.

Evaluating the Impact of Fractional Flow Reserve (FFR) on Decision-Making for Treatment of Borderline Coronary Artery Lesions:

Background: The primary reference criterion for evaluating coronary artery stenosis functional significance is fractional flow reserve (FFR). It helps the interventionist to define appropriate angiographic borderline coronary lesions that should or should not be treated with a stent. Objective: To evaluate the experience of the cardiology department, MUST University, on the use of FFR and its impact on patients with a borderline coronary lesion as regard revascularization decision-making. Patients and methods: A retrospective study were done on 86 patients with borderline lesions undergoing coronary angiograms for whom FFR was performed. Three experienced cardiac interventionists re-analyzed their coronary angiography and whether to delay or conduct revascularization with borderline stenotic lesions (40-70 %). A distinction was made between the findings of quantitative coronary angiography (QCA), visual and functional assessment of coronary stenosis severity. Result: Eighty-six patients (51 males and 35 females) with a mean age of 58.60 ± 9.20 were enrolled in the current study. FFR was 0.8 left main (LM) lesion and for the other vessels with severe coronary lesions, stenting was performed. Conclusion: In patients having borderline coronary artery stenosis, FFR is an important tool for clinical decisions making about procedures of revascularization. FFR results in alteration in the coronary intervention judgment.

Invasive Coronary Physiology Assessment for Patients With Stable Coronary Disease.

Visual assessment of coronary stenosis severity using conventional coronary angiography is associated with wide interoperator variability and a weak relationship with hemodynamics. Invasive coronary physiology assessment using fractional flow reserve (FFR) has been shown to be safe and beneficial. Large multicenter randomized trials have demonstrated the superiority of FFR-guided percutaneous coronary intervention in reducing the risk of major cardiac adverse events, number of stents used, and total cost in patients with multivessel coronary disease. FFR requires vasodilatory agents for the microvasculature to induce maximal hyperemia, which carry a slight risk, cost, and effort. Nonhyperemic pressure ratios provide a physiologic metric without vasodilator medications but with more limited clinical outcomes data. The transition from anatomy to physiology for coronary artery disease decision-making represents a cultural sea change in the cardiac catheterization laboratory that requires time and retooling.

Revascularization decisions in patients with stable angina and intermediate lesions: results of the second International Survey on Interventional Strategy (ISIS-2)

Abstract Background ISIS-1 survey (conducted in 2012–2013) demonstrated a significant disconnect between guideline recommendations on invasive functional and imaging assessment of coronary stenosis severity and effective intention to adoption in patients with chronic coronary syndromes (CCS). Ever since, more evidences and new indexes/tools have become available, supposedly resulting into a simplified adoption. Therefore, six years later the second survey was repeated (ISIS-2) with the aim to evaluate a possible evolution in the intended adoption of invasive diagnostic tools. Methods ISIS-2 was conducted via a web-based platform from June to December 2019. Here, five complete angiograms were provided, presenting only focal intermediate stenoses. FFR and quantitative coronary angiography (QCA) values were known and kept concealed to the participants. Estimation of stenosis significance was asked for each lesion. In case of uncertainty, the most appropriate adjunctive invasive diagnostic method among QCA, intravascular ultrasound, optical coherence tomography, or invasive functional test (i.e. with FFR or a non-hyperemic index) was to be selected. Primary endpoint of the study was the rate of requested adjunctive functional or imaging assessment, as indicated by guideline recommendations. Secondary endpoint was the rate and accuracy of purely angiography-based decisions. Results A total of 411 participants performed 3749 lesion evaluations in ISIS-2: 2237 (60%) decisions were taken solely on angiogram and expressed no need for further evaluation with adjunctive tools. This rate of angiographic reliance was significantly reduced in ISIS-2 as compared with ISIS-1 (3139 [71%]; p&amp;lt;0.001). Here the decision (significant or non-significant) was discordant with the known functional significance in 870 (39%) cases, markedly less as in ISIS-1 (1459, 46%; p&amp;lt;0.001). In ISIS-2, participants expressed the need for either invasive functional assessment or intravascular imaging in 1110 (29%) and 379 (11%) cases, respectively. These rates were significantly higher as compared with ISIS-1 (928 [21%]; p&amp;lt;0.001 and 354 [8%]; p&amp;lt;0.001, respectively). Conclusions ISIS-2 survey suggests an evolving pattern over 6 years in the intention to integrate coronary angiography with invasive coronary physiology and imaging testing in patients with CCS. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Unrestricted grant from Abbott Medical

Diagnostic accuracy of intracoronary optical coherence tomography-derived fractional flow reserve for assessment of coronary stenosis severity.

