This multicenter pilot study will enroll adult participants with a confirmed clinical diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) and heart failure (HF) controls with documentation within the past 2 years that either excludes ATTR-CM or indicates a low probability of ATTR-CM. Ocular imaging and other study data will be collected to assess the feasibility of developing and preliminarily evaluating a machine learning model to discriminate ATTR-CM cases from HF controls without ATTR-CM.

A participant who does not complete the study within 90 days from enrollment will be discontinued from the study. A participant may be discontinued from the study at any time at the discretion of the investigator for behavioral or compliance reasons. A participant may withdraw from the study at any time at the participant's own request for any reason (or without providing any reason) without any implication on participant's rights.

Inclusion Criteria:

• 1. Participant must be 18 years and older at the time of signing the informed consent form.
• 2. Participants with either of the following:
• - Positive ATTR-CM cases: Participants with a clinical diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) with amyloid deposits in cardiac or non-cardiac tissue confirmed by Congo Red (or equivalent) staining, or DPD-Tc, PYP-Tc, or HMDP-Tc scintigraphy with Grade 2 or 3 cardiac uptake in the absence of abnormal light chains ratio.
• - Control population: Participants with a clinical diagnosis of guideline-directed medical therapy-directed heart failure (HF) and either:
• a) Subgroup A: Definitively excluded ATTR-CM amyloidosis: negative cardiac or non-cardiac tissue biopsy for amyloid, or negative technetium scintigraphy within the past 2 years.
• b) Subgroup B: Low probability of ATTR-CM amyloidosis, not definitively excluded: absence of amyloid-suggestive features on echocardiography (ECHO), electrocardiography (ECG), or cardiac magnetic resonance imaging (MRI) within the past 2 years, with documented clinical assessment indicating HF etiology unlikely attributable to amyloidosis; no amyloid-specific testing (technetium scintigraphy or biopsy) performed.
• 3. Participant or legally authorized representative (LAR) must sign the informed consent form.

Exclusion Criteria:

• 1. Any known eye condition that may preclude clear imaging of the retina.
• 2. Any known history of amyloid light-chain (AL) amyloidosis.
• 3. Any ocular surgery that, in the opinion of the investigator, makes participation in the study undesirable.
• 4. Any medical condition that, in the opinion of the investigator, makes participation in the study undesirable, for example, if the participant is critically unwell or requires ongoing emergency treatment.
• 5. Involvement in the planning and/or conduct of the study.
• 6. In the opinion of the investigator, the participant is unlikely to comply with study procedures, restrictions, and requirements.
• 7. Previous enrollment in the present study.

The study population will comprise adult participants with a confirmed clinical diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) and heart failure (HF) controls who have documentation within the past 2 years that either excludes ATTR-CM or indicates a low probability of ATTR-CM.

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA PhRMA Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the anonymized individual patient-level data via secure research environment Vivli.org. Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.