With the advancement of wearable technology, continuous non-invasive monitoring of vital signs, arrhythmia burden, and physical status has become increasingly feasible. Devices such as smartwatches and electrocardiogram (ECG) straps can provide real-time physiological data, offering new opportunities for remote and proactive disease management. Despite the growing availability of such real-time data, the complex interaction between atrial fibrillation (AF) and heart failure (HF) necessitates highly personalized management. However, there remains a lack of high-quality clinical evidence on how to effectively integrate wearable device data into these personalized strategies for specific patient populations. Moreover, the prognostic impact of wearable device-assisted remote management has not been comprehensively evaluated. Therefore, robust clinical studies are needed to further evaluate whether wearable device-assisted remote monitoring can improve the long-term prognosis of this population after discharge from the cardiac care unit (CCU).

In this study (WARM-HF Stage 2), the investigators will conduct a prospective, multicenter, randomized controlled trial to determine whether wearable devices can reduce the composite endpoint of readmission or death in patients with HF.

Inclusion Criteria:

1. Age ≥ 18 years;
2. Subjects diagnosed with acute decompensated heart failure (ADHF) :

1)Heart failure with reduced ejection fraction (HFrEF), defined as left ventricular ejection fraction (LVEF) ≤ 40%; 2)New York Heart Association (NYHA) functional class II-IV; 3)NT-proBNP > 2500 pg/mL or BNP > 600 pg/mL 3. Atrial fibrillation (AF) diagnosed during hospitalization (documented AF episode lasting > 30 seconds on electrocardiogram [ECG] within the past 12 months)

Exclusion Criteria:

1. Intolerance to heart failure pharmacotherapy;
2. Severe anemia or untreated thyroid disease;
3. ST-segment elevation myocardial infarction within 3 months;
4. Known complex congenital heart disease; infiltrative cardiomyopathy (such as cardiac amyloidosis, sarcoidosis, lymphoma, or endomyocardial fibrosis); myocarditis; constrictive pericarditis; cardiac tamponade; hypertrophic cardiomyopathy; stress cardiomyopathy; or uncorrected primary valvular heart disease requiring surgical interventions;
5. Prior major cardiac surgery or mechanical circulatory support, or planned within 6 months, including coronary artery bypass grafting, cardiac valve repair or replacement, ventricular assist device or mechanical circulatory support device implantation, and heart transplantation;
6. Existing pacemaker or planned pacemaker implantation;
7. Contraindications to wearing a smartwatch (such as limb disability or known allergy to rubber/metal materials);
8. Inability to access the Internet or lack of proficiency in operating smart devices.