A novel method for computation of fractional flow reserve (FFR) from optical coherence tomography (OCT) was developed recently. This study aimed to evaluate the diagnostic accuracy of a new OCT-based FFR (OFR) computational approach, using wire-based FFR as the reference standard. Patients who underwent both OCT and FFR prior to intervention were analysed. The lumen of the interrogated vessel and the ostia of the side branches were automatically delineated and used to compute OFR. Bifurcation fractal laws were applied to correct the change in reference lumen size due to the step-down phenomenon. OFR was compared with FFR, both using a cut-off value of 0.80 to define ischaemia. Computational analysis was performed in 125 vessels from 118 patients. Average FFR was 0.80±0.09. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for OFR to identify FFR ≤0.80 was 90% (95% CI: 84-95), 87% (95% CI: 77-94), 92% (95% CI: 82-97), 92% (95% CI: 82-97), and 88% (95% CI: 77-95), respectively. The AUC was higher for OFR than minimal lumen area (0.93 [95% CI: 0.87-0.97] versus 0.80 [95% CI: 0.72-0.86], p=0.002). Average OFR analysis time was 55±23 seconds for each OCT pullback. Intra- and inter-observer variability in OFR analysis was 0.00±0.02 and 0.00±0.03, respectively. OFR is a novel and fast method allowing assessment of flow-limiting coronary stenosis without pressure wire and induced hyperaemia. The good diagnostic accuracy and low observer variability bear the potential of improved integration of intracoronary imaging and physiological assessment.

Comparison of Different Diastolic Resting Indexes to iFR: Are They All Equal?

BackgroundPressure measurement for the duration of the wave-free period (WFP) is considered essential for resting-state physiological assessment of coronary stenosis severity using the instantaneous wave-free ratio (iFR). ObjectivesThe aim of this study was to compare other diastolic resting indexes to iFR. MethodsIn the population of the VERIFY2 (Pd/Pa vs iFR in an Unselected Population Referred for Invasive Angiography) study, iFR calculated by proprietary software (Volcano Harvest, Volcano Corporation, Rancho Cordova, California) was compared with the ratio of resting distal coronary pressure and aortic pressure during the complete duration of diastole (dPR), 25% to 75% of diastole (dPR25–75), and midpoint of diastole (dPRmid), along with Matlab calculated iFR (iFRmatlab) and iFR-like indexes shortening the length of the WFP by 50 and 100 ms (iFR−50ms and iFR−100ms), respectively. Mutual differences, Spearman correlations, area under the curve values from receiver-operating characteristic analyses, and diagnostic performance with respect to iFR and fractional flow reserve (FFR) were calculated for all indexes. ResultsMedian iFR in 197 patients with 257 vessels was 0.91 with an interquartile range of 0.87 to 0.95. The mutual differences (± SD) with iFR were 0.006 ± 0.011 (dPR), 0.001 ± 0.007 (dPR25–75), 0.001 ± 0.008 (dPRmid), 0.005 ± 0.009 (iFRmatlab), 0.003 ± 0.008 (iFR−50ms), and 0.001 ± 0.009 (iFR−100ms). Correlations for all indexes with iFR were >0.99 (p < 0.001 for all). Area under the curve values for predicting iFR were >0.99 for all indexes as well. Diagnostic accuracy compared with FFR was 76% to 77% for all indexes including iFR. ConclusionsAll diastolic resting indexes tested were identical to iFR, both numerically and with respect to their agreement with FFR. A numerically equal value to iFR can be determined without restriction to the WFP. Cutoff values, guidelines, and clinical recommendations for iFR can therefore be extended to these other indexes. (Pd/Pa vs iFR in an Unselected Population Referred for Invasive Angiography [VERIFY2]; NCT02377310)

