**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.**
Laura De Michieli
Mayo Clinic, Rochester MN, USA and University of Padua, Padua Italy
demichieli.laura@mayo.edu

**Main Body of the Abstract**
Background: LSS and CTS often predate ATTR-CM by 5-10 years but the association between LSS/CTS with development of ATTR-CM over time is yet to be clarified. If LSS/CTS are prodromal for ATTR-CM, patients with LSS/CTS should have higher rates of cardiovascular events and worse overall survival.
Methods: Retrospective cohort study of patients with a history of LSS/CTS (ICD codes) from 1995- 2015, identified through the Rochester Epidemiology Project, age- and sex-matched with three controls (CNTRL). Composite cardiac outcome including survival, heart failure, atrial fibrillation/flutter, and pacemaker/defibrillator placement was modeled using stratified competing risk regression. Median follow-up was 8.3 years.
Results: 6111 LSS-cases (median age 68 years, 45% male) and 16342 CNTRL were included. Cumulative incidence and risk of the composite outcome was higher in LSS-cases (HR=1.15, 95% CI: 1.13-1.16; p<0.0001) than CNTRL (Figure-1a). OS was worse in LSS cases vs CNTRL (HR=1.26, 95% CI: 1.19 - 1.33; p<0.0001; 6847 deaths).  For the CTS cohort, 6695 cases (median age 63 years, 35% male) and 17565 CNTRL were included. Incidence of comorbidities was higher in CTS-cases and LSS-cases vs matched CNTRL. Cumulative incidence and risk of the composite outcome was higher in CTS-cases (HR=1.15, 95% CI: 1.13 - 1.17; p<0.0001) than CNTRL (Figure-1b). OS was not significantly different in CTS-cases vs CNTRL (HR=0.95, 95% CI: 0.90 - 1.01; p=0.10; 5895 deaths).
Conclusion: LSS/CTS is associated with increased risk of CV events (possible manifestations of ATTR-CM), but worse OS in LSS. These data support evaluation of ligamentum-flavum/flexor-tenosynovium to foster early diagnosis of ATTR-CM



**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.**
Laura De Michieli
Mayo Clinic, Rochester MN, USA and University of Padua, Padua Italy
demichieli.laura@mayo.edu

**Main Body of the Abstract**
**Background:** LSS and CTS often predate ATTR-CM by 5-10 years but the association between LSS/CTS with development of ATTR-CM over time is yet to be clarified. If LSS/CTS are prodromal for ATTR-CM, patients with LSS/CTS should have higher rates of cardiovascular events and worse overall survival.
**Methods:** Retrospective cohort study of patients with a history of LSS/CTS (ICD codes) from 1995- 2015, identified through the Rochester Epidemiology Project, age- and sex-matched with three controls (CNTRL). Composite cardiac outcome including survival, heart failure, atrial fibrillation/flutter, and pacemaker/defibrillator placement was modeled using stratified competing risk regression. Median follow-up was 8.3 years.
**Results:** 6111 LSS-cases (median age 68 years, 45% male) and 16342 CNTRL were included. Cumulative incidence and risk of the composite outcome was higher in LSS-cases (HR=1.15, 95% CI: 1.13-1.16; p<0.0001) than CNTRL (**Figure-1a**). OS was worse in LSS cases vs CNTRL (HR=1.26, 95% CI: 1.19 - 1.33; p<0.0001; 6847 deaths).  For the CTS cohort, 6695 cases (median age 63 years, 35% male) and 17565 CNTRL were included. Incidence of comorbidities was higher in CTS-cases and LSS-cases vs matched CNTRL. Cumulative incidence and risk of the composite outcome was higher in CTS-cases (HR=1.15, 95% CI: 1.13 - 1.17; p<0.0001) than CNTRL (**Figure-1b**). OS was not significantly different in CTS-cases vs CNTRL (HR=0.95, 95% CI: 0.90 - 1.01; p=0.10; 5895 deaths).
**Conclusion:** LSS/CTS is associated with increased risk of CV events (possible manifestations of ATTR-CM), but worse OS in LSS. These data support evaluation of ligamentum-flavum/flexor-tenosynovium to foster early diagnosis of ATTR-CM



Lumbar spinal stenosis (LSS) and carpal tunnel syndrome (CTS) as surrogates for wild-type transthyretin amyloid cardiomyopathy (ATTR-CM) OA3 (#420)

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.