Computed tomography derived fractional flow reserve testing in stable patients with typical angina pectoris: influence on downstream rate of invasive coronary angiography

Selective Use of CT Fractional Flow at a Large Academic Medical Center: Insights from Clinical Implementation after 1 Year of Practice

Purpose This special report outlines a retrospective observational study of CT fractional flow reserve (CT-FFR) analysis using dual-source coronary CT angiography (CTA) scans performed without heart rate control and its impact on clinical outcomes. Materials and Methods All patients who underwent clinically indicated coronary CTA between August 2020 and August 2021 were included in this retrospective observational study. Scans were performed in the late systolic to early diastolic period without heart rate control and analyzed at the interpreting physician's discretion. Demographics, coronary CTA features, and rates of invasive coronary angiography (ICA), percutaneous coronary intervention (PCI), myocardial infarction, and all-cause death at 3 months were assessed by chart review. Results During the study period, 3098 patients underwent coronary CTA, of whom 113 with coronary bypass grafting were excluded. Of the remaining 2985 patients, 292 (9.7%) were referred for CT-FFR analysis. Two studies (0.7%) were rejected from CT-FFR analysis, and six (2.1%) analyses did not evaluate the lesion of concern. A total of 160 patients (56.3%) had CT-FFR greater than 0.80. Among patients with significant stenosis at coronary CTA, patients who underwent CT-FFR analysis presented with lower rates of ICA (74.5% vs 25.5%, P = .04) and PCI (78.9% vs 21.1%, P = .05). Conclusion CT-FFR was implemented in patients not requiring heart rate control by using dual-source coronary CTA acquisition and showed the potential to decrease rates of ICA and PCI without compromising safety in patients with significant stenosis and an average heart rate of 65 beats per minute. Keywords: Angiography, CT, CT-Angiography, Fractional Flow Reserve, Cardiac, Heart, Arteriosclerosis Supplemental material is available for this article. © RSNA, 2024.

Clinical Outcomes Based on Coronary Computed Tomography-Derived Fractional Flow Reserve and Plaque Characterization

BACKGROUND

Coronary computed tomography angiography (CTA) followed by computed tomography angiography-derived fractional flow reserve (FFRCT) is now commonly used for the management of chronic coronary syndrome (CCS). CTA-verified high-risk plaque (HRP) characteristics have also been reported to be associated with a greater likelihood of adverse cardiac events but have not been used for management decisions.

OBJECTIVES

The aim of this study was to evaluate clinical outcomes based on a combination of point-of-care computed tomography angiography-derived fractional flow reserve (POC-FFRCT) and the presence of HRP in CCS patients initially treated medically or with revascularization based on invasive coronary angiography findings.

METHODS

CTA was performed as the initial test in 5,483 patients presenting with CCS between September 2015 and December 2020 followed by invasive coronary angiography and revascularization as necessary. POC-FFRCT assessment and HRP characterization were obtained subsequently in 745 consecutive patients. We investigated how HRP and POC-FFRCT, which were not available during the original clinical decision making, correlated with the endpoint defined as a composite of cardiac death, acute coronary syndrome, and a need for unplanned revascularization.

RESULTS

Cardiac events occurred in 20 patients (2.7%) during a median follow-up of 744 days. The event rate was significantly higher in patients with POC-FFRCT <0.80 compared with POC-FFRCT ≥0.8 (5.4 vs 0.5 per 100 vessel years; log-rank P < 0.0001) and in patients with HRP compared to those without HRP (3.6 vs 0.8 per 100 vessel years; log-rank P = 0.0001). POC-FFRCT <0.80 and the presence of HRP were the independent predictors of cardiac events (HR: 16.67; 95% CI: 2.63-105.39; P = 0.002) compared with POC-FFRCT ≥0.8 and absent HRP. For the vessels with POC-FFRCT <0.80 and HRP, a significantly higher rate of adverse events was observed in patients who did not undergo revascularization compared with those revascularized (16.4 vs 1.4 per 100 vessel years; log-rank P = 0.006).

CONCLUSIONS

POC-FFRCT <0.80 and the presence of HRP were the independent predictors of cardiac events, and revascularization of HRP lesions with abnormal POC-FFRCT was associated with a lower event rate.

Distal-vessel fractional flow reserve by computed tomography to monitor epicardial coronary artery disease

AIMS

Coronary computed tomography angiography (CTA) and fractional flow reserve by computed tomography (FFR-CT) are increasingly utilized to characterize coronary artery disease (CAD). We evaluated the feasibility of distal-vessel FFR-CT as an integrated measure of epicardial CAD that can be followed serially, assessed the CTA parameters that correlate with distal-vessel FFR-CT, and determined the combination of clinical and CTA parameters that best predict distal-vessel FFR-CT and distal-vessel FFR-CT changes.

METHODS AND RESULTS

Patients (n = 71) who underwent serial CTA scans at ≥2 years interval (median = 5.2 years) over a 14-year period were included in this retrospective study. Coronary arteries were analysed blindly using artificial intelligence-enabled quantitative coronary CTA. Two investigators jointly determined the anatomic location and corresponding distal-vessel FFR-CT values at CT1 and CT2. A total of 45.3% had no significant change, 27.8% an improvement, and 26.9% a worsening in distal-vessel FFR-CT at CT2. Stepwise multiple logistic regression analysis identified a four-parameter model consisting of stenosis diameter ratio, lumen volume, low density plaque volume, and age, that best predicted distal-vessel FFR-CT ≤ 0.80 with an area under the curve (AUC) = 0.820 at CT1 and AUC = 0.799 at CT2. Improvement of distal-vessel FFR-CT was captured by a decrease in high-risk plaque and increases in lumen volume and remodelling index (AUC = 0.865), whereas increases in stenosis diameter ratio, medium density calcified plaque volume, and total cholesterol presaged worsening of distal-vessel FFR-CT (AUC = 0.707).

CONCLUSION

Distal-vessel FFR-CT permits the integrative assessment of epicardial atherosclerotic plaque burden in a vessel-specific manner and can be followed serially to determine changes in global CAD.

Clinical and prognostic incremental value of FFRCT in screening of patients with obstructive coronary artery disease

BACKGROUND

Coronary computed tomography angiography (CCTA) -derived fractional flow reserve (FFRCT) is recommended to evaluate the functional consequences of obstructive coronary artery disease (OCAD). Real-world incremental impacts of FFRCT use still remains under debate.

