Functional Diagnostic Accuracy of Ultrasonic Flow Ratio in Assessment of Left Main Coronary Artery Stenosis

Study Overview
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Brief Summary
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This is a prospective, observational, single-center study. The main purpose of this study is to evaluate the diagnostic accuracy of offline computational ultrasonic flow ratio (UFR) in predicting functionally significant left main (LM) coronary stenosis with conventional pressure wire-based fractional flow reserve (FFR) as the standard reference. The study will be conducted in Fuwai Hospital, and a total of 120 patients with intermediated left main coronary vessel diameter stenosis ≥30% and ≤80% are planned to be recruited. Participants who meet the inclusion criteria and do not meet the exclusion criteria will undergo intravascular ultrasound (IVUS) followed by FFR examination. IVUS imaging will be sent to an independent core laboratory for UFR calculation. UFR analyses were performed offline in a blinded fashion without awareness of FFR measurement. Using FFR≤0.80 as the gold standard, the sensitivity and specificity of UFR in the functional significance of left main coronary artery stenosis will be analyzed.

Official Title
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Functional Diagnostic Accuracy of Ultrasonic Flow Ratio in Assessment of Left Main Coronary Artery Stenosis

Conditions
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Left Main Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: fractional flow reserve (FFR); ultrasonic flow ratio (UFR); intravascular ultrasound (IVUS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Stable angina pectoris, unstable angina pectoris, or after the acute phase of myocardial infarction Age ≥18 years Written informed consent Intermediated left main coronary lesions (diameter stenosis of 30%-80% by visual estimation from coronary angiography) Exclusion Criteria: Ineligible for diagnostic IVUS or FFR examination Prior coronary artery bypass grafting of the interrogated vessels Myocardial infarction within 72 h of coronary angiography Severe heart failure Serum creatinine levels >150 umol/L, or glomerular filtration rates <45 ml/ kg/1.73 m2 Allergy to the contrast agent or adenosine Life expectancy < 2 years Proximal LAD diffuse lesions (diameter stenosis > 50%) IVUS pullback not covering the entire lesion Severe myocardial bridge in the interrogated vessel

Ages Eligible for Study
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Minimum Age: 18 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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: fractional flow reserve (FFR); ultrasonic flow ratio (UFR); intravascular ultrasound (IVUS)|UFR is a novel IVUS-derived modality for fast computation of FFR without pressure wires and adenosine.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy of UFR in predicting functionally significant left main coronary stenosis, using FFR as the reference standard | Diagnostic accuracy is defined as UFFR (≤0.80 or >0.80) to identify hemodynamically-significant left main coronary stenosis with FFR (≤0.80 or >0.80) as the reference standard. | Immediately after the procedure | 
| Sensitivity and specificity of UFR in predicting functionally significant left main coronary stenosis, using FFR as the reference standard | Sensitivity is defined as the proportion of UFR ≤ 0.80 in vessels with hemodynamically-significant stenosis as measured by FFR (FFR ≤ 0.80); specificity is defined as the proportion of UFR > 0.80 in vessels without hemodynamically-significant stenosis as measured by FFR (FFR > 0.80). | Immediately after the procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of sensitivity and specificity of UFR and IVUS-derived minimal lumen area (MLA) in predicting functionally significant left main coronary stenosis, using FFR as the reference standard | Sensitivity is defined as the proportion of UFR ≤ 0.80 in vessels with hemodynamically-significant stenosis as measured by FFR (FFR ≤ 0.80); specificity is defined as the proportion of UFR > 0.80 in vessels without hemodynamically-significant stenosis as measured by FFR (FFR > 0.80). | Immediately after the procedure | 
| The AUC of UFR for left main coronary stenosis with FFR as the gold standard | AUC is defined as the area under the receiver-operating characteristic curve. | Immediately after the procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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intravascular ultrasound, ultrasonic flow ratio, fractional flow reserve