• Chronic symptomatic Heart Failure (HF) documented by one or more of the following:

  • Symptoms of HF requiring current treatment with diuretics for ≥ 30 days AND
  • NYHA class II with a history of > NYHA class II; OR NYHA class III, or ambulatory NYHA class IV symptoms (paroxysmal nocturnal dyspnea, orthopnea, dyspnea on mild or moderate exertion) at screening; or signs (any rales post cough, chest x-ray demonstrating pulmonary congestion,) within past 12 months; AND
  • ≥ 1 HF hospital admission (with HF as the primary, or secondary diagnosis); or treatment with intravenous (IV), or intensification of oral diuresis for HF in a healthcare facility within the 12 months prior to study entry; OR an NT-pro BNP value > 150 pg./ml in normal sinus rhythm, > 450 pg./ml in atrial fibrillation, or a BNP value > 50 pg./ml in normal sinus rhythm, > 150 pg./ml in atrial fibrillation within the past 6 months.
• Ongoing stable GDMT HF management and management of potential comorbidities according to the 2013 ACCF/AHA Guidelines for the management of Heart Failure (with no significant changes [>100% increase or 50% decrease], excluding diuretic dose change for a minimum of 4 weeks prior to screening) that is expected to be maintained without change for 6 months
• Age ≥ 40 years old, LV ejection fraction (EF) ≥ 40% within the past 3 months, without previously documented EF <30% (within the past 5 years)
• Elevated PCWP with a gradient compared to right atrial pressure (RAP), documented by end-expiratory PCWP during supine ergometer exercise ≥ 25mmHg, and greater than RAP by ≥ 5 mmHg

SELECT EXCLU

• MI and/or percutaneous cardiac intervention within past 3 months; CABG in past 3 months, or current indication for coronary revascularization; AVR (surgical AVR or TAVR) within the past 12 months.
• Cardiac Resynchronization Therapy initiated within the past 6 months

• Advanced heart failure defined as one or more of the below:

  • ACC/AHA/ESC Stage D heart failure, non-ambulatory NYHA Class IV HF;
  • Cardiac index < 2.0 L/min/m2
  • Inotropic infusion (continuous or intermittent) for EF< 40% within the past 6 months
  • Patient is on the cardiac transplant waiting list
• Inability to perform 6 minute walk test (distance < 50 m), OR 6 minute walk test > 600m
• History of stroke, transient ischemic attack (TIA), deep vein thrombosis (DVT), or pulmonary emboli within the past 6 months

• Presence of significant valve disease defined by the site cardiologist as:

  • Mitral valve regurgitation defined as grade ≥ 3+ MR
  • Tricuspid valve regurgitation defined as grade ≥ 2+ TR
  • Aortic valve disease defined as ≥ 2+ AR or > moderate AS
• Known clinically significant untreated carotid artery stenosis likely to require intervention
• Currently requiring dialysis; or estimated-GFR <25ml/min/1.73 m2 by CKD-Epi equation