Coronary Sinus Reducer for Treatment of Refractory Angina - COSIRA

Inclusion criteria

• Patient is older than 18 years of age
• Symptomatic CAD with chronic refractory angina pectoris classified as Canadian Cardiovascular Society grade III or IV despite attempted optimal medical therapy for thirty days prior to screening
• Patient has limited treatment options for revascularization by coronary artery bypass grafting or by percutaneous coronary intervention
• Evidence of reversible ischemia that is attributable to the left coronary arterial system by Dobutamine Echo
• Left ventricular ejection fraction greater than 25%
• Male or non-pregnant female (NB: Females of child bearing potential must have a negative pregnancy test)
• Patient understands the nature of the procedure and provides written informed consent prior to enrollment
• Patient is willing to comply with specified follow-up evaluation and can be contacted by telephone

Exclusion criteria

• Recent (within three months) acute coronary syndrome
• Recent (within six months) successful PCI or CABG
• Unstable angina (recent onset angina, crescendo angina, or rest angina with ECG changes) during the thirty days prior to screening
• De-compensated congestive heart failure (CHF) or hospitalization due to CHF during the three months prior to screening
• Life threatening rhythm disorders or any rhythm disorders that would require placement of an internal defibrillator and or pacemaker
• Severe chronic obstructive pulmonary disease (COPD) as indicated by a forced expiratory volume in one second that is less than 55% of the predicted value
• Patient cannot undergo exercise tolerance test (bicycle) for reasons other than refractory angina
• Severe valvular heart disease
• Patient with pacemaker or defibrillator electrode in the right atrium, right ventricle, or coronary sinus
• Patient having undergone tricuspid valve replacement or repair
• Chronic renal failure (serum creatinine >2 mg/dL), including patients on chronic hemodialysis
• Moribund patients, or patients with comorbidities limiting life expectancy to less than one year
• Contraindication to required study medications that cannot be adequately controlled with pre-medication
• Known allergy to stainless steel or nickel
• Contraindication to having an MRI performed (NB: Cardiac MRI subset patients only)
• Currently enrolled in another investigational device or drug trial that has not completed the primary endpoint or that clinically interferes with the current study endpoints
• Mean right atrial pressure higher than or equal to 15 mmHg
• Patient with anomalous or abnormal CS as demonstrated by angiogram. Abnormality defined as:

Abnormal CS anatomy (e.g., tortuosity, aberrant branch, persistent left SVC) and/or; CS diameter at the site of planned reducer implantation less than 9.5 mm or greater than 13 mm