**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.**
Jens Kaestel Skov, Aarhus University and Aarhus University Hospital, Palle Juul Jensens Boulevard 99, 8200 Aarhus N, DK.

**Main Body of the Abstract**
Background: Atrial fibrillation (AF) is a significant disease component of wild-type transthyretin amyloidosis (ATTRwt). Nonetheless, only few studies have investigated the incidence of AF after the time of diagnosis and the prognostic value of AF at time of diagnosis
Therefore, we investigated the cumulative risk of AF at 1-3 years after diagnosis and the prognostic value of AF at the time of diagnosis.
Methods: All patients with ATTRwt who was treated at Aarhus University Hospital in the period from 2017-2022 were enrolled (N=203) and most relevant clinical data was prospectively registered in an ATTRwt database. AF data and mortality data were retrospectively collected.
All-cause mortality was based on Kaplan-Meier estimates. Cumulative incidence of AF was estimated with death as a competing risk. AF within 35 days after diagnosis were defined as prevalent AF at time of diagnosis.
Results: At diagnosis patients with or without AF were similar regarding age and sex, but prevalent AF was associated to more progressed ATTRwt disease with respect to symptoms (NYHA), clinical stage (NAC) and echocardiographic parameters at diagnosis. We found AF at diagnosis to be a significant marker of poor prognosis for patients with ATTRwt (Figure 1A, age and sex adjusted HR of 1.89). We also found a high 3-year-cumulative incidence of AF (44%) after diagnosis (Figure 1B).
Conclusion: We conclude that patients with ATTRwt have a high incidence of AF after diagnosis and that having AF at time of diagnosis is a significant marker of worse prognosis.



**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.**
Jens Kaestel Skov, Aarhus University and Aarhus University Hospital, Palle Juul Jensens Boulevard 99, 8200 Aarhus N, DK.

**Main Body of the Abstract**
**Background:** Atrial fibrillation (AF) is a significant disease component of wild-type transthyretin amyloidosis (ATTRwt). Nonetheless, only few studies have investigated the incidence of AF after the time of diagnosis and the prognostic value of AF at time of diagnosis
Therefore, we investigated the cumulative risk of AF at 1-3 years after diagnosis and the prognostic value of AF at the time of diagnosis.
**Methods:** All patients with ATTRwt who was treated at Aarhus University Hospital in the period from 2017-2022 were enrolled (N=203) and most relevant clinical data was prospectively registered in an ATTRwt database. AF data and mortality data were retrospectively collected.
All-cause mortality was based on Kaplan-Meier estimates. Cumulative incidence of AF was estimated with death as a competing risk. AF within 35 days after diagnosis were defined as prevalent AF at time of diagnosis.
**Results:** At diagnosis patients with or without AF were similar regarding age and sex, but prevalent AF was associated to more progressed ATTRwt disease with respect to symptoms (NYHA), clinical stage (NAC) and echocardiographic parameters at diagnosis. We found AF at diagnosis to be a significant marker of poor prognosis for patients with ATTRwt (Figure 1A, age and sex adjusted HR of 1.89). We also found a high 3-year-cumulative incidence of AF (44%) after diagnosis (Figure 1B).
**Conclusion:** We conclude that patients with ATTRwt have a high incidence of AF after diagnosis and that having AF at time of diagnosis is a significant marker of worse prognosis.



Incidence and prognostic implications of atrial fibrillation in wild-type transthyretin amyloidosis cardiomyopathy PC70 (#400)

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.