**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.**
Brent Medoff, MD
UPMC Heart and Vascular Institute, Pittsburgh, PA

**Main Body of the Abstract**
Introduction:
Dynamic positron emission tomography (PET) has demonstrated severe abnormalities in rest and stress myocardial blood flow (MBF) in cardiac amyloidosis. Quantification of MBF can also be performed on SPECT myocardial perfusion imaging (MPI).  We explored MBF using PET or SPECT derived flow quantification in patients with ATTR-CA.
Methods:
Twenty-eight patients with ATTR-CA underwent Tc-99m sestamibi SPECT or N-13 ammonia PET MPI. Ejection fraction (EF) was categorized as reduced (rEF < 50%) or preserved (pEF ≥ 50%), and abnormal peak stress flow (PSF) was defined as < 1.8 ml/g/min. Baseline troponins were collected for all patients. A troponin I >0.10ng/mL and a high sensitivity troponin (hsTn) >90ng/L are considered definitively abnormal by our center.
Results:
There were 28 patients with ATTR-CA who underwent regadenoson PET (n=13) or SPECT (n=15) imaging with MBF quantification. There were no patients with a perfusion defect. There were 16 and 12 patients with pEF and rEF, respectively. Abnormal PSF was observed in all patients and, was significantly higher in patients with pEF compared to rEF (1.32 v 1.15, p = 0.02). Global MFR (2.50 v 2.17, p = 0.009) and rest flow (0.55 v 0.49, p= 0.01) were higher in patients with pEF.  Patients with rEF had a higher proportion of abnormal troponin (9/12 vs 3/16, p=0.003) and a higher mean hsTn compared to pEF (175.4 ng/L vs 51.6 ng/L, p=0.02)
Conclusion:
Patients with ATTR-CA and rEF have lower PSF and higher troponins compared to patients with pEF, which may have mechanistic implications.



A reduced ejection fraction is associated with more severe myocardial blood flow abnormality and biomarker elevation in ATTR cardiac amyloidosis PB125 (#431)

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.