Subject has given written informed consent;

Male or female, at least 18 years of age;

Diagnosis and treatment of HF (regardless of left ventricular ejection fraction (LVEF)) for >3 months and NYHA Class III HF at time of Screening;

Subjects should be on stable, optimally titrated medical therapy for at least 30 days, as recommended according to current American Heart Association (AHA)/American College of Cardiology (ACC) guidelines as standard-of-care for HF therapy in the United States, with any intolerance documented;

HF related hospitalization, HF treatment in a hospital day-care setting, or urgent outpatient clinic HF visit for IV diuretics within 12 month (last hospitalization should be 30 days before Screening /Enrollment) and/or N-terminal pro B-type Natriuretic Peptide (NT-proBNP) at time of Screening/ Enrollment defined as:

* (a) Subjects with LVEF <50%: NT-proBNP >1500 pg/mL.

* (b) Subjects with LVEF >50%: NT-proBNP >800 pg/mL .

Thresholds for NT-proBNP (for both LVEF <50% and LVEF >50%) will be corrected for body mass index (BMI) using a 4% reduction per BMI unit over 25 kg/m2;

Subjects should be on diuretic therapy;

Subjects who are physically able to hold the myCordella™ Patient Reader unit (approximate weight 1.3lb) against the ventral thoracic surface for up to 2 minutes per day while in a seated position, as well as dock and undock the myCordella™ Patient Reader;

Please contact study team for additional inclusion/exclusion criteria;

Intolerance to all neuro-hormonal antagonists (i.e., intolerance to angiotensin converting enzyme-inhibitors (ACE-I), angiotensin receptor blockers (ARB), angiotensin-neprilysin inhibitors (ARNI), and beta-blockers) due to hypotension or renal dysfunction;

ACC/AHA Stage D refractory HF (including having received or currently receiving pharmacologic circulatory support with inotropes);

Subjects with history of recurrent pulmonary embolism ( =/>2 episodes within 5 years prior to Screening Visit) and/or deep vein thrombosis (=/< 3 month prior to Screening Visit);

Subjects who have had a major cardiovascular (CV) event (e.g., myocardial infarction, stroke) within 3 months of the Screening Visit;

Unrepaired severe valvular disease;

Subjects with congenital heart disease or mechanical/tissue right heart valve(s);

Subjects with known coagulation disorders;

Subjects with a hypersensitivity or allergy to platelet aggregation inhibitors including aspirin, clopidogrel, prasugrel, and ticagrelor, or patients unable to take dual antiplatelet or anticoagulants for one- month post implant;

Known history of life threatening allergy to contrast dye;

Please contact study team for additional inclusion/exclusion criteria;

• Heart Failure

• Cardiovascular Disease

• ETX-HFS-PA-03

• Heart Disease

• Pulmonary Artery Pressure

• Cardiology

• Endotronix, Inc