New device aims to unclog the Heart's drain for stubborn heart failure patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Able to provide written informed consent and willing to participate in all required study follow-up assessments * Clinical indicated coronary angiography with invasive CRT testing or PET with CRF assessment prior to enrollment. Abnormal CFR of ≤ 2.5 or PET CFR ≤ 2.0 * Symptomatic HFpEF defined by (PAWP\>15mmHg at rest and /or PAWP\>25 mmHg on exertion) during clinically performed Right heat catheterization with exercise performed prior to enrollment or during screening visit (if not performed clinically ). * Non-Obstructive CAD (≤ 50% stenosis in epicardial vessels and/or iFR\>0.89 or FFR\>0.8 in vessels with 50 to 70% stenosis) Exclusion Criteria: * Significant epicardial CAD (angiographic stenosis ≥70% or positive FFR or iFR in any major epicardial coronary artery * Significant valvular heart disease moderate to severe regurgitation and or stenosis) * Primary cardiomyopathies (hypertrophic, infiltrative or restrictive) * Constrictive pericarditis * Severe myocardial bridging * Pregnancy * Recent (with 3 months) acute coronary syndrome * Subjects in Cardiogenic shock (systolic pressure\<80mm/Hg) * Mean right atrial pressure at rest \>15 mmHg * Anomalous or abnormal CS anatomy (e.g. tortuosity aberrant branch persistent left superior vena cava 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. * Known severe reaction to required procedural medications * Known allergy to stainless steel or nickel * Magnetic Resonance Imaging (MRI) within 8 weeks after Reducer implantation * Chronic renal failure (serum creatinine\>2mg/dL) * Severe chronic obstructive pulmonary disease (COPD) as indicated by forced expiratory volume in one second that is less than 55% of the predicted value or need for home daytime oxygen * Pacemaker electrode/lead in the coronary sinus * Moribund or with comorbidities limiting life expectancy to less than one year * Current or past participation within a specified timeframe in another clinical trial, as warranted by the administration of this intervention. * Inability or unwillingness of individual to give written informed consent. * Additional factors deemed unsuitable for trial enrollment per discretion of the Principal Investigator * Inmates