Role of On-site CT-derived FFR in the Management of Suspect CAD Patients

Study Overview
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Brief Summary
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The primary of this registry is to evaluate whether the availability of CTA/CT-FFR procedure could effectively optimize the flow of clinical practice of stable chest pain versus conventional clinical pathway in decision making, avoid the overuse of invasive procedure, finally improve clinical prognosis and reduce total medical expenditure. This registry is randomized, open labeled, prospective designed and will be performed in 6 Chinese hospitals. Approximately 1200 subjects will be enrolled and subsequently assigned to either routine clinically-indicated diagnostic care group (CID arm) or CTA/CT-FFR care group (CTA/CT-FFR arm) via computer-generated random numbers (1:1 ratio)

Detailed Description
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Based on the clinical fact that less stress single photon emission computed tomography (SPECT) and stress magnetic resonance imaging (MRI) are performed rather than stress exercise electrocardiogram (ECG) in China, more patients undergo coronary computed tomographic angiography (CTA) for determining whether they should be sent to catheter lab. However, nearly 30% of patients sent to catheter lab were found without obstructive coronary artery disease (CAD) and this invasive procedure was unnecessary and overused partly. Fortunately, fractional flow reserve (FFR) based non-invasive CT algorithm technology (CT-FFR) showed a great potential in detecting functional myocardial ischemia related to coronary specific lesion (Discovery-Flow, DEFACTO and NXT trial)[1-3]. Moreover, clinical care guided by CT-FFR could provide benefits with equivalent clinical outcomes and lower expenditure, compared with routine clinical care over 1-year follow-up (Platform trial). On the other aspect, ADVANCE trial revealed that CT-FFR modified treatment recommendation was associated with less negative invasive coronary angiography (ICA), predicted revascularization and identified subjects at low risk of adverse events through 90 days in real-world. However, these studies was not randomized designed and selection bias still existed. So our registry is aim to evaluate whether CTA/CT-FFR outperforms the regular diagnostic care in ruling out patients without significantly obstructive CAD before catheter lab and improving clinical prognosis during follow-up in a randomized design.

Official Title
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The Effect of On-site CT-derived Fractional Flow Reserve on the Management Making for the Patients With Stable Chest Pain (TARGET Trial)

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: CT-FFR


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: New or worsening chest pain suspicious for clinically significant coronary artery disease Coronary CTA result showed that the diameter stenosis is more than 30% in one major coronary artery at least (coronary artery diameter greater than 2.5mm) Intermediate likelihood of CAD based on CAD Consortium Score No prior evaluation for this episode of symptoms Agree to participate in this clinical study and sign written informed consent Exclusion Criteria: Diagnosed or suspected acute coronary syndrome requiring hospitalization or urgent or emergent testing Hemodynamically or clinically unstable condition systolic blood pressure < 90 mmHg or serious atrial or ventricular arrhythmias Persistent resting chest pain felt to be ischemic despite adequate therapy Known CAD with prior myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG) or any angiographic evidence of ≥50% stenosis in any major coronary artery Any invasive or non-invasive anatomic or functional cardiovascular test for detection of CAD, including ICA and exercise ECG within the previous 12 months Known significant congenital, valvular (moderate and above) or cardiomyopathy process (hypertrophic cardiomyopathy or reduced systolic left ventricular function ≤ 40%) which could explain cardiac symptoms Contraindication to undergo coronary CTA, including but not limited to allergy to iodinated contrast agent, unable to receive β-blockers if needed during CT procedural, pregnancy, serum creatinine ≥1.5 mg/dL Unable to provide written informed consent or participate in long-term follow-up

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CTA/CT-FFR care group<br>If the subjects are randomly allocated to CTA/CT-FFR arm, they will be examined by DeepFFR for three major epicardial arteries. If CT-FFR value of one or more major coronary arteries is less than 0.75, ICA will be performed directly; if CT-FFR is 0.75-0.8 (including 0.8), physicians will decide whether to start intensive drug therapy or ICA; if CT-FFR value is more than 0.8, only drug therapy will be needed. The clinical management plan will be suggested including optimal medical therapy, ICA, PCI, CABG and other intervention according to the result of this non-invasive examination. | Diagnostic Test: CT-FFR<br>* When subjects are randomized to the CTA/CT-FFR arm, FFR based on the coronary CTA imaging will be measured. DeepFFR workstation is very dedicated software utilizing the original CTA imaging to meter simulated FFR values in artificial intelligence model.The first step is to extract a 3D coronary artery model and generate coronary centerlines which are similar to the routine reconstruction of coronary CTA. The centerlines are extracted using a minimal path extraction filter. Then a novel path-based deep learning model, referred to DeepFFR, is used to predict the simulated FFR values on the vascular centerlines. Deep learning algorithm is used to establish characteristic sample database of coronary hemodynamics characteristic parameters. When deep training model is proved to be valid, it is applied to a new lesion-specific measurement. Lesion-specific CT-FFR is defined as simulated FFR value 2-3cm downstream of an interest lesion.<br>|
| No Intervention: routine clinically-indicated diagnostic care group<br>If the subjects are randomized to CID arm, attending physicians will decide next step of diagnosis and treatment, such as exercise ECG, stress cardiac echo, SPECT. According to the results of examination combined with risk factors assessment and clinical manifestations, physicians should provide recommendation whether the subjects would undergo ICA or not. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of ICA without obstructive CAD or intervention | Percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis≥50% by core lab quantitative analysis or invasive FFR≤0.8) is found or interventions (including stent implantation, balloon dilation and bypass graft) are performed during ICA within 90 days. | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major adverse cardiovascular event | Major adverse cardiovascular event include death, myocardial infarction (MI), major complications from cardiovascular (CV) procedures or testing, and unstable angina hospitalization | 90 days，6 months，12 months | 
| Medical expenditure | Medical expenditure by intention to treat at both 90 days and 12 months cumulatively | 90 days，12 months | 
| Quality of life score | Quality of life score evaluated as quality of life (QOL), which is measured by Seattle Angina Questionnaire Scale, used 11-item instrument that measures patient reported symptoms, function and QOL for subjects with CAD within 12 months | 12 months | 
| Cumulative radiation exposure | Cumulative radiation exposure for any examination within 90 days and 12 months | 90 days, 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary artery disease, Coronary computed tomographic angiography, Fractional flow reserve