Multicenter Registry of Coronary Flow-Derived Indexes for Coronary Microvascular Disease (Multicenter FLOW-CMD Registry)

Study Overview
=================
Brief Summary
-----------------
MulticenterFlow is a prospective, multi-center, registry study. The aim of the study is twofold: To evaluate prognostic implications of coronary microvascular disease (CMD) in patients with ischemic heart disease (IHD) undergoing revascularization decision using fractional flow reserve (FFR) or other non-hyperemic pressure ratios in deferred population To evaluate the efficacy of intravascular imaging-guided optimization to enhance post-revascularization coronary circulatory function, compared with angiography-only guided revascularization in revascularized population.

Detailed Description
-----------------
The diagnostic and therapeutic strategies in patients with coronary artery disease (CAD) have focused on identifying and alleviating both extent and severity of myocardial ischemia as it is the most important prognosticator. Thus, fractional flow reserve (FFR) has been a standard method for identifying ischemia-related epicardial coronary stenosis, accruing an abundance of clinical evidence on the benefit of FFR-guided treatment decisions. However, a high FFR value (>0.80) does not necessarily imply freedom from future events. Indeed, clinical events still occur in patients who are deferred based on high FFR.7 The microvasculature is one of the main components of coronary circulatory system, and the presence of microvascular disease can be the cause of clinical events in patients without epicardial coronary stenosis. In a cardiac catheterization laboratory, its presence can be assessed using a single pressure/temperature-sensor coronary wire or a Doppler wire. Previous studies have demonstrated the added prognostic implications of coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in patients with high FFR, and the recent European guidelines supported the importance of invasive physiologic assessment using CFR and IMR in patients with stable CAD. Furthermore, recent Expert Consensus Documents and the European Society of Cardiology guideline of Chronic Coronary Syndrome underlined an importance of evaluating coronary microvascular disease (CMD) in patients with ischemic heart disease (IHD) and proposed an universal definition of CMD based on 1) functionally non-obstructive CAD defined by a FFR>0.80 and 2) impaired coronary microvascular function determined by abnormal CFR and/or microvascular resistance. Another important issue in contemporary practice is how to improve patient's prognosis after percutaneous coronary intervention (PCI). Previous trials demonstrated that intravascular imaging-guided PCI optimization has significantly better clinical outcomes than angiography-only guided PCI. However, previous trial were limited with small sample size, dealt with very selected lesion subsets such as chronic total occlusion or long lesion, or could not explain the exact mechanism that can explain the potential benefit of intravascular imaging-guided PCI optimization for better clinical outcome. Although the fundamental purpose of PCI is to resolve inducible myocardial ischemia originated from the epicardial coronary stenosis, several studies have demonstrated that a substantial proportion of patients who underwent angiographically successful PCI had suboptimal post-PCI FFR18-20 or non-hyperemic pressure ratios that was independently associated with worse clinical outcomes. Previous studies demonstrated that intravascular imaging devices could identify correctable cause of suboptimal post-PCI FFR. In this regard, it can be expected that intravascular imaging-guided PCI optimization would have better post-PCI physiologic results such as higher post-PCI FFR and CFR, compared with angiography-only guided PCI. However, the abovementioned 2 important issues have not been fully clarified. For the first issue regarding the prognostic impact of CMD, only limited data has been available on the prognostic implications of CMD defined by the universal definition among patients with IHD, especially in patients with insignificant epicardial coronary disease defined by FFR>0.80. For the second issue regarding the potential physiologic benefit of intravascular imaging-guided PCI optimization, only 1 prospective study evaluated optical coherence tomography (OCT)-guided PCI for post-PCI FFR in patients with non-ST segment elevation myocardial infarction. None of prospective study evaluated potential physiologic benefit of intravascular imaging-guided PCI optimization using intravascular ultrasound (IVUS) or OCT in unselected patient population. Therefore, the primary objectives of the current multicenter prospective registry are 1) to evaluate prognostic implications of CMD in patients with IHD undergoing revascularization decision using FFR or other non-hyperemic pressure ratios 2) to evaluate physiologic benefit of intravascular imaging-guided PCI optimization over angiography-only guided PCI.

