Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.
Bryton Davis, Oregon Health & Science University, Portland, Oregon

Main Body of the Abstract
Introduction: While amyloid fibrils cause kidney disease in light chain amyloidosis (AL), it remains unclear if worsening kidney function in transthyretin amyloid cardiomyopathy (ATTR-CM) is related to amyloid fibril infiltration or progressive cardiomyopathy. 124I-evuzamitide (AT-01), a novel pan-amyloid PET radiotracer, allows for cardiac and renal assessment of amyloid deposition.
Methods: Cardiac (AL and ATTR) amyloidosis and renal AL amyloidosis were diagnosed by standard clinical, laboratory, biopsy, and imaging criteria. All subjects underwent PET/MRI with 124I-evuzamitide. Uptake was quantified using standardized uptake value ratio (SUVR, ratio of organ SUV/left ventricular (LV) blood pool SUV). Estimated glomerular filtration rate (eGFR) was measured immediately prior to tracer injection.
Results: We enrolled 50 patients (mean age: 72.0±9.1 years, 74% male, 56% ATTR, 24% AL, 20% control, 68% cardiac amyloidosis, 18% renal AL amyloidosis). Median 124I-evuzamitide myocardial SUVR in cardiac amyloidosis was 1.8 (1.7, 1.9) compared to 0.9 (0.9, 1.1) in those without. Median renal 124I-evuzamitide SUVR was 0.9 (0.8, 1.0) in ATTR-CM. Patients with ATTR-CM did not have the diffuse renal 124I-evuzamitide uptake seen in patients with renal AL amyloidosis. In patients with ATTR-CM, 52% had an eGFR < 45 mL/min (mean: 47.5±12.3 mL/min). eGFR did not correlate with renal 124I-evuzamitide uptake in patients with ATTR-CM (r=-0.014, p=0.946), while it did correlate with septal LV wall thickness (r=-0.535, p=0.004) and LV mass (r=-0.511, p=0.006).
Conclusion: Renal dysfunction in patients with ATTR-CM may be related to worsening cardiomyopathy rather than renal amyloid fibril deposition. Further studies correlating 124I-evuzamitide imaging with histopathological findings are necessary.

**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Bryton Davis, Oregon Health & Science University, Portland, Oregon

**Main Body of the Abstract**
**Introduction:** While amyloid fibrils cause kidney disease in light chain amyloidosis (AL), it remains unclear if worsening kidney function in transthyretin amyloid cardiomyopathy (ATTR-CM) is related to amyloid fibril infiltration or progressive cardiomyopathy. 124I-evuzamitide (AT-01), a novel pan-amyloid PET radiotracer, allows for cardiac and renal assessment of amyloid deposition.
**Methods:** Cardiac (AL and ATTR) amyloidosis and renal AL amyloidosis were diagnosed by standard clinical, laboratory, biopsy, and imaging criteria. All subjects underwent PET/MRI with 124I-evuzamitide. Uptake was quantified using standardized uptake value ratio (SUVR, ratio of organ SUV/left ventricular (LV) blood pool SUV). Estimated glomerular filtration rate (eGFR) was measured immediately prior to tracer injection.
**Results:** We enrolled 50 patients (mean age: 72.0±9.1 years, 74% male, 56% ATTR, 24% AL, 20% control, 68% cardiac amyloidosis, 18% renal AL amyloidosis). Median 124I-evuzamitide myocardial SUVR in cardiac amyloidosis was 1.8 (1.7, 1.9) compared to 0.9 (0.9, 1.1) in those without. Median renal 124I-evuzamitide SUVR was 0.9 (0.8, 1.0) in ATTR-CM. Patients with ATTR-CM did not have the diffuse renal 124I-evuzamitide uptake seen in patients with renal AL amyloidosis. In patients with ATTR-CM, 52% had an eGFR < 45 mL/min (mean: 47.5±12.3 mL/min). eGFR did not correlate with renal 124I-evuzamitide uptake in patients with ATTR-CM (r=-0.014, p=0.946), while it did correlate with septal LV wall thickness (r=-0.535, p=0.004) and LV mass (r=-0.511, p=0.006).
**Conclusion:** Renal dysfunction in patients with ATTR-CM may be related to worsening cardiomyopathy rather than renal amyloid fibril deposition. Further studies correlating 124I-evuzamitide imaging with histopathological findings are necessary.

Utilizing 124I-evuzamitide PET/MRI to Elucidate the Relationship between Renal Dysfunction and Amyloid Deposition in Transthyretin Amyloid Cardiomyopathy PB127 (#435)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.