**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.**
Morris Kim, MD
Knight Cardiovascular Institute, Oregon Health & Science University (OHSU)
Portland, OR

**Main Body of the Abstract**
Introduction: 124I-evuzamitide (AT-01) is a novel pan-amyloid PET radiotracer. Biomarkers in ATTR-CM measure down-stream effects of myocardial infiltration with amyloid fibrils. We investigated the relationship between 124I-evuzamitide myocardial uptake and prognostic biomarkers in ATTR-CM.
Methods: ATTR-CM was diagnosed by standard criteria. All subjects were prospectively enrolled and underwent hybrid cardiac PET/MRI with 124I-evuzamitide. Myocardial 124I-evuzamitide uptake was measured using LV SUVR (ratio of LV myocardium SUV/LV blood pool SUV). NT-proBNP, high-sensitivity troponin I (hsTnI), and eGFR were measured on the same day.
Results: 27 (54%) had ATTR-CM, and 13 (26%) were controls. Median (IQR) LV SUVR was 1.8 (1.7, 1.9) in ATTR-CM and 1.0 (0.9, 1.2) in controls. In the ATTR-CM group, median (IQR) NT-proBNP, hsTnI, and mean (SD) eGFR were 841pg/dl (404, 2,559), 35ng/L (16.8, 60.8), and 48ml/min/m2(12.4). In the whole cohort, NT-proBNP (r=0.39, p=0.012) and hsTnI (r=0.48, p=0.001) correlated with LV SUVR but eGFR (r=-0.25, p=0.120) did not. In the ATTR-CM group, 17 (63%), 6 (22%) and 4 (15%) patients were Mayo Stages I, II and III, and 16 (59%), 7 (26%), and 4 (15%) patients were NAC Stages I, II and III. There was no difference between mean SUVR (SD) between all Mayo Stages and NAC Stages, all p>0.05, Figure.
Conclusion: In this study, NAC and Mayo Stages did not correlate with myocardial amyloid burden measured by 124I-evuzamitide, while NT-proBNP and hsTnI did. Validation studies are needed to help understand the utility and significance of directly measuring myocardial amyloid load compared to down-stream effects of fibril infiltration.



**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.**
Morris Kim, MD
Knight Cardiovascular Institute, Oregon Health & Science University (OHSU)
Portland, OR

**Main Body of the Abstract**
**Introduction:** 124I-evuzamitide (AT-01) is a novel pan-amyloid PET radiotracer. Biomarkers in ATTR-CM measure down-stream effects of myocardial infiltration with amyloid fibrils. We investigated the relationship between 124I-evuzamitide myocardial uptake and prognostic biomarkers in ATTR-CM.
**Methods:** ATTR-CM was diagnosed by standard criteria. All subjects were prospectively enrolled and underwent hybrid cardiac PET/MRI with 124I-evuzamitide. Myocardial 124I-evuzamitide uptake was measured using LV SUVR (ratio of LV myocardium SUV/LV blood pool SUV). NT-proBNP, high-sensitivity troponin I (hsTnI), and eGFR were measured on the same day.
**Results:** 27 (54%) had ATTR-CM, and 13 (26%) were controls. Median (IQR) LV SUVR was 1.8 (1.7, 1.9) in ATTR-CM and 1.0 (0.9, 1.2) in controls. In the ATTR-CM group, median (IQR) NT-proBNP, hsTnI, and mean (SD) eGFR were 841pg/dl (404, 2,559), 35ng/L (16.8, 60.8), and 48ml/min/m2(12.4). In the whole cohort, NT-proBNP (r=0.39, p=0.012) and hsTnI (r=0.48, p=0.001) correlated with LV SUVR but eGFR (r=-0.25, p=0.120) did not. In the ATTR-CM group, 17 (63%), 6 (22%) and 4 (15%) patients were Mayo Stages I, II and III, and 16 (59%), 7 (26%), and 4 (15%) patients were NAC Stages I, II and III. There was no difference between mean SUVR (SD) between all Mayo Stages and NAC Stages, all p>0.05, Figure.
**Conclusion:** In this study, NAC and Mayo Stages did not correlate with myocardial amyloid burden measured by 124I-evuzamitide, while NT-proBNP and hsTnI did. Validation studies are needed to help understand the utility and significance of directly measuring myocardial amyloid load compared to down-stream effects of fibril infiltration.



Relationship Between Myocardial Amyloid Load Measured by 124I-evuzamitide and Prognostic Staging Systems in Transthyretin Amyloid Cardiomyopathy 

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.