Abstract 17077: Functional Class, Biomarker Stability, and Clinical Outcomes of Patients With Transthyretin Cardiac Amyloidosis Treated With Tafamidis

Abstract

Introduction: Tafamidis has been shown to improve survival and decrease heart failure (CHF) hospitalizations in transthyretin cardiac amyloidosis (ATTR-CM). In the ATTR-ACT trial, survival benefit emerged after approximately 18 months of treatment, with less clear benefit in those with NYHA class III symptoms. We sought to evaluate the short-term changes in NYHA class, biomarkers, and clinical outcomes in a real-world cohort of patients treated with tafamidis. Methods: A single center retrospective observational study of patients with ATTR-CM who were prescribed tafamidis since its FDA approval in May 2019. We collected data on prospectively assessed NYHA class, NTproBNP, Troponin I, and outcomes of CHF hospitalizations and death. Results: Fifty-one patients with ATTR-CM (mean age 73.3±7 years, 100.0% male) were prescribed tafamidis. Forty-five patients had wild-type and 6 had hereditary ATTR-CM. At the visit when tafamidis was initiated 6 (11.8%) patients were NYHA Class I, 24 (47.1%) Class II, 20 (39.2%) Class III, and 1 (2%) Class IV. Over a median follow up of 8 (IQR 6.0-11) months after starting tafamidis, there were no significant differences before and after tafamidis treatment in time-averaged median NYHA functional class (paired Wilcoxon test, p=0.1610; Figure 1A), time-averaged median NTproBNP (paired exact Wilcoxon test, p > 0.9999; Figure 1B), and time-averaged median troponin I (paired exact Wilcoxon test, p=0.9400; Figure 1C). Following initiation of tafamidis, 13 patients (25.5%) were admitted for CHF hospitalization. A total of 8 patients (15.7%) died a median of 9.5 (IQR 2.5-12.5) months after initiation of tafamidis. Conclusions: ATTR-CM patients taking tafamidis were observed to have stable functional status and biomarkers, including those with NYHA class III symptoms. Despite a higher proportion of worse NYHA functional class, the rate of death at 10 months appears comparable to the ATTR-ACT trial in this real-world population.