Impact of vessel morphology on computed tomography derived fractional flow reserve (FFRCT) in normal coronary artery disease: a novel marker for the predictor of FFRCT changes

Background

Computed tomography (CT) derived fractional flow reserve (FFRCT) decreases continuously from the proximal to the distal segments of the vessel even in normal coronary arteries. It has been empirically proved that the degree of FFRCT decline varies based on vessel morphology even in the same vessel length.

Purpose

To investigate the vessel morphological factors that influence FFRCT in normal coronary arteries.

Methods

A total of 1402 outpatients with suspected CAD who underwent CT angiography (CTA) with FFRCT analysis between January 2017 and October 2021 were evaluated. Among them, 234 consecutive patients who underwent both CT angiography including FFRCT and invasive coronary angiography, resulting in <20% stenosis in right coronary artery (RCA) were evaluated. RCA vessels from ostium to just proximal site of the posterior descending branch were analysed and divided into two groups according to distal FFRCT: FFRCT >0.80 (n=219) and FFRCT ≤0.80 (n=15). FFRCT was measured at proximal and distal segments of the RCA. Vessel morphology (vessel length, lumen diameter and volume, and plaque volume) and left ventricular mass were assessed. The ratio of lumen volume and vessel length was defined as the V/L ratio.

Results

Whereas vessel length was almost the same between FFRCT >0.80 and ≤0.80 (>0.80 vs. ≤0.80, 115.9±17.3 vs. 119.6±28.7 mm), lumen volume (1135.2±369.3 vs. 906.2±362.6 mm3, p<0.05) and V/L ratio (9.8±2.6 vs. 7.5±2.3, p<0.01) were significantly higher in FFRCT >0.80. Distal FFRCT correlated with plaque-related parameters [low-attenuation plaque, intermediate-attenuation plaque, and calcified plaque (CP)] and vessel-related parameters (proximal and distal vessel diameter, vessel length, lumen volume, and V/L ratio). Among all vessel-related parameters, V/L ratio showed the highest correlation with distal FFRCT (r=0.44, p<0.0001) (Figure 1). Multivariable analysis showed that CP volume was the strongest predictor of distal FFRCT (β-coefficient = −0.38, p<0.0001), followed by V/L ratio (β-coefficient = 0.95, p=0.007). V/L ratio was the strongest predictor of a distal FFRCT ≤0.80 (cut-off 8.2, AUC 0.73, sensitivity 66.7%, specificity 69.3%, 95% CI 0.60–0.86) (Figure 2).

Conclusions

Our study findings suggest that the V/L ratio can be a measure to predict subclinical coronary perfusion disturbance.

Funding Acknowledgement

Type of funding sources: None.

Epicardial adipose tissue thickness in COVID-19 hospitalized patients: a tool for risk stratification

Funding Acknowledgements

Type of funding sources: None.

Background

Coronavirus Disease 2019 (COVID-19) impacted public health systems,overwhelming the intensive care units(ICU)(1).Epicardial adipose tissue (EAT) thickness is a potential novel parameter, which can be assessed using standard computer tomography(CT) for the prediction of worse prognosis in COVID-19(2,3). 

Purpose

We aimed to investigate the association of right ventricle (RV)-EAT thickness with the need for invasive mechanical ventilation,vasopressor support or ICU admission and in-hospital mortality in COVID-19.

Methods

We analyzed 310 consecutive hospitalized patients with confirmed COVID–19 by RT-PCR, between March and April 2020.EAT thickness was assessed during the acute setting of the disease using low dose non-contrast chest CT.Maximal EAT thickness was determined on axial image series at the level of the RV free wall perpendicular to the surface of the heart(Figure 1).Intra- and interobserver reproducibility for the RV-EAT thickness measurement was assessed in 20 random patients after two weeks,by the primary and a second investigator.Data included demographics,clinical evaluation,comorbidities,treatment and complications.Peak lactate dehydrogenase (LDH), neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) were defined as the highest level during hospitalization.The primary combined endpoint was ICU admission,invasive mechanical ventilation and vasopressor therapy.The secondary outcome was in-hospital mortality. 

