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

AIMS: 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). METHODS AND RESULTS: 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. CONCLUSIONS: 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].

Influence of Obesity on Coronary Artery Disease and Clinical Outcomes in the ADVANCE Registry.

BACKGROUND: The relationship between body size and cardiovascular events is complex. This study utilized the ADVANCE (Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care) Registry to investigate the association between body mass index (BMI), coronary artery disease (CAD), and clinical outcomes. METHODS: The ADVANCE registry enrolled patients undergoing evaluation for clinically suspected CAD who had >30% stenosis on cardiac computed tomography angiography. Patients were stratified by BMI: normal <25 kg/m2, overweight 25-29.9 kg/m2, and obese ≥30 kg/m2. Baseline characteristics, cardiac computed tomography angiography and computed tomography fractional flow reserve (FFRCT), were compared across BMI groups. Adjusted Cox proportional hazards models assessed the association between BMI and outcomes. RESULTS: Among 5014 patients, 2166 (43.2%) had a normal BMI, 1883 (37.6%) were overweight, and 965 (19.2%) were obese. Patients with obesity were younger and more likely to have comorbidities, including diabetes and hypertension (all P<0.001), but were less likely to have obstructive coronary stenosis (65.2% obese, 72.2% overweight, and 73.2% normal BMI; P<0.001). However, the rate of hemodynamic significance, as indicated by a positive FFRCT, was similar across BMI categories (63.4% obese, 66.1% overweight, and 67.8% normal BMI; P=0.07). Additionally, patients with obesity had a lower coronary volume-to-myocardial mass ratio compared with patients who were overweight or had normal BMI (obese BMI, 23.7; overweight BMI, 24.8; and normal BMI, 26.3; P<0.001). After adjustment, the risk of major adverse cardiovascular events was similar regardless of BMI (all P>0.05). CONCLUSIONS: Patients with obesity in the ADVANCE registry were less likely to have anatomically obstructive CAD by cardiac computed tomography angiography but had a similar degree of physiologically significant CAD by FFRCT and similar rates of adverse events. An exclusively anatomic assessment of CAD in patients with obesity may underestimate the burden of physiologically significant disease that is potentially due to a significantly lower volume-to-myocardial mass ratio.

Evolving Developments in Cardiac CT.

In this review, the authors describe some of the latest cardiac CT advances in the evaluation of cardiovascular disease. This includes automated coronary plaque quantification and subtyping, and cardiac CT fractional flow reserve and CT perfusion as techniques to noninvasively assess the physiologic significance of coronary stenosis. The authors also focus on noncoronary applications involving the expanding role of cardiac CT in structural heart disease interventions. Developments in cardiac CT for the evaluation of diffuse myocardial fibrosis and infiltrative cardiomyopathy and for functional analysis of myocardial contractile dysfunction are discussed. Finally, the authors review studies evaluating photon-counting CT in cardiac disease.

Chest Pain Evaluation: Diagnostic Testing.

Chest pain/discomfort (CP) is a common symptom and can be a diagnostic dilemma for many clinicians. The misdiagnosis of an acute or progressive chronic cardiac etiology may carry a significant risk of morbidity and mortality. This review summarizes the different options and modalities for establishing the diagnosis and severity of coronary artery disease. An effective test selection algorithm should be individually tailored to each patient to maximize diagnostic accuracy in a timely fashion, determine short- and long-term prognosis, and permit implementation of evidence-based treatments in a cost-effective manner. Through collaboration, a decision algorithm was developed (www.chowmd.ca/cadtesting) that could be adopted widely into clinical practice.

La douleur ou la gêne thoracique sont des symptômes fréquents qui peuvent poser un dilemme diagnostique pour de nombreux médecins. Les erreurs de diagnostic d'une cause aiguë ou chronique progressive d'origine cardiaque peuvent d'ailleurs entraîner un risque considérable de morbidité et de mortalité. La présente synthèse porte sur les différentes options et modalités d'établissement du diagnostic et de la gravité d'une coronaropathie. Un algorithme efficace pour le choix des tests doit être adapté à chaque patient afin de maximiser l'exactitude diagnostique dans les plus brefs délais, de déterminer le pronostic à court et à long terme, et de permettre une mise en œuvre de traitements fondés sur des données probantes tout en tenant compte des coûts. Un algorithme décisionnel a donc été conjointement mis au point (www.chowmd.ca/cadtesting) et pourrait être largement adopté dans la pratique clinique.

