Table 1 Inclusion and exclusion criteria

1) Voluntarily participate, understand and sign the informed consent;

1) Have participated in other clinical studies

2) Symptomatic chronic heart failure, NYHA grade II–IV, chronic heart failure diagnosis according to ESC Guidelines for Heart Failure 2016 and China Guidelines for Heart Failure 2018; the condition is relatively stable, without intravenous medication

2) Hemodynamic instability

3) LVEF 40% or less

3) Allergic to drugs or their ingredients

4) Over 18 years old, less than 80 years old

4) Acute myocardial infarction

5) The patient has received standard optimized treatment for HFrEF and is treated according to the recommended drug dose in the guidelines, unless contraindication or intolerance

5) Active liver disease or severe liver insufficiency

6) eGFR ≥ 45 ml/min/1.73 m²

6) Known active infection or severe blood disease or endocrine dysfunction

7) Diagnosis of OSAHS according to the Diagnostic Guidelines for Adult Obstructive sleep apnea (2016); AHI ≥ 15 events/h

7) History of COPD, asthma, or other serious lung diseases

8) History of stroke, peripheral or central nerve abnormalities, cerebrovascular disease

9) Pregnant and lactating women

10) HbA1c ≥ 7.0%

11) Previous use of dapagliflozin