Fractional Flow Reserve Derived From Computed Tomography Research Articles

Feasibility and Utility of Anatomical and Physiological Evaluation of Coronary Disease With Cardiac CT in Severe Aortic Stenosis (FUTURE-AS Registry): Rationale and Design

BackgroundCoronary artery disease (CAD) in patients with severe aortic stenosis (AS) is common and may be associated with worse outcomes. Computed tomography coronary angiography (CTCA) and fractional flow reserve derived from computed tomography (FFRCT) are tools for comprehensive coronary assessment. The utility and safety of CTCA and FFRCT in the work-up for transcatheter aortic valve replacement (TAVR) is not established, especially in an evolving landscape that involves younger TAVR patients. The FUTURE-AS Registry will assess the utility and safety of cardiac-optimized CTCA and FFRCT to evaluate CAD and guide referral for downstream invasive coronary angiography (ICA) in patients with severe AS being considered for TAVR. MethodsFUTURE-AS is an international, prospective, multicenter registry of patients with severe AS referred for TAVR being assessed for CAD with CTCA and FFRCT. The primary end point is the per-patient sensitivity and negative predictive value of CTCA and FFRCT for identifying anatomical and physiologically significant CAD compared to ICA and invasive FFR. The safety end point is the incidence of symptomatic hypotension or bradycardia requiring intervention following the administration of nitroglycerin or β-blocker medications. Feasibility end points include the incidence of noninterpretable CTCA scans and CTCA scans not adequate for FFR analysis. Other utility end points include specificity, positive predictive value, and accuracy of CTCA and FFRCT. Lastly, the potential of a CTCA and FFRCT guided strategy to defer pre-TAVR ICA will be assessed. ConclusionsFUTURE-AS will characterize the utility, safety, and feasibility of CTCA and FFRCT for coronary assessment pre-TAVR.

Derivation and validation of a novel functional FFRCT score incorporating the burden of coronary stenosis severity and flow impairment to predict clinical events

BackgroundA score combining the burden of stenosis severity on coronary computed tomography angiography (CCTA) and flow impairment by fractional flow reserve derived from computed tomography (FFRCT) may be a better predictor of clinical events than either parameter alone. MethodsThe Functional FFRCT Score (FFS) combines CCTA and FFRCT parameters in an allocated point-based system. The feasibility of the FFS was assessed in cohort of 72 stable chest pain patients with matched CCTA and FFRCT datasets. Validation was performed using 2 cohorts: (a) 4468 patients from the ADVANCE Registry to define its association with revascularization and major adverse cardiovascular events (MACE); (b) 212 patients from the FORECAST trial to determine predictors of MACE. ResultsThe median calculation time for the FFS was 10 (interquartile range 6–17) seconds, with strong intra-operator and inter-operator agreement (Cohen's Kappa 0.89 (±0.37, p ​< ​0.001) and 0.83 (±0.04, p ​< ​0.001, respectively). The FFS correlated strongly with both the CT-SYNTAX and the Functional CT-SYNTAX scores (rS ​= ​0.808 for both, p ​< ​0.001).In the ADVANCE cohort the FFS had good discriminatory abilities for revascularization with an area under the curve of 0.82, 95 ​% confidence interval (CI) 0.81–0.84, p ​< ​0.001. Patients in the highest FFS tertile had significantly higher rates of revascularization (61 ​% vs 5 ​%, p ​< ​0.001) and MACE (1.9 ​% vs 0.5 ​%, p ​= ​0.001) compared with the lowest FFS tertile.In the FORECAST cohort the FFS was an independent predictor of MACE at 9-month follow-up (hazard ratio 1.04, 95 ​% CI 1.01–1.08, p ​< ​0.01). ConclusionThe FFS is a quick-to-calculate and reproducible score, associated with revascularization and MACE in two distinct populations of stable symptomatic patients.

