Inclusion Criteria:
1. Subject has given written informed consent
2. Male or female, at least 18 years of age
3. Diagnosis of HF ≥ 6 months with either preserved or reduced left ventricular ejection fraction (LVEF) and NYHA Class III HF at the time of Screening
4. HF related hospitalization, HF treatment in a hospital day-care setting, or unplanned outpatient clinic HF visit within 12 months prior to consent and/or increase of N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) (or Brain Natriuretic Peptide (BNP)) at time of Screening defined as:
1. Subjects with LVEF ≤ 40%: NT-proBNP ≥ 1000 pg/mL (or BNP ≥ 250 pg/mL).
2. Subjects with LVEF \> 40%: NT-proBNP ≥ 700 pg/mL (or BNP ≥ 175 pg/mL). Thresholds for NT-proBNP and BNP (for both LVEF ≤ 40% and LVEF \> 40%) will be corrected for body mass index (BMI) using a 4% reduction per BMI unit over 25 kg/m2
5. Subjects must be receiving appropriate medical management of HF for 3 months prior to Screening and clinically stable for at least 1 month prior to study entry
6. Subjects who are physically able to hold the myCordella™ Patient Reader unit (approximate weight 600g) 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
7. Subjects with sufficient eyesight, hearing, and mental capacity to respond to the myCordella™ Patient Reader's audio/visual cues and operate the myCordella™ Patient Reader
8. Subject has sufficient Cellular and/or Wi- Fi Internet coverage at home
9. Subject agrees to return to the treating Investigator for all scheduled follow up visits and can return to the hospital for follow up
Exclusion Criteria:
1. Subjects with primary pulmonary hypertension
2. Subjects with an active infection at the Cordella PA Sensor Implant Visit
3. Subjects with history of pulmonary embolism or deep vein thrombosis
4. Subjects who have had a major cardiovascular event (e.g., myocardial infarction, stroke) within 2 months of the Screening Visit
5. Subjects whereby RHC is contraindicated
6. Implanted with a Cardiac Rhythm Management (CRM) Device (Internal Cardiac Defibrillator (ICD) or pacemaker) or Cardiac Resynchronization Therapy (CRT)-Pacemaker (CRT-P) or CRT-Defibrillator (CRT-D) less than 90 days prior to screening visit
7. Any major surgery within 30 days of the Sensor Implant Visit.
8. Subjects with a Glomerular Filtration Rate (GFR) \<25 ml/min or who are on chronic renal dialysis
9. Specific liver enzymes \[Aspartate Aminotransferase (AST) (SGOT), and Alanine Aminotransferase (ALT) (SGPT) \>3 times the upper limit of normal
10. Received or are likely to receive an advanced therapy (e.g., mechanical circulatory support or lung or heart transplant) in the next 12 months
11. Subjects with congenital heart disease or mechanical/tissue right heart valve(s)
12. Subjects with known coagulation disorders
13. 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
14. Known history of life threatening allergy to contrast dye
15. Subjects who are pregnant or breastfeeding
16. Subjects who are unwilling or deemed by the Investigator to be unwilling to comply with the study protocol, or subjects with a history of non-compliance
17. Severe illness, other than heart disease, which would limit survival to \<1 year
18. Subjects whose clinical condition, in the opinion of the Investigator, makes them an unsuitable candidate for the study
19. Subjects enrolled in another investigational trial with an active Treatment Arm
20. Subject who is in custody by order of an authority or a court of law
21. Unrepaired severe valvular disease
22. Subjects with an inferior vena cava (IVC) filter