METHODS

1601 patients with suspected OCAD on CCTA (>50 ​% stenosis), including 808 (50.5 ​%) patients evaluated by FFRCT, were included from a 2013-2021 registry. Propensity adjusted impacts of FFRCT use on rates of invasive coronary angiography (ICA), myocardial revascularization (MR) and post MR major adverse cardiac events (MACE) were reported, including a sensitivity analysis in severe OCAD (>70 ​% stenosis) (n ​= ​450). Accuracy of numerical and comprehensive FFRCT interpretations in selection of patients requiring a MR were also compared.

RESULTS

1160 (72,5 ​%) ICA, 559 (34.9 ​%) MR and 137 (24.5 ​%) post MR MACE occurred at 4.7 ​± ​1.9 years. FFRCT use was independently associated with decreased rate of ICA and MR (OR: 0.66; 95 ​% CI 0.53-0.83, p ​< ​0.001 and OR: 0.71; 95 ​% CI 0.58-0.88, p ​< ​0.01, respectively). Compared to the numerical interpretation, the FFRCT comprehensive assessment increased the ratio of MR per ICA (61.7 ​% vs 50.1 ​%, p ​< ​0.01) and was more accurate in selection of patients requiring MR. FFRCT reduced post MR MACE (OR: 0.64; 95 ​% CI 0.43-0.96, p ​< ​0.05). All these associations were no longer observed in severe OCAD.

CONCLUSION

Implementing FFRCT in OCAD patients reduces ICA use, improves selection of patients requiring MR and reduces post MR MACE. However, these incremental values of FFRCT were no longer observed in severe OCAD.

Impact on stable chest pain pathways of CT fractional flow reserve

OBJECTIVES

To evaluate the impact of introducing CT fractional flow reserve (FFRCT) on stable chest pain pathways, concordance with National Institute for Health and Care Excellence (NICE) chest pain guidelines, resource usage and revascularisation of patients from a tertiary UK cardiac centre rapid access chest pain clinic (RACPC).

METHODS

Single-centre before and after study comparing data from electronic records and Strategic Tracing Service of all RACPC patients attending between 1 July 2017 and 31 December 2017, and 1 August 2018 and 31 January 2019.

RESULTS

Two hundred and sixty-eight and 287 patients (overall mean age 62 years, range 26-89 years, 48.3% male), were eligible for first-line CT coronary angiography (CTCA) pre-FFRCT and post-FFRCT, respectively. First-line CTCA use per NICE Guideline CG95 increased (50.6% pre-FFRCT vs 75.7% post-FFRCT, p<0.001). More patients reached pathway endpoint (revascularisation or assumed medical management) after one investigation (74.9% pre-FFRCT vs 84.9% post-FFRCT, p=0.005). There were fewer stress (22.8% pre-FFRCT vs 7.7% post-FFRCT, p<0.001) and rest (10.4% pre-FFRCT vs 4.2% post-FFRCT, p=0.007) myocardial perfusion scans and diagnostic-only angiograms (25.5% vs 13.7%, p<0.001). Despite fewer invasive procedures (29.3% pre-FFRCT vs 17.6% post-FFRCT, p=0.002), revascularisation rates remained similar (10.4% pre-FFRCT vs 8.8% post-FFRCT, p=0.561). Avoiding invasive investigations reduced inpatient admissions (39.0% pre-FFRCT vs 24.3% post-FFRCT, p<0.001). Time to revascularisation was unchanged (153.5 days pre-FFRCT vs 142.0 post-FFRCT, p=0.925). Unplanned hospital attendances, emergency admissions and adverse events were similar.

CONCLUSIONS

FFRCT adoption was associated with greater compliance with NICE guidelines, reduced invasive diagnostic angiography, planned admissions and needing more than one test to reach a pathway endpoint.

Performance of a Novel CT-Derived Fractional Flow Reserve Measurement to Detect Hemodynamically Significant Coronary Stenosis

BACKGROUND

Fractional flow reserve (FFR) based on computed tomography (CT) has been shown to better identify ischemia-causing coronary stenosis. However, this current technology requires high computational power, which inhibits its widespread implementation in clinical practice. This prospective, multicenter study aimed at validating the diagnostic performance of a novel simple CT based fractional flow reserve (CT-FFR) calculation method in patients with coronary artery disease.

METHODS

Patients who underwent coronary CT angiography (CCTA) within 90 days and invasive coronary angiography (ICA) were prospectively enrolled. A hemodynamically significant lesion was defined as an FFR ≤ 0.80, and the area under the receiver operating characteristic curve (AUC) was the primary measure. After the planned analysis for the initial algorithm A, we performed another set of exploratory analyses for an improved algorithm B.

RESULTS

Of 184 patients who agreed to participate in the study, 151 were finally analyzed. Hemodynamically significant lesions were observed in 79 patients (52.3%). The AUC was 0.71 (95% confidence interval [CI], 0.63-0.80) for CCTA, 0.65 (95% CI, 0.56-0.74) for CT-FFR algorithm A (P = 0.866), and 0.78 (95% CI, 0.70-0.86) for algorithm B (P = 0.112). Diagnostic accuracy was 0.63 (0.55-0.71) for CCTA alone, 0.66 (0.58-0.74) for algorithm A, and 0.76 (0.68-0.82) for algorithm B.

CONCLUSION

This study suggests the feasibility of automated CT-FFR, which can be performed on-site within several hours. However, the diagnostic performance of the current algorithm does not meet the a priori criteria for superiority. Future research is required to improve the accuracy.

Comprehensive Computed Tomography Imaging of Vessel-specific and Lesion-specific Myocardial Ischemia

Coronary computed tomographic angiography (CCTA) has emerged as a fast and robust tool with high sensitivity and excellent negative predictive value for the evaluation of coronary artery disease, but is unable to estimate the hemodynamic significance of a lesion. Advances in computed tomography (CT)-based diagnostic techniques, for example, CT-derived fractional flow reserve and CT perfusion, have helped transform CCTA primarily from an anatomic assessment tool to a technique that is able to provide both anatomic and functional information for a stenosis. With the results of the ISCHEMIA trial published in 2019, these advanced techniques can elevate CCTA into the role of a better gatekeeper for decision-making and can help guide referral for invasive management. In this article, we review the principles, limitations, diagnostic performance, and clinical utility of these 2 functional CT-based techniques in the evaluation of vessel-specific and lesion-specific ischemia.

