Abstract 4143171: Pattern of Disease Progression in ATTR-CM Patients Treated with Tafamidis: An Observational Study

Background: Consensus on a definition of disease progression in transthyretin amyloid cardiomyopathy (ATTR-CM) is lacking. Recent data showed that among a large cohort 50% of patients progressed as defined by either N-terminal pro-B type natriuretic peptide (Nt-proBNP) increase of 700 pg/ml AND 30% or increase of oral diuretics (ODI) after 1 year. However, most of the patients were not on disease modifying treatment (DMT). Aim: To describe the pattern of progression at 1 year in patients with ATTR-CM on tafamidis, the only approved drug for ATTR-CM. Methods: Patients diagnosed with ATTR-CM at Columbia University and treated with tafamidis after 2018 were enrolled in the study assuming they survived a year to measure disease progression and had data available at follow-up. A total of 16 patients died before the 1-year follow-up and were excluded from the study. Disease progression was defined as: increase in Nt-proBNP>700 pg/mL and >30% from baseline, ODI or increases in both compared to baseline. Survival analysis was done using Kaplan Meier curves and Cox regression adjusted for age and disease severity by National Amyloidosis Center stage. Results: A total of 157 patients were enrolled, with 62 (39.5%) having disease progression at 1-year. Of these 62 patients, 51 met one progression criterion (34 patients had ODI and 17 had NtproBNP increase), with 11 having both criteria of disease progression at 1 year. Survival analysis revealed a significantly increased risk for all-cause mortality during follow-up in patients with disease progression at 1-year (HR=2.13, 95%CI:1.04-4.35, p=0.03, Figure). Conclusion: The recently proposed criteria for disease progression performed well in a cohort of patients on DMT, which may reduce the number of patients progressing at 1 year.