The purpose of this clinical study is to evaluate the safety and efficacy of endocardial delivery of HS-001 CS into severe heart failure patients with reduced ejection fraction for 26 weeks after transplantation.

This is a multicenter, open-label, phase I/II study in 14 severe heart failure patients with reduced ejection fraction.

After screening period is completed, subjects undergo HS-001 CS transplantation by endocardial delivery. After transplantation, subjects take immunosuppressant and have efficacy/safety assessments.

Inclusion Criteria:

• Patients with resting left ventricular ejection fraction (LVEF) ≦40% based on institutional assessment on screening echocardiographic assessment
• New York Heart Association (NYHA) cardiac function classification of grade II or III at screening
• Other Criteria apply, please contact the investigator

Exclusion Criteria:

• Patients with cardiac devices such as pacemakers, implantable cardioverter defibrillators (ICDs), or cardiac resuscitation-enabled implantable cardioverter defibrillators (CRT-Ds)
• Patients with heart failure due to the primary disease hypertrophic cardiomyopathy (including the dilated phase), restrictive cardiomyopathy, amyloidosis, takotsubo cardiomyopathy, congenital heart disease, cardiac sarcoidosis, or constrictive pericarditis
• Other Criteria apply, please contact the investigator