Functional coronary angiography for the assessment of the epicardial vessels and the microcirculation

Over the last decade, steady progress has been made in the ability to assess coronary stenosis relevance by merging computerised analyses of angiograms with fluid dynamic modelling. The new field of functional coronary angiography (FCA) has attracted the attention of both clinical and interventional cardiologists as it anticipates a new era of facilitated physiological assessment of coronary artery disease, without the need for intracoronary instrumentation or vasodilator drug administration, and an increased adoption of ischaemia-driven revascularisation. This state-of-the-art review performs a deep dive into the foundations and rationale behind FCA indices derived from either invasive or computed angiograms. We discuss the currently available FCA systems, the evidence supporting their use, and the specific clinical scenarios in which FCA might facilitate patient management. Finally, the rapidly growing application of FCA to the diagnosis of coronary microvascular dysfunction is discussed. Overall, we aim to provide a state-of-the-art review not only to digest the achievements made so far in FCA, but also to enable the reader to follow the many publications and developments in this field that will likely take place in years to come.

[Contribution of coroscanner in chronic coronary syndrome]

Cardiac division imaging by coroscanner has progressed a lot in 20 years to gradually become an important and potentially indispensable tool of chronic coronary cardiology. The European and American recommendations are Grade I for the assessment of symptomatic patients at intermediate to high risk, at the same level as traditional functional tests. The development of sophisticated post-treatment algorithms that apply the equations of fluid mechanics makes it possible to calculate an FFR value at any point from the CT image of the coronary artery. This FFR-CT is correctly correlated with invasive FFR compared to a threshold value of 0.80 and helps guide therapeutic choices. Thus, the coroscanner is a complement or an alternative to traditional functional tests and is positioned as a filter of access to coronary angiography, especially since it combines, from the same examination, a precise anatomical description, and a functional evaluation of the various possible lesions. Which is the Holy Grail of coronary cardiology.

The role of cardiac computed tomography in predicting adverse coronary events

Cardiac computed tomography (CCT) is now considered a first-line diagnostic test for suspected coronary artery disease (CAD) providing a non-invasive, qualitative, and quantitative assessment of the coronary arteries and pericoronary regions. CCT assesses vascular calcification and coronary lumen narrowing, measures total plaque burden, identifies plaque composition and high-risk plaque features and can even assist with hemodynamic evaluation of coronary lesions. Recent research focuses on computing coronary endothelial shear stress, a potent modulator in the development and progression of atherosclerosis, as well as differentiating an inflammatory from a non-inflammatory pericoronary artery environment using the simple measurement of pericoronary fat attenuation index. In the present review, we discuss the role of the above in the diagnosis of coronary atherosclerosis and the prediction of adverse cardiovascular events. Additionally, we review the current limitations of cardiac computed tomography as an imaging modality and highlight how rapid technological advancements can boost its capacity in predicting cardiovascular risk and guiding clinical decision-making.

CT Fractional Flow Reserve: A Practical Guide to Application, Interpretation, and Problem Solving

CT fractional flow reserve (FFR_CT) is a physiologic simulation technique that models coronary flow from routine coronary CT angiography (CTA). To evaluate lesion-specific ischemia, FFR_CT is measured 2 cm distal to a stenotic lesion. FFR_CT greater than 0.8 is normal, 0.76-0.8 is borderline, and 0.75 or less is abnormal. FFR_CT should always be interpreted in correlation with clinical and anatomic coronary CTA findings. FFR_CT increases the specificity of coronary CTA in the evaluation of coronary artery disease, decreases the prevalence of nonobstructive disease in invasive coronary angiography (ICA), and helps with revascularization decisions and planning. Patients with intermediate-risk coronary anatomy at CTA and abnormal FFR_CT can undergo ICA and revascularization, whereas those with normal FFR_CT can be safely deferred from ICA. In borderline FFR_CT values, management is decided in the context of the clinical scenario, but many cases could be safely managed with medical treatment. There are some limitations and pitfalls of FFR_CT. Abnormal FFR_CT values can be seen in mild stenosis, and normal FFR_CTvalues can be seen in severe stenosis. Gradually decreasing or abnormal low FFR_CT values at the distal vessel without a proximal focal lesion could be due to diffuse atherosclerosis. Coronary stents, bypass grafts, coronary anomalies, coronary dissection, transcatheter aortic valve replacement, unstable angina, and acute or recent myocardial infarction are situations in which FFR_CT has not been validated and should not be used at this time. The authors provide a practical guide to the applications and interpretation of FFR_CT, focusing on common pitfalls and challenges. Online supplemental material is available for this article. ^©RSNA, 2022.

One-year outcomes of CCTA alone versus machine learning-based FFRCT for coronary artery disease: a single-center, prospective study

OBJECTIVES

To explore downstream management and outcomes of machine learning (ML)-based CT derived fractional flow reserve (FFR_CT) strategy compared with an anatomical coronary computed tomography angiography (CCTA) alone assessment in participants with intermediate coronary artery stenosis.

METHODS

In this prospective study conducted from April 2018 to March 2019, participants were assigned to either the CCTA or FFR_CT group. The primary endpoint was the rate of invasive coronary angiography (ICA) that demonstrated non-obstructive disease at 90 days. Secondary endpoints included coronary revascularization and major adverse cardiovascular events (MACE) at 1-year follow-up.

RESULTS

In total, 567 participants were allocated to the CCTA group and 566 to the FFR_CT group. At 90 days, the rate of ICA without obstructive disease was higher in the CCTA group (33.3%, 39/117) than that (19.8%, 19/96) in the FFR_CT group (risk difference [RD] = 13.5%, 95% confidence interval [CI]: 8.4%, 18.6%; p = 0.03). The ICA referral rate was higher in the CCTA group (27.5%, 156/567) than in the FFR_CT group (20.3%, 115/566) (RD = 7.2%, 95% CI: 2.3%, 12.1%; p = 0.003). The revascularization-to-ICA ratio was lower in the CCTA group than that in the FFR_CT group (RD = 19.8%, 95% CI: 14.1%, 25.5%, p = 0.002). MACE was more common in the CCTA group than that in the FFR_CT group at 1 year (HR: 1.73; 95% CI: 1.01, 2.95; p = 0.04).

CONCLUSION

In patients with intermediate stenosis, the FFR_CT strategy appears to be associated with a lower rate of referral for ICA, ICA without obstructive disease, and 1-year MACE when compared to the anatomical CCTA alone strategy.

