Chronic heart failure (HF) is a severe manifestation and terminal stage of various cardiovascular diseases, with high incidence and mortality rates. Myocardial infarction (MI) is currently one of the most common and significant causes of HF globally. The occurrence of HF after MI significantly increases the mortality risk for patients. Actively controlling risk factors and strengthening outpatient management of HF patients post-MI are crucial for alleviating clinical symptoms and enhancing exercise capacity. Recently, digital health interventions (DHI) have shown promising potential in managing cardiovascular disease patients. However, the application in patients with HF post-MI has not been well-reported. Therefore, this study independently and innovatively designed the HeartMed-HF digital therapeutics to demonstrate its effectiveness and safety in patients with HF after MI.

Acute myocardial infarction (AMI) is caused by acute occlusion of the coronary artery and interruption of blood flow, which leads to myocardium necrosis in the blood supply area of the culprit vessel. AMI can lead to the loss of cardiomyocytes, which in turn causes ventricular enlargement, myocardial hypertrophy, eventually leading to the decline of cardiac function. In severe cases，AMI may even result in acute or chronic heart failure (HF). Patients with HF after MI have significantly decreased quality of life, high mortality and poor clinical prognosis. Studies have shown that the incidence of HF in patients with ST-segment elevation myocardial infarction (STEMI) is about 21.8%, and the 30-day mortality rate of patients with HF after MI is up to 25%. The occurrence of HF after MI is associated with various factors. Advanced age, hypertension, diabetes, renal insufficiency, rapid heart rate, atrial fibrillation (AF), low left ventricular ejection fraction (LVEF), stroke are all risk factors. Actively controlling these factors is crucial. However, due to the lack of medical knowledge, poor self-mobility among HF patients, outpatient management faces severe challenges. Therefore, strengthening outpatient management for patients with HF after MI is of great significance in alleviating clinical symptoms and improving patients' exercise capacity.

Recently, the digital health intervention (DHI) industry composed of internet, artificial intelligence (AI), mobile terminals and wearable devices has developed rapidly worldwide, which plays an important role in health care. DHI has shown promising prospects in the management of cardiovascular diseases. It can be used for AF screening, blood pressure management, and reducing mortality in HF patients, among other applications. However, the use in patients with HF after MI lacks large-scale evidence-based medical support.

Therefore, this study has independently designed the HeartMed-HF digital heart failure clinical management system for patients with HF after MI. The system monitors patients' weight, heart rate, blood pressure, fluid intake and output, and other HF evaluation indicators at home using wearable devices. Combining data from patients' medical histories, laboratory test results, and surgical records, the system uses AI algorithms to generate personalized outpatient HF management plans, achieving precise home-based clinical management for patients. The core management components include health education, symptom management, continuous monitoring, risk warning, medication management, and cardiac exercise rehabilitation. Additionally, the study will form a comprehensive clinical management team consisting of physician assistants, rehabilitation trainers, nutritionists, psychologists, and health managers. Through an internet platform and mobile terminals, the system closely connects patients and doctors, extending inpatient treatment to the home and realizing a closed-loop clinical management model that integrates real-time monitoring, early warning, and timely intervention.

Inclusion Criteria:

1. Be of either sex with age ≥ 18 years and ≤ 75 years.
2. Hospitalization due to AMI (onset to randomization ≤ 2 weeks), including STEMI and NSTEMI.
3. Meeting the diagnostic criteria for chronic HF, including:

(1) Symptoms and/or signs of heart failure; (2) LVEF (Simpson's method) < 50%, and NT-proBNP ≥ 125pg/mL before enrollment. 4. Patients must be willing to comply with the study protocol and give the informed consent.

Exclusion Criteria:

1. Contraindications to cardiopulmonary exercise testing (bicycle ergometer) or 6-minute walking test.
2. Pregnancy, breastfeeding, or planning pregnacy within 1 year.
3. Patients who have undergone mechanical circulatory support (including intra-aortic balloon pump, Impella, ECMO, etc.) or endotracheal intubation.
4. History of viral cardiomytis or non-ischemic cardiomyopathy including dilated cardiomyopathy, hypertrophic cardiomyopathy, perinatal cardiomyopathy, etc.
5. Moderate to severe valvular heart disease or a history of valve replacement.
6. Severe liver dysfunction [ALT ≥ 3 times the upper limit of normal range or renal dysfunction (eGFR<60 mL /min/1.73m2)].
7. Malignant tumors or other diseases, with expected life expectancy <1 year.
8. Inability to use smartphones or communicate with the management team for any reason.
9. Enrolled in other clinical trials.
10. Any other clinical conditions unsuitable for this study by the investigator.