Results

Median age was 64 years (interquartile range:53 to 79 years,58.1% males).106(34.2%) patients reached the primary endpoint.In-hospital mortality rate was 19.5% (59 patients).Among patients with combined endpoint,the mortality rate was 35.8% (38 patients).RV-EAT thickness was higher in patients with combined endpoint (5.0 ±2.6 mm versus 4.3 ± 2.2 mm, p = 0.021).Additionally, patients with the composite endpoint had more diabetes mellitus (p = 0.028) and history of coronary artery disease (p = 0.020).Multivariable analysis showed that RV-EAT thickness predicted the primary endpoint,irrespective of risk factors and disease severity (p = 0.014,OR 1.157,95%CI 1.030-1.300; p = 0.031,OR 1.146,95%CI 1.013-1.298,respectively)(Figure 2).Moreover, peak CRP and peak LDH were associated with both endpoints(Figure 2).However, RV-EAT thickness was not predictive for mortality (p = 0.561, OR 1.039, 95%CI 0.913-1.183).

Intraobserver and interobserver reproducibility were good

0.88 (95%CI 0.66-0.95) and 0.86 (95%CI 0.65-0.94).

Conclusion

RV-EAT thickness,easily and rapidly assessed by standard low dose non-contrast chest CT was associated with higher incidence of ICU admission, need for mechanical ventilation and vasopressor support in hospitalized COVID-19 patients.Although no independent association between RV-EAT and in-hospital mortality was found, RV-EAT thickness may serve as surrogate marker of severity, before the rise of inflammatory biomarkers and may reflect inflammation changes within the myocardium in COVID-19. Abstract Figure 1. Examples of right ventricle ep  Abstract Figure 2. Predictors of invasive mechani

Persistent dyspnea 1 year after COVID - 19 infection in apparently healthy subjects: a potential indicator of subclinical cardiac dysfunction

Funding Acknowledgements

Type of funding sources: None.

Introduction

 Coronavirus disease 2019 (COVID-19) impacted healthcare systems worldwide, evolving into a global pandemic(1,2). Recent studies showed the presence of persistent exertional dyspnea or fatigue at one- to three-months follow-up after COVID-19(1,2). However, little is known regarding the mechanisms behind the possible cardiac-related symptoms post COVID-19 at mid- and long- term follow-up.

Purpose

 We investigated the presence of persistent dyspnea one year after the acute phase of COVID-19 in patients without previous cardiovascular or pulmonary disease. Secondly, we analyzed the potential subclinical cardiac dysfunction in these patients, assessed by echocardiography.

Methods

 310 COVID-19 patients were prospectively included between March and April 2020. 143 patients continued the follow-up at 6 months and one year.Patients with a previous history of cardiovascular or respiratory disease were excluded from the analysis.The follow-up consisted in clinical evaluation, and spirometry at 6 and 12 months, chest computed tomography and comprehensive transthoracic echocardiography (TTE) including speckle tracking and myocardial work analysis at one-year follow-up.

Results

 66 patients (mean age 49.64 ± 10.66 years, 37 (67.3%) males)were included in the final analysis.In these patients, TTE parameters were in the normal range, with a mean left ventricle ejection fraction of 56.98 ± 4.64%, mean global longitudinal strain (GLS) of -20.90 ± 2.37%, global constructive work (GCW) of 2381.45 ±463.68mmHg% and global work index (GWI) of 2132.49 ±419.22.Type 1 diastolic dysfunction was observed in 11(16.7%) patients.One (1.5%) patient had type 2 diastolic dysfunction. A normal respiratory pattern was reported in 31(47%) patients at 6 months spirometry evaluation, while 19(28.8%) patients presented pulmonary restriction patterns.23 (34.8%) patients reported exertional dyspnea at one year follow-up. No significant differences regarding clinical, laboratory or imaging findings at baseline were found between patients with and without dyspnea. TTE showed that GLS, GCW and GWI were different between symptomatic and asymptomatic patients (-19.97 ± 2.14 vs. -20.90 ± 2.37,p = 0.039; 2183.14 ± 2483.14 ± 422.42,p = 0.024; 1960.06 ± 396.21 vs 2221.17 ± 407.99, p = 0.030).(Figure 1) Multivariable analysis showed that GCW, GWI and normal respiratory pattern at 6 months were inversely associated with persistent dyspnea (p = 0.038,OR 0.998, 95% CI 0.996-1.000;  p = 0.042, OR 0.998, 95% CI 0.996-1.000;  p = 0.020, OR 0.195, 95% CI 0.049-0.773, respectively).(Figure.2) 

Conclusion

 Persistent exertional dyspnea one year after COVID-19 infection was present in more than a third of apparently healthy patients. GCW and GWI were independently associated with symptoms, suggesting a decrease in myocardial performance in this population. Further studies should focus on the long-term evolution of COVID-19 patients and the occurrence of possible cardiac consequences.