TCT-70 Influence of microcirculatory resistance on the assessment of coronary stenosis severity with Quantitative Flow Ratio (QFR): Results of an international multicentre study

QFR, an angiographic index of stenosis severity based on computational fluid dynamics, estimates fractional flow reserve (FFR) without coronary instrumentation. Although QFR incorporates TIMI frame count as a surrogate of flow, it is unknown whether QFR is influenced by microvascular dysfunction. We

The relationship between coronary artery distensibility and fractional flow reserve.

Discordance between angiography-based anatomical assessment of coronary stenosis severity and fractional flow reserve (FFR) has been attributed to several factors including lesion length and irregularity, and the myocardial territory supplied by the target vessel. We sought to examine if coronary arterial distensibility is an independent contributor to this discordance. There were two parts to this study. The first consisted of “in silico” models of 26 human coronary arteries. Computational fluid dynamics-derived FFR was calculated for fully rigid, partially distensible and fully distensible models of the 26 arteries. The second part of the study consisted of 104 patients who underwent coronary angiography and FFR measurement. Distensibility at the lesion site (DistensibilityMLA) and for the reference vessel (DistensibilityRef) was determined by analysing three-dimensional angiography images during end-systole and end-diastole. Computational fluid dynamics-derived FFR was 0.67±0.19, 0.70±0.18 and 0.75±0.17 (P<0.001) in the fully rigid, partially distensible and fully distensible models respectively. FFR correlated with both DistensibilityMLA (r = 0.36, P<0.001) and DistensibilityRef (r = 0.44, P<0.001). Two-way ANCOVA analysis revealed that DistensibilityMLA (F (1, 100) = 4.17, p = 0.031) and percentage diameter stenosis (F (1, 100) = 60.30, p < 0.01) were both independent predictors of FFR. Coronary arterial distensibility is a novel, independent determinant of FFR, and an important factor contributing to the discordance between anatomical and functional assessment of stenosis severity.

Reliability of physiological assessment of coronary stenosis severity using intracoronary pressure techniques: a comprehensive analysis from a large cohort of consecutive intermediate coronary lesions.

We sought to assess the reliability of the most frequently used intracoronary physiologic indices (including intravenous adenosine FFR [IV-FFR], intracoronary low-dose adenosine FFR [LD-IC-FFR], intracoronary high-dose adenosine FFR [HD-IC-FFR], Pd/Pa and iFR). We also sought to analyse factors affecting their reproducibility in a real-world patient population. A total of 91 lesions in 86 consecutive patients were included. Measurements of all physiological indices were repeated within a systematic standardised prospective protocol. All measured indices showed excellent test-retest reliability, with intraclass correlation coefficient (ICC) over 0.96. IV-FFR showed the highest coefficient of variation (CV) values among the studied measurements (Pd/Pa: 0.05; iFR: 0.10; LD-IC-FFR: 0.10; HD-IC-FFR: 0.08; IV-FFR: 0.12). Pd/Pa was significantly less variable than the other indices. On multivariate analysis, female gender, distal lesion location, history of hypertension or kidney failure, as well as presentation as an acute coronary syndrome, were associated with more variability in all physiological intracoronary measurements. The reliability of most frequently used intracoronary physiologic indices is high. Clinical and anatomic factors significantly influence the reliability of these physiologic indices.

Serum thioredoxin activity: a promising biomarker for assessment of coronary stenosis severity in patients with coronary artery disease

Serum thioredoxin activity: a promising biomarker for assessment of coronary stenosis severity in patients with coronary artery disease

Coronary Computed Tomographic Angiography Does Not Accurately Predict the Need of Coronary Revascularization in Patients with Stable Angina.