Pericoronary fat attenuation index and coronary plaque quantified from coronary computed tomography angiography identify ischemia-causing lesions

BackgroundThe association between pericoronary fat attenuation index (FAI), plaque characteristics, and lesion-specific ischemia identified by fractional flow reserve (FFR) remains unclear. MethodsCoronary computed tomography angiography (CCTA) stenosis, FAI, plaque characteristics, FFR derived from computed tomography (FFRCT) and FFR were assessed in 280 vessels of 247 patients. Stenosis ≥50% was considered obstructive. Optimal thresholds of FAI and plaque variables were defined by the area under the receiver-operating characteristics curve (AUC) analysis. Ischemia was defined by FFR ≤ 0.80. ResultsFAI ≥ −71.9 HU, low-attenuation plaque (LAP) ≥ 49.62 mm3 and aggregate plaque volume (APV) ≥ 28.91% predicted ischemia independent of other plaque characteristics. The addition of FAI ≥ −71.9 HU improved discrimination (AUC, 0.720 vs. 0.674, P = 0.035) and reclassification abilities (category-free net reclassification index [NRI], 0.470, P < 0.001; relative integrated discrimination improvement [IDI], 0.047, P < 0.001) of ischemia compared with stenosis evaluation alone, with further discrimination (AUC, 0.772 vs. 0.720, P = 0.028) and reclassification abilities (NRI, 0.385, P = 0.001; relative IDI, 0.077, P < 0.001) of ischemia by adding information regarding LAP ≥49.62 mm3 + APV ≥ 28.91%. And the diagnostic performance of combination approach was comparable to that of FFRCT alone (AUC, 0.772 vs. 0.762, P = 0.771). ConclusionsStenosis severity, FAI, plaque characteristics predicted lesion-specific ischemia. The combination of FAI and plaque assessment improved the discrimination of ischemia compared with stenosis assessment alone.

Diagnostic concordance and discordance between angiography-based quantitative flow ratio and fractional flow reserve derived from computed tomography in complex coronary artery disease

BackgroundBoth quantitative flow ratio (QFR) and fractional flow reserve derived from computed tomography (FFRCT) have shown significant correlations with invasive wire-based fractional flow reserve. However, the correlation between QFR and FFRCT is not fully investigated in patients with complex coronary artery disease (CAD). The aim of this study is to investigate the correlation and agreement between QFR and FFRCT in patients with de novo three-vessel disease and/or left main CAD. MethodsThis is a post-hoc sub-analysis of the international, multicenter, and randomized SYNTAX III REVOLUTION trial, in which both invasive coronary angiography and coronary computed tomography angiography were prospectively obtained prior to the heart team discussion. QFR was performed in an independent core laboratory and compared with FFRCT analyzed by HeartFlow™. The correlation and agreement between QFR and FFRCT were assessed per vessel. Furthermore, independent factors of diagnostic discordance between QFR and FFRCT were evaluated. ResultsOut of 223 patients, 40 patients were excluded from this analysis due to the unavailability of FFRCT and/or QFR, and a total of 469 vessels (183 patients) were analyzed. There was a strong correlation between QFR and FFRCT (R ​= ​0.759; p ​< ​0.001), and the Bland-Altman analysis demonstrated a mean difference of −0.005 and a standard deviation of 0.116. An independent predictor of diagnostic concordance between QFR and FFRCT was the lesion location in right coronary artery (RCA) (odds ratio 0.395; 95% confidence interval 0.174–0.894; P ​= ​0.026). ConclusionIn patients with complex CAD, QFR and FFRCT were strongly correlated. The location of the lesion in RCA was associated with the highest diagnostic concordance between QFR and FFRCT.

Diagnostic performance of fractional flow reserve derived from computed tomography in the stented coronary arteries

Abstract Background The current system of HeartFlow fractional flow reserve derived from computed tomography (FFRCT) is not available for stented coronary arteries. However, the latest version of HeartFlow FFRCT has the potential of rendering an accurate assessment for stented coronary arteries. Objectives To evaluate the feasibility of FFRCT for the stented coronary arteries. Methods We retrospectively enrolled patients with a history of coronary stent implantation who underwent invasive fractional flow reserve (FFR) for the stented coronary arteries within 3 months after coronary computed tomographic angiography (cCTA). As a subgroup analysis, we analyzed optical coherence tomography (OCT) images in patients who underwent OCT for stented vessels. OCT was performed as a part of the Kobe University Hospital OCT registry, which is a single-centre registry of consecutive patients who underwent OCT for the coronary arteries. The diagnostic performance of HeartFlow FFRCT for stented vessels was evaluated by comparing with that of cCTA alone. Minimum lumen area (MLA) within stent segments derived from cCTA was also compared with MLA derived from optical coherence tomography (OCT). Results A total of 30 vessels in 23 patients were studied. The diagnostic accuracy, sensitivity, specificity, positive and negative predictive value of FFRCT for myocardial ischemia using invasive FFR as a reference standard was 73.3%, 88.9%, 67.7%, 53.3% and 93.3%, respectively. FFRCT provided superior diagnostic performance than cCTA alone (p=0.016). FFRCT was significantly correlated with the invasive FFR (r=0.620, p&amp;lt;0.001), and Bland-Altman plot showed a mean bias of −0.041 with 95% limit of agreement of −0.173 to 0.092 (Figure 1). Among a total of 30 studied vessels, OCT was available for 25 vessels. MLA derived from cCTA correlated significantly with that derived from OCT (r=0.695, p&amp;lt;0.001), and Bland-Altman plot showed a mean bias of −0.32 mm2 with 95% limit of agreement of −2.89 to 2.25 mm2 (Figure 2). Conclusions The latest version of the HeartFlow FFRCT has the potential to be available for stented coronary arteries. Further investigation is required to elaborate our results. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Site vs. core laboratory variability in computed tomographic angiography-derived SYNTAX scores in the SYNTAX III trial

