**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.**
Kevin M. Alexander, Stanford Amyloid Center, Stanford University School of Medicine, Stanford, California, USA; Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Rm A260, Stanford, California, USA

**Main Body of the Abstract**
Background/Aim: This study investigated the ability to categorize ATTR amyloidosis phenotypes using code-based segmentation algorithm.
Methods: Data from 2017-2022 were extracted from Optum’s de-identified Clinformatics® Data Mart Database (USA) and Medical Data Vision Database (Japan). Patients aged ≥18 years with an ICD-10 diagnosis code for ATTR amyloidosis (E85) or a claim for an ATTR-specific treatment were included. The overall cohort was segmented using diagnosis codes with details on classification, treatment or procedures indicating specific phenotype, as well as cardiac and neuropathy related diagnoses. This segmentation identified four groups: ATTR-cardiomyopathy (ATTR-CM), ATTR-polyneuropathy (ATTR-PN), ATTR with mixed phenotype and unknown. Patients with evidence of AA or AL amyloidosis were excluded.
Results: The predominant phenotype observed was ATTR-CM in both the USA (45.6%) and Japan (57.2%), followed by ATTR with mixed phenotype (USA: 34.2%, Japan: 10.2%) and ATTR-PN (USA: 4.3%, Japan: 3.0%). The proportion of unknown phenotype was 15.8% in USA and 29.6% in Japan. In Japan, patients with ATTR-CM and ATTR with mixed phenotype were predominantly male, whereas in the US, patients of all phenotypes were predominantly female, with those having ATTR-CM and ATTR with mixed phenotype being older. Additional demographic differences are illustrated in Table.
Conclusions: These findings highlight a phenotypic heterogeneity associated with ATTR amyloidosis and differences between countries.  Caution is required when categorizing ATTR amyloidosis by phenotype based on claims data given the absence of a gold standard algorithm for patient segmentation.  Further analyses within the OverTTuRe study program, including validation studies are ongoing.



Characterization of ATTR Amyloidosis by Phenotype from Claims Data in the United States and Japan:  Preliminary Results from the OverTTuRe Study PA7 (#198)

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.