[64Cu]FBP8 PET for Early Detection of Intracardiac Thrombus in Amyloid Cardiomyopathy

Inclusion Criteria: * Have the ability to give written informed consent; * History of amyloid cardiomyopathy (ATTR-CM or AL-CM); * History of AF or AFL; * Retrospective enrollment: TEE to evaluate LAA within the previous 14 days, provided the anticoagulation regimen the patient is on is not changed after the TEE. If a patient has a negative TEE and continues the same stable anticoagulation regimen, then it is unlikely that a new thrombus will develop in the LAA within the next 14 days. Likewise, if a patient not taking any anticoagulation has a thrombus in the LAA, then it is unlikely that this thrombus will resolve spontaneously in the next 14 days if the patient remains off anticoagulation. If the TEE leads to a change being made in the anticoagulation regimen (started/stopped/dose modified), then a time window of 72 hours from the TEE to PET/MR imaging will be used. This scheme will ensure that the TEE can serve as an accurate gold standard; * Prospective: TEE to evaluate LAA thrombus scheduled in upcoming 14 days; Exclusion Criteria: * Electrical implants such as cardiac pacemaker/defibrillator, perfusion pump, direct brain stimulator; * Pregnancy or breastfeeding (a negative quantitative serum or urine hCG pregnancy test is required for females having child-bearing potential before the subject can participate); * Claustrophobia; * Subjects will be excluded if research-related radiation exposure exceeds current Radiology Department guidelines (i.e. 50 mSv in the prior 12 months); * Unable to lie comfortably on a bed inside the PET/MR scanner; * Subjects under direct or indirect (i.e., same department as PIs) supervision of the principal investigator; * Body weight over the weight limit for the moving table (\> 300 lbs for the MR table); * Metallic or electric implants contraindicated for PET/MR scanning; * Stroke, myocardial infarction, cardiac or major surgery within the last 3 months; * History of LAA ligation/exclusion or presence of a LAA occlusion device; * History of syncope within the last 6 weeks; * Heart rate persistently \>120 bpm or persistently \<50 bpm; * Daytime pauses \>3 seconds; * Lack of a prior transthoracic echocardiogram within the previous 6 months; * Does not have the ability to give written informed consent; * Determined by the investigator(s) to be clinically unsuitable for the study (e.g., based on screening visit and/or during study procedures);