¹²⁴I-evuzamitide PET/CT Shows Promise for Diagnosing Cardiac Amyloidosis: JAMA
USA: A new clinical trial has found that 124I-evuzamitide positron emission tomography/computed tomography (PET/CT) can accurately detect cardiac amyloidosis, demonstrating 94% sensitivity and 86% specificity in patients undergoing evaluation for suspected disease. The findings suggest that this imaging approach could offer a noninvasive method for identifying cardiac amyloidosis across different amyloid types, addressing limitations of currently available imaging techniques.
The study, published in JAMA, was led by Sharmila Dorbala of the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts, and colleagues. Researchers evaluated whether 124I-evuzamitide PET/CT could serve as a reliable diagnostic tool for cardiac amyloidosis.
Cardiac amyloidosis can be difficult to diagnose, and existing imaging methods have important limitations, particularly because some approaches are primarily useful for detecting transthyretin (ATTR) amyloidosis. A technique capable of directly visualizing amyloid deposits and potentially identifying different forms of the disease could therefore improve diagnostic assessment.
The prospective, multicenter, single-group REVEAL clinical trial was conducted across 18 US centers between January 2025 and March 2026. Investigators enrolled 195 adults who were suspected of having cardiac amyloidosis but did not have an established diagnosis of cardiac or systemic amyloidosis.
Participants underwent PET/CT imaging 3 to 5 hours after receiving 1 mCi of intravenous 124I-evuzamitide. Oral potassium iodide was administered for three days, beginning at least 30 minutes before the radiotracer injection, to support the imaging protocol.
Three physicians experienced in cardiac PET/CT independently assessed the scans for cardiac uptake of 124I-evuzamitide while remaining blinded to the patients’ clinical information. Separately, three amyloidosis specialists reviewed clinical information without access to PET/CT findings and established the diagnosis using the standard-of-care diagnostic algorithm.
The trial revealed the following findings:
- The final analysis included 170 patients, with a median age of 72 years; 75.3% were men, 19.2% were Black, and 79% were White.
- Median N-terminal pro–brain natriuretic peptide (NT-proBNP) level was 471 pg/mL, and 61.7% had NYHA class II or III heart failure symptoms.
- 124I-evuzamitide PET/CT showed 94% sensitivity for detecting cardiac amyloidosis.
- The imaging technique demonstrated 86% specificity.
- The positive predictive value was 85%, while the negative predictive value was 94%.
- Diagnostic accuracy was high for both transthyretin (ATTR) and light chain cardiac amyloidosis.
- The imaging approach demonstrated an acceptable safety profile.
The study was limited by an imperfect reference standard and 60-day follow-up. Of 13 patients deemed negative by the adjudication committee, 7 were considered positive by their enrolling centers and had positive PET scans, suggesting some apparent false positives may reflect early disease. The small light chain amyloidosis subgroup also limited detailed analysis.
Overall, the findings support 124I-evuzamitide PET/CT as a promising diagnostic test for patients with suspected cardiac amyloidosis, including both ATTR and light chain disease.
Reference:
Dorbala S, Maurer MS, Cuddy SAM, et al. 124I-Evuzamitide Positron Emission Tomography/Computed Tomography for Diagnosing Cardiac Amyloidosis: The REVEAL Nonrandomized Clinical Trial. JAMA. Published online August 30, 2026. doi:10.1001/jama.2026.17361
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