KEY POINTS

• In stable patients with intermediate stenosis, ML-based FFR_CT strategy was associated with a lower referral ICA rate, a lower normalcy rate of ICA, and higher revascularization-to-ICA ratio than the CCTA strategy. • Compared with the CCTA strategy, ML-based FFR_CTshows superior outcome prediction value which appears to be associated with a lower rate of 1-year MACE. • ML-based FFR_CT strategy as a non-invasive "one-stop-shop" modality may be the potential to change diagnostic workflows in patients with suspected coronary artery disease.

Prognostic value of coronary computed tomography angiographic derived fractional flow reserve: a systematic review and meta-analysis

Objectives

To obtain more powerful assessment of the prognostic value of fractional flow reserve_CT testing we performed a systematic literature review and collaborative meta-analysis of studies that assessed clinical outcomes of CT-derived calculation of FFR (FFR_CT) (HeartFlow) analysis in patients with stable coronary artery disease (CAD).

Methods

We searched PubMed and Web of Science electronic databases for published studies that evaluated clinical outcomes following fractional flow reserve_CT testing between 1 January 2010 and 31 December 2020. The primary endpoint was defined as ‘all-cause mortality (ACM) or myocardial infarction (MI)’ at 12-month follow-up. Exploratory analyses were performed using major adverse cardiovascular events (MACEs, ACM+MI+unplanned revascularisation), ACM, MI, spontaneous MI or unplanned (>3 months) revascularisation as the endpoint.

Results

Five studies were identified including a total of 5460 patients eligible for meta-analyses. The primary endpoint occurred in 60 (1.1%) patients, 0.6% (13/2126) with FFR_CT>0.80% and 1.4% (47/3334) with FFR_CT ≤0.80 (relative risk (RR) 2.31 (95% CI 1.29 to 4.13), p=0.005). Likewise, MACE, MI, spontaneous MI or unplanned revascularisation occurred more frequently in patients with FFR_CT ≤0.80 versus patients with FFR_CT >0.80. Each 0.10-unit FFR_CT reduction was associated with a greater risk of the primary endpoint (RR 1.67 (95% CI 1.47 to 1.87), p<0.001).

Conclusions

The 12-month outcomes in patients with stable CAD show low rates of events in those with a negative FFR_CT result, and lower risk of an unfavourable outcome in patients with a negative test result compared with patients with a positive test result. Moreover, the FFR_CT numerical value was inversely associated with outcomes.

Coronary CT angiography derived FFR in patients with left main disease

The presence of left main coronary artery disease (LMCAD) is associated with an unfavorable clinical outcome. The clinical utility of FFR_CT testing for non-invasive physiological assessment in LMCAD remains largely unknown. In this single center observational study LMCAD patients were retrospectively identified between November 2015 and December 2017. We evaluated the relationship between LMCAD diameter stenosis and downstream FFR_CT values, and the clinical consequences following FFR_CT testing in patients with LMCAD. The composite endpoint (all-cause death, myocardial infarction, unplanned revascularization) was determined over a median follow-up of 1.1 years. LMCAD was registered in 432 of 3202 (13%) patients having coronary CTA. FFR_CT was prescribed in 213 (49%), while 59 (14%) patients were referred directly to invasive angiography or myocardial perfusion imaging. FFR_CT was performed in 195 (45%) patients. LM stenosis severity was inversely related to downstream FFR_CT values. In patients with simple LMCAD with stenosis ≥ 50%, > 80% had FFR_CT > 0.80 in non-diseased proximal and downstream segments (n = 7). No patients with simple LMCAD and FFR_CT > 0.80 (n = 20) suffered an adverse clinical outcome. FFR_CT testing in patients with LMCAD is feasible. LM stenosis severity is inversely related to FFR_CT value. Patients with LMCAD and FFR_CT > 0.80 have favorable clinical outcomes at short-term follow-up. Large-scale studies assessing the clinical utility and safety of deferring invasive catheterization following FFR_CT testing in patients with LMCAD are warranted.

Computed Tomography-Derived Fractional Flow Reserve in Patients With Chronic Coronary Syndrome: A Real-World Cohort Study

OBJECTIVE

This study aimed to investigate the outcome of computed tomography (CT) angiography with optional CT-derived fractional flow reserve (FFRCT) of intermediate-range coronary artery disease in non-emergent patients referred on a suspicion of chronic coronary syndrome.

METHODS

Patients were classified as high risk and low-intermediate risk according to the presence of typical angina or either atypical or nonangina chest pain. Outcome was assessed as the cumulative incidence proportion of a composite end point of unstable angina pectoris, unplanned revascularization, nonfatal myocardial infarction, and all-cause mortality.

RESULTS

The study included 743 patients. Mean follow-up was 2.2 (range, 0.1-2.5) years. Low-intermediate-risk and high-risk patients who had invasive coronary angiography deferred had comparable proportions of adverse events (1.4% vs 2.6% [P = 0.27]). Adverse events in high-risk patients with FFRCT >0.80 was 3.3% versus 1.4% in patients where no additional testing was performed (P = 0.79).

CONCLUSIONS

Computed tomography-derived fractional flow reserve >0.8 conveys an excellent prognosis. Computed tomography angiography with optional FFRCT allows for the safe cancellation of invasive coronary angiography in high-risk patients.

Expanding the coronary tree reconstruction to smaller arteries improves the accuracy of FFRCT

OBJECTIVES

We attempted to improve the accuracy of coronary CT angiography (CCTA)-derived fractional flow reserve (FFR) (FFR_CT) by expanding the coronary tree in the computational fluid dynamics (CFD) domain. An observational study was performed to evaluate the effects of extending the coronary tree analysis for FFR_CT from a minimal diameter of 1.2 to 0.8 mm.

METHODS

Patients who underwent CCTA and interventional FFR were enrolled retrospectively. Seventy-six patients qualified based on the inclusion criteria. The three-dimensional (3D) coronary artery tree was reconstructed to generate a finite element mesh for each subject with different lower limits of luminal diameter (1.2 mm and 0.8 mm). Outlet boundary conditions were defined according to Murray's law. The Newton-Krylov-Schwarz (NKS) method was applied to solve the governing equations of CFD to derive FFR_CT.

RESULTS

At the individual patient level, extending the minimal diameter of the coronary tree from 1.2 to 0.8 mm improved the sensitivity of FFR_CT by 16.7% (p = 0.022). This led to the conversion of four false-negative cases into true-positive cases. The AUC value of the ROC curve increased from 0.74 to 0.83. Moreover, the NKS method can solve the computational problem of extending the coronary tree to an 0.8-mm luminal diameter in 10.5 min with 2160 processor cores.

