This study will aim to collect proof of concept data to inform the study design of a larger paired comparison study to establish key research questions about the Heartfelt device. The current study will be run with 2 parallel workstreams. Both are presented here:

Data collected from Work Stream 1 (WS1) is expected to give an indication of the usefulness of the volumes measured by the Heartfelt device in optimising diuretic therapy for patients undergoing ambulatory-IV diuretic treatment, as well as looking at the usefulness of foot volume changes monitoring post IV Diuretic treatment. As these patients are often managed in a home / community setting, objective indicators to assess oedema during treatment are currently limited.

Data collected from Work Stream 2 (WS2), patients recently discharged after a heart failure hospitalisation (HFH), is expected to determine if the Heartfelt device can be used to monitor heart failure stability and detect fluid overload in patients recently discharged from hospital after an episode of decompensated heart failure. The investigators may also be able to get an indication of the number of days prior to hospital admission during which the Heartfelt device can detect changes in foot volume.

Both workstreams will provide qualitative feedback, from health care practitioners, patients and carers in both groups about their experience using the Heartfelt Device.

Heart failure hospitalisations are common, but some are potentially preventable through early detection and timely optimisation of pharmacotherapies, most often diuretic titration.

Peripheral oedema is a cardinal feature of heart failure decompensation, though not all patients seek medical attention at this time. The detection of this increase in volume may therefore be a useful tool in preventing heart failure decompensation and hospitalisation.

This study will evaluate a completely automated (no contact) device which captures volumes of the patient's feet in their home, with the ultimate aim of this data being accessible to the heart failure team. However for the purpose of this study, the clinical team will be blinded to the data in order to be able to assess the temporal relationship (and time) between an alert being generated by the device and a hospital admission, or medication change. However if for example a patient fall is detected by the device, a designated Manchester clinician can be contacted to act.

Peripheral oedema is a cardinal feature of heart failure decompensation, though not all patients seek medical attention at this time. The detection of this increase in volume may therefore be a useful tool in preventing heart failure decompensation and hospitalisation.

In WS1 of the current study, the investigators will specifically be looking at whether the use of the Heartfelt Technology can be used to support the remote monitoring of clinical response to home-based intravenous(IV) diuretic interventions as part of an admission avoidance strategy. Our hypothesis is that the Heartfelt technology coupled with this home intervention could provide clinically useful objective measurement of peripheral oedema, which could be used by the heart failure team to titrate the diuretics and guide duration of treatment.

This pilot study will examine change in longitudinal volumes measured by the device and home IV diuretic dosage as well as daily clinical observations. This will help confirm the validity of the readings provided by the device.

Once the home-based intravenous(IV) diuretic intervention is complete, patients will continue to be monitored for a total of 3 months, to observe relative stability or detect further clinically significant decompensations.

In WS2 of the current study, the investigators will be looking at whether Heartfelt alert can offer a window of opportunity in which to perform a theoretical clinical intervention. In order to establish the lead time, recently discharged patients, a population known to be at high risk of re-admission, will be provided with the Heartfelt device and a post-hoc analysis of the data will be performed to establish the number of days between the alert being raised by the Heartfelt device and the date of diagnosis of decompensation +/- hospital admission where this occurs.

This study will be a small-scale pilot to collect information which will support the set-up of a larger study. The pilot will be purely observational as the investigators will not intervene based on the Heartfelt readings. The post-hoc analysis will be undertaken to inform the design of the larger study. As soon as a patient has had the device disconnected, their data can be reviewed for analysis as their participation in the study is completed at that point. This may allow for preliminary analysis to be completed part way through the wider study.

During the pilot the investigators will also collect acceptability ratings from patients and carers.

Research in Heart failure has been reported to often recruit non representative patient groups (Younger patients generally and fewer women and BAME patients than expected for example). So the investigators plan to compare data from the study participants to the ones of the overall HF population seen at the hospital (already recorded as part of the NICOR records). The demographic that the investigators plan to compare are: deprivation level (from postcode), age, sex and ethnicity.

Work stream 1 Inclusion Criteria:

1. Patient is willing and able to provide written informed consent.

2. Diagnosis of heart failure

3. Patient with peripheral oedema requiring IV diuretics

4. Patient accepted for co-management by the MFT Heart Failure and home IV team*

   • There may be some instances where the patient is under the management of the MFT HF team but attends the day unit for IVs due to capacity or other logistical considerations. These patients can also be enrolled in the evaluation.

Work stream 1 Exclusion Criteria:

1. Patient has bandages to lower limbs everyday
2. Patient has an amputation of the foot
3. Patient lacks capacity to consent
4. Patient is not ambulant or unable to mobilise unaided around the house
5. Patient is of no fixed abode
6. Patient has potentially reversible cause of decompensated heart failure and is awaiting intervention (revascularisation/ valvular intervention)
7. Patient taking part in a conflicting evaluation/study that could confound the results of this evaluation by and/or impact clinical interventions and patient outcomes
8. Patient must not be pregnant, and is taking relevant birth control if of child-bearing potential*

Note that a patient not able to comply with daily weights is NOT an exclusion criteria as the Heartfelt Device should provide data for these patients despite their lack of ability to adhere to the usual monitoring protocol.

*Note that criteria (h) has been requested by the insurance for clinical trial cover. However we do not expect participants of this study to be trying to get pregnant (the typical age of patients is expected in an earlier evaluation was around 70 years ).

Work stream 2 Inclusion Criteria:

1. Patient is willing and able to provide written informed consent.
2. Diagnosis of heart failure
3. Patient under follow up with the MFT HF service
4. Patient with a recent admission with decompensated heart failure in last 12 months OR who received home IV diuretics within the last 12-months
5. Patient has been discharged on at least furosemide 80mg or equivalent diuretic dose

Work stream 2 Exclusion Criteria:

1. Patient has bandages everyday
2. Patient has an amputation of the foot
3. Patient lacks capacity to consent
4. Patient is not ambulant or unable to mobilise unaided around the house
5. Patient is of no fixed abode
6. Patient has potentially reversible cause of decompensated heart failure and is awaiting intervention (revascularisation/ valvular intervention)
7. Patient taking part in a conflicting evaluation/study that could confound the results of this evaluation by increasing clinic workload burden for that patient and/or impact clinical interventions and patient outcomes
8. Patient must not be pregnant, and is taking relevant birth control if of child-bearing potential*

Note that a patient not able to comply with daily weights is NOT an exclusion criteria as the Heartfelt Device should provide data for these patients despite their inability to use weighing scales at times.

*Note that criteria (h) has been requested by the insurance for clinical trial cover. However we do not expect participants of this study to be trying to get pregnant (the typical age of patients is expected in an earlier evaluation was around 70 years).

Patients must be aged 18 years or older with a diagnosis of heart failure at the time of signing the informed consent form and be under the care of the Heart Failure service at Manchester University NHS Foundation Trust.