PurposeTo evaluate the ability of coronary computed tomographic angiography (CCTA) to predict the need of coronary revascularization in symptomatic patients with stable angina who were referred to a cardiac catheterization laboratory for coronary revascularization.Materials and MethodsPre-angiography CCTA findings were analyzed in 1846 consecutive symptomatic patients with stable angina, who were referred to a cardiac catheterization laboratory at six hospitals and were potential candidates for coronary revascularization between July 2011 and December 2013. The number of patients requiring revascularization was determined based on the severity of coronary stenosis as assessed by CCTA. This was compared to the actual number of revascularization procedures performed in the cardiac catheterization laboratory.ResultsBased on CCTA findings, coronary revascularization was indicated in 877 (48%) and not indicated in 969 (52%) patients. Of the 877 patients indicated for revascularization by CCTA, only 600 (68%) underwent the procedure, whereas 285 (29%) of the 969 patients not indicated for revascularization, as assessed by CCTA, underwent the procedure. When the coronary arteries were divided into 15 segments using the American Heart Association coronary tree model, the sensitivity, specificity, positive predictive value, and negative predictive value of CCTA for therapeutic decision making on a per-segment analysis were 42%, 96%, 40%, and 96%, respectively.ConclusionCCTA-based assessment of coronary stenosis severity does not sufficiently differentiate between coronary segments requiring revascularization versus those not requiring revascularization. Conventional coronary angiography should be considered to determine the need of revascularization in symptomatic patients with stable angina.

Combining Baseline Distal-to-Aortic Pressure Ratio and Fractional Flow Reserve in the Assessment of CoronaryStenosis Severity.

This study sought to understand the physiological basis of baseline distal-to-aortic pressure ratio (Pd/Pa) and fractional flow reserve (FFR) agreement and discordance, using coronary flow reserve (CFR), stenosis resistance, and microcirculatory resistance measurements, and form there, to investigate the potential value of combining Pd/Pa with FFR in the diagnostic rationale. Pd/Pa is always available before FFR assessment, and emerging data supports the notion that baseline indices can determine the ischemic potential of coronary stenosis in selected subsets. A total of 467 stenosed vessels from 363 patients were investigated with pressure and flow sensors during baseline and hyperemia: 168 vessels (135 patients) with thermodilution-derived flow, and 299 vessels (228 patients) with Doppler-derived flow. Pd/Pa correlated more strongly with CFR than FFR (ρ difference= 0.129; p for ρ comparison<0.001). Although Pd/Pa and FFR were closely correlated (ρ= 0.798; 95% confidence interval: 0.767 to 0.828), categorical discordance was observed in 19.3% of total vessels. Such discordance was associated with the patients' clinical profile and was characterized by contrastive changes in stenosis resistance, microcirculatory resistance, and the underlying CFR. Notably, all stenosis with Pd/Pa≤0.83 (n= 74, 15.8%) progressed to FFR≤0.80, and although no Pd/Pa cutoff was able to exclude the development of FFR≤0.80 in the high end of values, only 15 (10.1%) vessels with Pd/Pa≥0.96 (n=149,31.9%) developed FFR≤0.80, from which none had definite ischemia, as defined by CFR≤1.74. Combining baseline Pd/Pa with FFR seems to provide a more comprehensive physiological examination of stenosed coronary arteries and a closer pressure-based appraisal of the flow reserve of the downstream myocardialbed.

TCT-303 Diagnostic Performance of Instantaneous Wave-Free Ratio for Physiological Assessment of Coronary Stenosis Severity: A Bivariate Meta-analysis

Instantaneous Wave-free Ratio (iFR) is a novel technology for physiological assessment of severity of coronary stenosis that precludes the use of adenosine. Conversely, Fractional Flow Reserve (FFR), which is generally considered the reference standard, uses adenosine. We sought to evaluate the

TCT-300 Combining baseline distal-to-aortic pressure ratio and fractional flow reserve in the assessment of coronary stenosis severity

TCT-300 Combining baseline distal-to-aortic pressure ratio and fractional flow reserve in the assessment of coronary stenosis severity

Physiological assessment of coronary lesion severity: fractional flow reserve versus nonhyperaemic indices.

