**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.**
Joban Vaishnav MD, Johns Hopkins University, Baltimore, MD

**Main Body of the Abstract**
Background: Current treatments for ATTR-CM aim to diminish clinical deterioration. There are limited real-world data on treatment response in ATTR-CM.
Methods: ATTR-CM patients seen at our center treated for ≥6 months (stabilizer or silencer) were included. Non-responders (NR) met at least one clinical (≥1 HF hospitalization or acute visit, ≥50% increase in loop diuretic dose, or increase in NYHA class) and one biomarker/imaging endpoint (≥30% increase in NT-proBNP, ≥30% decrease in eGFR, or ≥10% decrease in LVEF).
Results: Of 134 patients, 51 (38%) were NR over a median follow-up of 1.93 years. At baseline, NR were more likely V122I (90.3% vs. 51.4%, p<0.01) and NAC stage 3 (28.0% vs 5.1%), had lower eGFR (52.0 [34.0, 70.0] v 63.0 [51.0, 81.0] mL/min/1.72m2), higher loop diuretic dose (40.0 [40.0, 80.0] v 40.0 [20.0, 40.0] mg), prior HF hospitalization (58.3% v 21.1%) compared to responders (R), all p<0.01. On echocardiogram, NR had lower LVEF (41.9 [13.1] vs. 50.7 [13.9]%) and higher right ventricular systolic pressure (43.7 [10.2] vs. 35.0 [12.8] mmHg) compared with R, p<0.01. NR vs R had lower survival at 5 years, though better than a historical untreated cohort (log-rank p-value <0.01). Survival was worse in patients who met ≥3 NR criteria, compared to 1-2 and no criteria (log-rank p-value <0.01).
Conclusion: Over one-third of ATTR-CM patients have treatment non-response with significantly worse survival compared to responders, more likely to occur in patients with V122I disease. Early identification of treatment NR and novel therapeutics are pivotal to improving outcomes in 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.**
Joban Vaishnav MD, Johns Hopkins University, Baltimore, MD

**Main Body of the Abstract**
**Background:** Current treatments for ATTR-CM aim to diminish clinical deterioration. There are limited real-world data on treatment response in ATTR-CM.
**Methods:** ATTR-CM patients seen at our center treated for ≥6 months (stabilizer or silencer) were included. Non-responders (NR) met at least one clinical (≥1 HF hospitalization or acute visit, ≥50% increase in loop diuretic dose, or increase in NYHA class) and one biomarker/imaging endpoint (≥30% increase in NT-proBNP, ≥30% decrease in eGFR, or ≥10% decrease in LVEF).
**Results:** Of 134 patients, 51 (38%) were NR over a median follow-up of 1.93 years. At baseline, NR were more likely V122I (90.3% vs. 51.4%, p<0.01) and NAC stage 3 (28.0% vs 5.1%), had lower eGFR (52.0 [34.0, 70.0] v 63.0 [51.0, 81.0] mL/min/1.72m2), higher loop diuretic dose (40.0 [40.0, 80.0] v 40.0 [20.0, 40.0] mg), prior HF hospitalization (58.3% v 21.1%) compared to responders (R), all p<0.01. On echocardiogram, NR had lower LVEF (41.9 [13.1] vs. 50.7 [13.9]%) and higher right ventricular systolic pressure (43.7 [10.2] vs. 35.0 [12.8] mmHg) compared with R, p<0.01. NR vs R had lower survival at 5 years, though better than a historical untreated cohort (log-rank p-value <0.01). Survival was worse in patients who met ≥3 NR criteria, compared to 1-2 and no criteria (log-rank p-value <0.01).
**Conclusion:** Over one-third of ATTR-CM patients have treatment non-response with significantly worse survival compared to responders, more likely to occur in patients with V122I disease. Early identification of treatment NR and novel therapeutics are pivotal to improving outcomes in ATTR-CM.



Comparison of treatment responders versus non-responders in transthyretin amyloid cardiomyopathy PC145 (#540)

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.