Wearable Device-Assisted Remote Management in Atrial Fibrillation Complicated by Heart Failure: WARM-HF Trial (WARM-HF)

Wearable Device-assisted Remote Management for Patients With Atrial Fibrillation Complicated by Heart Failure: A Prospective, Open-label, Multi-center, Randomized Controlled Trial

Patients with acute decompensated heart failure (HF) have a significantly high risk of death and HF re-hospitalization during the vulnerable phase post discharge. Therefore, early post-discharge management is crucial, and the cornerstone of HF treatment-particularly for HF with reduced ejection fraction (HFrEF)-is guideline-directed medical therapy (GDMT), a comprehensive pharmacotherapeutic strategy supported by robust clinical evidence. Timely titration of GDMT, especially within the first few weeks after discharge, has been shown to improve clinical outcomes, reduce readmissions, and enhance long-term prognosis. However, ensuring optimal follow-up and therapeutic adjustments remains a major challenge in real-world practice. Atrial fibrillation (AF) is a common comorbidity in patients with HF, especially in those with severe HF. The presence of AF significantly complicates the clinical course and worsens the prognosis of HF.

Advances in wearable technology have made continuous, non-invasive monitoring of vital signs, arrhythmia burden, and physical status increasingly feasible. Devices such as smartwatches and ECG belts can provide real-time physiological data, offering new opportunities for remote and proactive disease management. Despite the growing availability of such data, the complex interplay between AF and HF demands highly personalized management. Currently, there is a lack of high-quality clinical evidence on how to effectively integrate wearable device data into personalized strategies for this specific patient population.

This is an open-label, multi-center, endpoint-blinded, parallel-group randomized clinical trial supported by the American Heart Association. The primary objective is to determine whether wearable device-assisted digital consultations can optimize GDMT in patients with AF complicated by acute decompensated HF. The study plans to enroll 400 participants, who will be randomly assigned to either a wearable device-assisted intervention group or a conventional treatment control group. The primary endpoint is the change in HF GDMT score 3 months after randomization.

Apple Inc. provided funding, devices, and technical support for this study. Apple was not a sponsor of the trial and was not involved in its execution, data analysis, interpretation, or manuscript preparation.

Study Overview

• Status: Not yet recruiting
• Conditions: AF - Atrial Fibrillation; HFrEF - Heart Failure With Reduced Ejection Fraction
• Intervention / Treatment: Other: Wearable Device-Assisted Intervention

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zhiyao Wei, MD., PhD.; Phone Number: 010-15521192379; Email: weizhiyaoyx@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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. History of heart transplantation or on the heart transplant waiting list
3. Current use of or planned implantation of a ventricular assist device (VAD)
4. Current use of or planned implantation of a pacemaker/implantable cardioverter-defibrillator (ICD)
5. Contraindications to wearing a smartwatch (e.g., limb disability or known allergy to rubber/metal materials)
6. Inability to access the Internet or lack of proficiency in operating smart devices
7. Pregnant or lactating women
8. Organ transplantation within the past 12 months
9. Expected survival time of less than 1 year for any reason
10. Refusal to participate or inability to comply with follow-up requirements
11. Deemed ineligible for participation in the study by the investigators

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Wearable Device-Assisted Intervention Group	Other: Wearable Device-Assisted Intervention; This intervention comprises two core components: (A) A data collecting system via smartwatch and ECG belt; and (B) A decision-support algorithms for risk stratification and medication dose adjustment based on real-time data. Participants will be instructed to wear both the Apple Watch and ECG belt for a minimum of 12-18 hours per day to monitor parameters, such as heart rhythm and respiratory rate. Participants will be prompted via the research APP to complete questionnaires for symptom, blood pressure, and body weight data. All collected data are automatically uploaded to a secure cloud-based platform. A centralized decision-support system analyzes the integrated information using a suite of predefined, multi-layered algorithms to identify patients requiring intervention. Patients will be stratified into three tiers based on integrated physiological metrics and symptom reports: Normal subgroup, Abnormal subgroup, and E-alarm subgroup.
No Intervention: Conventional Treatment Control Group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Heart Failure Guideline-directed Medical Therapy (GDMT) Score	High score favorable	3 Months After Randomization

Secondary Outcome Measures

Outcome Measure	Time Frame
AF recurrence monitored by Apple Watch and ECG belt	3 Months After Randomization
AF burden monitored by ECG belt	12 Months After Randomization
Time to first HF hospitalization and/or cardiovascular death	12 Months After Randomization

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in NT-proBNP level		3 Months After Randomization
Change in 6-minute walk test (6MWT) result		3 Months After Randomization
Change in Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS)	High score favorable	3 Months After Randomization
Change in Minnesota Heart Failure Quality of Life Scale (MLHFQ)	Low score favorable	3 months from randomization
Change in 5-level EuroQol 5-Dimension Questionnaire (EQ-5D-5L)	Low score favorable	3 months from randomization
Time to first cardiovascular death		12 Months After Randomization
Time to first hospitalization for AF		12 Months After Randomization
Time to first readmission for AF or HF		12 Months After Randomization
Time to AF catheter ablation		12 Months After Randomization

Collaborators and Investigators

• Sponsor: Beijing Anzhen Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: January 26, 2026
• First Submitted That Met QC Criteria: February 8, 2026
• First Posted (Actual): February 13, 2026

Study Record Updates

• Last Update Posted (Actual): February 13, 2026
• Last Update Submitted That Met QC Criteria: February 8, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation
• Other Study ID Numbers: KS2025250

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No