CONCLUSIONS

Extending the reconstructed coronary tree to a smaller luminal diameter can considerably improve the sensitivity of FFR_CT. The NKS method can achieve favorable computational times for future clinical applications.

KEY POINTS

• Extending the reconstructed coronary tree to a smaller luminal diameter can considerably improve the sensitivity of FFR_CT. • The NKS method applied in our study can effectively reduce the computational time of this process for future clinical applications.

The value of coronary CTA in the diagnosis of coronary artery disease

OBJECTIVE

To investigate the diagnostic value of coronary computed tomography angiography (CTA) in the detection of coronary artery disease.

METHODS

From January 2017 to December 2019, 150 patients with suspected coronary artery disease admitted to the Affiliated People's Hospital of Ningbo University were recruited as the research cohort for this study. All the patients underwent a coronary CTA and a coronary angiography. The results of the patients' coronary CTAs and coronary angiographies were compared. Analyses were performed on the practical implications of coronary CTA in the detection of coronary artery disease and the detection and coincidence rates of coronary CTA for determining the severity of coronary stenosis.

RESULTS

There were no statistical differences in the detection of positive results of coronary artery diseases or the identification of coronary stenosis between the coronary CTAs and the coronary angiographies. The sensitivity of coronary CTA in the examination of coronary artery diseases was 81.8%. The specificity was 87.5%, the negative predictive value was 63.6%, and the positive predictive value was 94.7%. In contrast to the coronary angiography, the coincidence rates of coronary CTA for determining the location of coronary lesions were 89.1% for LAD lesions, 80.0% for LCX lesions, and 100% for RCA lesions.

CONCLUSIONS

Coronary CTA has a significant value in the detection of coronary artery diseases, as it can accurately examine the severity of coronary stenoses and locate the sites of the stenotic lesions. It is worthy of clinical use.

Novel Non-invasive Fractional Flow Reserve from Coronary CT Angiography to Determine Ischemic Coronary Stenosis

Coronary artery disease (CAD) patients may have an obstructive disease on invasive coronary angiography, but few of these patients have had flow-limiting obstructive disease diagnosed on invasive fractional flow reserve (FFR). FFR is infrequently performed because of its cost- and time-effectiveness. Advancement in non-invasive imaging has enabled FFR to be derived non-invasively using coronary CT angiography (CCTA), without the need for induction of hyperemia or modification of the standard CCTA acquisition protocol. FFR derived from CCTA (FFRCT) has been shown to have excellent correlation with invasive FFR, and remains an effective diagnostic tool in the presence of reduced signal-to-noise ratio, coronary calcification and motion artifact. The utility of FFRCT has also helped to deepen our understanding of hemodynamically significant CAD. Hence, there is now interest in exploring the possible interplay between these mechanistic forces and their effect on the development of coronary plaque and the vulnerability of these plaques.

A 2-year investigation of the impact of the computed tomography-derived fractional flow reserve calculated using a deep learning algorithm on routine decision-making for coronary artery disease management

OBJECTIVE

This study aims to investigate the safety and feasibility of using a deep learning algorithm to calculate computed tomography angiography-based fractional flow reserve (DL-FFRCT) as an alternative to invasive coronary angiography (ICA) in the selection of patients for coronary intervention.

MATERIALS AND METHODS

Patients (N = 296) with symptomatic coronary artery disease identified by coronary computed tomography angiography (CTA) with stenosis over 50% were retrospectively enrolled from a single centre in this study. ICA-guided interventions were performed in patients at admission, and DL-FFRCT was conducted retrospectively. The influences on decision-making by using DL-FFRCT and the clinical outcome were compared to those of ICA-guided care for symptomatic CAD at the 2-year follow-up evaluation.

RESULT

Two hundred forty-three patients were evaluated. Up to 72% of diagnostic ICA studies could have been avoided by using a DL-FFRCT value > 0.8 as a cut-off for intervention. A similar major adverse cardiovascular event (MACE) rate was observed in patients who underwent revascularisation with a DL-FFRCT value ≤ 0.8 (2.9%) compared to that of ICA-guided interventions (3.3%) (stented lesions with ICA stenosis > 75%) (p = 0.838).

CONCLUSION

DL-FFRCT can reduce the need for diagnostic coronary angiography when identifying patients suitable for coronary intervention. A low MACE rate was found in a 2-year follow-up investigation.

KEY POINTS

• Seventy-two percent of diagnostic ICA studies could have been avoided by using a DL-FFRCT value > 0.8 as a cut-off for intervention. • Coronary artery stenting based on the diagnosis by using a 320-detector row CT scanner and a positive DL-FFRCT value could potentially be associated with a lower occurrence rate of major adverse cardiovascular events (2.9%) within the first 2 years. • A low event rate was found when intervention was performed in tandem lesions with haemodynamic significance based on DL-FFRCT < 0.8 as a cut-off value.

Functional cardiac CT-Going beyond Anatomical Evaluation of Coronary Artery Disease with Cine CT, CT-FFR, CT Perfusion and Machine Learning

The aim of this review is to provide an overview of different functional cardiac CT techniques which can be used to supplement assessment of the coronary arteries to establish the significance of coronary artery stenoses. We focus on cine-CT, CT-FFR, CT-myocardial perfusion and how developments in machine learning can supplement these techniques.

Coronary flow impairment in asymptomatic patients with early stage type-2 diabetes: Detection by FFRCT

PURPOSE

To determine the occurrence of physiological significant coronary artery disease (CAD) by coronary CT angiography (CTA) derived fractional flow reserve (FFRCT) in asymptomatic patients with a new diagnosis (<1 year) of type-2 diabetes mellitus (T2DM).

METHODS

FFRCT-analysis was performed from standard acquired coronary CTA data sets. The per-patient minimum distal FFRCT-value (d-FFRCT) in coronary vessels (diameter ⩾1.8 mm) was registered. The threshold for categorizing FFRCT-analysis as abnormal was a d-FFRCT ⩽0.75. Total plaque volume and volumes of calcified plaque, non-calcified plaque, and low-density non-calcified plaque (LD-NCP) were assessed by quantitative plaque analysis.

RESULTS

Overall, 76 patients; age, mean (SD): 56 (11) years; males, n (%): 49(65), were studied. A total of 57% of patients had plaques. The d-FFRCT was ⩽0.75 in 12 (16%) patients. The d-FFRCT, median (IQR), was 0.84 (0.79-0.87). Median (range) d-FFRCT in patients with d-FFRCT ⩽0.75 was 0.70 (0.6-0.74). Patients with d-FFRCT⩽0.75 versus d-FFRCT >0.75 had numerically higher plaque volumes for all plaques components, although only significant for the LD-NCP component.

