Using [64Cu]FBP8 PET/MR to find intracardiac blood clots in cardiac amyloidosis

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

We'll test whether a [64Cu]FBP8 PET/MR scan can find blood clots inside the heart of people with cardiac amyloidosis who have atrial fibrillation or atrial flutter.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 20 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Brigham and Women's Hospital (Academic / other)
• Drugs / interventions: radiation
• Locations: 1 site (Boston, Massachusetts)
• Trial ID: NCT07560306 on ClinicalTrials.gov

What this trial studies

This Phase 3 pilot will enroll 20 participants with transthyretin or light-chain cardiac amyloidosis and atrial fibrillation or atrial flutter to undergo simultaneous [64Cu]FBP8 PET/MR imaging. Imaging results will be compared to transesophageal echocardiogram (TEE) as the reference standard, with the primary hypothesis that PET/MR will identify >90% of confirmed intracardiac thrombi. The protocol permits retrospective enrollment if a qualifying TEE was done within 14 days (or within 72 hours if anticoagulation was changed) and requires coordinated TEE timing for prospective participants. Secondary analyses will explore relationships between thrombus presence, left atrial function, and left ventricular amyloid burden.

Who should consider this trial

Good fit: Adults with confirmed transthyretin or light-chain cardiac amyloidosis who have atrial fibrillation or atrial flutter, can give informed consent, and have a recent or planned TEE per the protocol are the intended participants.

Not a fit: People without cardiac amyloidosis or without atrial fibrillation/flutter, or those who cannot undergo PET/MR (for example due to MRI-incompatible implants or severe claustrophobia) are unlikely to benefit from this imaging approach.

Why it matters

Potential benefit: If successful, PET/MR with [64Cu]FBP8 could offer a noninvasive way to detect intracardiac thrombi and potentially reduce reliance on transesophageal echocardiography.

How similar studies have performed: Animal models and a first-in-human series in atrial fibrillation patients showed that [64Cu]FBP8 can detect thrombi with accuracy over 90%, so the approach has promising prior support.

Eligibility criteria

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);

Where this trial is running

Boston, Massachusetts

• Brigham and Women's Hospital — Boston, Massachusetts, United States (Recruiting)

Study contacts

• Study coordinator: Vicente Morales Oyarvide, MD, MPH

Conditions Cardiac Amyloidosis; Amyloidosis; Cardiac; Heart; Imaging; Diagnosis; Thrombosis