Evaluate the Effect of Injectable Neucardin on the Cardiac Function of Subjects With Chronic Systolic Heart Failure

Inclusion Criteria:

1. Aged 18-75 years, male or female;

2. Confirmed diagnosis of heart failure, in stable condition currently, NYHA classII-III, left ventricular ejection fraction (LVEF)≤40% (measured by echocardiographywith modified Simpson's method at Screening 1, and measured by CMR at Screening 2and baseline);

3. Male NT-proBNP ≤1700 pg/ml or female NT-proBNP≤4000 pg/ml (detected by Roche kit inthe central laboratory at screening 1);

4. Receiving standard basic therapeutic medication for heart failure for more than 3months, at the target dose or maximum tolerated dose for more than 1 month, or nochange in dose within the last 1 month;

5. Understand and sign the informed consent form.

Exclusion Criteria:

1. Atrial fibrillation during the screening period;

2. Conditions limiting CMR examination, such as installation of pacemakers, ICDs, CRTsor other similar devices contraindicated for CMR, or have claustrophobia;

3. Hypertrophic cardiomyopathy with outflow tract obstruction, constrictivepericarditis, significant and uncorrected valvular heart disease (severeregurgitation or severe stenosis or valvular disease requiring surgery), congenitalheart disease requiring surgery but not yet undergoing surgical treatment, primarypulmonary hypertension or secondary severe pulmonary hypertension (≥ 70 mmHg);

4. Right heart failure due to lung disease;

5. Subjects with chronic heart failure complicated with acute hemodynamic disturbanceor acute decompensation within recent 1 month (symptoms and signs indicate chronicheart failure is aggravated, and intravenous drug therapy may be required);

6. Angina pectoris within 3 months;

7. Myocardial infarction within the past 6 months;

8. Cerebrovascular accident, revascularization (PCI or other surgery), cardiac surgery,carotid artery or other large vessel surgery within the past 6 months;

9. Prepare to install pacemaker, ICD, CRT or other similar devices within 6 months;

10. History of heart transplantation, use of ventricular assist device (VAD) orpreparation for heart transplantation, VAD;

11. Diagnosis of peripartum or chemotherapy-induced cardiomyopathy within the past 12months;

12. Serious arrhythmia (sustained ventricular tachycardia or other conditions meet thecriteria according to the investigator's judgement );

13. Clinical diagnosis of pericardial effusion, pleural effusion or B ultrasound showedpericardial effusion (greater than 50ml or 3 mm) or pleural effusion (greater than 200ml or 10 mm);

14. Liver or kidney dysfunction, chronic liver disease may have a potential impact onliver function, non-heart failure induced bilirubin or alkaline phosphatase > 2times the upper limit of normal, aspartate aminotransferase or alanineaminotransferase > 3 times the upper limit of normal, eGFR calculated using the MDRDmethod < 30 ml/min/1.73m2 ;

15. Systolic blood pressure < 90 mmHg or > 160 mmHg;

16. Blood K + < 3.2 mmol/L or > 5.5 mmol/L;

17. Subjects with an absolute change in LVEF > 5% as detected by CMR between screening 2and baseline;

18. Women of childbearing age who are planning to become pregnant within 2 years (womenof childbearing age are defined as all women with physiological capability to becomepregnant), and pregnant or lactating women;

19. Patients whose survival time is expected to be less than 6 months as judged by theinvestigator;

20. Those who have participated in any drug clinical trial within the previous 3 months;

21. Severe neurological disorders (Alzheimer's disease, progressive parkinsonism);

22. The subjects with tumor history or is suffering from tumor now, or with precancerouslesions confirmed by pathological examination (such as breast ductal carcinoma insitu, or cervical dysplasia), or with malignant mass found by examination (physicalexamination, X-ray examination or B ultrasound examination or other means);

23. The subjects with proliferative glands or adenomas that are found to have endocrineactivity that affects cardiac function or endocrine function detected byexaminations (physical examination, X-ray examination, B ultrasound examination orother means), such as pheochromocytoma, thyromegaly, etc. (patients with euthyroidthyroid or normal thyroid function do not need to be excluded);

24. The subject, in the judgment of the Investigator, is unable to complete the study orto comply with the requirements of the study (for administrative or other reasons).