Official Title
-----------------
Prospective Registry of Coronary Flow-Derived Indexes in Patients With Coronary Artery Disease

Conditions
-----------------
Coronary Microvascular Disease, Coronary Artery Disease, Ischemic Heart Disease

Intervention / Treatment
-----------------
* Diagnostic Test: Invasive physiologic assessment
* Diagnostic Test: Intravascular imaging


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Subject must be ≥18 years Patients suspected with IHD or CAD Patients undergoing physiologic assessment (CFR, IMR, and FFR) for evaluation of severity of CAD Subject is able to verbally confirm understandings of risks, benefits and treatment alternatives of receiving invasive physiologic or imaging evaluation and he/she or his/her legally authorized representative provides written informed consent to any study related procedure. Exclusion Criteria: Cardiogenic shock (systolic blood pressure <90mmHg or requiring inotropics to maintain blood pressure >90mmHg) or cardiac arrest Non-cardiac co-morbid conditions are present with life expectancy <2 year (per site investigator's medical judgment). Inability to undergo physiologic assessment (CFR, IMR, and FFR) Pregnant or lactating women

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Deferred Population: Patients with CMD (CFR<2.0 and IMR≥25)<br>Among patients who did not undergo PCI at the discretion of the operator, patients diagnosed CMD (CFR<2.0, IMR≥25) in physiologic assessment. | Diagnostic Test: Invasive physiologic assessment<br>* All coronary physiologic parameters are measured following diagnostic angiography. Resting pd/pa, FFR, CFR and IMR will be calculated using coronary physiologic parameters. In patients treated by PCI, post-PCI physiologic assessment including CFR, IMR, and FFR will be performed.<br>|
| Deferred Population: Patients with preserved microvascular function (CFR≥2.0 OR IMR<25)<br>Among patients who did not undergo PCI at the discretion of the operator, patients with preserved microvascular function (CFR≥2.0 OR IMR<25) in physiologic assessment. | Diagnostic Test: Invasive physiologic assessment<br>* All coronary physiologic parameters are measured following diagnostic angiography. Resting pd/pa, FFR, CFR and IMR will be calculated using coronary physiologic parameters. In patients treated by PCI, post-PCI physiologic assessment including CFR, IMR, and FFR will be performed.<br>|
| Revascularized Population: Patients treated by intravascular imaging-guided PCI optimization<br>Among patients who received PCI, patients whose PCI was optimized through intravascular imaging device (IVUS or OCT). | Diagnostic Test: Invasive physiologic assessment<br>* All coronary physiologic parameters are measured following diagnostic angiography. Resting pd/pa, FFR, CFR and IMR will be calculated using coronary physiologic parameters. In patients treated by PCI, post-PCI physiologic assessment including CFR, IMR, and FFR will be performed.<br>Diagnostic Test: Intravascular imaging<br>* By the operator's discretion, stent-optimization will be performed under intravascular imaging devices (IVUS [Boston Scientific, Natick, Massachusetts, USA] or OCT [Abbott Vascular], St. Paul, MN, USA]).<br>|
| Revascularized Population: Patients treated by angiography-only guided PCI<br>Among patients who received PCI, patients whose PCI was optimized through angiography-only. | Diagnostic Test: Invasive physiologic assessment<br>* All coronary physiologic parameters are measured following diagnostic angiography. Resting pd/pa, FFR, CFR and IMR will be calculated using coronary physiologic parameters. In patients treated by PCI, post-PCI physiologic assessment including CFR, IMR, and FFR will be performed.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient-oriented composite outcomes (POCO) | a composite of all-cause death, MI, any repeat revascularization, or admission for heart failure | 24-month after the index procedure | 
| The proportion of functionally optimized post-PCI results | The proportion of functionally optimized post-PCI results (post-PCI FFR>0.80 and CFR>2.0) | Immediate after the index procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient-oriented composite outcomes (POCO) | Patient-oriented composite outcomes (POCO) | at 60-month | 
| All-cause death | All-cause death | 24-month, and up to 60-month | 
| Cardiac death | Cardiac death | 24-month, and up to 60-month | 
| Target-vessel MI | Target-vessel MI | 24-month, and up to 60-month | 
| Non-target vessel MI | Non-target vessel MI | 24-month, and up to 60-month | 
| MI | MI | 24-month, and up to 60-month | 
| Target vessel revascularization (ischemia-driven or all) | Target vessel revascularization (ischemia-driven or all) | 24-month, and up to 60-month | 
| Non-target vessel revascularization (ischemia-driven or all) | Non-target vessel revascularization (ischemia-driven or all) | 24-month, and up to 60-month | 
| Any repeat revascularization (ischemia-driven or all) | Any repeat revascularization (ischemia-driven or all) | 24-month, and up to 60-month | 
| Admission for congestive heart failure | Admission for congestive heart failure | 24-month, and up to 60-month | 
| Stroke (ischemic and hemorrhagic) | Stroke (ischemic and hemorrhagic) | 24-month, and up to 60-month | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Coronary Microvascular Disease, Coronary Artery Disease, Ischemic Heart Disease, Coronary Flow Reserve, Index of Microcirculatory Resistance, Fractional Flow Reserve, Intravascular Ultrasound, Optical Coherence Tomography