CONCLUSION

Every sixth asymptomatic patient with a new diagnosis of T2DM has hemodynamic significant CAD as evaluated by FFRCT. Flow impairment by FFRCT was associated with coronary plaque characteristics.

Temporal changes in FFRCT-Guided Management of Coronary Artery Disease - Lessons from the ADVANCE Registry

BACKGROUND

The ADVANCE registry is a large prospective study of outcomes and resource utilization in patients undergoing coronary computed tomography angiography (CCTA) and CT-based fractional flow reserve (FFR_CT). As experience with new technologies and practices develops over time, we investigated temporal changes in the use of FFR_CT within the ADVANCE registry.

METHODS

5083 patients with coronary artery disease (CAD) on CCTA were prospectively enrolled in the ADVANCE registry and were divided into 3 equally sized cohorts based on the temporal order of enrollment per site. Demographics, CCTA and FFR_CT findings, and clinical outcomes through 1-year follow-up, were recorded and compared between tertiles.

RESULTS

The number of patients with a ≥70% stenosis on CCTA was similar over time (33.6%, 30.9%, and 33.8% for cohort 1-3). The rate of positive FFR_CT ≤0.80 was higher for cohorts 2 (67.3%) and 3 (74.6%) than for cohort 1 (57.1%, p < 0.001). Invasive FFR rates decreased from 25.8% to 22.4% between cohort 1 and 3 (p = 0.023). Moreover, patients with a FFR_CT ≤0.80 were less frequently referred for invasive coronary angiography (ICA) (from 62.9% to 52.9%, p < 0.001), and underwent fewer revascularizations between cohort 1 and 3 (from 41.9% to 32.0%, p < 0.001). The prevalence of major events was low (1.2%) and similar between cohorts.

CONCLUSIONS

Growing experience with FFR_CT improved the likelihood of identifying hemodynamically significant CAD and safely reduced the need for ICA and revascularization in patients with anatomically significant disease even in the instance of an abnormal FFR_CT.

Cardiac Computed Tomography for Comprehensive Coronary Assessment: Beyond Diagnosis of Anatomic Stenosis

Cardiac computed tomography angiography (CCTA) has evolved into a versatile imaging modality that can depict atherosclerosis burden, determine functional significance of a stenotic lesion, and guide the management and treatment of stable coronary artery disease.1 With newer-generation scanners, diagnostic CCTA can be obtained in the majority of patients with a very acceptable radiation dose. We discuss the ability of CCTA to provide comprehensive assessment of a patient with suspected CAD, including functional techniques of stress-rest myocardial perfusion assessment using a vasodilator and a purely post-processing approach that assesses fractional flow reserve derived by CCTA. In addition, recent data validated the role of CCTA in managing stable patients with chest pain and suspected CAD, serving as a gatekeeper for invasive coronary angiogram as well as optimizing the preprocedural planning of percutaneous coronary revascularization and coronary artery bypass surgery.

Fractional Flow Reserve Derived from Coronary Computed Tomography Angiography Safely Defers Invasive Coronary Angiography in Patients with Stable Coronary Artery Disease

OBJECTIVES

In the United States, the real-world feasibility and outcome of using fractional flow reserve from coronary computed tomography angiography (FFR_CT) is unknown. We sought to determine whether a strategy that combined coronary computed tomography angiography (CTA) and FFR_CT could safely reduce the need for invasive coronary angiography (ICA), as compared to coronary CTA alone.

METHODS

The study included 387 consecutive patients with suspected CAD referred for coronary CTA with selective FFR_CT and 44 control patients who underwent CTA alone. Lesions with 30-90% diameter stenoses were considered of indeterminate hemodynamic significance and underwent FFR_CT. Nadir FFR_CT ≤ 0.80 was positive. The rate of patients having ICA, revascularization and major adverse cardiac events were recorded.

RESULTS

Using coronary CTA and selective FFR_CT, 121 patients (32%) had at least one vessel with ≥50% diameter stenosis; 67/121 (55%) patients had at least one vessel with FFR_CT ≤ 0.80; 55/121 (45%) underwent ICA; and 34 were revascularized. The proportion of ICA patients undergoing revascularization was 62% (34 of 55). The number of patients with vessels with 30-50% diameter of stenosis was 90 (23%); 28/90 (31%) patients had at least one vessel with FFR_CT ≤ 0.80; 8/90 (9%) underwent ICA; and five were revascularized. In our institutional practice, compared to coronary CTA alone, coronary CTA with selective FFR_CT reduced the rates of ICA (45% vs. 80%) for those with obstructive CAD. Using coronary CTA with selective FFR_CT, no major adverse cardiac events occurred over a mean follow-up of 440 days.

CONCLUSION

FFR_CT safely deferred ICA in patients with CAD of indeterminate hemodynamic significance. A high proportion of those who underwent ICA were revascularized.

Fractional Flow Reserve Derived from CT: The State of Play in 2020

Fractional flow reserve derived from CT is a rapidly developing technique, with an increasing burden of literature supporting its potential role in the workup of patients suspected of having coronary artery disease.

Coronary CT Angiography-derived Fractional Flow Reserve Testing in Patients with Stable Coronary Artery Disease: Recommendations on Interpretation and Reporting

Noninvasive fractional flow reserve derived from coronary CT angiography (FFRCT) is increasingly used in patients with coronary artery disease as a gatekeeper to the catheterization laboratory. While there is emerging evidence of the clinical benefit of FFRCT in patients with moderate coronary disease as determined with coronary CT angiography, there has been less focus on interpretation, reporting, and integration of FFRCT results into routine clinical practice. Because FFRCT analysis provides a plethora of information regarding pressure and flow across the entire coronary tree, standardized criteria on interpretation and reporting of the FFRCT analysis result are of crucial importance both in context of the clinical adoption and in future research. This report represents expert opinion and recommendation on a standardized FFRCT interpretation and reporting approach. Published under a CC BY 4.0 license.

FFRCT and CT perfusion: A review on the evaluation of functional impact of coronary artery stenosis by cardiac CT

Coronary computed tomography angiography (CCTA) is at the frontline of the diagnostic strategies to detect coronary artery disease (CAD). Anatomical information have proven to be insufficient to detect hemodynamic significant epicardial stenosis. In the present invited review we discuss on FFR_CT and stress CTP, emerging technologies for an accurate and comprehensive evaluation of patients with suspected CAD, offering both anatomical (i.e. luminal and plaque) and functional assessment in one single technique.

