**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.**
Núria Orta, Hospital Universitari Son Espases/IdISBa, Palma, Spain

**Main Body of the Abstract**
Symptomatic carpal tunnel syndrome(CTS) and lumbar stenosis(LS) seem to precede the cardiac manifestations of cardiac amyloidosis(CA) due to transthyretin amyloidosis(ATTR), so they could represent early markers of CA.Our purpose is to evaluate the prevalence of amyloidosis in patients undergoing CTS or LS surgery,in an endemic area of the TTR mutation Val50Met(ATTRv).

237 operated patients have been included(183-CTS,54-LS) in whom an intraoperative biopsy was obtained for histopathological analysis using Congo Red staining for amyloid detection and immunohistochemistry(IHC) or mass spectrometry(MS) for subtyping in amyloid A(AA), kappa, lambda and ATTR.A blood and urine test to rule out a monoclonal component and a cardiac scintigraphy(CS) with 99mTc-DPD to detect myocardial uptake were performed,which analysis was visual by Perugini scale and semiquantitative by heart-to-contralateral-lung ratio(H/CL).A cardiac SPECT/CT was performed in cases with a positive CS.

Total of 204 biopsies were obtained(154-CTS,50-LS),16 of them were amyloid positive(8-CTS,8-LS).203 laboratory tests and CS have been performed:5/203 CS were positive(grade 2-3) in 4 patients who underwent CTS surgery(2 with positive biopsies for amyloid and 2 without biopsy) and 1-LS with also positive biopsy.In 15/203 laboratory tests,a monoclonal component was detected.Positivity for amyloid has been obtained in 18/237 cases(7.6%):16 positive biopsies(2 of them with positive blood/urine test and 3 of them with positive CS) and 2 positive CS without biopsy.
In the follow-up(2.41 years) of patients with positivity,27.8%(5/18) manifests cardiomyopathy,4 of them with positive CS,and 88.9%16/18) has previously other orthopedic manifestations.

The estimated prevalence of amyloidosis in our series of surgically treated patients with CTS or LS is 7.6%



Multidisciplinary approach for the early detection of amyloid in patients who undergo carpal tunnel syndrome or lumbar stenosis surgery. PB64 (#158)

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.