The Journal of cardiovascular computed tomography: A year in review 2021.

This review aims to summarize original articles published in the Journal of Cardiovascular Computed Tomography (JCCT) for the year 2021, focusing on those that had the most scientific and educational impact. The JCCT continues to expand; the number of submissions, published manuscripts, cited articles, article downloads, social media presence, and impact factor continues to increase. The articles selected by the Editorial Board of the JCCT in this review focus on coronary artery disease, coronary physiology, structural heart disease, and technical advances in cardiovascular CT. In addition, we highlight key consensus documents and guidelines published in the Journal in 2021. The Journal recognizes the tremendous work done by each author and reviewer this year - thank you.

Conventional versus modified delivery system technique in commissural alignment from the Evolut low-risk CT substudy.

OBJECTIVES: We assessed the impact of conventional delivery system (DS) insertion technique on "Hat-marker" orientation/commissural alignment in patients who underwent transcatheter aortic valve replacement (TAVR) in the Evolut Low Risk Trial CT substudy versus a modified technique. BACKGROUND: Unlike surgical aortic valve replacement, where alignment of the surgical valve commissures with native commissures can be achieved virtually 100% of the time, commissural alignment during TAVR is not achieved consistently. This may subsequently impact the feasibility of both coronary access and reintervention after TAVR. METHODS: "Hat-marker" orientations during deployment were characterized as outer curve (OC), center front (CF), inner curve, and center back. Severe commissure-to-CA overlap was 0-20°. "Hat-marker" orientations and CA overlap were compared to 240 patients from a single center using the modified 3-o'clock flush port DS technique. RESULTS: In the CT substudy in which conventional DS insertion was performed (flush port at 12 o'clock); 154/249 had both analyzable CT and procedural fluoroscopy to validate "Hat-marker" to C-tab/commissural orientation. On post-TAVR CT, Evolut valve commissural orientation and coronary artery (CA) ostia were identified. Compared to conventional DS technique in the CT substudy, the modified technique had higher rates of "Hat-marker" at OC/CF orientation, improved commissural alignment and reduced severe CA overlap; (left main, 14.2 vs. 27.9%; right coronary artery, 11.7 vs. 27.3% both, 5.0 vs. 13.6%; 1 or both CA, 20.8 vs. 41.6%, all p < 0.01). CONCLUSIONS: The modified technique improved initial "Hat-marker" orientation during Evolut deployment and resulted in better commissural alignment and reduced CA overlap.

CT Angiography Followed by Invasive Angiography in Patients With Moderate or Severe Ischemia-Insights From the ISCHEMIA Trial.

OBJECTIVES: This study aimed to examine the concordance of coronary computed tomographic angiography (CCTA) assessment of coronary anatomy and invasive coronary angiography (ICA) as the reference standard in patients enrolled in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches). BACKGROUND: Performance of CCTA compared with ICA has not been assessed in patients with very high burdens of stress-induced ischemia and a high likelihood of anatomically significant coronary artery disease (CAD). A blinded CCTA was performed after enrollment to exclude patients with left main (LM) disease or no obstructive CAD before randomization to an initial conservative or invasive strategy, the latter guided by ICA and optimal revascularization. METHODS: Rates of concordance were calculated on a per-patient basis in patients randomized to the invasive strategy. Anatomic significance was defined as ≥50% diameter stenosis (DS) for both modalities. Sensitivity analyses using a threshold of ≥70% DS for CCTA or considering only CCTA images of good-to-excellent quality were performed. RESULTS: In 1,728 patients identified by CCTA as having no LM disease ≥50% and at least single-vessel CAD, ICA confirmed 97.1% without LM disease ≥50%, 92.2% with at least single-vessel CAD and no LM disease ≥50%, and only 4.9% without anatomically significant CAD. Results using a ≥70% DS threshold or only CCTA of good-to-excellent quality showed similar overall performance. CONCLUSIONS: CCTA before randomization in ISCHEMIA demonstrated high concordance with subsequent ICA for identification of patients with angiographically significant disease without LM disease.

Ethnic differences in coronary anatomy, left ventricular mass and CT-derived fractional flow reserve.