The year 2018 in the European Heart Journal - Cardiovascular Imaging: Part I

The European Heart Journal - Cardiovascular Imaging has become one of the leading multimodality cardiovascular imaging journal, since it was launched in 2012. The impact factor is an impressive 8.366 and it is now established as one of the top 10 cardiovascular journals. The journal is the most important cardiovascular imaging journal in Europe. The most important studies from 2018 will be highlighted in two reports. Part I of the review will focus on studies about myocardial function and risk prediction, myocardial ischaemia, and emerging techniques in cardiovascular imaging, while Part II will focus on valvular heart disease, heart failure, cardiomyopathies, and congenital heart disease.

Clinical Use of CT-Derived Fractional Flow Reserve in the Emergency Department

OBJECTIVES

This study sought to examine the feasibility, safety, clinical outcomes, and costs associated with computed tomography-derived fractional flow reserve (FFR_CT) in acute chest pain (ACP) patients in a coronary computed tomography angiography (CTA)-based triage program.

BACKGROUND

FFR_CT is useful in determining lesion-specific ischemia in patients with stable ischemic heart disease, but its utility in ACP has not been studied.

METHODS

ACP patients with no known coronary artery disease undergoing coronary CTA and coronary CTA with FFR_CT were studied. FFR_CT ≤0.80 was considered positive for hemodynamically significant stenosis.

RESULTS

Among 555 patients, 297 underwent coronary CTA and FFR_CT (196 negative, 101 positive), whereas 258 had coronary CTA only. The rejection rate for FFR_CT was 1.6%. At 90 days, there was no difference in major adverse cardiac events (including death, nonfatal myocardial infarction, and unexpected revascularization after the index visit) between the coronary CTA and FFR_CT groups (4.3% vs. 2.7%; p = 0.310). Diagnostic failure, defined as discordance between the coronary CTA or FFR_CT results with invasive findings, did not differ between the groups (1.9% vs. 1.68%; p = NS). No deaths or myocardial infarction occurred with negative FFR_CT when revascularization was deferred. Negative FFR_CT was associated with higher nonobstructive disease on invasive coronary angiography (56.5%) than positive FFR_CT (8.0%) and coronary CTA (22.9%) (p < 0.001). There was no difference in overall costs between the coronary CTA and FFR_CT groups ($8,582 vs. $8,048; p = 0.550).

CONCLUSIONS

In ACP, FFR_CT is feasible, with no difference in major adverse cardiac events and costs compared with coronary CTA alone. Deferral of revascularization is safe with negative FFR_CT, which is associated with higher nonobstructive disease on invasive angiography.

Prognosis of CT-derived Fractional Flow Reserve in the Prediction of Clinical Outcomes

Purpose

To examine the prognostic implication of fractional flow reserve (FFR) derived from coronary CT (FFR_CT) in routine clinical practice.

Materials and Methods

Patients referred for FFR_CT analysis at a single center between October 2015 and June 2017 were retrospectively included and followed up for rates of invasive angiography and clinical events. Two hundred seven patients underwent successful FFR_CT analysis with seven lost to follow-up, leaving 200 (mean age ± standard deviation, 62.4 years ± 10.0; 49 [24.5%] women) patients for analysis. At coronary CT angiography, patients were categorized as having significant stenosis (SS) in the presence of a diameter stenosis greater than or equal to 50% (hereafter, SS positive) and flow limitation in the presence of a postlesion (that is, FFR_CT measured 2 cm to the distal aspect of the lesion) FFR_CT less than 0.80 (hereafter, FFR_CT positive). Vessel-oriented clinical events (VOCEs) were defined as vessel-related late revascularization (>90 days), myocardial infarction, and cardiac mortality.

Results

At CT angiography, 130 (65%) studies were SS positive and 63 (31.5%) were FFR_CT positive. At median follow-up of 477 days (range, 252-859 days), there were 26 VOCE end points in 22 patients: 22 revascularizations and four nonfatal myocardial infarctions. VOCE end points occurred in zero of 58 (0%) of SS-negative and FFR_CT negative patients, in eight of 79 (10.1%) of SS-positive and FFR_CT-negative patients, in zero of 12 (0%) of SS-negative and FFR_CT-positive patients, and in 18 of 51 (35.3%) of SS-positive and FFR_CT-positive patients (log-rank χ² = 30.1; P < .001). At multivariable Cox regression, both FFR_CT (hazard ratio per 0.1 decrease, 1.54 [95% confidence interval: 1.1, 2.2] P = .013) and stenosis (hazard ratio per unit increase, 2.16 [95% confidence interval: 1.25, 3.72] P = .006) were independently associated with VOCE.

Conclusion

Stenosis and FFR_CT are independent predictors of intermediate-term outcomes. In the absence of a stenosis greater than 50%, a positive FFR_CT result is not associated with an increased intermediate risk.© RSNA, 2019Supplemental material is available for this article.See also commentary by Fairbairn and Bull in this issue.

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 (FFR_CT) is unknown. Purpose To determine the prognostic value of FFR_CT when compared with coronary CT angiography and describe the relationship of the numeric value of FFR_CT 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 FFR_CT. 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 FFR_CT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFR_CT 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 FFR_CT. The incidence of the primary end point was more frequent in participants with positive FFR_CT 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 FFR_CT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFR_CT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFR_CT, 0.76 vs coronary CT angiography, 0.54; P < .001) and MACE (FFR_CT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFR_CT 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 FFR_CT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFR_CT 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 (FFR_CT) 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 FFR_CT 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.

Current Evidence in Cardiothoracic Imaging: Computed Tomography-derived Fractional Flow Reserve in Stable Chest Pain

High-accuracy diagnostic imaging is needed to diagnose and manage coronary artery disease as well as to allow risk stratification for future events. Advancements in multidetector computed tomography and image postprocessing allow for routine computed tomography coronary angiography to provide anatomic luminal assessment similar to invasive coronary angiography, and, similarly, computational fractional flow reserve derived from computed tomography facilitates determination of hemodynamically relevant stenosis comparable to invasive fractional flow reserve. In this review article, we describe the diagnostic performance and the potential impact of fractional flow reserve derived from computed tomography in clinical practice.