Prognostic value of coronary artery calcium score in hospitalized COVID - 19 patients

Funding Acknowledgements

Type of funding sources: None.

Background

The association of known cardiovascular risk factors with poor prognosis of coronavirus disease 2019 (COVID-19) has been recently emphasized (1). Coronary artery calcium (CAC) score is considered a risk modifier in primary prevention of cardiovascular disease and has shown to improve cardiovascular risk prediction in addition to classical risk factors (2). 

Purpose

We hypothesized that the absence of CAC might have an additional predictive value for an improved cardiovascular outcome of hospitalized COVID-19 patients.

Methods

We prospectively included 310 consecutive hospitalized patients with COVID-19. Thirty patients with a history of coronary artery disease were excluded. Low dose non - contrast chest computed tomography (CT) was performed in all patients at admission. Visual assessment of CAC in every coronary artery was obtained by using an ordinal scoring of 0, 1, 2 or 3 corresponding to absent, mild, moderate or severe CAC score. A total score was calculated by summing the score of each vessel, which was further categorized as 0 (undetectable), 1-3 (mild), 4-5 (moderate) and ≥ 6 (severe). (Figure 1). Demographics, medical history, clinical characteristics, laboratory findings, imaging data, in-hospital treatment, and outcomes were retrospectively analyzed. A composite endpoint of major adverse cardiovascular events (MACE) was defined as all - cause mortality, heart failure, acute coronary syndrome, atrial fibrillation and stroke.

Results

Two hundred eighty patients (63.2 ± 16.7 years old, 57.5% male) were included in the analysis. One hundred thirty one (46.7%) patients had a CAC score of 0. MACE rate was 21.8% (61 patients). Multivariable logistic regression showed that the absence of CAC was inversely associated with MACE (OR 0.209, 95% CI 0.052–0.833, p = 0.027), with a negative predictive value of 84.5% (sensitivity 72%, specificity 55%), independent of age, risk factors or disease severity (Figure 2).

Conclusion

The absence of CAC had a high negative predictive value for MACE in patients hospitalized with COVID-19, independent of the presence of cardiac risk factors or disease severity. These findings reinforce the idea that the assessment of CAC could be a useful marker for risk stratification and management of COVID - 19 patients. Future directions should focus on the implementation of CAC score into mid - term and long - term follow - up of this particular population, to provide a more precise and earlier estimation of cardiovascular risk. Abstract Figure.  Abstract Figure.

Prognostic value of coronary artery calcium score in hospitalized COVID-19 patients

Background

The association between known cardiovascular risk factors and poor prognosis of patients diagnosed with coronavirus disease 2019 (COVID-19) has been recently emphasized (1). Coronary artery calcium (CAC) score assessed by computed tomography (CT) is considered a risk modifier in primary prevention of cardiovascular disease and has shown to improve cardiovascular risk prediction in addition to classical risk factors (2).

Purpose

We hypothesized that the absence of CAC might have an additional predictive value for an improved cardiovascular outcome of hospitalized COVID-19 patients.

Methods

We prospectively included 310 consecutive hospitalized patients with COVID-19. Thirty patients with a history of coronary artery disease were excluded.Low dose non-contrast chest CT was performed in all patients at admission. Visual assessment of CAC in every coronary artery was obtained by using an ordinal scoring of 0, 1, 2 or 3 corresponding to absent, mild, moderate or severe CAC score. A total score was calculated by summing the score of each vessel, which was further categorized as 0 (undetectable), 1–3 (mild), 4–5 (moderate) and ≥6 (severe). (Figure 1). Demographics, medical history, clinical characteristics, laboratory findings, imaging data, in–hospital treatment and outcomes were retrospectively analyzed. A composite endpoint of major adverse cardiovascular events (MACE) was defined as all-cause mortality and cardiovascular events (heart failure, myocarditis, arrhythmia, acute coronary syndrome, stroke, pulmonary embolism).