To investigate the variability between site and core laboratory (CL) calculation of the anatomical SYNTAX score (SS) based on coronary computed tomography angiography (CTA) alone and functional SS based on coronary CTA and fractional flow reserve derived from computed tomography (FFRCT) in the SYNTAX III trial. The SYNTAX III trial was a multicentre, international study that included 223 patients with three-vessel disease with or without left main involvement. Functional SS was computed by subtracting non-flow limiting stenoses (FFRCT > 0.80) from anatomical SS. SS was combined with clinical information to generate the SYNTAX score II (SS II) that provides treatment recommendations. The mean anatomical SS based on coronary CTA alone was 33.4 ± 12.7 by sites and 37.1 ± 13.4 by CL (P < 0.001). The mean functional SS based on coronary CTA and FFRCT was 30.5 ± 13.0 by sites and 33.3 ± 13.6 by CL (P < 0.001). The intraclass correlation coefficient was 0.49 [95% confidence interval (CI) 0.37-0.59) in anatomical SS and 0.62 (95% CI 0.52-0.70) in functional SS. The Cohen's κ comparing treatment recommendation between sites and CL was 0.68 (95% CI 0.58-0.78) based on anatomical SS and 0.71 (95% CI 0.60-0.82) based on functional SS. The mean anatomical SS derived from coronary CTA alone and functional SS based on coronary CTA and FFRCT were higher when assessed by the CL than by the sites themselves. However, substantial agreement in treatment recommendation by SS II between sites and CL was demonstrated. NCT02385279.

Visual Assessment Of Coronary Plaque Characteristics Improves The Utility Of FFRct

Introduction: Fractional flow reserve derived from computed tomography (FFRct) is used to evaluate hemodynamically significance in coronary stenosis on coronary CT angiography (CTA). However, the previous studies have shown that more than half of patients with intermediate stenosis have normal FFRct. We sought to see if visual plaque assessment on CTA improves the utility of FFRct. .

Impact of machine learning-based coronary computed tomography angiography fractional flow reserve on treatment decisions and clinical outcomes in patients with suspected coronary artery disease.

This study investigated the impact of machine learning (ML)-based fractional flow reserve derived from computed tomography (FFRCT) compared to invasive coronary angiography (ICA) for therapeutic decision-making and patient outcome in patients with suspected coronary artery disease (CAD). One thousand one hundred twenty-one consecutive patients with stable chest pain who underwent coronary computed tomography angiography (CCTA) followed ICA within 90 days between January 2007 and December 2016 were included in this retrospective study. Medical records were reviewed for the endpoint of major adverse cardiac events (MACEs). FFRCT values were calculated using an artificial intelligence (AI) ML platform. Disagreements between hemodynamic significant stenosis via FFRCT and severe stenosis on qualitative CCTA and ICA were also evaluated. After FFRCT results were revealed, a change in the proposed treatment regimen chosen based on ICA results was seen in 167 patients (14.9%). Over a median follow-up time of 26 months (4-48 months), FFRCT ≤ 0.80 was associated with MACE (HR, 6.84 (95% CI, 3.57 to 13.11); p < 0.001), with superior prognostic value compared to severe stenosis on ICA (HR, 1.84 (95% CI, 1.24 to 2.73), p = 0.002) and CCTA (HR, 1.47 (95% CI, 1.01 to 2.14, p = 0.045). Reserving ICA and revascularization for vessels with positive FFRCT could have reduced the rate of ICA by 54.5% and lead to 4.4% fewer percutaneous interventions. This study indicated ML-based FFRCT had superior prognostic value when compared to severe anatomic stenosis on CCTA and adding FFRCT may direct therapeutic decision-making with the potential to improve efficiency of ICA. • ML-based FFRCT shows superior outcome prediction value when compared to severe anatomic stenosis on CCTA. • FFRCT noninvasively informs therapeutic decision-making with potential to change diagnostic workflows and enhance efficiencies in patients with suspected CAD. • Reserving ICA and revascularization for vessels with positive FFRCT may reduce the normalcy rate of ICA and improve its efficiency.

