**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.**
Joseph P Donohue MD, University of Pittsburgh Medical Center, Pittsburgh Pennsylvania.

**Main Body of the Abstract**
Background:
Cardiac Scintigraphy with Tc-99m labelled bone-seeking tracers has been transformative for the field of ATTR cardiac amyloidosis (CA) by facilitating a highly accurate noninvasive diagnosis. With the increasing application of this test in suspected cardiac amyloidosis, we sought to assess changes in referral patterns and test yield of Tc-99m PYP scintigraphy over time.
Methods:
We conducted a retrospective analysis of clinical Tc-99m PYP scans from 2015 (year of first use) to 2023 at a single institution (Presbyterian Hospital, University of Pittsburgh Medical Center). Scans were performed as per the recommendations of the American Society of Nuclear Cardiology and interpreted for clinical use by a pool of 5 experienced readers. Annual rates of percent of positive scans were determined. The Cochran-Armitage test was used to determine if the proportion of positive tests changed significantly over the years studied.
Results:
A total of 1,005 PYP scans were performed during the analysis period. There was a progressive 8-fold increase in total scans performed from 23 scans in 2015 to 183 scans 2023. Scan yield was surprisingly constant over the 8-year period with average positivity of 28.1% ± 4.7% (range 21-6-38.3%). Figure 1 shows the percentage of positive and negative scans. There was no statistically significant change in positivity rate over the studied time period. (p=0.895)
Conclusion:
Despite a dramatic increase in the utilization of Tc-99m PYP scintigraphy for suspected ATTR CA, the yield of testing has remained surprisingly constant in this single center experience.



Lack of Temporal Change in the Yield of Tc-99m PYP scintigraphy: A single-center experience PB137 (#512)

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.