Results

Two-hundred eighty patients (63.2±16.7 years old, 57.5% male) were included in the analysis. One hundred thirty one (46.7%) patients had a CAC score of zero. MACE-rate was 24.2% (68 patients). Multivariate logistic regression showed that the absence of CAC was inversely associated with MACE (OR 0.264, 95% 0.071–0.981, p=0.047), with a negative predictive value (NPV) of 81.4%, sensitivity 70%, specificity 55%, independent of age, risk factors or disease severity (Table 1).

Conclusion

The absence of CAC translated into a low risk for MACE in COVID-19 patients, even in the presence of cardiac risk factors, which reinforces the idea that the assessment of CAC score in COVID-19 patients could be a useful marker for patients risk stratification and management. Future directions should focus on the implementation of CAC score into mid-term and long-term follow-up of this particular population, to provide a more precise and earlier estimation of cardiovascular risk

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

Effects of left ventricular mass index on computed tomography derived fractional flow reserve in significant obstructive coronary artery disease

Background

In significant obstructive coronary artery disease (SOCAD), a mismatched assessment of the severity of coronary artery stenosis may occur between invasive coronary angiography and computed tomography (CT) derived fractional flow reserve (FFRCT). The exact mechanisms of unexpected underestimation of FFRCT remain unknown.

Purpose

The aims of this study are (1) to clarify the mechanisms of underestimation on FFRCT; and (2) to identify the predictive factors of FFRCT underestimation above the value of 0.80 in SOCAD vessels.

Methods

A total of 1160 outpatients who underwent CT angiography (CTA) with FFRCT analysis for suspected coronary artery disease (CAD) between January 2017 and June 2020 were evaluated. Among them, 141 consecutive patients who had both CTA coupled to FFRCT analysis and invasive angiogram showing >75% coronary stenosis were included for analysis. Vessels were divided into two groups according to FFRCT at the distal vessel: FFRCT >0.80 (n=12) and FFRCT ≤0.80 (n=153). Vessel-related parameters, including vessel morphology (vessel length and lumen volume) and plaque components (non-calcified plaque volume and calcified plaque volume) and left ventricular (LV) myocardial-related parameters, including LV wall thickness at each site of the myocardium, and LV mass were evaluated semi-automatically.

Results

Vessel morphology and plaque components did not differ between FFRCT >0.80 and ≤0.80, whereas LV wall thickness (average; 10.7±2.7 vs. 8.4±1.6 mm, and maximal; 13.5±3.0 vs. 10.6±1.8 mm, all p value <0.001), LV mass (136.4±38.4 vs. 98.8±26.8 g, p<0.001), and LV mass index (73.8±22.6 vs. 51.8±12.2 g/m2, p<0.001) were significantly higher in FFRCT >0.80. Next, we investigated the parameters that correlated with FFRCT. Of all, vessel morphology and plaque components were not related to FFRCT, whereas maximal LV wall thickness, r=0.24, p=0.01; LV mass, r=0.19. p=0.04; and LV mass index, r=0.30, p=0.001) correlated with FFRCT. In the vessels showing FFRCT >0.80, only LV mass (r=0.84, p=0.005) and LV mass index (r=0.67, p=0.047) correlated with FFRCT. (Figure 1). LV mass index was the strongest predictor of a distal FFRCT of >0.80 with the area under curve (AUC) 0.81, 95% CI 0.62 – 1.00, P<0.0001 and an optimal cut-off value of 66.5 g/m2 sensitivity 77.8%, specificity 89.6% (Figure 2).

Conclusions

FFRCT is affected not by vessel-related parameters but LV myocardial-related parameters in SOCAD. The presence of an excessive LV mass is a major predictor of underestimation of FFRCT in SOCAD vessels. LV myocardial-related parameters should be considered when interpreting numerical values of FFRCT to avoid the possibility of overlooked SOCAD.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Impact of vascular morphology and plaque characteristics on computed tomography derived fractional flow reserve in early stage coronary artery disease

Background

FFRCT gradually decreases from the proximal to the distal part of a vessel and reach the pathological threshold for significant ischemia even in the absence of obstructive coronary artery disease (CAD). The exact mechanisms of such gradual FFRCT decline remain unknown.

Purpose

The aims of this study are (1) to clarify the mechanisms of the gradual decline of computed tomography (CT) derived fractional flow reserve (FFRCT); and (2) to identify the predictive factors of an FFRCT decline below the pathological value of 0.80 in no apparent CAD vessels.

