Feasibility and Efficacy of Coronary Sinus Narrowing in Patients With Coronary Microvascular Dysfunction

Study Overview
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Brief Summary
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This study is being done to evaluate the role of a novel implantable device, called The Neovasc Reducer™ System, in improving microvascular function, symptoms and quality of life in symptomatic patients with coronary microvascular dysfunction.

Official Title
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A Phase II Study Testing the Feasibility and Efficacy of Coronary Sinus Narrowing in Patients With Coronary Microvascular Dysfunction

Conditions
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Coronary Microvascular Dysfunction

Intervention / Treatment
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* Device: The Neovasc Reducer™ System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Age >18 Able to provide written informed consent and willing to participate in all required study follow-up assessments Symptomatic CAD with refractory angina defined as CCS class II to IV, despite optimal tolerated medical therapy Abnormal coronary microvascular function indices: CFR≤2.5 and/or IMR≥25 Exclusion Criteria Recent (within 3 months) acute coronary syndrome Patients with prior coronary artery bypass surgery Unstable angina (recent onset angina, crescendo angina, or rest angina with ECG changes) during the last 30 days Subjects in cardiogenic shock (systolic pressure < 80mm/Hg, on vasopressors or intraaortic counter pulsation) at the time of consenting. Subjects who recover from cardiogenic shock by the time of consenting are eligible. Obstructive CAD on coronary angiography (>70% stenosis or 50-70% stenosis with iFR<0.89 or FFR<0.8 in epicardial artery) Inability to perform invasive coronary flow evaluation and/or measure CFR and IMR in the LAD Severe valvular heart disease LVEF<30% Decompensated congestive heart failure (CHF) or hospitalizatoin due to CHF during the last 3 months Patient with a pacemaker electrode in the CS Mean right atrial pressure >15 mmHg Anomalous or abnormal CS anatomy (e.g., tortuosity, aberrant branch, persistent left superior vena cava (SVC) as demonstrated on angiogram CS diameter at the site of planned implantation greater than 13mm or less than 9.5 mm as measured by angiogram Severe chronic obstructive pulmonary disease (COPD) indicated by a forced expiratory volume in one second that is less than 55 percent of the predicted value Tricuspid valve replacement or repair (tissue or mechanical) Chronic renal failure (serum creatinine >2mg/dL), and or on chronic hemodialysis Moribund, or with comorbidities limiting life expectancy to less than one year Known severe reaction to required procedural medication Known allergy to stainless steel or nickel Magnetic Resonance Imaging (MRI) within 8 weeks of Reducer implantation Participation in another ongoing investigational trial Additional factors deemed unsuitable for trial enrollment per discretion of principal investigator Inmates

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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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Chronic Refractory Angina<br>Subjects with chronic refractory angina will undergo implantation of the Neovasc Reducer™ System in the cardiac catheterization laboratory. | Device: The Neovasc Reducer™ System<br>* A stainless-steel mesh pre-mounted on a customized hourglass shaped balloon catheter, is designed to create a focal narrowing in the lumen of the CS to generate a pressure gradient across it.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Coronary Flow Reserve (CFR) | Calculated as the ratio of hyperemic to rest coronary blood flow | Baseline, 4 months post Reducer implantation | 
| Change in Index of Myocardial Resistance (IMR) | Calculated as the ratio of coronary pressure divided by coronary blood flow at maximal hyperemia | Baseline, 4 months post Reducer implantation |