1. Symptomatic heart failure

• A primary diagnosis of HFmrEF or HFpEF (LVEF > 40%), and
• NYHA class II to ambulatory NYHA class IV (IVa), and

1. Documentation of at least one of the following from the date of initial informed consent:

• greater than or equal to 1 prior HF hospitalization(s) requiring IV HF therapy in the prior 12 months; AND/OR
• EITHER BNP value > 35 pg/ml or > 125 pg/ml in permanent or long-term persistent atrial fibrillation; OR
• NT-proBNP > 125 pg /ml or > 375 pg /ml in permanent or long-term persistent atrial fibrillation

1. There is objective evidence of cardiogenic pulmonary congestion based on hemodynamic criteria obtained by right heart catheterization (RHC) at exercise, and confirmed by hemodynamics core lab as:

• Pulmonary capillary wedge pressure at 20 Watts exercise (PCWP 20W) as measured at end-expiration is elevated to greater than or equal to 25 mmHg and PCWP 20W exceeds right atrial pressure (RAP 20W) by &greater than or equal to 8 mmHg

1. In the judgment of the treating physician and the Central Screening Committee the patient is on GDMT for HFpEF/HFmrEF for >30 days prior to screening and baseline assessments, that is expected to be maintained without change for 6 months.

Key

1. Severe heart failure defined as one or more of the below:

• ACC/AHA/ESC Stage D HF, non-ambulatory NYHA Class IV HF
• If Body Mass Index (BMI) < 30, cardiac index < 2.0 L/min/m2
• If BMI greater than or equal to 30, cardiac index < 1.8 L/min/m2
• Inotropic infusion (continuous or intermittent) within the past 6 months
• Patient is on the cardiac transplant waiting list
• Prior diagnosis of HF with reduced ejection fraction (HFrEF), including patients with improvement in LVEF to > 40%

1. Valve disease:

• Degenerative mitral regurgitation > moderate
• Functional or secondary mitral valve regurgitation defined as grade > moderate
• Mitral stenosis > mild
• Primary or secondary tricuspid valve regurgitation defined as grade > moderate
• Aortic valve disease defined as aortic regurgitation grade > moderate or aortic stenosis > moderate

1. More than mild right ventricular (RV) dysfunction as determined by the echo core lab, taking into account the following available parameters:

• Tricuspid annular plane systolic excursion (TAPSE) <1.4 cm, or
• RV size greater than or equal to LV size
• Right ventricular ejection fraction (RVEF) < 35%; OR
• Imaging or clinical evidence of congestive hepatopathy
• Mean right atrial pressure (mRAP) > 15 mmHg at rest
• Pulmonary vascular resistance (PVR) greater than or equal to 5.0 WU

1. BMI greater than or equal to 45
2. Myocardial infarction (MI) and/or any therapeutic invasive, non-valvular cardiovascular procedure within past 3 months or current indication for coronary revascularization
3. Stroke, transient ischemic attack (TIA), deep vein thrombosis (DVT) or pulmonary embolus within the past 6 months
4. Renal insufficiency as determined by creatinine (sCr) level > 2.5 mg/dL or estimated glomerular filtration rate (eGFR) < 25ml/min/1.73 m2 by CKD-Epi equation; or currently requiring dialysis
5. Performance of the six-minute walk test (6MWT) with a distance < 50m OR > 450m
6. Active endocarditis or infection requiring intravenous antibiotics within 3 months