A Study to Evaluate the Safety and Efficacy of NT-88

Prior treatment

• Known allergy to any component of the investigational product;
• Uncontrolled hypertension, defined as resting systolic blood pressure ≥180 mmHg and/or diastolicblood pressure ≥110 mmHg at two separate assessments prior to randomization;
• Major surgery within 6 months;
• Known hypersensitivity to any study drug, or history of chronic urinary tract infection, or prior orplanned bariatric surgery;

Other illness

• Complicated with cardiogenic shock, acute severe myocarditis, poorly controlled malignantarrhythmia, hypertrophic obstructive cardiomyopathy, constrictive pericarditis, cardiac tamponade, severevalvular disease requiring surgical intervention, or pulmonary embolism, among others;
• Hospitalization for acute heart failure decompensation within the past 3 months;
• Implantation of implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy(CRT) within 3 months;
• Acute coronary syndrome, stroke, or transient ischemic attack within 3 months; cardiac, carotid, orother major vascular surgery; percutaneous coronary intervention (PCI), carotid angioplasty, coronary arterybypass grafting (CABG), or other cardiac surgery within 3 months; or recent onset of non-cardiac conditions affecting exercise capacity, or conditions that may be exacerbated by vigorous exercise (such as infection,hepatic or renal failure, thyrotoxicosis, etc.);
• Serious primary diseases of the liver, kidney, hematopoietic system, nervous system, endocrinesystem, or other severe systemic diseases; malignancy; or psychiatric disorders;
• Acute infection;
• Positive for human immunodeficiency virus (HIV) antibody, positive syphilis test, or hepatitis B orhepatitis C infection;

Lab values

• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST), or total bilirubin \>3 times theupper limit of normal (ULN) due to non-cardiac causes; estimated glomerular filtration rate (eGFR) \<15mL/min/1.73 m²; or serum potassium \>5.5 mmol/L;

Other

• Life expectancy \<1 year;
• Women who are pregnant, breastfeeding, or planning pregnancy;
• Participation in another clinical study within 3 months;
• Subjects deemed unsuitable for participation in this trial by the investigator.

• Aged ≥18 years, no gender restriction;
• Willing to participate in the study, understand and sign the informed consent form (ICF);
• Established diagnosis of heart failure with signs and/or symptoms of heart failure; Symptoms: Dyspnea, reduced exercise tolerance, fatigue, exhaustion, etc.;Signs: Scattered moist rales in limited lung fields (clinically defined as: sparse, discontinuous, fine bubbling sounds heard in 1-2 localized lung areas during mid-to-late inspiration) or accompanied by mild cardiac murmur; Diagnostic examinations (key for confirmation): Echocardiography, natriuretic peptide testing, electrocardiography.
• Cardiac imaging examination (primarily echocardiography) demonstrating LVEF 41%-49%;
• New York Heart Association (NYHA) functional Class II-III (see Appendix 1);
• Clinically stable condition with no significant changes in symptoms, signs, or treatment regimen for at least 3 months;
• Normal cognitive function.