A Research Study to Look at the Distribution and Effects of Coramitug on Amyloid Deposits in Heart Tissue Using PET/CT Imaging in People With ATTR Amyloidosis.

Inclusion Criteria: * Informed consent obtained before any study-related activities. Study-related activities are any procedures that are carried out as part of the study, including activities to determine suitability for the study. * Male or female. * Age greater than or equal to (≥) 60 years or above at the time of signing the informed consent. * For participants with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): * Have an established diagnosis of ATTR-CM, with either wild-type Transthyretin (TTR) or variant TTR genotype (ATTRwt) or (ATTRv), with cardiac amyloid infiltration, increased left ventricular (LV) wall thickness, \& heart failure (HF): a) Cardiac amyloid infiltration demonstrated by: i. Cardiac biopsy positive for TTR amyloid, OR ii. Grade 2 or Grade 3 cardiac uptake at pyrophosphate/3,3-diphosphono-1,2-propanodicarboxylic acid/hydroxymethylene diphosphonate (PYP/DPD/HMDP) scintigraphy with Single-Photon Emission Computed Tomography (SPECT/CT) combined with an extracardiac biopsy positive for TTR amyloid, OR iii. Grade 2 or Grade 3 cardiac uptake at PYP/DPD/HMDP scintigraphy with SPECT/CT combined with normal serum free light chain ratio \& negative serum \& urine immunofixation (Serum Immunofixation \[SPIE\] and Urine Immunofixation \[UPIE\]) Note: Bone tracer scintigraphy using 99m technetium (Tc)-labelled pyrophosphate (99mTc-PYP)/99mTc-labelled 3,3-diphosphono-1,2- propanodicarboxylic acid (99mTc-DPD)/99mTc-labeled hydroxymethylene diphosphonate (99m-Tc-HMDP) b. Increased LV wall thickness, as assessed by echocardiography showing LV posterior and septal wall thickness greater than or equal to (≥)13 millimeter (mm) for women and ≥ 14 mm for men (Note: Pre-existing echocardiogram up to 2 years old can be used). c. Chronic HF with: i. At least 1 documented hospitalisation for HF occurring greater than (\>) 3 months but less than (\<) 2 years, OR ii. History of HF manifested by signs or symptoms of volume overload or elevated intracardiac pressures (e.g., elevated jugular venous pressure, shortness of breath, signs of pulmonary con-gestion on x-ray or auscultation, or peripheral oedema) requiring ongoing treatment with a loop diuretic. Exclusion Criteria: * Known or suspected hypersensitivity to study intervention(s) or related products. * Previous participation in this study. Participation is defined as signed informed consent. * Female who is pregnant, breast-feeding or intends to become pregnant or is of childbearing potential. * Current participation (i.e., signed informed consent) in any other interventional clinical study. * Participation in research studies involving exposure to radiation within a year preceding the screening period in this study.