P1252Diagnostic performance of quantitative flow ratio from coronary angiography versus fractional flow reserve from computed tomography

Abstract Background QFR and FFRCT are recently developed, less-invasive techniques for functional assessment of coronary artery disease. Objectives We compared the diagnostic performance between fractional flow reserve derived from computed tomography (FFRCT) and quantitative flow ratio (QFR) derived from coronary angiography, using FFR as the standard reference. Methods We measured FFRCT, QFR and FFR in 152 patients (233 vessels) with stable coronary artery disease. Results QFR was highly correlated with FFR (r=0.78, p&lt;0.001), while FFRCT was moderately correlated with FFR (r=0.63, p&lt;0.001). Both QFR and FFRCT showed good agreements with FFR, presenting small values of mean difference and root-mean-squared deviation (FFR -QFR: 0.02±0.09 and FFR -FFRCT: 0.03±0.11). The AUC of QFR was significantly greater than that of 3D-QCA-derived %DS (0.93 vs. 0.78; difference: 0.15; 95% CI: 0.09 to 0.20; p&lt;0.001). The AUC of FFRCTwas significantly greater than that of CCTA-derived %DS (0.82 vs. 0.70; difference: 0.12; 95% CI: 0.05 to 0.19; p&lt;0.001). The AUC of QFR was significantly greater than that of FFRCT (0.93 vs. 0.82; difference: 0.11; 95% CI: 0.05 to 0.16; p&lt;0.001). The sensitivity, specificity, positive predictive value, and negative predictive valueof QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% [95% confidence interval: 81% to 89%], while that of FFRCT≤0.80 for predicting FFR ≤0.80was 76% [95% confidence interval: 70% to 80%]. Figure 1. Comparison of FFR ≤0.80 predictors Conclusions Both QFR and FFRCTpossessed the ability to accurately evaluate the functional severity of coronary stenosis.

QFR Versus FFR Derived From Computed Tomography for Functional Assessment of Coronary Artery Stenosis

ObjectivesThe aim of this study was to compare diagnostic performance between quantitative flow ratio (QFR) derived from coronary angiography and fractional flow reserve derived from computed tomography (FFRCT) using fractional flow reserve (FFR) as the reference standard. BackgroundQFR and FFRCT are recently developed, less invasive techniques for functional assessment of coronary artery disease. MethodsQFR, FFRCT, and FFR were measured in 152 patients (233 vessels) with stable coronary artery disease. ResultsQFR was highly correlated with FFR (r = 0.78; p < 0.001), whereas FFRCT was moderately correlated with FFR (r = 0.63; p < 0.001). Both QFR and FFRCT showed moderately good agreement with FFR, presenting small values of mean difference but large values of root mean squared deviation (FFR-QFR, 0.02 ± 0.09; FFR-FFRCT, 0.03 ± 0.11). The sensitivity, specificity, positive predictive value, and negative predictive value of QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% (95% confidence interval [CI]: 81% to 89%), whereas that of FFRCT ≤0.80 for predicting FFR ≤0.80 was 76% (95% CI: 70% to 80%). ConclusionsQFR and FFRCT showed significant correlation with FFR. Mismatches between QFR and FFR and between FFRCT and FFR were frequent.

Coronary computed tomography angiography in coronary heart disease: clinical applications and limitations

Coronary computed tomography angiography (CCTA) is increasingly being used to assess patients with stable coronary artery disease (CAD) at low-intermediate risk because it has high sensitivity, specificity and negative predictive value for the detection of CAD. Technological advancements in the quantification and functional assessment of epicardial coronary stenosis by means of fractional flow reserve derived from computed tomography (FFRCT) have raised the possibility of expanding CCTA use to guide decision-making regarding revascularization strategies in CAD patients. Recent data have shown that initial diagnostic evaluation of coronary anatomy by CCTA vs standard of care in patients with suspected CAD is associated with lower rates of cardiac death or nonfatal myocardial infarction without long-term use of coronary angiography or coronary revascularization, suggesting a prognostic value of anatomic assessment in patients with suspected CAD. Good quality images are needed for reliable interpretations and results. Radiation exposure is still a concern.