Coronary angiography alone cannot accurately identify the haemodynamic impact of a coronary artery stenosis. Current international guidelines for myocardial revascularization recommend that inducible ischaemia should be demonstrated before the consideration of percutaneous coronary intervention. Invasive physiological assessment of coronary stenosis severity has increasingly been utilized for this purpose and use of the best validated technique, fractional flow reserve (FFR), has been shown to improve clinical outcomes in patients with stable and unstable coronary artery disease. This has led to the use of FFR being recommended in international revascularization guidelines, despite which, clinical uptake has been limited. One potential reason for slow adoption has been the requirement for maximal hyperaemia at the time of FFR measurement, usually achieved by the administration of pharmacological vasodilators such as adenosine. In some healthcare systems, adenosine is expensive and, in addition, its use can be associated with significant, albeit transient, adverse effects that patients (and some operators) find uncomfortable. Consequently, several methods of nonhyperaemic lesion assessment and their potential role in decision making have been reported. In this review we will review and discuss the current evidence for hyperaemic and nonhyperaemic methods of lesion assessment. We will also look at hybrid strategies that utilize both hyperaemic and nonhyperaemic methods as a means of potentially maintaining diagnostic accuracy while minimizing the requirement for adenosine administration and discuss whether or not they represent viable clinical alternatives.

Is Hyperaemia Essential for Accurate Functional Assessment of Coronary Stenosis Severity?

Fractional flow reserve (FFR) requires the use of maximal hyperaemia as described in the original preclinical and clinical validation studies and subsequent practice changing randomized controlled trials. A perception that the need for hyperaemia (usually induced with adenosine) was one of the obstacles to more widespread adoption of FFR has led to interest in the use of resting non-hyperaemic indices to assess the functional significance of coronary stenoses. We examine the current evidence base and conclude that resting indices agree with FFR in only 80 % of lesions when a binary cut-off is employed but closer to 90 % when hybrid strategies utilising both resting indices and FFR are utilised. It seems counter intuitive to sacrifice diagnostic accuracy when in most patients and healthcare systems the induction of hyperaemia with adenosine is safe and emminently affordable.

Fractional flow reserve versus angiography in guiding management to optimize outcomes in non–ST-elevation myocardial infarction (FAMOUS-NSTEMI): Rationale and design of a randomized controlled clinical trial

BackgroundIn patients with acute non–ST-elevation myocardial infarction (NSTEMI), coronary arteriography is usually recommended; but visual interpretation of the angiogram is subjective. We hypothesized that functional assessment of coronary stenosis severity with a pressure-sensitive guide wire (fractional flow reserve [FFR]) would have additive diagnostic, clinical, and health economic utility as compared with angiography-guided standard care.Methods and designA prospective multicenter parallel-group 1:1 randomized controlled superiority trial in 350 NSTEMI patients with ≥1 coronary stenosis ≥30% severity (threshold for FFR measurement) will be conducted. Patients will be randomized immediately after coronary angiography to the FFR-guided group or angiography-guided group. All patients will then undergo FFR measurement in all vessels with a coronary stenosis ≥30% severity including culprit and nonculprit lesions. Fractional flow reserve will be disclosed to guide treatment in the FFR-guided group but not disclosed in the “angiography-guided” group. In the FFR-guided group, an FFR ≤0.80 will be an indication for revascularization by percutaneous coronary intervention or coronary artery bypass surgery, as appropriate. The primary outcome is the between-group difference in the proportion of patients allocated to medical management only compared with revascularization. Secondary outcomes include the occurrence of cardiac death or hospitalization for myocardial infarction or heart failure, quality of life, and health care costs. The minimum and average follow-up periods for the primary analysis are 6 and 18 months, respectively.ConclusionsOur developmental clinical trial will address the feasibility of FFR measurement in NSTEMI and the influence of FFR disclosure on treatment decisions and health and economic outcomes.

The haemodynamic response to intravenous adenosine and its impact on fractional flow reserve: results of the AFFECTS (Adenosine For the Functional assEssment of Coronary sTenosis Severity) study

The haemodynamic response to intravenous adenosine and its impact on fractional flow reserve: results of the AFFECTS (Adenosine For the Functional assEssment of Coronary sTenosis Severity) study