Diagnostic Performance of Exercise Stress Tests for the Detection of Epicardial and Microvascular Coronary Artery Disease

Study Overview
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Brief Summary
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Prospective, single-arm, multicenter study of patients with an intermediate pre-test probability of CAD and positive exercise stress tests referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references.

Detailed Description
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The Redefining the Diagnostic Performance of Non-invasive Tests for the Detection of Coronary Artery Disease: UZ Clear is an investigator-initiated, single-arm, multicenter, prospective study of patients presenting with chest pain with an intermediate probability of CAD. The intermediate pre-test probability of CAD was defined based on the European Society of Cardiology Guidelines as a score between 15% and 85% based on age, sex, and the nature of symptoms. All patients had a positive exercise stress test and were referred for an invasive evaluation. Patients underwent a study protocol with an invasive diagnostic procedure (IDP) consisting of measurements of FFR and IMR in at least one coronary vessel. Exclusion criteria are acute coronary syndromes, known coronary artery disease, previous myocardial infarction, previous revascularization, and abnormal baseline electrocardiogram (ECG). All data were centrally collected and analyzed by the core laboratory. The primary objective was to determine the false discovery rate of exercise stress tests using an interventional diagnostic procedure (IDP) with indexes of epicardial (FFR) and microvascular resistance (IMR) as clinical references. The secondary objective was to assess the impact of an IDP accounting for the presence of CMD on the accuracy of exercise stress tests.

Official Title
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Diagnostic Performance of Exercise Stress Tests for the Detection of Epicardial and Microvascular Coronary Artery Disease

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: Index of Microvascular Resistance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - 1. Stable angina-like chest pain (typical or atypical) with intermediate (15-85%) pre-test probability of coronary artery disease using the ESC criteria. 2. Positive non-invasive exercise test, or inconclusive stress with additional positive imaging. Exclusion Criteria: Age <30 or >80-year old Acute coronary syndromes. Known coronary artery disease Inability to perform exercise tests. Previous myocardial infarction. Previous CABG/PCI Left ventricular dysfunction EF <35% or NYHA class III-IV Uncontrolled or recurrent ventricular tachycardia Atrial fibrillation Severe renal dysfunction, defined as an eGFR <30 ml/min/1.73m2 Contra-indication to adenosine (e.g. asthma bronchial, severe COPD) Active cancer Recent stroke Cardiomyopathy (dilated, hypertrophic, amyloidosis, arrhythmogenic right ventricular dysplasia) Left Bundle Branch Block or baseline ST-segment depression >1mm. Congenital heart disease More than moderate valve disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Index of Microvascular Resistance|The invasive diagnostic procedure will be performed in at least one coronary artery. The left anterior descending coronary artery will be the preferred target vessel; however, if technical factors precluded guidewire-based assessment of this artery (e.g., tortuous anatomy), then the left circumflex or right coronary artery can be selected. In the case of multiple measurements per patient, the lowest FFR or highest IMR will be used for analysis. A coronary wire with a pressure and temperature sensor (PressureWire X, Abbott Vascular, Santa Clara, CA, USA) will be advanced to the mid to distal segment of the coronary artery. Bolus thermodilution technique with three 3-cc saline injections in rest and hyperemia will be used.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary objective was to determine the false discovery rate of exercise stress tests using an interventional diagnostic procedure (IDP) with indexes of epicardial (FFR) and microvascular resistance (IMR) as clinical references. | Diagnostic performance of exercise tests with false discovery rate | Immediately post-procedural | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| to assess the impact of an IDP accounting for the presence of CMD on the accuracy of exercise stress tests. | Comparison of false discovery rates using QCA, FFR and IMR as gold standards | Immediately post-procedural |