Real World Utilization of Computed Tomography Derived Fractional Flow Reserve: Single Center Experience in the United States.

Fractional flow reserve derived from computed tomography (FFRct) has shown higher accuracy for detection of significant coronary artery disease (CAD) compared to coronary computed tomography angiography (CCTA). The performance of a combined comprehensive qualitative interpretation of both CCTA and FFRct in patient management is unknown. We aimed to explore the clinical application of this combined approach. We retrospectively reviewed cases referred to FFRct testing at our institution over a one-year period. Patients had documentation of whether invasive coronary angiography (ICA) was performed and revascularization were needed. Interpretations and recommendations of the adopted comprehensive approach (C-FFRct), that took into account focal versus diffuse disease, depth of ischemia and myocardium at risk, were compared to those of CCTA (binary > 50% stenosis) alone and FFRct binary approach (FFRct ≤ 0.8). C-FFRct performance was measured against the decision made upon revascularization. A total of 207 cases were referred to FFRct testing, 163 (79%) accepted and 44 (21%) rejected for quality. C-FFRct changed interpretations and recommendations of 39 (24%) and 14 (9%) CCTA and FFRct, respectively. ICA was deferred in 32 (59%) and 13 (32%) cases; whereas ICA referral rate was 7 (6%) and 1 (0.8%) cases, based on CCTA and FFRct, respectively. No major cardiac events were observed during follow up time (median = 6 months). C-FFRct sensitivity, specificity, and accuracy compared to decision upon revascularization were 89%, 79% and 82%. C-FFRct number needed to treat was 4, and 6, compared to CCTA and FFRct, respectively. FFRct is a feasible tool to improve the diagnostic performance of CCTA in CAD real-world workup. However, qualitative interpretation of the FFRct report combined with CCTA findings may yield more impactful results on patient management. Further prospective studies are warranted to validate the application of this approach and better define its components.

TCT-384 Diagnostic utility of noninvasive fractional flow reserve derived from coronary computed tomography angiography in patients with stable coronary artery disease

Noninvasive fractional flow reserve derived from computed tomography (FFRct) recently provided high diagnostic accuracy for detecting coronary artery disease (CAD). However, the feasibility of FFRct compared to invasive FFR measurements have not fully evaluated in entire coronary lesions. We

TCT-385 Diagnostic Performance of Noninvasive Fractional Flow Reserve derived from Computed Tomography in Diabetic Patients

Fractional flow reserve derived from computed tomography (FFRct) has high diagnostic performance in stable coronary artery disease (CAD). However the diagnostic performance of FFRct in diabetic patients, who are often difficult to evaluate the functional lesion severity because of morphological

Noninvasive FFR Derived From Coronary CT Angiography: Management and Outcomes in the PROMISE Trial

ObjectivesThe purpose of this study was to determine whether noninvasive fractional flow reserve derived from computed tomography (FFRCT) predicts coronary revascularization and outcomes and whether its addition improves efficiency of referral to invasive coronary angiography (ICA) after coronary computed tomography angiography (CTA). BackgroundFFRCT may improve the efficiency of an anatomic CTA strategy for stable chest pain. MethodsThis observational cohort study included patients with stable chest pain in the PROMISE (PROspective Multicenter Imaging Study for Evaluation of Chest Pain) trial referred to ICA within 90 days after CTA. FFRCT was measured at a blinded core laboratory, and FFRCT results were unavailable to caregivers. We determined the agreement of FFRCT (positive if ≤0.80) with stenosis on CTA and ICA (positive if ≥50% left main or ≥70% other coronary artery), and predictive value for a composite of coronary revascularization or major adverse cardiac events (death, myocardial infarction, or unstable angina). We retrospectively assessed whether adding FFRCT ≤0.80 as a gatekeeper could improve efficiency of referral to ICA, defined as decreased rate of ICA without ≥50% stenosis and increased ICA leading to revascularization. ResultsFFRCT was calculated in 67% (181 of 271) of eligible patients (mean age 62 years; 36% women). FFRCT was discordant with stenosis in 31% (57 of 181) for CTA and 29% (52 of 181) for ICA. Most patients undergoing coronary revascularization had an FFRCT of ≤0.80 (91%; 80 of 88). An FFRCT of ≤0.80 was a significantly better predictor for revascularization or major adverse cardiac events than severe CTA stenosis (HR: 4.3 [95% confidence interval [CI]: 2.4 to 8.9] vs. 2.9 [95% CI: 1.8 to 5.1]; p = 0.033). Reserving ICA for patients with an FFRCT of ≤0.80 could decrease ICA without ≥50% stenosis by 44%, and increase the proportion of ICA leading to revascularization by 24%. ConclusionsIn this hypothesis-generating study of patients with stable chest pain referred to ICA from CTA, an FFRCT of ≤0.80 was a better predictor of revascularization or major adverse cardiac events than severe stenosis on CTA. Adding FFRCT may improve efficiency of referral to ICA from CTA alone.

