Monitoring Oedema in Heart Failure to Improve Function and Reduce Hospitalisation Risk

Not Applicable

Not yet recruiting

• Conditions: Heart Failure

• Registration Number: NCT07067658
• Lead Sponsor: Heartfelt Technologies

Brief Summary

This study will evaluate the Heartfelt device, a novel, passive monitoring system that detects early signs of fluid build-up in patients (oedema) with heart failure by measuring changes in foot and lower leg volume through capture of 3D images. The trial will assess whether this device, when added to standard NHS care, improves quality of life and reduces heart failure-related events compared to standard care alone.

Detailed Description

Heart failure often causes fluid build-up in the legs and lungs, leading to symptoms like swelling and breathlessness. Spotting these signs early is important to help prevent worsening health and hospital admissions. While patients are encouraged to monitor their weight and symptoms, this can be hard to keep up with.

The study will involve 300 participants from at least 15 NHS hospitals and GP practices across the UK. People will be randomly placed into one of two groups: one will receive standard NHS care (including regular weight checks and symptom monitoring), and the other will receive the same care plus the Heartfelt device. The trial is partly blinded: participants may see technical messages (e.g. if the device goes offline), but only the group using the device will trigger clinical alerts.

The Heartfelt device takes daily images of the feet to track changes in size, without the need for any extra effort from the user. If important changes are spotted, alerts are sent to the clinical team so they can act quickly.

The study will look at quality of life, how often the device sends useful data, healthcare use, and how teams respond to alerts. It will also explore how easy the device is to use and whether it offers good value for money.

Patients will help shape the study to make sure the findings are relevant and useful for future care.

Study Timeline

• Status Verified: 2025-07
• Study First Submitted: 2025-07-04
• Study First Submitted QC: 2025-07-15
• Last Update Submitted: 2025-07-15
• Study First Posted: 2025-07-16
• Last Update Posted: 2025-07-16
• Study Start: 2025-09-01
• Primary Completion: 2026-10-31
• Study Completion: 2028-02-29

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 300

Inclusion Criteria

• Adults >18 years
• Diagnosis of heart failure (any aetiology or left ventricular ejection fraction classification), any timeframe
• Currently prescribed ≥40 mg/day of furosemide (or equivalent loop diuretic) for at least one month.
• Heart failure hospital admission and moderate or severe leg oedema in the previous 12 months.
• Lives in the UK, with a home environment suitable for installation of the Heartfelt device.

Exclusion Criteria

• Amputation of both feet
• Bed-bound for more than 20h per 24h period
• Bandages to lower limbs every day
• Regular wheelchair user inside their home
• No fixed abode
• Participation in another interventional trial that may interfere with endpoints
• Life expectancy <6 months, in the opinion of the investigator
• Inability to provide informed consent due to cognitive impairment
• Language barriers that preclude understanding of trial procedures (unless translation resources are available in relevant language)
• Inability to install the device (even with assistance) allowing at least 6 months of data capture by the end of the study.
• Patients with severe aortic stenosis or awaiting a heart procedure or surgery
• Patient with end stage renal disease (eGFR <20)
• Pregnancy or lack of contraceptive measures if of child-bearing potential

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Composite Clinical Events	Over 12-months period.	Unplanned hospital attendance (clinic, emergency, or admission) or death due to heart failure, cardiovascular, respiratory, or renal causes. Recurrent events will be included and adjudicated, providing a comprehensive measure of clinical deterioration over 12 months.
Health-Related Quality of Life (EQ-5D-5L)	Collected at baseline, 3, 6, 9, and 12 months	Patient-reported quality of life measured using EQ-5D-5L, collected at baseline and follow-up (3, 6, 9, 12 months), with primary analysis at 12 months. This validated instrument captures overall health status across five domains and includes a visual analogue scale.; * Measured using the EQ-5D-5L index; * Collected at baseline, 3, 6, 9, and 12 months.; * Primary time point: 12 months.; EQ-5D-5L responses will be converted to utility scores on a scale from -0.59 to 1, where 1 represents the best health state, using the UK EQ-5D-5L value set. Patients with at least two or more utility scores during follow-up will be included in the analysis.

Secondary Outcome Measures

Name	Time	Method
Days Lost to Hospitalisation or Death	Over 12-months period.	Total number of days lost due to hospitalisation for cardiovascular, respiratory, or renal conditions, or due to all-cause mortality.
Daily Data Availability	Over 12-months period.	Proportion of days with successful data capture from the Heartfelt device and weighing scales, based on device-generated records or contemporaneous self-report.
Guideline-Recommended Medication Score	Over 12-months period.	Adherence to guideline-recommended heart failure medications will be assessed using a guideline-recommended medication score, calculated at 3, 6, 9, and 12 months and averaged across these time points. The score is based on the number of eligible medication classes prescribed, with 1 point assigned per class (e.g., ACEi/ARB/ARNI, beta-blocker, mineralocorticoid receptor antagonist \[MRA\]). The score ranges from 0 to 3, with 3 being the optimal medication score.; The score is adjusted for patient eligibility: will be calculated only for patients with heart failure with reduced ejection fraction (HFrEF).
All-Cause Hospitalisations	Over 12-months period.	Number of hospitalisations from any cause, analysed as recurrent events and adjusted for the competing risk of death.
Loss of Independence or Mortality	During the 12-month trial period.	Composite measure of new admission to a long-term care facility or all-cause mortality.
Death and Cause of Death	During 12-months trial period.	Classification of all deaths recorded during the trial as heart failure-related, other cardiovascular, or non-cardiovascular causes, based on clinical records.