Finding the Invasive Haemodynamic Threshold for Symptom Relief in Stable Angina

Study Overview
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Brief Summary
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ORBITA-FIRE is a randomised, double-blinded, placebo controlled experimental study that will identify the fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) thresholds that correlate with symptoms of angina for 58 patients measured invasively under experimental conditions.

Official Title
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Finding the Invasive Haemodynamic Threshold for Symptom Relief in Stable Angina

Conditions
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Stable Angina

Intervention / Treatment
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* Diagnostic Test: Rest-angina physiological assessment
* Diagnostic Test: Exercise-angina physiological assessment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Eligibility for percutaneous coronary intervention (PCI) due to angina or angina-equivalent symptoms on exertion Anatomical evidence of significant single-vessel coronary stenosis defined by either: ≥70% stenosis on invasive coronary angiography (ICA) Severe stenosis on CT coronary angiography (CTCA) Physiological evidence of ischaemia with a positive test on at least one of the following: Stress echocardiography Cardiac magnetic resonance perfusion Myocardial perfusion scintigraphy Invasive metrics of coronary physiology Exclusion Criteria: Age <18 years Recent acute coronary syndrome Previous coronary artery by-pass graft Significant left main stem disease Multivessel disease (defined as >50% angiographic stenosis in other vessels) Chronic total occlusion in the target artery Moderate to severe valvular disease Moderate to severe left ventricular impairment Chronotropic incompetence with a pacemaker Contraindication to PCI or a drug-eluting stents Contraindication to antiplatelet therapy Contraindication to adenosine Moderate to severe respiratory disease Physical inability to exercise Pregnant Inability to consent

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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with stable angina<br>Symptomatic Anatomically severe single-vessel coronary artery disease Physiological evidence of myocardial ischaemia | Diagnostic Test: Rest-angina physiological assessment<br>* The degree of stenosis required to cause angina at rest will be measured under double-blinded placebo controlled conditions using sequential intracoronary balloon inflations. This will then be correlated with various physiological indices, including FFR and iFR.<br>Diagnostic Test: Exercise-angina physiological assessment<br>* The degree of stenosis required to cause angina during exercise will be measured under double-blinded placebo controlled conditions using sequential intracoronary balloon inflations. This will then be correlated with various physiological indices, including FFR and iFR.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The FFR and iFR value at which the patient experiences angina in a rest state | Values 0.00-1.00 (Lower = More significant disease) | Intra-procedural | 
| The FFR and iFR value at which the patient experiences angina in an exercise state | Values 0.00-1.00 (Lower = More significant disease) | Intra-procedural | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The FFR difference between the rest and exercise states | Values 0.00-1.00 (Lower = More significant disease) | Intra-procedural | 
| The iFR difference between the rest and exercise states | Values 0.00-1.00 (Lower = More significant disease) | Intra-procedural | 
| Angina severity score at the angina threshold | The patient scores the severity of the angina experienced during the procedure between 0-10 (Higher = More severe) | Intra-procedural | 
| Angina similarity score at the angina threshold | The patient scores the similarity of the angina experienced during the procedure against the angina experienced before the procedure between 0-10 (Higher = Most similar) | Intra-procedural | 
| Angina symptom type at the angina threshold | The patient will list all symptoms experienced at the angina threshold | Intra-procedural | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Symptoms, Angina, Physiology, Placebo