BACKGROUND: Studies have observed higher incidence of cardiovascular mortality in South Asians (SA), and lower prevalence in East Asians (EA), compared with Caucasians. These observations are not entirely explained by ethnic differences in cardiovascular risk factors and mechanistic factors such as variations in cardiac anatomy and physiology may play a role. This study compared ethnic differences in CT-assessed left ventricular (LV) mass, coronary anatomy and non-invasive fractional flow reserve (FFRCT). METHODS: Three-hundred symptomatic patients (age 59 ± 7.9, male 51%) underwent clinically-mandated CT-coronary-angiography (CTA) were matched for age, gender, BMI and diabetes (100 each ethnicity). Assessment of coronary stenosis, luminal dimensions and vessel dominance was performed by independent observers. LV mass, coronary luminal volume and FFRCT were quantified by blinded core-laboratory. A sub-analysis was performed on patients (n = 187) with normal/minimal disease (0-25% stenosis). RESULTS: Stenosis severity was comparable across ethnic groups. EA demonstrated less left-dominant circulation (2%) compared with SA (8.2%) and Caucasians (10.1%). SA compared with EA and Caucasians demonstrated smallest indexed LV mass, coronary luminal volumes and dimensions. EA compared with Caucasians had comparable indexed LV mass, coronary luminal dimensions and highest luminal volumes. The latter was driven by higher prevalence of right-dominance including larger and longer right posterior left ventricular artery. FFRCT in the left anterior descending artery (LAD) was lowest in SA (0.87) compared with EA (0.89; P = 0.009) and Caucasians (0.89; P < 0.001), with no difference in other vessels. All observed differences were consistent in patients with minimal disease. CONCLUSION: This single-centre study identified significant ethnic differences in CT-assessed LV mass, coronary anatomy and LAD FFRCT. These hypotheses generating results may provide a mechanistic explanation for ethnic differences in cardiovascular outcomes and require validation in larger cohorts.

Alterra Adaptive Prestent and SAPIEN 3 THV for Congenital Pulmonic Valve Dysfunction: An Early Feasibility Study.

OBJECTIVES: The aim of this study was to demonstrate the safety and functionality of the Alterra Adaptive Prestent and SAPIEN 3 transcatheter heart valve (THV) in patients with dysfunctional, dilated right ventricular outflow tract (RVOT) greater or equal to moderate pulmonary regurgitation (PR). BACKGROUND: Significant variations in the size and morphology of the RVOT affect the placement of transcatheter pulmonary valves. The Alterra Prestent internally reduces and reconfigures the RVOT, providing a stable landing zone for the 29-mm SAPIEN 3 THV. METHODS: Eligible patients had moderate or greater PR, weighed >20 kg, and had RVOT diameter 27 to 38 mm and length >35 mm. The primary endpoint was device success, a 5-item composite: 1 Alterra Prestent deployed in the desired location, 1 SAPIEN 3 THV implanted in the desired location within the Prestent, right ventricular-to-pulmonary artery peak-to-peak gradient <35 mm Hg after THV implantation, less than moderate PR at discharge, and no explantation 24 h post-implantation. The secondary composite endpoint was freedom from THV dysfunction (RVOT/pulmonary valve (PV) reintervention, greater or equal to moderate total PR, mean RVOT/PV gradient ≥ 35 mm Hg at 30 days and 6 months. Descriptive statistics are reported. RESULTS: Enrolled patients (N = 15) had a median age and weight of 20 years and 61.7 kg, respectively; 93.3% were in New York Heart Association functional class I or II. Device success was 100%. No staged procedures were necessary. No THV dysfunction was reported to 6 months. No serious safety signals were reported. CONCLUSIONS: This early feasibility study demonstrated the safety and functionality of the Alterra Adaptive Prestent in patients with congenital RVOT dysfunction and moderate or greater PR. Durability and long-term outcome data are needed.

The Impact of Coronary Physiology on Contemporary Clinical Decision Making.

