Inclusion Criteria:
1. Subject or legal representative has signed the Informed Consent Form (ICF).
2. Age ≥ 18 years.
3. Body Surface Area (BSA) ≥ 1.2 m².
4. NYHA Class III B or NYHA Class IV.
5. Left ventricular ejection fraction (LVEF) ≤ 25%.
6. a) Inotrope-dependent; OR b) Cardiac Index (CI) \< 2.2 L/min/m² in the absence of inotropes, and the subject must also meet one of the following:
* Receiving optimal medical management per current heart failure guidelines for at least 45 days out of the preceding 60 days, with evidence of treatment failure;
* Advanced heart failure for at least 14 days AND dependent on intra-aortic balloon pump (IABP) support for at least 7 days.
7. Females of childbearing potential must agree to use adequate contraception throughout the study.
Exclusion Criteria:
1. Heart failure caused by thyroid disease, hypertrophic obstructive cardiomyopathy, pericardial disease, amyloidosis or restrictive cardiomyopathy.
2. History of any solid organ transplantation (including heart transplantation).
3. Moderate to severe aortic regurgitation that was not corrected concomitantly at the time of LVAD implantation.
4. Irreversible severe right heart failure that cannot be corrected by medications or right ventricular assist device.
5. Pre-existing technical barriers at the time of LVAD implantation conferring an abnormally high surgical risk as judged by the heart team.
6. Planned biventricular assist device (Bi-VAD) support prior to LVAD implantation.
7. Presence of an aortic mechanical valve that was not replaced with a bioprosthesis or sutured closed during LVAD implantation.
8. Presence of any risk factor indicating severe end-organ dysfunction or failure:
1. INR ≥2.0 not attributable to anticoagulation therapy
2. Total bilirubin\>43 μmol/L (2.5 mg/dL), shock liver, or biopsy-proven liver cirrhosis
3. History of severe chronic obstructive pulmonary disease (COPD): FEV1/FVC\<0.7 and FEV1\<50% of predicted value
4. Fixed pulmonary hypertension with latest pulmonary vascular resistance (PVR) ≥8 Wood units and no response to pharmacotherapy
5. History of stroke within 90 days prior to enrollment; or cerebrovascular disease with severe (\>80%) uncorrected carotid artery stenosis
6. Serum creatinine ≥221 μmol/L (2.5 mg/dL) or requirement for chronic renal replacement therapy
7. Severe peripheral vascular disease (PVD) with rest pain or limb ulceration
9. Abnormal nutritional status: If only one test result is available, prealbumin\<150 mg/L (15 mg/dL) OR albumin\<30 g/L (3 g/dL); if both results are available, prealbumin\<150 mg/L (15 mg/dL) AND albumin\<30 g/L (3 g/L).
10. Untreated abdominal aortic aneurysm (AAA) diagnosed within 6 months prior to enrollment with diameter\>5 cm.
11. Inability to tolerate anticoagulation, antiplatelet therapy, or any other perioperative/postoperative treatment required by the investigator based on the subject's condition.
12. Platelet count \<100×10⁹/L (100,000/μL).
13. Known hypocoagulable or hypercoagulable state, such as disseminated intravascular coagulation, heparin-induced thrombocytopenia.
14. Active uncontrolled systemic infection, including but not limited to sepsis, active infective endocarditis, and LVAD-related pump infection.
15. Confirmed malignancy with estimated survival less than 1 year.
16. Receipt of mechanical circulatory support other than intra-aortic balloon pump (IABP) at enrollment.
17. Presence of psychiatric disorders, irreversible cognitive impairment or psychosocial problems that may impair protocol compliance and left ventricular assist system (LVAS) management.
18. History of severe hypersensitivity to the investigational product (exosome formulation) or excipients.
19. Participation in another interventional clinical trial (device/cell/biological product) within 30 days prior to enrollment.
20. Female subjects who are pregnant or breastfeeding; positive pregnancy test at screening for women of childbearing potential.
21. Any other condition judged by the investigator to render the subject unsuitable for participation in this study.
