Trial to Evaluate Safety And Effectiveness of Mechanical Circulatory Support in Patients With Advancing Heart Failure

Inclusion Criteria:

1. Subject has provided written informed consent by signing the study Informed ConsentForm (ICF) prior to any clinical investigation-related procedure

2. LVEF ≤30% and Cardiac Index ≤ 2.5 L/min/m²

3. Limited functional status as demonstrated by 6MWT ≤ 350 m due to HF related reasonsOR peak VO2 ≤ 14 mL/kg/min (or <50% of predicted peak VO2 value)

4. NYHA Class IIIB or NYHA Class IV

5. Subject has ≥ 1 Heart Failure Hospitalization in the last 12 months

6. Subject is already implanted with a CardioMEMS PA Sensor OR willing to undergo aCardioMEMS PA Sensor implant

7. Subject is willing and able to be implanted with the HM3 LVAS if randomized to HM3Group

Randomization Criteria:

1. Subject has been implanted with a CardioMEMS PA Sensor for at least 90 days.

2. Subject is receiving guideline directed medical therapy with optimal doses (ordocumented medication contraindication or intolerance) of betablockers,Angiotensin-Converting-Enzyme-inhibitors or Angiotensin II Receptor Blockers orangiotensin receptor neprilysin inhibitor (if eligible), Mineralocorticoid ReceptorAntagonists, Sodium-Glucose co-Transporter-2 (SGLT2) inhibitors, and diuretics forat least 30 of the last 90 days.

3. mean PAP ≥ 30 mmHg.

4. The subject will not be randomized if they have any other factor that representsinordinate risk for either continued GDMT or LVAD implant.

Single Arm Registry Criteria:

1. Subject has received a CardioMEMS PA Sensor implant following enrollment in thetrial.

2. Subject is receiving guideline directed medical therapy with optimal doses (ordocumented medication contraindication or intolerance) of betablockers,Angiotensin-Converting-Enzyme-inhibitors or Angiotensin II Receptor Blockers orangiotensin receptor neprilysin inhibitor (if eligible), Mineralocorticoid ReceptorAntagonists, Sodium-Glucose co-Transporter-2 (SGLT2) inhibitors, and diuretics forat least 30 of the last 90 days.

3. mean PAP <30 mmHg

Exclusion Criteria:

1. Subject is < 18 years of age at the time of informed consent.

2. Dependent on IV inotrope in the last 30 days.

3. Contra-indications to HM3 LVAS or CardioMEMS HF system.

4. Etiology of HF due to or associated with uncorrected thyroid disease, obstructivecardiomyopathy, pericardial disease, amyloidosis, or restrictive cardiomyopathy.

5. Technical obstacles to LVAD or CardioMEMS implantation which pose an inordinatelyhigh surgical risk, in the judgment of the implanter.

6. Existence of ongoing MCS.

7. Presence of mechanical aortic valve that will not be either converted to abioprosthesis or oversewn at the time of LVAD implant.

8. History of any solid organ transplant.

9. Psychiatric disease/disorder, irreversible cognitive dysfunction or psychosocialissues that are likely to impair compliance with the study protocol and LVASmanagement.

10. Presence of an active, uncontrolled infection.

11. Complex congenital heart disease.

12. Currently Pregnant or capable of becoming Pregnant and Unwilling to UseContraception with LVAD.

13. History of pulmonary embolism within 30 days prior to enrollment or history ofrecurrent (>1 episode) pulmonary embolism and/or deep vein thrombosis.

14. Planned VAD or Bi-VAD support prior to enrollment.

15. Presence of any one of the following risk factors for or indications of severe endorgan dysfunction or failure:

16. An INR ≥ 2.0 not due to anticoagulation therapy

17. An eGFR < 30 mL/min/1.73 m2 and nonresponsive to diuretic therapy or receivingchronic dialysis.

18. Biopsy proven liver cirrhosis.

19. Need for chronic renal replacement therapy.

20. History of severe chronic obstructive pulmonary disease (COPD) defined byForced Expiratory Volume FEV1 < 30% predicted.

21. History of cerebrovascular disease with significant (> 80%) uncorrectedinternal carotid stenosis.

22. Significant peripheral vascular disease (PVD) accompanied by ischemic rest painor extremity ulceration.

23. Any condition other than HF that could limit survival to less than 24 months.

24. Participation in any other clinical investigation with an active treatment arm thatis likely to confound study results or affect the study outcome.