Physiological assessment of coronary artery disease (CAD) has become one of the cornerstones of decision making for myocardial revascularization, with a large body of evidence supporting the benefits of using fractional flow reserve and other pressure-based indexes for functional assessment of coronary stenoses. Furthermore, physiology allows the identification of specific vascular dysfunction mechanisms in patients without obstructive CAD. Currently, more than 10 modalities of functional coronary assessment are available, although the overall adoption of these physiological tools, of either intracoronary or image-based nature, is still low. In this paper the authors review these modalities of functional coronary assessment according to their timing of use: outside the catheterization laboratory, in the catheterization laboratory prior to the percutaneous coronary intervention (PCI), and in the catheterization laboratory during or after PCI. The authors discuss how the information obtained can be used in setting the indication for PCI, in planning and guiding the procedure, and in documenting the final functional result of the intervention. The advantages and limitations of each modality in each setting are discussed. Furthermore, the key value of intracoronary physiology in diagnosing mechanisms of microcirculatory dysfunction, which account for the presence of ischemia in many patients without obstructive CAD, is revisited. On the basis of the opportunities generated by the multiplicity of diagnostic tools described, the authors propose an algorithmic approach to physiological coronary investigations in clinical practice, with the key aims of: 1) avoiding unneeded revascularization procedures; 2) improving procedural PCI and long-term outcomes in patients with obstructive CAD; and 3) diagnosing vascular dysfunction mechanisms that can be effectively treated in patients with NOCAD. The authors believe that such structured approach may also contribute to the wider adoption of available technologies for functional assessment of patients with CAD.

Comparison Between the Performance of Quantitative Flow Ratio and Perfusion Imaging for Diagnosing Myocardial Ischemia.

OBJECTIVES: This study compared the performance of the quantitative flow ratio (QFR) with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) myocardial perfusion imaging (MPI) for the diagnosis of fractional flow reserve (FFR)-defined coronary artery disease (CAD). BACKGROUND: QFR estimates FFR solely based on cine contrast images acquired during invasive coronary angiography (ICA). Head-to-head studies comparing QFR with noninvasive MPI are lacking. METHODS: A total of 208 (624 vessels) patients underwent technetium-99m tetrofosmin SPECT and [15O]H2O PET imaging before ICA in conjunction with FFR measurements. ICA was obtained without using a dedicated QFR acquisition protocol, and QFR computation was attempted in all vessels interrogated by FFR (552 vessels). RESULTS: QFR computation succeeded in 286 (52%) vessels. QFR correlated well with invasive FFR overall (R = 0.79; p < 0.001) and in the subset of vessels with an intermediate (30% to 90%) diameter stenosis (R = 0.76; p < 0.001). Overall, per-vessel analysis demonstrated QFR to exhibit a superior sensitivity (70%) in comparison with SPECT (29%; p < 0.001), whereas it was similar to PET (75%; p = 1.000). Specificity of QFR (93%) was higher than PET (79%; p < 0.001) and not different from SPECT (96%; p = 1.000). As such, the accuracy of QFR (88%) was superior to both SPECT (82%; p = 0.010) and PET (78%; p = 0.004). Lastly, the area under the receiver operating characteristics curve of QFR, in the overall sample (0.94) and among vessels with an intermediate lesion (0.90) was higher than SPECT (0.63 and 0.61; p < 0.001 for both) and PET (0.82; p < 0.001 and 0.77; p = 0.002), respectively. CONCLUSIONS: In this head-to-head comparative study, QFR exhibited a higher diagnostic value for detecting FFR-defined significant CAD compared with perfusion imaging by SPECT or PET.

Reduced Cognitive Assessment Scores Among Individuals With Magnetic Resonance Imaging-Detected Vascular Brain Injury.