Long-term serial non-invasive multislice computed tomography angiography with functional evaluation after coronary implantation of a bioresorbable everolimus-eluting scaffold: the ABSORB cohort B MSCT substudy

Multimodality invasive imaging of the first-in-man cohort demonstrated at 5 years stable lumen dimensions and a low rate of major adverse cardiac events (MACE). However, the long-term non-invasive assessment of this device remains to be documented. The objective was to describe the 72-month multislice computed tomography (MSCT) angiographic and functional findings after the implantation of the second iteration of the fully resorbable everolimus-eluting polymeric scaffold. In the ABSORB Cohort B trial patients with non-complex de novo lesions were treated with second iteration bioresobable vascular scaffold (BVS). MSCT angiography was performed as an optional investigation at 18 months; patients were reconsented for a second investigation at 72 months. MSCT data were analysed at independent core laboratories for quantitative analysis of lumen dimensions and for calculation of fractional flow reserve derived from computed tomography (FFRCT). From the overall Cohort B (101 patients), 53 patients underwent MSCT imaging at 72 months. The MACE rate was 1.9% (1/53). At 72 months, the median minimal lumen area (MLA) was 4.05 mm2 (interquartile range [IQR]: 3.15-4.90) and the mean percentage area stenosis was 18% (IQR: 4.75-31.25), one scaffold was totally occluded. In 39 patients with paired MSCT analysis, the MLA significantly increased from the first to the second follow-up (Δ = 0.80 mm2, P = 0.002). The change in the median FFRCT scaffold gradient between time points was zero. The long-term serial non-invasive MSCT evaluation with FFRCT assessment after bioresorbable scaffold implantation confirmed in-scaffold late lumen enlargement with the persistence of normalization of the FFRCT. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00856856.

Enhanced diagnostic utility achieved by myocardial blood analysis: A meta-analysis of noninvasive cardiac imaging in the detection of functional coronary artery disease

AimThe aim of this study is to determine the diagnostic utility of 6 cardiac imaging modalities using fractional flow reserve (FFR) as the reference standard. MethodsStudies reporting diagnostic performance of computed tomographic perfusion imaging (CTP), fractional flow reserve derived from computed tomography (FFRCT), cardiac magnetic resonance (CMR), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and dobutamine stress echocardiography (DSE) for diagnosis of ischemia-causing lesions were included. ResultsOn vessel-based and patient-based analyses, CMR, PET, CTP and FFRCT exhibited comparable sensitivity (per-vessel: 87% vs. 86% vs. 89% vs. 86%; per-patient: 88% vs. 90% vs. 88% vs. 90%, P>0.05) and specificity (per-vessel: 89% vs. 88% vs. 89% vs. 83%; per-patient: 84% vs. 84% vs. 87% vs. 75%, P>0.05); whereas SPECT yielded significantly lower sensitivity (per-vessel: 72%; per-patient: 78%, P<0.05) and specificity (per-vessel: 79%; per-patient: 79%, P<0.05) and DES yielded significantly lower sensitivity (per-vessel: 62%, per-patient: 69%, P<0.05). On the other hand, within the same imaging modality, myocardial blood flow (MBF) derived by CTP had a higher sensitivity (90% vs. 80%, P=0.048) but lower specificity (77% vs. 93%, P=0.02) than that of perfusion defect (PD). Moreover, MBF derived by CMR had a lower specificity than that of PD (60% vs. 93%, P=0.02), while coronary flow reserve (CRF) derived by PET had a lower specificity than that of MBF (81% vs. 89%, P=0.005). ConclusionCMR, PET, CTP and FFRCT expressed similar and high accuracy in detecting functional CAD, whereas different analysis methods for each imaging modality may vary their diagnostic utility.