Methods

A total of 1058 outpatients with suspected CAD and who underwent CT angiography (CTA) with FFRCT analysis between January 2017 and December 2019 were evaluated. Among them, 150 consecutive patients who had both a CTA coupled to an FFRCT analysis and an invasive angiogram showing <25% coronary stenosis were included for analysis. Vessels were divided into two groups according to FFRCT at the distal vessel: FFRCT >0.80 (n=317) and FFRCT ≤0.80 (n=114). ΔFFRCT was defined as the magnitude of the change in FFRCT from the proximal to the distal vessel. Plaque characterization and vessel morphology measurements were performed semi-automatically. Vessel constituents were characterized based on Hounsfield units (HU) into lumen volume (<−50 HU), non-calcified plaque (NCP) (−50–150 HU), and calcified plaque (>150 HU).

Results

FFRCT decreased continuously from the proximal to distal across the three major vessels in both FFRCT>0.80 and FFRCT ≤0.80 groups (Figure 1). Compared to FFRCT>0.80 group, NCP volume was significantly higher in all three major vessels in FFRCT ≤0.80 group (210.2±83.6 mm3 vs. 140.9±139.3 mm3 for the RCA, p=0.01; 177.5±150.2 mm3 vs. 133.2±112.2 mm3 for the LAD, p=0.04; 127.6±91.5 mm3 vs. 58.7±57.7 mm3 for the LCX, p<0.01). Next, we investigated the vessel parameters that correlated with ΔFFRCT. ΔFFRCT was correlated with lumen volume in FFRCT>0.80 group (r=−0.24, p<0.0001), whereas ΔFFRCT was correlated with NCP volume in FFRCT ≤0.80 group (r=0.42, p<0.001) (Figure 2). An NCP volume above 44.8 mm3 was the strongest predictor of distal FFRCT of ≤0.80 (area under the curve 0.69, p<0.0001, sensitivity 95%, specificity 39%).

Conclusions

FFRCT is affected by vascular morphology and plaque characteristics even in the early stage of coronary artery disease. Our study highlights that subclinical coronary artery disease strongly influences FFRCT by effects unrelated to coronary stenosis. The presence of NCP is a major predictor of the gradual decrease of FFRCT toward pathological values. Anatomical findings as vessel morphology and plaque characteristics should be taken into consideration when interpreting numerical values of FFRCT to avoid unnecessary referrals for invasive coronary angiography or percutaneous coronary intervention.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Troponin T in COVID-19 hospitalized patients: kinetics matter

Background

Coronavirus disease 2019 (COVID-19) pandemic continues to overwhelm healthcare systems worldwide, due to high numbers of critical cases over a short period of time (1,2). Elevated cardiac troponin (cTn), suggestive for myocardial damage, was associated with increased mortality of COVID-19 patients (3,4). However, data addressing the role of cTn in major adverse cardiovascular events (MACE) in COVID-19 patients is scarce.

Objectives

We aimed to assess the role of baseline cTnT and cTnT kinetics in the prediction of MACE and in - hospital mortality in COVID-19 patients. Furthermore, we assessed the association between cTnT kinetics and the need of cardiac imaging evaluation.

Methods

310 patients were included prospectively (age 64.6±16.7 years, 180 (58.1%) males), between March 2020 and April 2020. Clinical data including demographics,medical history,comorbidities,clinical evaluation,laboratory exams,in-hospital treatment,complications and outcomes were collected at admission and during hospitalization by physicians in charge. Two hundred and two patients (65.1%) with at least two cTnT values assessed during hospitalization, at 24–48 hours interval were included in the final analysis. cTnT-values >0.011 micrograms/L were considered elevated, according to hospital laboratory cut-offs. Patients were divided into 3 groups according to cTnT kinetics profile: 1 – variable, 2 – descending and 3 – constant. cTnT slope was defined as the ratio of the cTnT change and the change in time. MACE were considered as the primary endpoint and were composed by all-cause mortality, acute heart failure, acute coronary syndrome, pericarditis, myocarditis, atrial fibrillation or flutter and pulmonary embolism. In-hospital mortality was considered as the secondary endpoint.