Background and Purpose- Little is known about the association between covert vascular brain injury and cognitive impairment in middle-aged populations. We investigated if scores on a cognitive screen were lower in individuals with higher cardiovascular risk, and those with covert vascular brain injury. Methods- Seven thousand five hundred forty-seven adults, aged 35 to 69 years, free of cardiovascular disease underwent a cognitive assessment using the Digital Symbol Substitution test and Montreal Cognitive Assessment, and magnetic resonance imaging (MRI) to detect covert vascular brain injury (high white matter hyperintensities, lacunar, and nonlacunar brain infarctions). Cardiovascular risk factors were quantified using the INTERHEART (A Global Study of Risk Factors for Acute Myocardial Infarction) risk score. Multivariable mixed models tested for independent determinants of reduced cognitive scores. The population attributable risk of risk factors and MRI vascular brain injury on low cognitive scores was calculated. Results- The mean age of participants was 58 (SD, 9) years; 55% were women. Montreal Cognitive Assessment and Digital Symbol Substitution test scores decreased significantly with increasing age (P<0.0001), INTERHEART risk score (P<0.0001), and among individuals with high white matter hyperintensities, nonlacunar brain infarction, and individuals with 3+ silent brain infarctions. Adjusted for age, sex, education, ethnicity covariates, Digital Symbol Substitution test was significantly lowered by 1.0 (95% CI, -1.3 to -0.7) point per 5-point cardiovascular risk score increase, 1.9 (95% CI, -3.2 to -0.6) per high white matter hyperintensities, 3.5 (95% CI, -6.4 to -0.7) per nonlacunar stroke, and 6.8 (95% CI, -11.5 to -2.2) when 3+ silent brain infarctions were present. No postsecondary education accounted for 15% (95% CI, 12-17), moderate and high levels of cardiovascular risk factors accounted for 19% (95% CI, 8-30), and MRI vascular brain injury accounted for 10% (95% CI, -3 to 22) of low test scores. Conclusions- Among a middle-aged community-dwelling population, scores on a cognitive screen were lower in individuals with higher cardiovascular risk factors or MRI vascular brain injury. Much of the population attributable risk of low cognitive scores can be attributed to lower educational attainment, higher cardiovascular risk factors, and MRI vascular brain injury.

Cardiovascular risk scoring and magnetic resonance imaging detected subclinical cerebrovascular disease.

AIMS: Cardiovascular risk factors are used for risk stratification in primary prevention. We sought to determine if simple cardiac risk scores are associated with magnetic resonance imaging (MRI)-detected subclinical cerebrovascular disease including carotid wall volume (CWV), carotid intraplaque haemorrhage (IPH), and silent brain infarction (SBI). METHODS AND RESULTS: A total of 7594 adults with no history of cardiovascular disease (CVD) underwent risk factor assessment and a non-contrast enhanced MRI of the carotid arteries and brain using a standardized protocol in a population-based cohort recruited between 2014 and 2018. The non-lab-based INTERHEART risk score (IHRS) was calculated in all participants; the Framingham Risk Score was calculated in a subset who provided blood samples (n = 3889). The association between these risk scores and MRI measures of CWV, carotid IPH, and SBI was determined. The mean age of the cohort was 58 (8.9) years, 55% were women. Each 5-point increase (∼1 SD) in the IHRS was associated with a 9 mm3 increase in CWV, adjusted for sex (P < 0.0001), a 23% increase in IPH [95% confidence interval (CI) 9-38%], and a 32% (95% CI 20-45%) increase in SBI. These associations were consistent for lacunar and non-lacunar brain infarction. The Framingham Risk Score was also significantly associated with CWV, IPH, and SBI. CWV was additive and independent to the risk scores in its association with IPH and SBI. CONCLUSION: Simple cardiovascular risk scores are significantly associated with the presence of MRI-detected subclinical cerebrovascular disease, including CWV, IPH, and SBI in an adult population without known clinical CVD.

Performance of the TRUE dilatation balloon valvuloplasty catheter beyond rated burst pressure: A bench study.

OBJECTIVES: We undertook an independent bench test assessing the performance of the TRUE dilatation (TD) balloon valvuloplasty catheter (Bard Vascular Inc., Tempe, AZ) beyond its rated burst pressure (RBP). BACKGROUND: The TD balloon has a RBP of six atmospheres (atm), and its performance beyond this RBP is poorly understood. Techniques such as bioprosthetic valve fracture require inflation pressures beyond manufacturer recommendations. METHODS: A 20, 22, 24, 26, and 28 mm TD balloon were inflated to increasing pressures in increments of 3 atm until balloon failure. Measurements were performed at the proximal, middle, and distal balloon segments with scientific digital calipers. Z-MED balloons (Braun Interventional Systems Inc., Bethlehem, PA) were used as a comparator. RESULTS: The mean diameter at the middle of the 20, 22, 24, 26, and 28 mm TD balloon at nominal pressure (3 atm) was 20.02 ± 0.09, 21.77 ± 0.07, 23.9 ± 0.06, 25.82 ± 0.08, and 27.62 ± 0.08 mm, respectively. The maximal mean diameter at the middle of the 20, 22, 24, 26, and 28 mm TD balloon was 20.39 ± 0.03 mm (15 atm), 22.35 ± 0.03 mm (15 atm), 24.55 ± 0.02 mm (15 atm), 26.48 ± 0.02 mm (12 atm), and 28.39 ± 0.03 mm (12 atm), respectively. The 20/22/24 and 26/28 mm balloon failed when inflated beyond 15 atm and 12 atm, respectively. Failure was due to either leakage or longitudinal balloon rupture. TD balloons were more likely to maintain dimensions similar to their labeled size and less likely to fail at higher pressures as compared to Z-MED balloons. CONCLUSION: The TD balloon catheter maintains a similar diameter to its labeled size, when inflated beyond its RBP. When inflated beyond 12 atm, the TD balloon can fail due to either leakage or rupture. This has implications for percutaneous structural heart interventions.

