Effects of Low-Sodium Salt on Death, HF Hospitalization/ Emergency Department Visits and Quality of Life in HF Patients

Who May Qualify: 1. Aged between 18 and 75 years; 2. Hospitalized due to heart failure in the past year; 3. NYHA functional class II-III; 4. Echocardiographic evidence of LVEF \< 40% within the past 6 months; 5. Receiving guideline-directed medical therapy for heart failure; 6. Stable heart failure status, defined as heart failure stability for more than 4 weeks, with no increase in diuretic dose within the past 4 weeks; 7. Having a primary caregiver and frequently dining together at home; 8. Consuming commercially processed food no more than once a week; 9. Providing written willing to sign a consent form. Who Should NOT Join This Trial: 1. End-stage heart failure; 2. Hospitalization due to cardiovascular causes within the past month; 3. Uncorrected hyponatremia (Na \< 130 mmol/L); 4. Dialysis-dependent patients, or eGFR \< 20 mL/min/1.73m²; 5. Uncontrolled hyperglycemia, with fasting blood glucose \> 16 mmol/L; 6. Malignant cancer patients with a life expectancy of less than 1 year; 7. Conditions that, in the investigator's opinion, may interfere with adherence to the protocol, such as habitual reliance on takeout meals or dining at company cafeterias; 8. Planned hospitalization during the study period; 9. Unexplained weight loss greater than 5 kg in the past year; 10. The subject or family members have concerns about using the salt substitute in this study, or are planning for pregnancy, pregnant, or breastfeeding; 11. Another family member is already participating in this study; 12. The subject or family members are participating in other interventional clinical trials. Always talk to your doctor about whether this trial is right for you.