**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.**
Andrew Staron, Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine and Boston Medical Center, Boston, MA USA

**Main Body of the Abstract**
Background: Sudden unexpected death (SUD) was the second leading cause of death in a prior 40-year natural history study of AL amyloidosis from our center. Here, we explored factors related to early-SUD.
Methods: We performed a review of patients with AL amyloidosis from 1980–2023 who suffered SUD using the database at the Boston University Amyloidosis Center. SUD was defined as unexplained death occurring within 1 hour (witnessed) of symptom onset or within 24 hours (unwitnessed) of being seen in normal condition; e.g., death during sleep. Causes of death were adjudicated by treating clinicians using information from medical records, family members and/or official death documents.
Results: Among 2794 patients, 1935 had died. Primary cause of death was ascertainable in 1291 cases, of which 280 (22%) were SUDs. The cumulative incidence of SUD at 1, 2 and 5 years of diagnosis was 5%, 7% and 9%, respectively. Nearly half (n=138, 49%) of SUDs were early; i.e., within 1 year of diagnosis. Characteristics of patients suffering early-SUD are shown in Table 1, with a reference cohort of patients who survived or died of non-SUD causes during 1-year follow-up for comparison. Most (94%) patients suffering early-SUD had cardiac involvement. Gastrointestinal tract and autonomic nervous system involvement were also more common. Cardiac (BNP, troponin, BU stage), hemodynamic (syncope, blood pressure) and bleeding (factor X level) risk parameters were associated with early-SUD.
Conclusions: We identified clinical factors related to early-SUD in AL amyloidosis. More progress is needed in understanding potential underlying mechanisms and preventative management strategies.



**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.**
Andrew Staron, Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine and Boston Medical Center, Boston, MA USA

**Main Body of the Abstract**
**Background:** Sudden unexpected death (SUD) was the second leading cause of death in a prior 40-year natural history study of AL amyloidosis from our center. Here, we explored factors related to early-SUD.
**Methods:** We performed a review of patients with AL amyloidosis from 1980–2023 who suffered SUD using the database at the Boston University Amyloidosis Center. SUD was defined as unexplained death occurring within 1 hour (witnessed) of symptom onset or within 24 hours (unwitnessed) of being seen in normal condition; e.g., death during sleep. Causes of death were adjudicated by treating clinicians using information from medical records, family members and/or official death documents.
**Results:** Among 2794 patients, 1935 had died. Primary cause of death was ascertainable in 1291 cases, of which 280 (22%) were SUDs. The cumulative incidence of SUD at 1, 2 and 5 years of diagnosis was 5%, 7% and 9%, respectively. Nearly half (n=138, 49%) of SUDs were early; i.e., within 1 year of diagnosis. Characteristics of patients suffering early-SUD are shown in Table 1, with a reference cohort of patients who survived or died of non-SUD causes during 1-year follow-up for comparison. Most (94%) patients suffering early-SUD had cardiac involvement. Gastrointestinal tract and autonomic nervous system involvement were also more common. Cardiac (BNP, troponin, BU stage), hemodynamic (syncope, blood pressure) and bleeding (factor X level) risk parameters were associated with early-SUD.
**Conclusions:** We identified clinical factors related to early-SUD in AL amyloidosis. More progress is needed in understanding potential underlying mechanisms and preventative management strategies.



Clinical Factors Associated with Early Sudden Unexpected Death in Systemic AL Amyloidosis: Insights from 138 Cases OA11 (#209)

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.