Real-world clinical utility and impact on clinical decision-making of coronary computed tomography angiography-derived fractional flow reserve: lessons from the ADVANCE Registry

AIMS

Non-invasive assessment of stable chest pain patients is a critical determinant of resource utilization and clinical outcomes. Increasingly coronary computed tomography angiography (CCTA) with selective CCTA-derived fractional flow reserve (FFRCT) is being used. The ADVANCE Registry, is a large prospective examination of using a CCTA and FFRCT diagnostic pathway in real-world settings, with the aim of determining the impact of this pathway on decision-making, downstream invasive coronary angiography (ICA), revascularization, and major adverse cardiovascular events (MACE).

METHODS AND RESULTS

A total of 5083 patients with symptoms concerning for coronary artery disease (CAD) and atherosclerosis on CCTA were enrolled at 38 international sites from 15 July 2015 to 20 October 2017. Demographics, symptom status, CCTA and FFRCT findings, treatment plans, and 90 days outcomes were recorded. The primary endpoint of reclassification between core lab CCTA alone and CCTA plus FFRCT-based management plans occurred in 66.9% [confidence interval (CI): 64.8-67.6] of patients. Non-obstructive coronary disease was significantly lower in ICA patients with FFRCT ≤0.80 (14.4%) compared to patients with FFRCT >0.80 (43.8%, odds ratio 0.19, CI: 0.15-0.25, P < 0.001). In total, 72.3% of subjects undergoing ICA with FFRCT ≤0.80 were revascularized. No death/myocardial infarction (MI) occurred within 90 days in patients with FFRCT >0.80 (n = 1529), whereas 19 (0.6%) MACE [hazard ratio (HR) 19.75, CI: 1.19-326, P = 0.0008] and 14 (0.3%) death/MI (HR 14.68, CI 0.88-246, P = 0.039) occurred in subjects with an FFRCT ≤0.80.

CONCLUSIONS

In a large international multicentre population, FFRCT modified treatment recommendation in two-thirds of subjects as compared to CCTA alone, was associated with less negative ICA, predicted revascularization, and identified subjects at low risk of adverse events through 90 days.

Fractional Flow Reserve Derived from Coronary Computed Tomography Angiography Datasets: The Next Frontier in Noninvasive Assessment of Coronary Artery Disease

Fractional flow reserve (FFR) derived from coronary CTA datasets (FFR_CT) is a major advance in cardiovascular imaging that provides critical information to the Heart Team without exposing the patient to excessive risk. Previously, invasive FFR measurements obtained during a cardiac catheterization have been demonstrated to reduce contrast use, number of stents, and cost of care and improve outcomes. However, there are barriers to routine use of FFR in the cardiac catheterization suite. FFR_CT values are obtained using resting 3D coronary CTA images using computational fluid dynamics. Several multicenter clinical trials have demonstrated the diagnostic superiority of FFR_CT over traditional coronary CTA for the diagnosis of functionally significant coronary artery disease. This review provides a background of FFR, technical aspects of FFR_CT, clinical applications and interpretation of FFR_CT values, clinical trial data, and future directions of the technology.

The Relationship between Compound Danshen Dripping Pills with Isosorbide Mononitrate in the Treatment of Elderly Patients with Unstable Angina Pectoris

Objective

To evaluate the clinical efficacy and safety of Compound Danshen Dripping Pill (CDDP) and Isosorbide Mononitrate (ISMN) in the treatment of unstable angina pectoris (UAP) in the elderly.

Materials and Methods

CNKI, Wanfang, VIP, CBM, and PubMed databases were searched for appropriate articles without language limitations on keywords. RevMan 5.3 software was used to perform the meta-analysis.

Results

This analysis compared CDDP with ISMN of 21 randomized controlled trials (RCTs) that involved a total of 2356 patients with UAP. When the treatment lasted for four weeks, the clinical effective rate was OR = 3.97, 95% CI = 2.97, 5.30, and P < 0.00001, the ECG efficiency was OR = 3.43, 95% CI = 2.13, 5.53, and P < 0.00001, and incidence of adverse reactions was OR = 0.73, 95% CI = 0.52, 1.04, and P = 0.08 > 0.05. When the treatment lasted for eight weeks, clinical efficiency rate was OR = 4.22, 95% CI = 2.37, 3.79, and P < 0.00001, incidence of adverse reactions was OR = 0.58, 95% CI = 0.26, 1.27, and P = 0.17 > 0.05, whole blood low-cut blood viscosity was SMD = -0.61 and 95% CI -1.60, 0.38, whole blood high-cut blood viscosity was SMD = -0.38 and 95% CI -0.97, 0.21, and blood cells specific volume was SMD = -0.80 and 95% CI -2.61, 1.01.

Conclusion

Based on this meta-analysis, the CDDP was superior to ISMN with UAP in the elderly. However, there is still a need to further verify the clinical efficacy and safety of CDDP with more strictly designed RCTs with large sample and multiple centers in the future.

FFRCT for Complex Coronary Artery Disease Treatment Planning: New Opportunities

Coronary computed tomography (CT) is well established for the assessment of symptomatic patients with suspected but not yet confirmed coronary artery disease with high diagnostic accuracy and risk prediction. Until recently, coronary computed tomography angiography (CTA) has played a limited role in the management of complex coronary artery disease (CAD) and in planning revascularisation strategies. With the advent of FFR_CT, enabling anatomy and physiology with a single study and the ability to adjudicate lesion specific pressure loss, the potential of combined coronary CT angiography (CCTA) and fractional flow reserve (FFR) computed from non-invasive CT angiography (FFR_CT) to inform treatment decision-making and help guide revascularisation has been recognised. In this review, we highlight the evolving role of FFR_CT in the management of complex CAD; the opportunities, the data and the unanswered questions.

Coronary CT Angiography Derived Fractional Flow Reserve: The Game Changer in Noninvasive Testing

PURPOSE OF REVIEW

To summarize the scientific basis of CT derived fractional flow reserve (FFR_CT) and present an updated review on the evidence from clinical trials and real-world observational data RECENT FINDINGS: In prospective multicenter studies of patients with stable coronary artery disease (CAD), FFR_CT showed high diagnostic performance. More recently, FFR_CT has advanced to the realm of clinical utility and real-world clinical practice with emerging data showing that FFR_CT when compared to standard care is efficient in safely reducing downstream utilization of invasive coronary angiography (ICA), and costs, as well as improving the diagnostic yield of ICA. Moreover, FFR_CT may broaden applicability of frontline coronary CTA testing to patients with high pre-test risk of CAD. Introducing FFR_CT into clinical practice has the potential to significantly improve the management of patients with stable CAD. The optimal FFR_CT testing interpretation strategy, as well as the relative cost-efficiency of FFR_CT against standard noninvasive functional testing, need further investigation.