Results

Mean hospitalization was 13.9±0.9 days. MACE occurred in 60 patients (29.7%) and in-hospital mortality in 40 (19.8%) patients. Baseline cTnT independently predicted MACE, (p=0.047, HR 1.805, 95% CI 1.009–3.231) and in-hospital mortality (p=0.009, HR 2.322, 95% CI 1.234–4.369) (Figure 1A, 1B). An increased cTnT slope independently predicted in-hospital mortality (p=0.041, HR 1.006, 95% CI 1.000–1.011). Constant cTnT was associated with lower MACE and mortality rates (p=0,000, HR 3.080, 95% CI, 1.914–4.954, p=0.000, HR 2.851. 95% CI 1.828–4.447, respectively) (Figure 1C, 1D, 2). Cardiac imaging evaluation was performed in 8 (16%) patients with constant cTnT, 30 (60%) with variable cTnT, and 12 (24%) with descending cTnT.(p<0.001)

Conclusions

Increased baseline cTnT independently predicted MACE and in-hospital mortality in COVID-19 patients. The magnitude of cTnT increase over time was associated with in-hospital mortality. On the contrary, patients with constant cTnT had lower MACE and in-hospital mortality rates. These finding emphasize the additional role of cTnT testing in COVID-19 patients for risk stratification and improved diagnostic pathway and management

Funding Acknowledgement

Type of funding sources: None.

P2721FFRct analysis for screening of obstructive coronary artery disease: a propensity score adjusted study

Background

Guidelines recommend functional assessment in stable coronary artery disease (CAD) to guide further treatment. Computed tomography fractional flow reserve (FFRCT) has been proposed for non-invasive assessment of stable CAD. A cutoff value of FFRCT ≥0.8 has been shown cost-effective, and allowing to avoid inappropriate invasive coronary angiography (ICA). However, no results from real-life hospital registries have been reported yet.

Purpose

We aimed to compare the impact of FFRCT with conventional coronary CT angiography (CTA) for detecting obstructive CAD in the daily practice of a tertiary referral hospital.

Methods

Patients referred to CTA for suspected CAD between 2013 and 2017 were included. FFRCT analysis was introduced in 2015 and performed at the discretion of the radiologist by Heartflow Inc. FFRCT was considered abnormal if FFR was <0.8 in at least one of 3 main vessels. Obstructive CAD was defined on both CTA and ICA by the presence of a stenosis ≥50% in at least one of 3 main vessels, or an invasive FFR<0.8. Propension to perform a FFRCT was modeled, based on gender, cardiovascular risk factors, completion of stress test and echocardiography and presence of a lesion of more than 50% stenosis on CTA. A logistic regression adjusted for the propensity score was then performed on the use of ICA, the presence of significant CAD on ICA and revascularization rate either by PCI or CABG.

Results

2906 patients (50% of male, 56±12) were included in this registry. Diabetes, hypertension, dyslipidemia and smoking were present in respectively 12.3, 30.5, 27.5 and 9% of patients. A stress ECG and a transthoracic echo were obtained in respectively 37.1 and 49% of patients. FFRCT was performed in 757 (26%) and was abnormal in 323 (42.7%) of the patients. An ICA was performed in 622 (21.4%) patients and was abnormal in 292 (46.9%). After propensity score weighting, FFRCT was associated with an increase in ICA (OR=1.58, 95% CI: 1.23–2.02, p<0.01). There were no significant changes regarding ICA showing obstructive CAD with FFRCT (OR=1.13, 95% CI: 0.78–1.66, p=0.5) but a trend towards an increase of revascularization (OR=1.48, 95% CI: 0.98–2.24, p=0.06). In patient undergoing an ICA, a FFRCT ≥0.8 was decreasing the presence of significant CAD (OR=0.27, 95% CI: 0.16–0.48, p<0.001), whereas a FFRCT <0.8 increased the rate of revascularization (OR=24.7, 95% CI: 12.3–49.7, p<0.001).

Conclusion

These real life data showed that, adding FFRCT to conventional CTA, and interpreting only the numerical values of FFRCT, would increase the use of ICA in patients suspected of CAD. A trend towards an increase in revascularization was also observed. Therefore, another index than the minimal FFRCT should be used to improve discrimination regarding the presence of obstructive CAD. However, normal values of FFRCT were strong predictors of the absence of significant CAD, and abnormal values of FFRCT for the need of a revascularization.