Effect of FFRCT-angio in Functional Diagnosis of Coronary Artery Stenosis: a Prospective, Multicenter Clinical Study
Trial ID: NCT04493086
Status: UNKNOWN
Study type: OBSERVATIONAL
Start date: 2020-10-01
Completion date: 2021-12-31
Sponsor: First Affiliated Hospital of Harbin Medical University
Conditions: Coronary Artery Disease
Interventions: FFRCT-angio
Locations: the first affiliated hospital of Harbin medical university
Countries: China
Enrollment: 500
Age range: 18 Years - 90 Years
Sex: ALL

Summary:
Coronary CT angiography (CTA) or invasive coronary angiography (CAG) is usually performed to evaluate the severity of coronary stenosis depending on the probability of CAD. However, the stenosis severity is not closely corresponding with the hemodynamic significance in coronary arteries.

As a result, fractional flow reserve (FFR) with pressure wire measurement was introduced to functionally assess the coronary stenosis. FFR is defined as the ratio of maximum blood flow distal to a stenotic lesion under hyperemia state to normal maximum flow in the same vessel. The cutoff value of FFR to detect significant ischemia is set to be 0.80, indicating that PCI should be considered if FFR≤0.80. However, FFR does have some limitations, such as risks of pressure wire injury, extra time and cost, and side effects of hyperemic agents.

To overcome the limitations of FFR, CTA- and CAG-based methods to functionally assess coronary stenosis were proposed, i.e. FFR derived from CTA (FFRCT) and FFR derived from angiography-based quantitative flow ratio (QFR), which can simultaneously evaluate anatomic and hemodynamic significance of stenotic lesions. A number of studies have demonstrated that FFRCT has high sensitivity and specificity in identifying myocardial ischemia. However, the diagnostic accuracy of FFRCT depends on the image quality of coronary CTA, and it is relatively low in lesions with severe calcification and/or tortuosity. Besides, the methodology of FFRCT relies on computational fluid dynamics, which is complicated and time consuming. As for QFR, it is a novel method for deriving FFR based on 3-dimensional quantitative coronary angiography (3D-QCA) and contrast frame counting during CAG. Recent studies have shown that QFR has good diagnostic performance in evaluating the functional significance of coronary stenosis. The accuracy of QFR is also highly associated with anatomic information, thereby its diagnostic accuracy may be decreased in diffuse, tandem, thrombus-containing, calcified, or torturous lesions, and it is not suitable for prior infarction-related or collateral donor arteries as well. Given the above issues concerning FFRCT and QFR, we proposed a novel approach that integrates coronary CTA and CAG images to calculate FFR (FFRCT-angio) using artificial intelligence. The present study was undertaken to test the diagnostic accuracy of FFRCT-angio in patients with SCAD.

Eligibility criteria:
Inclusion Criteria:

* Patients with stable coronary heart disease undergoing CTA.
* Patients with at least one coronary artery stenosis of 50% - 90% in diameter ≥ 2mm.
* Within 30 days after CTA, CAG and FFR were determined by clinicians according to their condition.

Exclusion Criteria:

* Patients with myocardial infarction within 72 hours.
* Patients with coronary artery thrombosis.
* Patients with a history of allergy to contrast media or adenosine.
* NYHA class III-IV patients.
* Patients with previous CABG, target vessel PCI, pacemaker, ICD.
* Patients with a history of prosthetic valve implantation.
* Patients with myocardial bridges in the target vessels.
* Patients with severe arrhythmia.

Outcomes:
By taking FFR value as the standard, evaluating the accuracy of FFRCT-angio in the functional significance of coronary stenosis