The HEARTFELT Study

Participants will be recruited through Remote Patient Monitoring Providers (RPMPs) based in the US, using crossover randomization between standard care and Heartfelt device usage with health alerts sent to RPMPs. The RPMPs will follow a protocolized intervention when responding to raised alerts.

The study design is a crossover randomization between:

• Standard care (control), 162 days: The device is installed in the home and captures data but no health alerts are sent, and the RPMP does not receive data from the device. (Health alerts are generated and stored for review at the end of the study period to correlate with health issues which occurred during usual care).
• Standard care + Heartfelt (intervention), 162 days: The device captures data and transmits volume measurements and health alerts to the RPMP for review. RPMPs follow a pre-specified alert protocol, potentially following up with the patient.

At consent, patients get randomized to an install date over a period from 21 to 60 days following consent, subject to scheduling this at least 14 days after the most recent recorded hospital discharge at the time of consent, or the discharge from their current hospitalization if hospitalized at the time of consent.

Total study length is 366 days (days 0 to 365). There are two 21-day "washout" periods to prevent carryover between study arms. The first washout period extends from day 0-20 inclusive, and the second from day 183-203 inclusive

At the completion of both crossover arms, patients will be offered the opportunity to keep the device for as long as the study remains active (potentially up to an additional 4 years, for those patients recruited early in the study). During this long-term follow-up, the device will be placed in "Intervention" mode, with randomized 100-day periods where the device is switched into "Standard care" mode (control).

Inclusion criteria

• Provision of signed and dated informed consent form (wet or digital signature)
• Male or female, aged 22 to [No maximum age]
• Diagnosed with Chronic Heart failure at least 2 months prior to randomization
• Documented history of peripheral edema (edema in feet and lower legs), defined as at least one clinical mention in the medical record indicative of oedema during prior clinical assessment.
• Evidence of heart failure decompensation or elevated risk of future hospitalization, defined by one or more of the following:

a.Hospitalization for heart failure occurring at least once in the past 6 months or at least twice in the past 12 months; OR b.Receipt of intravenous/subcutaneous diuretic therapy for heart failure (inpatient or outpatient setting) occurring at least once in the past 6 months or at least twice in the past 12 months; OR c.Emergency department or urgent care visit for heart failure decompensation, occurring at least once in the past 6 months or at least twice in the past 12 months; OR d.Clinician assessment that the participant is at high risk of heart failure hospitalization within the next 6-12 months, based on documented recent clinical course (e.g. worsening congestion, escalating diuretic requirements, recurrent decompensation, and/or comorbidity burden).

• Patients who are treated with daily diuretics.
• Evidence of non-adherence defined by one or more of the following:

• Participants with ≥180 days of historical monitoring/device data available

● Failure to collect ≥50% of expected days of prescribed home physiological monitoring data (e.g. weight, blood pressure, or other clinician-recommended measurements), assessed over a continuous 180-day period; OR

● Discontinuation from a remote patient monitoring/home monitoring program due to non-adherence; OR

● Failure to adhere to a prescribed home-based therapy/monitoring intervention, supported by device usage data showing <50% of expected days of use over a continuous 180-day period.

• Participants without ≥180 days of historical monitoring/device data available: Evidence of non-adherence may be demonstrated by low data capture over shorter windows, defined as any of the following :

● ≤2 days of monitoring data recorded for each of the most recent 4 consecutive weeks during which any remote monitoring device was continuously available in the patient's home; OR

● ≤3 days of monitoring data recorded in any consecutive 8 week period period during which any remote monitoring device was continuously available in the patient home; AND/OR

• by documented non-adherence in the medical record within the last 3 years:

• Historical documentation of persistent medication and/or dietary non-adherence, defined as either a clear statement of ongoing non-adherence or ≥2 documented instances of non-adherence concerns (including dosing and/or timing, where available); OR
• Historical documentation on repeated clinical assessments indicating persistent difficulty adhering to recommended self-management activities (e.g. repeated failure to follow monitoring instructions, incomplete engagement with care plan, or repeated non-attendance at scheduled reviews).
• For participants not previously enrolled in RPM or without sufficient historical monitoring data, non-adherence will be assessed prospectively using connected scales provided at study initiation. Objective adherence metrics derived from scale usage during the initial monitoring period will be used both to characterise baseline adherence and to support predefined subgroup analyses.
• Clinical teams/PIs discretion as patients being non-adherent.
• For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation and for an additional 6 weeks after the end of the study.
• Patients who are covered by an insurance plan that covers IDE-B costs (e.g. Medicare Part-B), OR written contract signed by the patient, or their provider or payor, stating that they will be liable for any trial-associated costs that Medicare would ordinarily cover if the patient were covered by Medicare.

• Participant has bandages to lower limbs every day 2. Participant has an amputation of both feet 3. Participant is a regular wheelchair user inside their home 4. Participant is bed-bound 5. Participant is of no fixed abode 6. Participant is taking part in a conflicting evaluation/study that could confound the results of this evaluation and/or impact clinical interventions and participant outcomes 7. Participant is unable to take diuretics 8. Participant is on a regular schedule of dialysis 9. Participant has a history of recurrent leg or feet deep vein thrombosis (DVT) (two or more episodes within the last 12 months).

• Participant has a history of recurrent leg or feet cellulitis episodes (two or more episodes within the last 12 months).

• Participant is prescribed diltiazem or verapamil on an ongoing basis. 12. Participant is pregnant or is not taking medically approved birth control if of child-bearing potential.