2019 Canadian Cardiovascular Society Position Statement for Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) or replacement has rapidly changed the treatment of patients with severe symptomatic aortic stenosis. It is now the standard of care for patients believed to be inoperable or at high surgical risk, and a reasonable alternative to surgical aortic valve replacement for those at intermediate surgical risk. Recent clinical trial data have shown the benefits of this technology in patients at low surgical risk as well. This update of the 2012 Canadian Cardiovascular Society TAVI position statement incorporates clinical evidence to provide a practical framework for patient selection that does not rely on surgical risk scores but rather on individual patient evaluation of risk and benefit from either TAVI or surgical aortic valve replacement. In addition, this statement features new wait time categories and treatment time goals for patients accepted for TAVI. Institutional requirements and recommendations for operator training and maintenance of competency have also been revised to reflect current standards. Procedural considerations such as decision-making for concomitant coronary intervention, antiplatelet therapy after intervention, and follow-up guidelines are also discussed. Finally, we suggest that all patients with aortic stenosis might benefit from evaluation by the heart team to determine the optimal individualized treatment decision.

Prognostic Value and Risk Continuum of Noninvasive Fractional Flow Reserve Derived from Coronary CT Angiography.

Background Coronary CT angiography with noninvasive fractional flow reserve (FFR) predicts lesion-specific ischemia when compared with invasive FFR. The longer term prognostic value of CT-derived FFR (FFRCT) is unknown. Purpose To determine the prognostic value of FFRCT when compared with coronary CT angiography and describe the relationship of the numeric value of FFRCT with outcomes. Materials and Methods This prospective subanalysis of the NXT study (Clinicaltrials.gov: NCT01757678) evaluated participants suspected of having stable coronary artery disease who were referred for invasive angiography and who underwent FFR, coronary CT angiography, and FFRCT. The incidence of the composite primary end point of death, myocardial infarction, and any revascularization and the composite secondary end point of major adverse cardiac events (MACE: cardiac death, myocardial infarction, unplanned revascularization) were compared for an FFRCT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFRCT result. Results Long-term outcomes were obtained in 206 individuals (age, 64 years ± 9.5), including 64% men. At median follow-up of 4.7 years, there were no cardiac deaths or myocardial infarctions in participants with normal FFRCT. The incidence of the primary end point was more frequent in participants with positive FFRCT compared with clinically significant stenosis at coronary CT angiography (73.4% [80 of 109] vs 48.7% [91 of 187], respectively; P < .001), with the majority of outcomes being planned revascularization. Corresponding hazard ratios (HRs) were 9.2 (95% confidence interval [CI]: 5.1, 17; P < .001) for FFRCT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFRCT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFRCT, 0.76 vs coronary CT angiography, 0.54; P < .001) and MACE (FFRCT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFRCT compared with coronary CT angiography (15.6% [17 of 109] vs 10.2% [19 of 187], respectively; P = .02), driven by unplanned revascularization. MACE HR was 5.5 (95% CI: 1.6, 19; P = .006) for FFRCT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFRCT reduction was independently associated with greater incidence of primary end point (HR, 1.7; 95% CI: 1.4, 1.9; P < .001) and MACE (HR, 1.4; 95% CI: 1.1, 1.8; P < .001). Conclusion In stable patients referred for invasive angiography, a CT-derived fractional flow reserve (FFRCT) value of 0.8 or less was a predictor of long-term outcomes driven by planned and unplanned revascularization and was superior to clinically significant stenosis on coronary CT angiograms. Additionally, the numeric value of FFRCT was an independent predictor of outcomes. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Dennie and Rubens in this issue.