Cardiac amyloidosis is a condition where the heart muscle, amongst other tissues, is infiltrated by the abnormal build-up of proteins called amyloid. This stiffens and thickens the heart muscle over time which makes it less efficient and puts further stress and strain on the other chambers of the heart, leading to heart failure. The commonest form, that affects predominantly the elderly, is called 'wild-type' ATTR amyloid (TTR is the protein that accumulates). In this condition a patient has a 60% chance of admission to hospital each year after diagnosis. There is no current treatment for ATTR amyloid other than using water tablets to reduce excess fluid and prevent more serious fluid build up in lungs and other tissues. Increasing body weight is the most reliable clinical sign of this fluid build up.

Tele-monitoring is the practice of monitoring patients from a distance and has been shown to reduce heart failure admissions and death in patients with heart failure from any cause. Due to reduced access to primary and secondary care during COVID-19 the investigators instigated tele-monitoring of heart failure in ATTR amyloid patients. This appeared to be an effective intervention in the pilot study. The investigators propose to monitor the weight of patients with cardiac amyloidosis at home and intervene where a build up of fluid is observed by telephone discussion with a doctor. The investigators propose to evidence this in a prospective clinical trial. The investigators will evaluate the effect fairly by comparing tele-monitoring with usual care.

Inclusion Criteria:

1. Adults aged ≥18 at the date of signing informed consent which is defined as the beginning of the Screening Period.
2. An established diagnosis of ATTR cardiomyopathy as defined by protocol.
3. Ability to provide written, personally signed and dated informed consent to participate in the study, in accordance with the ICH Good Clinical Practice (GCP) Guideline E6 (R2) (2016) and applicable regulations, before completing any study-related procedures.
4. An understanding, ability, and willingness to fully comply with study procedures and restrictions.
5. Currently a patient at a study site (NAC).

Exclusion Criteria:

1. An inability to have or use BodyTrace device scales at usual residence (for example no mobile network cellular signal)
2. On dialysis or end-stage renal failure (eGFR <25mL/min)
3. Serum albumin <20g/dL or other non-hypervolaemia cause of tissue oedema (e.g. protein-losing enteropathy, nephrotic syndrome)
4. Use of greater than 2 oral diuretics (e.g. on maximum oral diuretic therapy)

Sharing of personal data with other organisations is not planned

It is not possible to mask this type of intervention for participant or care provider, but outcomes will be assessed in a blinded fashion.